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Exercise

Aerobic exercise featured article

Aerobic exercise can be defined as physical activity that increases aerobic metabolism, meaning energy-generating processes that require oxygen. Common examples of aerobic exercises are walking, running, swimming, dancing, and other activities that increase heart rate and breathing. Exercise elicits a wide range of physiological changes in the body that improve cardiovascular, neurological, and metabolic health.

Current physical activity guidelines from the United States Department of Health and Human Services recommend the following.

  • Adults should do at least 150 minutes of moderate-intensity exercise or 75 minutes per week of vigorous-intensity aerobic physical activity.
  • Physical activity of moderate intensity beyond 300 minutes per week provides additional health benefits.
  • Adults should also do muscle-strengthening activities of moderate or greater intensity...

Episodes

Posted on April 28th 2025 (about 2 months)

Dr. Rhonda Patrick covers lithium microdosing, reducing homocysteine, aluminum's link to cancer, and beta-alanine and alpha-lipoic acid supplements.

Posted on April 22nd 2025 (about 2 months)

Dr. Andy Galpin & Dr. Rhonda Patrick discuss nutrition, supplement, and recovery strategies for improving exercise performance.

Posted on April 1st 2025 (3 months)

In this clip from the Rich Roll Podcast, Dr. Rhonda Patrick explains how exercise-driven brain changes support learning, memory, and mental health.

Topic Pages

  • Aerobic exercise

    Aerobic exercise is an exercise subset employing sustained rhythmic contractions that upregulate mitochondrial oxidative phosphorylation and systemic cardiorespiratory adaptations.

  • Age-related decline of muscle power (powerpenia)

    Resistance power training attenuates powerpenia by preserving motor-unit recruitment, type II fiber area, and neuromuscular junction integrity.

  • Autophagy

    Endurance exercise activates AMPK, inhibits mTORC1, thereby initiating ULK1-mediated autophagy, facilitating mitochondrial turnover and metabolic homeostasis.

  • Berberine

    Exercise and berberine independently activate AMPK signaling, convergently increasing glucose transport, lipid oxidation, and insulin sensitivity.

  • Beta-hydroxybutyrate

    Prolonged or high-intensity exercise lowers glycogen, accelerating hepatic fatty-acid β-oxidation and ketogenesis, thereby elevating circulating β-hydroxybutyrate.

  • Brain-derived neurotrophic factor (BDNF)

    Aerobic exercise elevates hippocampal BDNF transcription via activity-dependent Ca2+/CREB signaling and PGC-1α–FNDC5–irisin endocrine pathways.

  • Butyrate

    Endurance exercise shifts gut microbiota toward butyrate-producing Firmicutes, elevating luminal butyrate that strengthens intestinal epithelial tight-junctions.

  • Depression

    Aerobic exercise alleviates depression by increasing monoamine and BDNF signaling, stimulating hippocampal neurogenesis, and dampening systemic inflammation and HPA-axis activity.

  • Exercise and Cognitive Function

    Physical exercise enhances cognitive function via upregulated neurotrophic factor expression, improved cerebrovascular perfusion, and reduced neuroinflammatory signaling.

  • Exercise and Weight Loss

    Exercise mechanistically drives exercise-and-weight-loss interventions via elevated energy expenditure, enhanced mitochondrial fat oxidation, and lean-mass preservation during caloric deficit.

  • Exercise Intensity

    Exercise elicits physiological adaptations whose magnitude and specificity scale mechanistically with intensity via graded metabolic demands and neuromuscular loading.

  • Metformin

    Both activate AMPK; concomitant metformin can attenuate exercise-driven mitochondrial biogenesis and insulin sensitivity by modulating ROS–mTOR signaling.

  • Nicotinamide mononucleotide

    Exercise upregulates skeletal muscle NAMPT, elevating endogenous nicotinamide mononucleotide and NAD⁺, thereby augmenting sirtuin-mediated metabolic adaptation.

  • Resveratrol

    Exercise and resveratrol converge on AMPK–SIRT1–PGC-1α signaling, promoting mitochondrial biogenesis, endothelial nitric-oxide production, and metabolic homeostasis.

  • Sauna

    Exercise and sauna each impose passive or active thermogenic stress that elevates heart rate, peripheral vasodilation, and heat-shock protein synthesis.

  • Vitamin C

    Exercise-induced oxidative stress increases ascorbate turnover; vitamin C neutralizes reactive oxygen species and facilitates collagen synthesis during recovery.

News & Publications

  • Some bodybuilders push their bodies to extremes in pursuit of the ideal physique—but that pursuit may come at a steep cost. Reports of sudden deaths among elite competitors have raised new concerns about the long-term health risks of this demanding sport. A recent study found that bodybuilders, especially professionals, may be up to five times more likely to die of sudden cardiac death, often linked to enlarged hearts and cardiovascular complications.

    The study involved more than 20,000 male athletes who participated in International Federation of Bodybuilding and Fitness events over a fifteen-year period. Researchers identified deaths during the study period and calculated death rates based on whether the athletes were still actively competing at that time.

    During the study period, researchers noted 121 deaths. Of these, 73 were sudden, including 46 confirmed sudden cardiac deaths. Approximately one-third occurred in bodybuilders who were still actively competing, often during or just after a contest. Sudden cardiac deaths were most common among professional bodybuilders, who were more than five times more likely to die from heart-related causes than amateurs. Interestingly, unlike other elite athletes, bodybuilders in this study exhibited a higher overall death rate, even after retiring from competition.

    These findings suggest that bodybuilding may carry considerable—and often overlooked—health risks. It’s noteworthy that resistance training (the foundation of bodybuilding) promotes pathological changes in the heart’s structure. However, incorporating aerobic exercise into a resistance training schedule can counter these effects. Learn more in this clip featuring cardiologist Dr. Ben Levine.

  • The progression of type 2 diabetes is not inevitable, and early-stage disease can often be reversed. However, standard clinical approaches tend to focus on disease management rather than remission. A recent study found that combining a high-protein diet, moderate exercise, and weight-loss medications promoted diabetes remission in nearly 87% of newly diagnosed people with type 2 diabetes, compared to 17% in those receiving standard care.

    Researchers randomly assigned 61 adults with obesity and either prediabetes or newly diagnosed type 2 diabetes to one of two groups. Both received diabetes medications and general lifestyle advice, but one group also participated in a structured program that combined a high-protein diet with supervised moderate exercise (30 minutes daily, five times a week) for 12 months.

    After a year, 73% of participants with prediabetes in the intensive program returned to normal blood glucose levels, compared to just 8% in the standard care group. Among those with type 2 diabetes, 87% experienced remission in the intensive group, while only 17% did in the standard group. People in the intensive group also lost an average of 19 kilograms (~42 pounds)—roughly 17 kilograms (~38 pounds) more than those in standard care—and showed greater reductions in body fat, liver fat, and visceral fat.

    These findings suggest that when paired with medications (including metformin and GLP1 receptor agonists), an intensive yet manageable lifestyle program can dramatically improve blood glucose and body composition. Learn about Ozempic, a widely used GLP1 receptor agonist, in this episode featuring Dr. Rhonda Patrick.

  • Exercise may be one of the most effective—and underused—tools in cancer care. However, a recent study found that a structured, long-term exercise program reduced the risk of cancer recurrence or death by 28% in people treated for colon cancer.

    The study included 889 people with stage II or III colon cancer who had completed chemotherapy. Researchers assigned half to a three-year supervised exercise program that included moderate-intensity aerobic activity and strength training. The other half received health-education materials but no structured physical activity plan. Throughout the study, participants completed surveys about their activity levels and underwent fitness assessments, treadmill tests, and body measurements. The researchers monitored the patients for nearly eight years to track cancer recurrence and overall survival.

    The benefits of exercise were substantial. Five years after treatment, 80% of the exercise group remained cancer-free, compared to 74% in the education group. After eight years, 90% of those who exercised were still alive, versus 83% of the education group. Patients in the exercise group also reported better physical functioning throughout the study. However, musculoskeletal complaints—like joint or muscle pain—were more common in the exercise group (19%) than in the education group (12%).

    These findings suggest that a structured, long-term exercise program can help colon cancer survivors live longer and stay cancer-free. Participants also reported sustained improvements in physical functioning, further supporting the role of exercise in post-treatment recovery, despite a modest increase in musculoskeletal complaints. Learn more about the science of exercise for cancer in this episode featuring Dr. Kerry Courneya.

  • In people with post-traumatic stress disorder (PTSD), traumatic experiences can resurface as vivid flashbacks and intense avoidance, often lasting months or even years. While therapy and medications can help, many people don’t respond fully. A recent study in mice found that exercise enhances the brain’s natural ability to forget, reducing trauma-related behaviors.

    Researchers used a mouse model of PTSD to test whether increasing neurogenesis—the process of forming new neurons—could weaken fear-based memories. They focused on the hippocampus, a brain region that links memories to specific places and contexts. They used several strategies to stimulate neurogenesis, including voluntary exercise, targeted genetic techniques, and drug-based interventions designed to promote the growth and integration of new neurons.

    They found that when the animals' neurogenesis increased, their fear-based memories faded more quickly, and PTSD-related behaviors, such as heightened anxiety and exaggerated fear responses, became less severe. Exercise proved especially effective, not only reducing fear but also easing anxiety-like behaviors. The same neurogenesis-boosting strategies also weakened reward-based memories associated with drug exposure, suggesting this approach could help in treating addiction.

    These findings indicate that enhancing the brain’s natural ability to reorganize itself—particularly through interventions like exercise—helps weaken persistent, harmful memories, offering a promising new approach to treating PTSD and substance use disorders by focusing on memory mechanisms rather than just symptoms. Evidence suggests psychedelic drugs may be beneficial in treating PTSD, too. Learn more in this clip featuring Dr. Roland Griffiths.

  • Even a minor fall can cause a life-altering fracture for women with osteoporosis. Stronger bones can mean the difference between maintaining independence and facing long-term disability. A recent study found that combining high-intensity interval training (HIIT) with daily vitamin D supplements more than doubled the gains in bone mineral density compared to each intervention alone.

    Researchers enrolled 120 sedentary women aged 30 to 50, all diagnosed with osteoporosis. They randomly assigned participants to one of four groups: a control group, a vitamin D group (800 IU per day), an exercise-only group (16 weeks of HIIT), and a combined group that did both. Before and after the intervention, researchers measured bone mineral density of the hips and spine and markers of bone turnover in the blood.

    They found that the group combining HIIT and vitamin D supplementation showed the greatest improvements in bone mineral density at the hips and lumbar spine, with a 3.2% improvement in hip bone mineral density, surpassing the 1.5% increase in the HIIT-only group and the 1.2% increase in the vitamin D-only group. Blood levels of calcium and osteocalcin increased the most in the combined group, while bone-specific alkaline phosphatase (a marker of bone breakdown) decreased. Improvements in bone mineral density were linked to higher calcium and osteocalcin levels and lower body mass index.

    These findings suggest that pairing HIIT with vitamin D supplements boosts bone strength in women with osteoporosis, helping to slow or even reverse bone loss during midlife. Learn more about the effects of HIIT on bone density in this clip featuring Dr. Martin Gibala.

  • Vitamin D, a fat-soluble nutrient, is sequestered in adipose tissue, limiting its circulation—an effect amplified in obesity. Obese adults, for example, exhibit a 57 % smaller rise in circulating vitamin D₃ after whole-body ultraviolet exposure and are more than half as likely to reach sufficient vitamin D levels than normal-weight adults. Against this backdrop, the VitaDEx randomized trial showed that ten weeks of indoor exercise during winter sharply attenuated seasonal vitamin D loss and fully preserved its active hormone, 1,25(OH)₂D₃—without weight loss or supplementation.

    • Active hormone maintained: Exercise fully prevented the winter decline in 1,25(OH)₂D₃, while controls experienced a 15 % drop. (The precursor 25-hydroxy-vitamin D fell only 15 % in exercisers versus 25 % in sedentary controls.)
    • Adipose sequestration puzzle: Contrary to expectations, adipose vitamin D concentrations remained largely unchanged. “Exercise did not drive a greater decrease in adipose tissue concentrations of vitamin D…there was no correlation between the change in serum 25(OH)D and changes in adipose vitamin D₃ concentrations.”
    • Mechanistic pivot: Researchers suggested possible transient vitamin D mobilization, depot-specific effects, or direct metabolic adaptations improving vitamin D efficiency. They speculated that regular physical activity might enable “more ‘efficient’ vitamin D metabolism, making better use of the available substrate to generate the active metabolite without tipping the balance into a negative feedback loop.”

    Taken together, the findings indicate exercise is not merely releasing vitamin D from fat stores; it is altering the flux and enzymatic handling of the hormone, offering a route to restore endocrine availability where supplementation often fails in obesity.

    Press Release: Regular Exercise Helps Maintain Vitamin D Levels During Winter
    Study: Exercise without Weight Loss Prevents Seasonal Decline in Vitamin D Metabolites: The VitaDEx Randomized Controlled Trial

  • Training in hot conditions can drive marked improvements in endurance by triggering cardiovascular and thermoregulatory adaptations. However, access to heat training chambers is limited, and the physical demands of exercising in high temperatures can be risky or impractical. A recent study found that sitting in a sauna or soaking in hot water after exercise—a practice known as “passive heat acclimation"—might offer some of the same benefits as working out in the heat, but the evidence was weak and inconsistent.

    Researchers reviewed 10 studies involving nearly 200 healthy adults, comparing those who used post-exercise heat exposure via sauna or hot water immersion to those who did not. All participants completed similar exercise training programs, and the researchers analyzed outcomes related to performance in hot or neutral conditions, aerobic capacity, heart rate, body temperature, sweat response, and perceived exertion.

    The analysis revealed little to no improvement in performance for those using passive heat acclimation, identifying only a 4% difference between groups—an effect that was statistically weak and inconsistent across individuals. Heat exposure slightly improved maximum oxygen uptake, sweat rate, and thermal discomfort ratings. However, the overall certainty of the evidence was low to very low, due to small study sizes and inconsistent reporting.

    These findings suggest that while passive heat exposure may exert some physiological effects, its ability to improve exercise performance remains unclear. More rigorous, well-controlled trials are needed before recommending hot tubs or saunas as a reliable substitute for training in the heat. Learn more about heat exposure in this peer-reviewed article by Dr. Rhonda Patrick.

  • Resistance training is a powerful tool for improving the health and well-being of older adults, but many guidelines focus on higher training volumes that may be difficult for some to achieve or maintain. A recent study found that once-weekly, low-volume resistance training boosted physical functioning, energy, and social engagement in older adults, reducing pain by up to 40% and improving strength by 30%.

    Researchers assigned 31 older adults (average age, 66) to one of four groups. Participants trained once a week for six weeks, doing leg press exercises with either a slower, controlled pace or a more explosive effort and using lighter or heavier weekly exercise “doses” (either three or five sets of five repetitions). The researchers assessed the participants' quality of life, functional capacity, strength, and body mass at baseline and weeks 3 and 6.

    They found that participants moved more easily, felt more energetic, and reported less pain after the intervention. Their balance and strength improved, and many participants reported more frequent physical activity—an average increase of 25%—and a 20% improvement in mental health. Most participants (85%) continued exercising after the study, and 95% said they would recommend the program. Many valued the structure and support, with 75% finding the shorter three-by-five routine practical and sustainable.

    These findings suggest that lower-dose, once-weekly resistance training interventions can produce meaningful health improvements in older adults. One of the principal benefits of resistance training is building muscle, which is critical for maintaining health during aging. Learn how it’s never too late to start building muscle in this clip featuring Dr. Rhonda Patrick.

  • As people age, sleeping problems become more common, often affecting mood, memory, and overall health. A recent study found that resistance training improves sleep in older adults better than other forms of exercise.

    Researchers analyzed 25 clinical trials involving more than 2,100 people to see how different kinds of physical activity influenced sleep quality. They looked specifically at the Pittsburgh Sleep Quality Index, a subjective measure of a person’s sleep quality. The studies compared people who exercised to those who adhered to their usual routines, received health education, or did no physical activity at all.

    Strength training was the most effective approach for improving sleep scores, followed by aerobic activity and then a combination of both. People who engaged in strength exercises were more likely to report better sleep, with the strongest improvement observed across all comparisons. Aerobic activity also helped but wasn’t as effective, and combined exercise had a more modest benefit.

    These findings suggest that resistance training does more than build muscle—it also improves sleep. Resistance training builds bone, too, a critical component of aging well. Learn more in this clip featuring Dr. Brad Schoenfeld.

  • Taking an omega-3 supplement may do more than support heart health—it might enhance the effects of your workout. A recent study found that combining omega-3 supplementation with exercise training improved body composition and cardiometabolic health better than exercise alone.

    Researchers conducted a systematic review and meta-analysis of 21 studies comparing exercise training combined with omega-3 supplementation to exercise training alone. The studies involved 673 adults aged 30 to 70, with an average body mass index (BMI) of 24 to 37. The analysis focused on outcomes such as body fat, blood pressure, blood fats, blood sugar, inflammation, and muscle mass, while accounting for variations across the studies.

    They found that adding omega-3 supplements to an exercise routine resulted in modest improvements. Participants lost just over 1 kilogram (2.3 pounds) more body fat and lowered their triglyceride levels by 10% compared to those who exercised without supplements. They also experienced drops in blood pressure—around 4 mmHg lower for both systolic and diastolic pressures—and slightly reduced levels of tumor necrosis factor-alpha, a marker of inflammation. However, LDL cholesterol increased slightly. Notably, participants also improved their lower-body strength but observed no additional benefits in other areas such as BMI, lean body mass, or blood glucose control.

    These findings indicate that omega-3 supplements enhance certain health benefits of exercise, particularly in decreasing fat mass, lowering blood pressure, and boosting muscle strength. Although the changes were modest, they could accumulate over time, especially for adults aiming to improve their cardiometabolic health. Some evidence suggests that omega-3s exert anabolic effects, too. Learn more in this episode featuring Dr. Chris McGlory.

  • Even if you work out, spending most of your day sitting may still adversely affect your health in ways that don’t become apparent until later in life. A recent study found that 35-year-olds who engaged in 30 minutes of vigorous exercise each day had cholesterol levels comparable to those of sedentary 30-year-olds, suggesting that vigorous exercise can offset up to five years of age-related decline in heart health.

    Researchers analyzed data from adults aged 28 to 49 who participated in the Colorado Adoption/Twin Study of Lifespan Behavioral Development and Cognitive Aging. They tracked the time participants spent sitting each day and how often they engaged in moderate or vigorous physical activity. To isolate the effects of behavior from shared genetics and environment, the researchers also compared identical twins with differing activity and sitting patterns. They examined two key health markers: body mass index and the ratio of total to high-density lipoprotein cholesterol—a strong predictor of heart disease risk.

    They found that people who spent more time sitting tended to have higher body mass index and worse cholesterol ratios as they aged. However, among those who sat for the same amount of time—about four hours daily—participants who exercised vigorously for at least 30 minutes daily had cholesterol profiles that resembled those of people five years younger. In some cases, vigorous activity was associated with health markers typical of people up to 10 years younger, but the protective effect weakened with longer sitting durations. In other words, exercise helped—but only to a point.

    These findings suggest that while vigorous exercise offers clear benefits, reducing sitting time is just as important for maintaining good health. “Exercise snacks” can offset the harmful effects of prolonged sitting. Learn more in this clip featuring Dr. Rhonda Patrick and Brady Holmer.

  • Creatine monohydrate—one of the most widely studied and popular supplements—has a well-earned reputation for helping increase lean body mass, but some of those gains may come from changes in body water rather than actual muscle growth. A recent study found that creatine monohydrate alone, even without exercise, can boost lean body mass in the short term—especially in women.

    Researchers randomly assigned 63 healthy adults to take either 5 grams of creatine monohydrate daily or nothing. After a one-week “wash-in” period with the supplement, everyone began a 12-week resistance training program. The researchers measured lean body mass using a body scan before and after the wash-in and after the training program.

    After one week of taking creatine without exercising, those who used the supplement had gained about 0.5 kilograms (roughly 1.1 pounds) more lean body mass than the control group—a difference most apparent in women. Once training began, both groups gained about 2 kilograms (4.4 pounds) of lean body mass over 12 weeks, but creatine users did not gain more than those who did not take it, indicating the supplement gave an early bump in lean body mass but did not enhance long-term gains from resistance training.

    These findings suggest that short-term creatine use can raise lean body mass measurements, likely by increasing body water. The investigators posited that higher doses or different timing strategies may be necessary to see continued benefits beyond that initial increase. Learn more about creatine in this episode featuring Dr. Darren Candow.

  • Heart disease is the leading cause of death worldwide, and clogged arteries—caused by a buildup of fatty plaques—are a major culprit. While some plaques remain stable, others can rupture and trigger heart attacks. A recent study found that high-intensity interval training (HIIT) may help shrink fatty arterial plaquesin people with coronary artery disease who have undergone stent placement, reducing plaque size by 1.2% in just six months.

    Researchers randomly assigned 60 patients with stable coronary artery disease to a supervised HIIT program or standard preventive care twice a week. After six months, they used intravascular ultrasound to measure changes in plaque size inside the coronary arteries.

    They found that patients who did HIIT had a 1.2% reduction in plaque size, while those who followed standard preventive care saw no change. The total plaque volume in the HIIT group also dropped by about 9 cubic millimeters, but it remained the same in the standard care group. Even small reductions in plaque size can be meaningful because they reflect a slowing—or even a reversal—of coronary artery disease progression.

    These findings suggest that HIIT may help slow or even reverse the progression of coronary artery disease. It’s important to note that these patients were closely supervised to minimize risk. Learn about some of the contraindications and considerations for HIIT in this episode featuring Dr. Martin Gibala.

  • If you’re struggling to remember things, a robust workout might help. Scientists have discovered that exercise can increase levels of brain-derived neurotrophic factor (BDNF), a protein that supports learning and memory. A recent study in rats found that low-speed uphill exercise raises blood lactate levels, increasing lactate and BDNF in key brain regions involved in cognition.

    Researchers divided rats into three groups: One remained inactive, another walked on a flat treadmill, and a third walked uphill at a 40% incline. The exercise sessions lasted either 30 or 90 minutes. To see if lactate from the blood contributed to brain changes, some rats also received a direct lactate injection.

    Uphill exercise increased lactate levels in the animals' blood and brains, while flat treadmill walking did not. After 90 minutes, uphill exercise also raised BDNF levels in brain regions linked to memory and learning. The lactate injection showed that blood lactate passed into the brain, reinforcing that exercise-induced increases in blood lactate can influence brain chemistry.

    These findings suggest that walking uphill—even slowly—provides cognitive benefits by raising brain lactate and stimulating BDNF production. This type of exercise could be a practical and safe way to support brain health, especially for older adults or those looking to enhance memory and learning. To learn more strategies to boost brain health, check out the Cognitive Enhancement Blueprint, a member-only perk.

  • Tendons are essential for force transmission between muscles and bones. However, as people age, tendons lose collagen and stiffen, impairing athletic performance and increasing injury risk. A recent study found that combining resistance exercise with collagen supplementation enhanced tendon health in middle-aged men.

    Researchers investigated the effects of 12 weeks of resistance exercise and collagen supplementation on patellar tendon properties in 20 middle-aged men. Both groups engaged in progressive lower-body resistance training twice weekly and received either 30 grams of hydrolyzed collagen or a placebo after training. The researchers evaluated the participants' tendon size, stiffness, and strength before and after the intervention.

    They found that participants who took collagen experienced a greater increase in patellar tendon cross-sectional area (+6.8 mm²) than the placebo group (+1.2 mm²). They also experienced a twofold greater increase in tendon stiffness and measures of tendon strength than the placebo group. Both groups experienced muscle strength and explosive power improvements, but tendon adaptations were more pronounced with collagen supplementation.

    These findings suggest that 12 weeks of resistance training with collagen supplementation enhances patellar tendon properties in middle-aged men. The patellar tendon is a strong, fibrous connective tissue that connects the bottom of the kneecap (patella) to the top of the shinbone (tibia). It plays a crucial role in movements like walking, running, jumping, and squatting, as it helps control the movement and stability of the knee joint. Learn more about the benefits of collagen supplementation in our overview article.

  • Infrared saunas are gaining in popularity among athletes as a recovery tool, but their effects on strength training adaptations remain uncertain. While traditional saunas can impair performance, infrared saunas may offer a more effective and comfortable recovery option. A recent study found that using infrared saunas after exercise enhances power production but doesn’t influence muscle growth.

    Forty female team sport athletes participated in the study, with half using an infrared sauna after training sessions for six weeks. Sauna sessions were done three times weekly for 10 minutes at 50°C (122°F) following their training. All participants underwent body composition measurements and physical performance tests, including sprint tests, jumps, and leg press exercises, before and after the training period.

    Both groups improved in neuromuscular performance and muscle size. However, the infrared sauna group showed greater jump height and peak power improvements, with a 25% increase in jump height and a 6.8% increase in peak power. Five-minute sprint times were also faster in the infrared sauna group, though not statistically significant. While both groups gained lean mass, the infrared sauna group experienced small body mass and fat mass increases. There were no marked differences between the groups in muscle hypertrophy or other body composition changes.

    These findings suggest that post-exercise infrared sauna use enhances power output over time but doesn’t affect muscle growth. Learn more about the benefits of infrared and traditional sauna use in our overview article.

  • Intense exercise—especially eccentric movements like downhill running or heavy weightlifting—can cause microscopic muscle damage, inflammation, and soreness. While this process is part of adaptation, excessive damage can delay recovery and hinder performance. A recent study found that curcumin, a compound derived from turmeric, may help reduce muscle damage and soreness, potentially speeding up recovery.

    Researchers analyzed the findings of 11 studies on curcumin and exercise-induced muscle damage. The various studies focused on healthy adults who exercised regularly and took curcumin before, during, or after workouts.

    The analysis revealed that curcumin supplementation may ease muscle soreness, reduce inflammation, and improve recovery after strenuous exercise. However, the benefits depended on dose (which ranged from 90 milligrams to 2.5 grams), bioavailability, and timing, with post-exercise supplementation appearing most effective.

    These findings suggest that curcumin could be a useful supplement for athletes looking to minimize muscle soreness and recover faster. However, its low bioavailability may limit its effectiveness. In addition, the investigators noted that many of the studies were small, limiting their findings' applicability. Curcumin is a polyphenolic compound. Learn more about polyphenols in our overview article.

  • Cancer remains one of the leading causes of death globally, with millions of new cases and deaths each year. Despite treatment advancements, cancer patients are at a greater risk of death due to muscle loss, heart complications, and inadequate physical activity. A recent study found that higher muscle strength and cardiorespiratory fitness reduce the risk of death in cancer patients, with a 31% to 46% lower likelihood of premature death.

    Researchers conducted a systematic review and meta-analysis of 42 studies involving more than 47,000 cancer patients across various types and stages to examine how muscle strength and cardiorespiratory fitness influence survival rates. They sought to determine whether higher fitness levels were associated with better outcomes in terms of overall and cancer-specific death.

    Their analysis revealed that patients with higher muscle strength or cardiorespiratory fitness were 31% to 46% less likely to die prematurely from any cause than those with lower fitness levels. Each increase in muscle strength was associated with an 11% lower risk of all-cause mortality. Furthermore, patients with advanced cancer stages, as well as those with lung and digestive cancers, saw significant reductions in death risks—ranging from 8% to 46% lower for all-cause mortality. Increments in cardiorespiratory fitness were particularly important, with each improvement in cardiorespiratory fitness linked to an 18% reduced risk of dying specifically from cancer.

    These findings suggest that boosting muscle strength and cardiorespiratory fitness can improve cancer patients' survival rates. Given the strong connection between physical fitness and mortality risk, health professionals should prioritize fitness assessments for cancer patients as part of their treatment strategies. Learn more about the role of exercise in cancer prevention and recurrence in this episode featuring Dr. Kerry Courneya.

  • Sitting for long periods isn’t just harmful to your back—it may also increase your risk of cardiometabolic disorders, such as diabetes and cardiovascular disease. Some research indicates that breaking up sedentary time with movement can enhance cardiometabolic health, but scientists are uncertain about the best frequency for these breaks. A recent study discovered that taking frequent breaks—at least every 30 minutes—might be more effective at managing blood sugar than having less frequent interruptions.

    Researchers conducted a systematic review and meta-analysis of randomized crossover trials that compared different frequencies of activity breaks during prolonged sitting. They included data from 13 studies with 211 participants, examining the effects of more frequent movement breaks (every 30 minutes or less) versus less frequent ones (every 30 minutes or more) on glucose, insulin, triglycerides, blood pressure, and vascular function.

    Their analysis revealed that taking more frequent movement breaks—every 30 minutes or more—reduced blood glucose levels more effectively than less frequent breaks. However, they found no significant differences between the two approaches for insulin levels, blood pressure, triglycerides, or vascular function. In addition, they rated the overall quality of evidence as low, highlighting the need for further research.

    These findings suggest that interrupting sedentary time at least every 30 minutes is a practical strategy for improving blood sugar control. An effective way to interrupt sedentary time is to engage in “exercise snacks"—short bursts of activity that improve cardiorespiratory fitness. Watch this video to learn about a two-minute exercise snack that improves blood glucose, mitochondrial health, and more.

  • The pathological brain changes that drive Alzheimer’s disease may begin as much as 20 years before cognitive signs become evident. However, evidence indicates that exercise can slow or prevent these changes. A recent study involving older rats found that regular aerobic exercise reduces age-related inflammation in the brain and improves the balance between nerve fibers and their protective myelin coating.

    Researchers had older rats exercise on a treadmill for eight weeks. Then, they examined the rats' brain tissue and analyzed changes in tau protein, amyloid plaques, and iron levels.

    They discovered that older rats engaging in regular physical exercise experienced reduced age-related inflammation and improved balance between nerve fibers and their protective myelin coating. They also learned that excessive iron in oligodendrocytes—cells that support and insulate nerve fibers—triggers a type of cell death known as ferroptosis, possibly contributing to the formation of amyloid-beta plaques linked to Alzheimer’s. They identified statistical connections between tau and amyloid proteins (hallmarks of Alzheimer’s), iron levels, and cells in the hippocampus, a brain region crucial for memory.

    These findings indicate that iron plays a critical role in Alzheimer’s pathology, but exercise can mitigate some of these effects. Learn more about preventing and reversing Alzheimer’s disease in this episode featuring Dr. Dale Bredesen.

  • Regular exercise has long been known to protect cognitive functions such as attention, memory, and processing speed as we age. A recent study found that exercise may also improve older adults' language comprehension by enhancing cardiorespiratory fitness—the body’s capacity to deliver and use oxygen-rich blood.

    The study included 160 monolingual or bilingual older adults. Half of the participants followed a 26-week home-based high-intensity interval training (HIIT) program with three weekly sessions, starting with a four-week familiarization period. Afterward, they aimed for over 80% of their peak heart rate. Researchers measured their cardiorespiratory fitness and language comprehension before and after the intervention, using reaction times to spoken-word monitoring tasks.

    They found that monolinguals who participated in the HIIT program responded faster on comprehension tasks than non-exercisers. This improvement was linked to increased VO2peak (a measure of cardiorespiratory fitness), supporting the idea that exercise boosts language processing abilities in older adults. However, bilinguals did not experience these improvements, suggesting that the effects of exercise on language processing may be influenced by language proficiency.

    These findings support the growing evidence demonstrating that cardiorespiratory fitness protects cognitive function. HIIT robustly improves cardiorespiratory fitness. Learn more in this clip featuring Dr. Martin Gibala.

  • Cancer is the second leading cause of death worldwide, claiming the lives of nearly 10 million people yearly. A recent study found that people who exercise regularly are nearly half as likely to die of cancer than those who are inactive.

    Researchers assessed the physical activity of more than 28,000 people diagnosed with stage 1 cancer in the year before their diagnosis based on data gathered from fitness devices, gym logs, and organized fitness events. They categorized the participants' activity as none, low (less than 60 minutes weekly), and medium to high (60 minutes or more weekly). Then, they measured their time to cancer progression and death rates.

    They found that participants with low physical activity were 16% less likely to experience cancer progression and 33% less likely to die than those who were inactive. However, those with medium to high activity levels were 27% less likely to experience progression and 47% less likely to die than those who were inactive.

    These findings highlight exercise’s protective role in reducing cancer progression and improving survival. Exercise boosts the body’s immune system, helping it to combat cancer. It also promotes shear—the frictional drag exerted by blood flowing against the inner walls of blood vessels. Shear damages cancer cells, driving their death. Learn more in this clip featuring Dr. Rhonda Patrick.

  • How fit you are may matter more than how much you weigh when it comes to your risk of dying early. A recent review and meta-analysis found that poor cardiorespiratory fitness increases the risk of early death from cardiovascular disease and other causes, regardless of body weight.

    Researchers analyzed the findings of 20 studies investigating the effects of cardiorespiratory fitness and body weight on the rates of early death from cardiovascular disease and all other causes. The various studies included nearly 400,000 participants and compared the risks among people who were overweight or obese to those who were normal weight.

    They found that overweight, fit people were about 50% more likely to die from cardiovascular disease and had roughly the same overall risk of early death as those with normal weight. Obese, fit people were 62% more likely to die from cardiovascular disease and had an 11% higher overall risk of early death, but these differences were not statistically significant.

    However, being unfit was linked to a much higher risk of death. Normal-weight people who were unfit were about twice as likely to die from cardiovascular disease and all causes. Overweight, unfit people had roughly 2.5 times the risk of cardiovascular death and 82% higher overall risk of early death. Obese, unfit people had more than triple the risk of cardiovascular death and twice the risk of dying from any cause compared to those with normal weight.

    These findings suggest that cardiorespiratory fitness robustly predicts the risk of early death from cardiovascular disease and other causes. Vigorous exercise, such as high-intensity interval training, is a great way to boost cardiorespiratory fitness and prevent early death. Learn more in this episode featuring Dr. Rhonda Patrick.

  • Cardiorespiratory fitness measures the body’s aerobic capacity—the ability to deliver oxygen to skeletal muscles—during sustained physical activity. A recent study found that better cardiorespiratory fitness boosts cognitive performance, even among people at greater risk for cognitive decline, such as older adults and APOE4 carriers.

    Researchers collected information from more than 600 older adults regarding their age, sex, education, use of beta-blockers (drugs that lower heart rate), and APOE4 gene status (a genetic risk factor for Alzheimer’s). The participants underwent cardiorespiratory fitness testing on a treadmill. They also completed a comprehensive battery of neuropsychological tests to assess their cognitive function across multiple domains, including processing speed, executive function, working memory, episodic memory, and attention control.

    Participants with higher cardiorespiratory fitness performed better on all cognitive assessment domains than those with poorer fitness—even among those at greater risk for cognitive decline, such as older adults and APOE4 carriers. Additionally, women, participants with fewer years of education, and those taking beta-blockers demonstrated greater cognitive performance in processing speed and executive function.

    These findings suggest that better cardiorespiratory fitness in later life protects against cognitive decline.Although robust exercise is the best way to boost cardiorespiratory fitness, sauna use does, too. Learn more in our members-only report, Sauna Use: Implications for Aging and the Brain.

  • Creatine helps supply energy to muscles during high-intensity exercise and is commonly used to boost performance and muscle mass. However, determining the most effective creatine supplementation protocol has proven challenging. A recent study found that combining creatine with dextrose for five days rapidly increases muscle total creatine, with continued consumption maintaining this high level.

    Researchers provided healthy young men with one of four creatine supplementation protocols: Group 1: Four doses of 5 grams of creatine daily for five days, followed by 5 grams daily for 28 days.
    Group 2: Four doses of 5 grams of creatine plus 95 grams of dextrose daily for five days. Group 3: Split from Group 2 after the initial five days:
    Group 3A: 5 grams of creatine daily for 28 days.
    Group 3B: 5 grams of creatine plus 95 grams of dextrose daily for 28 days. Group 4: Four doses of 5 grams of creatine with 14 grams of protein, 7 grams of phenylalanine, 7 grams of leucine, and 57 grams of dextrose daily for five days, followed by a single daily dose of the same combination for the next 28 days.
    The researchers collected muscle biopsies from the participants at baseline, after five days, and after 33 days.

    They found that muscle total creatine increased in Groups 1, 2, and 4 after five days. The largest increase occurred in Group 2, reaching an average maximum of 150 mmol/kg. However, after 33 days:
    Group 1 total creatine increased further to approximately 150 mmol/kg.
    Group 3A showed a tendency to decline.
    Group 3B remained unchanged from the level observed at five days.
    Group 4 remained unchanged from the level observed at five days and was lower than Group 1. Creatine transporter gene expression changed slightly in all groups. However, the more creatine levels increased after five days, the smaller the change in this gene’s activity.

    These findings suggest that combining creatine with dextrose for five days rapidly increases total muscle creatine. Continued consumption of creatine with dextrose helps maintain this high level. While ingesting creatine alone also boosts total muscle creatine, it takes longer to reach levels similar to those in combination with dextrose. Learn more about creatine in this episode featuring Dr. Rhonda Patrick.

  • Working memory, the brain’s system for temporarily storing and managing information, is crucial for recalling strategies and adapting to rapidly changing situations. A recent meta-analysis found that athletes outperform non-athletes by as much as 63% on working memory tasks.

    Researchers analyzed 21 studies involving more than 1,400 participants across various sports, including basketball, football, and fencing. They assessed working memory through tasks like recalling sequences or matching stimuli after delays. The various studies compared athletes to non-athletes, including sedentary people, and examined factors like sports type and activity level.

    The analysis revealed that athletes had a slight but consistent advantage in working memory compared to non-athletes, with a 30% improvement overall. When athletes were compared to sedentary people, their working memory performance was 63% better. However, the advantage dropped to just 15% when sedentary participants were excluded, suggesting a notable disadvantage for people with inactive lifestyles.

    These findings suggest that sports expertise may enhance working memory, likely due to the cognitive demands of high-level performance. Moreover, sedentary lifestyles hinder working memory, underscoring the importance of regular physical activity for maintaining cognitive health. Physical activity also promotes longevity. Learn more about the longevity and brain-boosting effects of exercise in this episode featuring Dr. Rhonda Patrick.

  • Muscle contraction, the hallmark of exercise, releases signaling molecules called myokines that influence cell function throughout the body. However, the mechanical forces it generates may also play a role. A recent lab study found that biochemical and mechanical signals from contracting muscle work synergistically to promote nerve growth and maturation.

    Researchers grew muscle cells on a specialized gel that mimicked the movements of contracting muscles. Then, by adding tiny magnetic particles, they stretched the cells to simulate exercise. They assessed how these forces and the myokines released by the muscle cells influenced the growth of nerve cells.

    They found that nerve cells grew and migrated more readily when exposed to myokines from contracting muscle cells, with more robust effects at higher levels of muscle activity. Stretching the nerve cells mechanically produced similar growth, but further analysis demonstrated that chemical signals were more effective in activating genes related to nerve growth and forming connections.

    These findings suggest that exercise influences nerve health through biochemical and mechanical pathways, providing new insights into how muscle activity supports the nervous system. Myokines also exert anti-cancer effects. Learn more in this episode featuring Dr. Rhonda Patrick.

  • Frailty isn’t just about getting older—it’s a key indicator of biological age that can signal an increased risk for many health concerns, including dementia. A recent study found that rapid increases in frailty increase the risk of dementia by as much as 73%, especially among females.

    Researchers analyzed data from four large studies involving nearly 88,000 adults aged 60 and older. They measured participants' frailty levels at the start and monitored their health, including the development of dementia, over several years.

    They found that in the years before dementia began to manifest, frailty tended to increase. Participants with the most rapid increases in frailty were 18% to 73% more likely to develop dementia than those with slower frailty progression. Frailty was more common in females than males among those who developed dementia, with the greatest differences seen in the years leading up to dementia onset.

    These findings suggest that measuring frailty could help identify people at greater risk for dementia, serving as an early target for strategies to reduce dementia risk through public health interventions and lifestyle changes. One powerful lifestyle approach for reducing dementia risk is exercise—especially the vigorous kind. Learn more in this episode featuring Dr. Rhonda Patrick.

  • Hypertension—high blood pressure—is a major global health issue affecting more than 1 billion people and contributing to millions of deaths each year. Although robust evidence indicates that structured exercise lowers blood pressure, the effects of daily activity patterns in real-life settings on blood pressure are less clear. A recent study found that spending as little as five minutes daily engaging in exercise-like activities like running to catch a bus or climbing stairs can meaningfully reduce blood pressure.

    Researchers used data from thigh-worn accelerometers and blood pressure measurements from more than 14,700 adults in the Prospective Physical Activity, Sitting, and Sleep (ProPASS) consortium. They analyzed participants' daily activities, including sleep, sedentary time, standing, and different intensities of walking and exercise-like activities, while considering other relevant health factors.

    They found that more time spent exercising was linked to lower blood pressure, with even a five-minute increase in exercise driving systolic and diastolic blood pressure reductions of 0.68 mmHg and 0.54 mmHg, respectively. However, increasing exercise-like activities by 20 to 27 minutes decreased systolic blood pressure by 2 mmHg and diastolic by 1 mmHg (considered clinically significant), potentially reducing the global prevalence of cardiovascular disease by as much as 28%.

    These findings suggest that small, achievable increases in daily exercise can help manage blood pressure effectively. Brief periods of exercise throughout one’s day—often called “exercise snacks"—also help maintain healthy blood glucose levels. Learn more in this clip featuring Dr. Martin Gibabla.

  • Exercise boosts brain health, but some evidence suggests that even ordinary activities like dog walking or gardening can sharpen the mind. A recent study found that physical activity—no matter the intensity—can improve mental speed.

    The study involved 90 healthy participants between the ages of 40 and 65. Using smartphones, participants reported their physical activity five times daily and completed brief cognitive tasks to measure mental speed and memory. The smartphones captured activity levels ranging from light chores to vigorous exercise and assessed how these influenced brain function in real-time.

    The results indicated that being active within the previous 3.5 hours improved mental speed, equating to the cognitive function of someone four years younger. Both light and moderate-to-vigorous activities offered similar benefits. While memory accuracy did not improve, reaction times in memory tasks mirrored the gains in mental speed, especially in people who were more active overall.

    These findings suggest that everyday physical activity can deliver immediate cognitive benefits, potentially offering a simple way to boost brain health at any intensity level. Learn more about the brain benefits of exercise in the Cognitive Enhancement Blueprint, a members-only perk.

  • Metabolic dysfunction-associated steatohepatitis (MASH) is a form of fatty liver disease that promotes inflammation and damage over time. Closely connected to conditions like obesity and insulin resistance, MASH affects nearly one-third of people worldwide. A recent study found that a long-term intervention combining calorie restriction and high-intensity interval training (HIIT) in people with MASH improved liver function, doubling insulin sensitivity.

    Researchers assigned people with MASH to either a treatment group (16 participants) that received lifestyle counseling and exercise training or a control group (eight participants) that continued with standard medical care. The treatment group engaged in supervised HIIT three times a week while reducing caloric intake. The researchers assessed the participants' liver fat, measured blood biochemistries, and evaluated insulin sensitivity before and after the intervention.

    They found that the treatment group experienced notable reductions in body weight, fat mass, and liver injury. Their cardiorespiratory fitness improved considerably, and they exhibited a twofold increase in peripheral insulin sensitivity compared to the control group. Both groups saw reductions in total energy intake and liver fat.

    These findings suggest that combining caloric restriction with regular high-intensity exercise can yield marked improvements in liver health and insulin sensitivity, likely by redistributing excess nutrients to skeletal muscle. Learn more about calorie restriction in this clip featuring Dr. David Sinclair, and HIIT in this clip featuring Dr. Martin Gibala.

  • Hunger cues are influenced by more than just an empty stomach, with hormones like ghrelin playing powerful roles as appetite regulators. A recent study found that both exercise intensity and sex significantly influence ghrelin levels, markedly influencing appetite.

    Researchers measured lactate threshold and peak oxygen consumption in 14 untrained males and females engaging in three different cycling sessions: a control session with no exercise, a moderate-intensity session at lactate threshold, and a high-intensity session at 75% of the difference between lactate threshold and peak oxygen consumption. Then, they assessed the participants' appetite perception.

    They found that females had considerably higher total ghrelin and deacylated ghrelin levels at baseline than males. In both groups, high-intensity exercise promoted lower levels of deacylated ghrelin than moderate-intensity and no-exercise sessions. Notably, only females exhibited reduced acylated ghrelin levels during high-intensity exercise. Additionally, hunger scores were higher during moderate-intensity sessions than they were during no exercise.

    Ghrelin, often called the “hunger hormone,” is primarily produced in the stomach and stimulates appetite. Deacetylated ghrelin has different effects on appetite regulation than its acylated counterpart.

    These findings suggest that high-intensity exercise is more effective than moderate-intensity exercise in lowering ghrelin levels and suppressing hunger, with noticeable differences between sexes in this response. High-intensity exercise also promotes brain health. Learn more in this clip featuring Dr. Martin Gibala.

  • Mental fatigue can severely impair cognitive and physical performance, especially in older adults, increasing their risk of falls, accidents, and other health concerns. A recent study found that combining cognitive and physical exercise training may help improve mental and physical function in older adults, particularly when tired.

    Researchers randomly assigned 24 women aged 65 to 78 to one of three groups: brain+exercise training, exercise-only training, or no training (control). The brain+exercise and exercise-only groups completed three weekly sessions for eight weeks consisting of 20 minutes of resistance training (squats and bicep curls) and 25 minutes of endurance exercise (walking outside). The brain training consisted of various assessments that measure reaction time and cognitive inhibition—the brain’s ability to block distractions or irrelevant information—completed four times throughout the study.

    The researchers found that the brain+exercise and exercise-only groups performed better than the control group on cognitive and physical tasks regardless of how tired they were. However, the brain+exercise group showed greater improvements, particularly when tired. On average, cognitive performance increased by 7.8% in the brain+exercise group compared to 4.5% in the exercise-only group. Similarly, physical performance improved by nearly 30% in the brain+exercise group compared to 22.4% in the exercise-only group.

    The findings from this small study suggest that combining cognitive and physical training boosts mental and physical abilities in older adults, particularly when tired. This approach may help mitigate age-related declines and reduce the risk of falls and other health complications. Learn about the brain-protective effects of physical exercise in this episode featuring Dr. Rhonda Patrick.

  • Contact sports can take a toll on the brain, even without obvious concussions, and new evidence indicates that repetitive, subconcussive head impacts may cause subtle but considerable brain injury over time. A recent review and analysis found that some evidence points to lower brain injury markers among athletes who took omega-3 fatty acid supplements—especially among those with higher play time—but overall, results are mixed.

    Researchers conducted a systematic review and meta-analysis using data from three studies on American football players—who often receive multiple subconcussive head impacts during a typical season. They examined whether supplementation with omega-3s reduced levels of neurofilament-light, a protein that rises in the blood following brain injury.

    They found that across the three studies, omega-3 supplementation reduced neurofilament-light levels by 60% to 100% compared to a placebo in one study, prevented marked increases in another, and showed no effect in the third, with reductions primarily observed in starter players.

    A subconcussive head impact is a minor blow to the head that does not cause immediate symptoms of a concussion but can still lead to cumulative brain damage over time. Athletes frequently sustain hundreds of these minor impacts each season, allowing them to accumulate unnoticed. Because these injuries are usually asymptomatic, players may not receive the treatment or restrictions they need for recovery, exacerbating neurological damage.

    These findings indicate that omega-3 supplementation may protect the brain from the cumulative effects of subconcussive head impacts in contact sports. However, the investigators cautioned that their review only included three studies—with mixed results—and further research is needed to establish the optimal dose and timing for this potential protective effect. Learn about the many health benefits of omega-3s in this episode featuring Dr. Bill Harris.

  • Asthma affects millions of children, and finding ways to prevent it before birth could be a game-changer. Some evidence suggests that physical activity during pregnancy promotes fetal lung development, potentially reducing children’s asthma risk. A recent study found that the children of mothers who engaged in regular physical activity during pregnancy were nearly half as likely to develop asthma.

    Researchers analyzed data from 963 mother-child pairs participating in the Kuopio Birth Cohort study. They gathered information on maternal physical activity during pregnancy, potential influencing factors, and asthma diagnoses in the children when they were between the ages of 5 and 7 years.

    They found that the children of mothers who engaged in physical activity three or more times per week during pregnancy were 46% less likely to develop asthma. This relationship held steady even after adjusting for factors like the length of pregnancy, delivery method, maternal health conditions, and family environment.

    These findings suggest that regular physical activity during pregnancy could effectively reduce asthma risk in children. Experts recommend that pregnant women aim for about 150 minutes of moderate-intensity exercise every week. Learn about other healthy lifestyle practices for pregnancy in Aliquot #100: Optimizing for a Healthy Pregnancy and Early Childhood.

  • Injuries often leave one limb immobilized, driving a rapid decline in muscle strength and size. But what if training the opposite limb could help preserve the strength of the immobilized one? A recent study found that targeted exercise of one arm can help maintain strength and size in the opposite immobilized arm, offering potential benefits for rehabilitation.

    Researchers immobilized the nondominant forearms of 16 adult participants for four weeks using a cast. Then, they randomly assigned them to a resistance training or non-exercising group. Participants in the training group performed eccentric wrist flexion exercises with the non-immobilized arm three times a week. Both groups underwent testing before and after the intervention to measure muscle strength, thickness, and cross-sectional area using ultrasound and computed tomography.

    The researchers found that those in the training group experienced only a 2.4% reduction in strength in the immobilized arm compared to a 21.6% reduction in the non-training group. In addition, the training group saw a 1.3% increase in muscle size of the immobilized forearm, while the non-training group showed a 2.3% decrease. They also observed strength gains in the non-immobilized arm, with a 30.8% improvement in the training group compared to a 7.4% decline in the non-training group.

    These findings suggest that engaging in targeted resistance training of the non-immobilized limb can help preserve the size of an immobilized limb and maintain strength across different types of muscle contractions. The researchers posited that the immobilized arm retained more muscle mass and strength due to neural adaptations from training the opposite arm, a phenomenon known as cross-education effects. Interestingly, sauna use can also help maintain muscle mass during periods of disuse due to immobilization. Learn more in our overview article.

  • As we age, our muscles' response to resistance training diminishes to varying degrees, with some people responding and others not. This non-responsiveness can make maintaining muscle mass and strength challenging in later years. A recent study found that increasing resistance training volume—the number of sets performed—overcomes non-responsiveness in older adults.

    The study involved 85 older adults (average age, 68) who completed a 10-week resistance training program. Participants followed a low-volume protocol (one set) for one leg and a high-volume protocol (four sets) on the other leg while performing knee extensions twice weekly. Researchers measured their muscle size and assessed their leg strength before and after the intervention.

    They found that 51 participants didn’t respond to the low-volume training. However, they experienced considerable muscle size and strength improvements when they increased their volume. Responders—those who saw muscle gains from the one-set protocol—also benefited from the higher volume, but their strength gains were similar regardless of volume.

    These findings suggest that older adults who don’t see improvements from resistance training can achieve meaningful gains by increasing the number of sets performed. Learn more about resistance training in this clip featuring Dr. Brad Schoenfeld.

  • The brain’s hippocampus is vital for memory and learning but tends to shrink with age, contributing to cognitive decline. A recent study found that high-intensity interval training (HIIT) improves hippocampal-dependent cognitive abilities in older adults better than other forms of exercise.

    Researchers randomly assigned 151 healthy adults aged 65 to 85 to one of three exercise regimens: low-intensity training, medium-intensity training, or HIIT. Over six months, participants attended 72 supervised sessions, underwent monthly cognitive testing, and provided blood samples. The researchers assessed the participants' brain volumes using magnetic resonance imaging (MRI) brain scans at various time points, with follow-ups continuing for five years.

    They found that the HIIT group experienced marked improvements in hippocampal function. HIIT also reduced age-related brain volume loss, particularly in the hippocampus, and strengthened the connections between critical brain networks. The HIIT group’s cognitive improvements were associated with higher levels of brain-derived neurotrophic factor—a growth factor that supports brain function—and cortisol.

    These findings suggest that HIIT protects against age-related cognitive decline and highlights its potential to preserve brain health in older adults. Learn more about the brain benefits of HIIT in this episode featuring Dr. Rhonda Patrick.

  • When it comes to managing knee and hip arthritis, resistance exercise might be the ticket. A recent meta-analysis found that resistance exercise dramatically reduces pain and improves daily function in people with knee and hip arthritis.

    Researchers analyzed data from randomized controlled trials comparing resistance exercise to other interventions, including no treatment, other forms of exercise, non-exercise interventions, or a combination of these. They examined the effects on pain and function and the relationship between increased leg strength and improved outcomes. They included 250 studies on knee arthritis and 15 on hip arthritis.

    They found that patients who performed resistance exercises for knee arthritis were 25% to 30% more likely to experience improvements in pain and function than those receiving no treatment. Additionally, greater strength gains in the legs were linked to better pain relief and functional outcomes. They noted moderate benefits for hip arthritis, but in some cases, non-exercise interventions performed better than resistance exercise alone.

    These findings suggest that resistance exercise benefits people with knee arthritis, particularly in reducing pain and improving mobility. However, combining treatments may be more effective for hip arthritis than exercise alone. One form of therapy that may help reduce the inflammation that drives arthritis is cold exposure. Learn more in our overview article.

  • Exercise can profoundly affect your brain, boosting memory and enhancing cognitive performance. But imagine if your daily exercise routine could boost your grandchildren’s brainpower. A recent study in mice found that cognitive benefits from physical activity can be passed down to future generations, even if they don’t exercise.

    Researchers compared the cognitive performance of male mice whose grandfathers exercised regularly with those whose grandfathers were sedentary. They also analyzed genetic markers related to brain function in both groups.

    Mice with active grandfathers had better memory recall, particularly in tasks requiring spatial (recalling locations) and non-spatial (recalling facts and events) memory. Although their cognitive abilities improved, these mice didn’t experience the new brain cell growth observed in the exercising grandfathers. Additionally, the researchers identified 35 microRNA molecules related to brain function, with two associated with poorer cognitive performance.

    microRNAs are small molecules that regulate gene activity by determining which proteins are produced in cells. They play a key role in many biological functions, including development, disease progression, and how cells respond to changes in their environment.

    These findings suggest that the cognitive benefits of exercise can be passed down to future generations. Check out the Cognitive Enhancement Blueprint—a members' only perk—to learn more about the effects of exercise on brain health and function.

  • If you’re struggling with exercise performance, your gut health might be partly to blame. The gut microbiota is critical for boosting exercise performance and regulating energy metabolism. A recent study found that mice without gut microbes, known as germ-free mice, had lower exercise capacity and used oxygen and glucose less efficiently during physical activity.

    Researchers compared germ-free mice to mice with normal gut bacteria. They fed both groups a regular diet and allowed them to exercise on running wheels. They measured the animals' body composition, oxygen and carbon dioxide usage, and glucose levels to assess how the absence of gut microbes affected exercise performance and energy use.

    They found that germ-free mice gained less weight, had lower fat mass, and had lower aerobic exercise capacity than mice with normal gut bacteria. Germ-free mice also exhibited reduced glucose storage and usage, impairing their capacity to fuel physical activity. Additionally, their fat tissue adapted by breaking down more fat, making them leaner and less prone to obesity, but at the cost of reduced energy availability during physical activity.

    These findings suggest that the absence of gut bacteria limits the body’s ability to store and use glucose, adversely affecting exercise performance. They also highlight gut microbes' vital role in supporting metabolism and physical endurance. Learn more about gut microbes' effects on metabolism in this clip featuring Dr. Michael Snyder.

  • Keeping our hearts strong and healthy becomes increasingly challenging as we age, especially for older women. However, physical activity, especially resistance training, may benefit the heart. A recent study found that a 24-week resistance training program improved heart function in older women.

    Researchers assigned 73 physically independent older women (average age, 68) to either an exercise training or sedentary group. The training group participated in a supervised resistance training program three times weekly for 24 weeks, using machines and free weights. Each session included exercises targeting the whole body, with three sets of eight to 12 repetitions each. The researchers measured the participants' cardiac function before and after the program.

    They found that women in the training group experienced several improvements in heart function, including: - A 10.6% decrease in left ventricular volume versus a 1.1% increase in the sedentary group. - A 9.1% decrease in left atrial volume versus a 3.9% increase in the sedentary group. - Better heart relaxation, indicated by a 4.8% reduction in the diastolic function index.

    These findings suggest that regular resistance training improves heart structure and function in older women, potentially reducing the risk of age-related cardiac decline. Finding the time for resistance training can be difficult, however. Listen as Drs. Brad Schoenfeld and Stuart Phillips describe time-efficient ways to incorporate resistance training into a busy schedule.

  • Study link:

    Athletes often warm up before a big race, but does heating your muscles make a difference? An early study found that warming muscles boosts performance by 11% during intense exercise—but at a cost.

    Researchers asked four young, healthy adults to perform 20-second high-intensity sprints on an exercise bike under four different muscle temperature conditions: room temperature, after leg immersion in hot water (44°C/111.2°F), and after immersion in cool water (18°C/64.4°F and 12°C/53.6°F). They measured the participants' muscle temperature and analyzed their peak force and power output during each sprint.

    They found that increasing muscle temperature using warm water immersion boosted peak force and power 11% more than resting at room temperature. In contrast, cooling the legs in 18°C (64.4°F) and 12°C (53.6°F) water decreased power output 12% and 21% more, respectively. However, higher muscle temperatures also led to quicker fatigue during the sprints. The beneficial effect of temperature was greater at higher pedaling speeds, with a 10% increase in power for every degree (1°C/1.8°F) increase in temperature at the fastest speed.

    It’s important to note that this was a small study that was conducted several years ago. However, the findings suggest that warming muscles before high-intensity exercise enhances power and performance, particularly at faster speeds. This benefit comes with a trade-off of earlier fatigue, potentially limiting endurance activity performance. Cooling, on the other hand, may reduce power output but could extend endurance by slowing the onset of fatigue.

    Interestingly, research shows that warming the body after exercise—in a sauna, for example—can boost performance. In contrast, cCooling the body after exercise may improve glucose and lipid metabolism, decrease inflammation, improve cognitive performance, and enhance immune function — possibly at the cost of reductions in hypertrophy. Learn more in this episode featuring Dr. Rhonda Patrick.

  • Cellular processes are messy. They produce copious amounts of harmful waste products and damaged parts that can accumulate inside the cell, creating havoc and even cell death. A recent study found that resistance training activates critical cellular cleanup processes in muscles, facilitating waste disposal and supporting muscle cell health.

    The study had two phases: an acute exercise phase with intense workouts to trigger an immediate muscle response and a six-week adaptation phase to see how muscles adjust to repeated mechanical stress. In the acute phase, participants performed resistance exercises, including leg extensions, leg presses, and drop jumps, using heavy weights and incorporating eccentric movements. During the adaptation phase, they performed the exercises at a lower intensity twice a week, allowing the muscles to adapt to the consistent workload gradually. Researchers took muscle samples before and after these sessions at the start and end of the study, analyzing changes in critical proteins and focusing on a cellular protein called BAG3.

    BAG3 facilitates a cellular cleanup process called chaperone-assisted selective autophagy, or CASA. Unlike ordinary autophagy, which generally recycles various cell parts, CASA specifically targets and breaks down damaged or misfolded proteins with the help of unique proteins called chaperones. BAG3 is one of these chaperones. Under resting conditions, two phosphorous molecules tether BAG3 in place, keeping it inactive.

    However, the researchers found that when cells experienced mechanical stress, the phosphorous molecules released BAG3, activating it and allowing it to perform its chaperoning job. Notably, BAG3 release was essential for eliminating damaged mitochondria—a process called mitophagy—in skeletal muscles.

    These findings suggest resistance exercise supports cellular health and mitophagy by boosting in-house cleanup processes. Learn more about mitophagy in this clip featuring Dr. Guido Kroemer.

  • Genes play critical roles in determining how long a person lives, but a new study suggests that the secret to longevity may be as simple as “food as medicine.” Centenarians—people who live 100 years or more—typically eat healthy, balanced diets and require fewer medications than their shorter-lived peers.

    Researchers analyzed studies examining the lifestyles, medication use, and overall health of centenarians and near-centenarians aged 95 to 118. Their analysis included 34 studies and involved more than 59,000 participants.

    They identified several healthy lifestyle habits of long-lived adults: Engaging in regular physical activity Avoiding alcohol and tobacco Adhering to a diverse, macronutrient-balanced diet Preferring less salty foods Using few medications—with just over four taken daily, primarily blood pressure medicines or other cardiovascular drugs

    Multiple drug use—known as polypharmacy—is common in older adults. Defined as taking more than five medications daily, polypharmacy is linked with many adverse health effects, especially among older adults, who are at risk of a “prescription cascade”—where the side effects of drugs can be misdiagnosed as symptoms of another disease, creating a vicious cycle of more drug use.

    This analysis suggests that using food as medicine—through healthy, balanced diets—combined with lower drug use contributes to healthy aging and longevity. Learn how other healthy lifestyle behaviors like exercise and dietary supplementation also promote longevity in this episode featuring Dr. Rhonda Patrick.

  • Resistance training remodels muscle fibers and connective tissues, driving muscle mass and strength gains. This phenomenon has led to the plausible theory that enhancing collagen synthesis could boost functional strength. However, recent research suggests otherwise. A study found that collagen supplementation was no more effective than a placebo at promoting muscle fiber and connective tissue synthesis.

    In this small study, 25 young men performed strenuous resistance exercise training for one week. About half of the men took 15 grams of hydrolyzed collagen peptides twice daily during the intervention, while the other half took a placebo. Researchers measured their muscle fiber and connective tissue protein synthesis daily.

    They found that connective protein synthesis was 48% higher than muscle fiber synthesis following resistance training. Although plasma levels of collagen peptides increased among participants taking the supplemental collagen, supplementation did not increase muscle fiber or connective tissue synthesis more than the placebo. Learn more about the disappointing results of this particular role for collagen supplementation in the episode featuring Dr. Luc van Loon.

    The good news is that collagen supplementation may have benefits beyond this specific role. Collagens are major structural proteins in many body tissues, including tendons, ligaments, cartilage, skin, blood vessels, muscles, gut tissue, and dentin. They are the most abundant proteins in the body, making up about 30 percent of the total protein mass. Hydrolyzed collagen, also known as collagen peptides or hydrolysate, is made by breaking down collagen into smaller amino acid chains (called peptides) using heat or enzymes. Read more about hydrolyzed collagen in our overview article.

  • Although a person’s genes play a pivotal role in whether they develop diabetes, lifestyle factors—like diet, exercise, and body weight—influence their risk, too. A recent study found that lifestyle interventions reduce the risk of developing diabetes, especially among those at high genetic risk.

    The study involved nearly 1,000 middle-aged men with metabolic syndrome—a constellation of health conditions that increases the for diabetes. About half of the men had a low genetic risk for the disease, while the remainder had a high genetic risk. The men participated in a three-year-long group-based lifestyle intervention program that involved dietary counseling, exercise guidance, and weight management. Researchers monitored the men’s health and diabetes incidence throughout the study period.

    They found that the intervention reduced the risk of developing diabetes by 70% among participants with high genetic risk and 31% among those with low genetic risk. However, the latter reduction wasn’t statistically significant. The intervention promoted weight loss and prevented increased blood glucose levels in both groups.

    These findings suggest that lifestyle interventions can have marked effects on diabetes incidence in people at risk. Exercise, in particular, makes the body’s tissues more sensitive to insulin, helping to maintain healthy blood glucose levels. Learn more about how exercise may prevent diabetes in this episode featuring Dr. Guido Kroemer.

  • Many factors influence the extent to which exercise promotes weight loss, including exercise intensity, dietary habits, and overall lifestyle. Evidence suggests genetic differences play a role, too. A recent study found that mice with certain variants of PGC1-alpha—a key regulator of metabolism—consume less oxygen and burn less fat during workouts and are more likely to gain weight despite increased activity.

    Researchers analyzed gene expression in mice to determine the distribution of the three variants of PGC1-alpha: A, B, and C. Then, they assessed the animals' muscle growth, fat burning, and oxygen consumption during rest, short-term exercise, and long-term exercise. They performed the same assessments on 20 men, half of whom had type 2 diabetes.

    They found that although the three variants have similar functions, the A variant is widely distributed throughout the body, but the B and C variants are primarily found in brown adipose tissue, skeletal muscle, and the heart. They found that mice lacking the B and C variants had a diminished response to exercise, consuming less oxygen and burning less fat. These mice gained weight, developed high insulin levels, and were intolerant of cold temperatures. Men who had higher expression of the B and C variants consumed more oxygen and had less body fat, even among those with type 2 diabetes.

    These findings suggest that variants of PGC1-alpha influence the body’s response to exercise and highlight potential strategies for treating obesity.

  • A sedentary lifestyle contributes to systemic inflammation, a critical player in the pathogenesis of many chronic diseases. However, evidence suggests it’s never too late to experience the benefits of regular exercise. A recent study found that physical performance measures in older adults who initiated an exercise regimen improved by as much as 31%.

    Researchers collected data from two observational cohorts of older adults—an active group (318 participants) and a sedentary one (146 participants). All participants completed a battery of physical performance tests at baseline, six months, and one year later, including the six-minute walk test, the 30-second chair stand, and the timed up-and-go.

    The researchers found that the two groups' physical performance differed considerably after one year. Exercising adults' performance improved in all measures, while sedentary adults' performance declined:

    *A decrease indicates faster speed.

    These findings suggest that regular, sustained exercise confers protection against age-related declines in physical performance in older adults. They also highlight the importance of interventions to reduce sedentary behavior and increase physical activity to support overall health and function. Learn more about how exercise, especially vigorous exercise, promotes longevity in this episode featuring Dr. Rhonda Patrick.

  • Parkinson’s disease affects more than 10 million people worldwide. Evidence suggests that exercise markedly improves the quality of life for those with the condition. A recent study found that different exercise training intensities have varied effects on symptoms of Parkinson’s disease.

    Researchers randomly assigned 29 people with Parkinson’s disease to either 10 weeks of high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT). They measured the participants' change in maximal oxygen consumption (VO2peak, a measure of cardiorespiratory fitness) and changes in their motor symptoms, fatigue, cardiovascular measures, gait, balance, strength, and endurance.

    They found that exercise training increased the participants' VO2peak, especially among those in the HIIT group. Participants' motor symptoms improved over time, but with little difference between the two groups. Both groups reported less fatigue, but their gait, balance, blood pressure, and heart rate did not change. Participants' strength increased similarly in both groups, but only the HIIT group showed increased muscular endurance.

    These findings suggest that high-intensity interval training and moderate-intensity continuous training effectively improve cardiorespiratory fitness and reduce motor symptoms and fatigue in people with Parkinson’s. However, HIIT may provide additional benefits, such as greater improvements in VO2peak and increased muscular endurance. Learn more about exercise as a treatment for Parkinson’s disease in this episode featuring Dr. Giselle Petzinger.

  • Exercise boosts brain health, but what kind of exercise provides the greatest benefit? A recent study found that high-intensity exercise improved cognitive function and maintained brain volume in older adults—with effects lasting five years or more.

    The study involved 151 older adults (65-85 years old) who engaged in low, moderate, or high-intensity exercise three times a week for six months. They underwent regular cognitive testing (to assess hippocampal function), blood sampling, and MRI scans (to measure brain volume and connectivity) before, during, and after the intervention.

    Only the participants who engaged in high-intensity exercise showed improvement in their hippocampal function. They also maintained higher brain volumes and connectivity and higher levels of brain-derived neurotrophic factor (BDNF) than those who engaged in low to moderate-intensity exercise. Higher BDNF levels correlated with better hippocampal-dependent cognitive performance, which endured for five years or longer.

    These findings suggest that high-intensity exercise markedly improves brain function in older adults. Learn more about the brain-boosting effects of high-intensity exercise in this episode featuring Dr. Rhonda Patrick.

  • Insufficient physical activity increases the risk of many chronic health conditions, including cardiovascular disease, diabetes, and certain cancers. Unfortunately, physical inactivity is rising globally, worsening health outcomes and increasing healthcare costs. A recent study found that nearly one-third of adults worldwide don’t engage in sufficient physical activity – an increase of almost 8% over the past two decades.

    Researchers analyzed physical activity data from more than 500 studies across 163 countries and territories involving more than 5.7 million people. They defined insufficient physical activity as not doing 150 minutes of moderate-intensity activity, 75 minutes of vigorous-intensity activity, or an equivalent combination per week.

    They found that the global prevalence of insufficient physical activity in 2022 was 31.3%, a 7.9% increase since 2000 and a 4.9% increase since 2010. Insufficient activity was more common among females and adults over 60. Interestingly, the prevalence decreased in about half of the countries (primarily high-income Western countries) but increased in the remainder.

    These findings suggest that physical inactivity is increasing worldwide, especially among females and older adults. Physical activity, especially vigorous exercise, increases VO2 max, a measure of cardiorespiratory fitness. Evidence indicates that increasing VO2 max from low to normal may extend life by more than two years, while raising it from low to high normal may extend life by approximately three years. Learn more about the effects of vigorous exercise in this episode featuring Dr. Rhonda Patrick.

  • Fatigue is a common condition characterized by persistent tiredness or exhaustion that can affect daily activities. Inflammation is critical in fatigue because it disrupts normal cellular function and energy production. A recent review and meta-analysis found that astaxanthin, a potent antioxidant and anti-inflammatory carotenoid compound, reduces fatigue.

    Researchers analyzed the findings of studies investigating the effects of astaxanthin supplementation on fatigue, cognition, and exercise efficiency. The analysis included 11 randomized controlled trials involving 346 healthy participants. Four of the studies included amateur or professional athletes.

    The researchers found that supplementing with astaxanthin for eight to 12 weeks improved cognition slightly but did not improve reaction time. However, when combined with exercise, astaxanthin enhanced fat oxidation and improved physical performance. Further analysis revealed that the benefits of astaxanthin were more pronounced with aerobic exercise but were dose-dependent, with doses of 20 milligrams or more and supplementation for longer than 12 weeks providing the greatest benefit.

    These findings suggest that astaxanthin reduces fatigue and improves aspects of performance. Astaxanthin is widely available as a dietary supplement but is also present in salmon and salmon roe. Learn more about salmon roe in our overview article.

  • Hypertension – high blood pressure – affects more than 1.3 million adults worldwide. However, hypertension is becoming increasingly common in teens, too, raising concerns about the condition’s effects. A recent study found that teens with high blood pressure and arterial stiffness exhibit poor cognitive function.

    The study involved 116 male and female teens (average age, 16 years). Researchers measured their physical activity and sedentary time with a combined accelerometer and heart rate monitor. They assessed their cognitive function through psychomotor function, attention, working memory, and learning tests. They measured the participants' blood pressure and evaluated aspects of their arterial health, including pulse wave velocity—a measure of arterial stiffness.

    They found that more than half (50.4%) of the teens were pre-hypertensive or had stage 1 or 2 hypertension. Teens with higher systolic blood pressure exhibited poorer overall cognition and slower reaction times than those who were normotensive. Those with increased pulse wave velocity exhibited diminished accuracy in working memory tasks.

    These findings suggest that high blood pressure and arterial stiffness contribute to poor cognitive function in teens. Preventing high blood pressure during this critical developmental period could support better cognitive outcomes, highlighting the importance of cardiovascular health in youth.

    The average teen spends several hours each day in screen time, contributing to increased sedentary behavior and higher blood pressure. Learn more about the harmful effects of excessive screen time in teens and children in this short video featuring Dr. Rhonda Patrick.

  • Smoking has numerous harmful effects on health, including increased risks of lung cancer, heart disease, and stroke. Evidence indicates smoking also contributes to cognitive decline, affecting memory and fluency. A recent study found that smoking accelerates cognitive decline by as much as 17% over time.

    Researchers examined data from more than 32,000 cognitively healthy adults aged 50 to 104 from 14 European countries. They grouped participants according to whether they smoked, engaged in regular exercise, were socially active, and drank moderately—defined as less than or equal to two alcoholic drinks per day for men or one drink per day for women. Then, they analyzed the effects of lifestyle on memory and fluency decline over 10 years.

    They found that non-smokers maintained relatively stable memory and fluency scores over the 10 years. However, smokers experienced up to 17 percent greater decline in memory and up to 16 percent greater decline in fluency, even after considering other factors that influence cognitive aging, including age at baseline, gender, country, education, wealth, and chronic conditions. Interestingly, healthy lifestyle behaviors offset some of the risks associated with smoking, with smokers who exercised, socialized, and drank moderately exhibiting cognitive declines comparable to non-smokers.

    These findings suggest that smoking markedly increases cognitive decline, increasing the risk for Alzheimer’s disease and other forms of dementia. Quitting smoking can be challenging, but mindfulness techniques can help. Learn more about mindfulness in this clip featuring Dr. Ashley Mason.

  • Muscle contraction relies on a magnesium-dependent calcium transport system. Consequently, magnesium levels drop after exercise, increasing muscle soreness and impairing performance. A recent review found that magnesium supplementation reduces muscle soreness, improves performance, and protects against muscle damage.

    Researchers reviewed the findings of four studies investigating the effects of magnesium supplementation on muscle soreness. The studies included 73 participants (60 males and 13 females) between the ages of 19 and 27. One study focused on muscle soreness, one on running performance, and two on team sports performance.

    They found that 350 milligrams of magnesium glycinate daily reduced muscle soreness and improved recovery after resistance training. Similarly, 500 milligrams of magnesium oxide and stearate taken daily for a week reduced muscle soreness in recreational runners with low dietary magnesium intake. Markers of muscle damage decreased in elite basketball players who took 400 milligrams of magnesium daily throughout the season. Competitive cyclists experienced similar effects at the same dose.

    These findings suggest that magnesium supports muscle health and performance in recreational and competitive athletes. The review’s authors posited that physically active people need 10% to 20% more magnesium than the recommended doses taken two hours before physical activity, even during the off-season. For more information about magnesium, check out our deep-dive podcast and our comprehensive overview article.

  • Drop sets are a popular resistance-training method for promoting muscle growth. They involve performing an exercise to muscle failure at a given weight, then reducing the weight and immediately continuing to muscle failure again. A recent review and meta-analysis found that drop sets promote muscle hypertrophy as effectively as traditional training but require less time commitment.

    Researchers analyzed the findings of six studies investigating the effects of drop-set training on muscle hypertrophy. They found that both drop-set and traditional training groups experienced marked muscle growth after training. The drop-set group showed slightly greater improvement than the traditional group, but the difference between the two groups wasn’t statistically significant. Drop-set training took half to one-third the time of traditional training.

    These findings suggest that drop sets are a time-efficient resistance-training strategy for promoting muscle growth. Some of the mechanisms that promote muscle hypertrophy with resistance training include mechanical tension and metabolic stress. Mechanical tension arises from muscle fiber force generation and stretch, while metabolic stress involves the accumulation of exercise-induced metabolites. Drop sets might enhance muscle hypertrophy by causing greater muscle fatigue than traditional sets, potentially activating all motor units and maximizing muscle growth. Learn more about drop sets and other time-efficient strategies for promoting muscle growth in this clip featuring Dr. Brad Schoenfeld.

  • Mild cognitive impairment is often a precursor to Alzheimer’s disease, marking the initial stages of cognitive decline that precede more severe dementia. Evidence suggests lifestyle factors mediate the progression of mild cognitive impairment. A recent study found that intensive lifestyle modification improves cognitive and functional performance and slows disease progression in older adults with mild cognitive impairment.

    Researchers conducted a randomized controlled trial involving 49 participants aged 45-90 with mild cognitive impairment or early dementia due to Alzheimer’s disease. Half of the participants received the usual care, while the other half received a 20-week intensive lifestyle intervention. The researchers assessed the participants' cognitive and functional performance and measured plasma biomarkers associated with Alzheimer’s before and after the intervention.

    They found that participants in the intervention group showed considerable improvements in cognition and function compared to the control group. In addition, Aβ42/40 ratios increased in the intervention group but decreased in the control group.

    The Aβ42/40 ratio is a measure of the relative levels of two forms of amyloid-beta protein (Aβ42 and Aβ40) in the blood or cerebrospinal fluid. It is a biomarker used to assess the presence and progression of Alzheimer’s disease. Lower ratios typically indicate higher levels of brain amyloid-beta plaques, a hallmark of the disease. An increase in the Aβ42/40 ratio, as observed in the intervention group, suggests a potential reversal or slowing of amyloid-beta plaque accumulation, indicating an improvement in disease pathology.

    These findings suggest that intensive lifestyle modification has profound effects on Alzheimer’s disease progression in older adults with mild cognitive impairment. FoundMyFitness has a wealth of information about the various components used in this intensive protocol, which included:

  • As people age, they often experience muscle function and size declines, adversely affecting their health and overall quality of life. However, evidence suggests exercise can forestall these effects. A recent study found that one year of supervised resistance training with heavy loads exerts lasting benefits on muscle function in older adults.

    Researchers conducted a randomized controlled trial involving 451 older adults at retirement age. They assigned participants to one of three groups: heavy resistance training, moderate-intensity training, or a non-exercising control group. They measured participants' leg extensor power, isometric leg strength, and body composition before and after the one-year intervention and again at two and four years after the study started.

    They found that participants in the heavy resistance training group maintained their baseline isometric leg strength without notable decline over the four years. In contrast, participants in the moderate-intensity and control groups experienced decreased leg strength over time.

    The heavy resistance training protocol involved a full-body workout performed three times a week, using machines in a commercial gym while under supervision. Participants spent the first six to eight weeks getting accustomed to the routine and then completed three sets of six to 12 repetitions for each exercise at about 70% to 85% of their maximum effort.

    These findings suggest that one year of heavy resistance training can help preserve muscle function in older adults, potentially mitigating typical age-related declines in muscle strength. They also highlight the importance of incorporating resistance training into exercise programs for older adults to promote healthy aging. Learn more about resistance training for older adults in this clip featuring Dr. Brad Schoenfeld.

  • Fat tissue produces leptin, a hormone that communicates with the brain to regulate energy balance. When fat mass increases, leptin levels in the blood also rise, signaling the brain to curb appetite and increase energy use. However, in obesity, the body’s sensitivity to leptin is reduced, blunting these regulatory effects. A recent study in mice found that vitamin D allocates excess calories to muscle growth instead of fat storage by regulating leptin and myostatin, a hormone involved in muscle growth.

    Researchers fed mice diets containing low, moderate, or high doses of vitamin D for four weeks to induce deficient, normal, and high vitamin D concentrations, respectively. Then, they measured changes in the animals' blood concentrations of leptin and myostatin and assessed their strength.

    They found that high doses of vitamin D increased leptin production and sensitivity while decreasing myostatin production. These changes elicited a greater allocation of excess calories to muscle and linear growth instead of fat storage.

    These findings suggest that high-dose vitamin D could effectively manage obesity and related conditions by redirecting calories from fat storage to muscle growth. They also highlight the interplay between vitamin D, leptin, and myostatin. Learn more about vitamin D in our comprehensive overview article.

  • Psychosis is a neuropsychiatric condition characterized by a disconnection from reality, often manifesting as hallucinations or delusions. Evidence suggests that lifestyle factors reduce the risk of developing psychosis. A recent study found that using a sauna three or more times a week reduces the risk of psychosis by more than half, regardless of fitness levels.

    Researchers drew on data from the Kuopio Ischemic Heart Disease Risk Factor Study, an ongoing investigation of adult men living in Finland. The researchers assessed the men’s cardiorespiratory fitness and collected information about their weekly sauna use, categorized as low use (fewer than two sessions) or high use (three or more sessions). They identified participants who had been diagnosed with psychosis during a period of about 25 years.

    They found that cardiorespiratory fitness markedly reduced the risk of psychosis, with medium fitness reducing risk by 35 percent and high fitness reducing risk by 25 percent. However, they found that high sauna use reduced the risk of developing psychosis by 50 percent compared to low use, even when they took fitness levels into account.

    These findings suggest that frequent sauna use and medium to high cardiorespiratory fitness independently reduce the risk of psychosis. However, frequent sauna use might lower the risk of psychosis regardless of fitness levels and could be a stronger predictor of reduced psychosis risk than cardiorespiratory fitness.

    Sauna use exposes the body to extreme heat, stressing the body. Heat stress reduces systemic inflammation, oxidative stress, and cortisol levels, which may play roles in the development of psychosis. Learn more about the brain benefits of sauna use in this episode featuring Dr. Rhonda Patrick.

  • Type 2 diabetes is a metabolic disorder characterized by high blood glucose, increasing the risk for a wide range of complications, including kidney dysfunction, vision loss, and circulatory problems. However, evidence suggests that exercise improves blood glucose control. A 2002 study found that resistance training improved blood glucose control in people with type 2 diabetes.

    The study involved 62 older adults with type 2 diabetes. Half of the participants engaged in a 16-week high-intensity resistance training program (gradually increasing in intensity), while the other half maintained their typical activities. Researchers measured participants' glycated hemoglobin levels (HbA1c, a measure of long-term blood glucose control), body composition, and muscle glycogen stores before and after the intervention.

    They found that among resistance training participants, HbA1c decreased by approximately 12 percent, muscle glycogen increased by 31 percent, and muscle strength increased by 33 percent. Those who engaged in resistance training also experienced reductions in blood pressure and body fat, and their need for diabetes medications decreased.

    These findings suggest that resistance training is a robust adjunct to type 2 diabetes treatments, effectively improving blood glucose control and metabolic health. Resistance training involves pushing or pulling against the resistance of an object, such as weights, bands, or even one’s body weight. Older adults starting a resistance training program may benefit from using lighter weights and performing more repetitions, especially if they have chronic joint problems. Learn more in this episode featuring Dr. Brad Schoenfeld.

  • Physical exertion and strong emotions activate the body’s stress response, triggering the release of hormones that restrict blood flow to the body’s tissues, including the heart. A 2016 study found that these stressors increase the risk of myocardial infarction (heart attack).

    Researchers conducted a case-control study involving more than 12,000 cases of acute MI among people living in 52 countries. They asked the participants about their physical activities and emotional state in the hours before the onset of symptoms. They estimated the odds of acute MI within one hour of triggers.

    They found that 28 percent of those who experienced an acute MI had engaged in physical activity or were emotionally upset one hour before symptom onset. The likelihood of experiencing an acute MI was 2.31 times higher after physical exertion and 2.44 times higher after emotional upset. However, those who reported both physical exertion and emotional upset were 3.05 times more likely to experience an acute MI within one hour. The increased risk was consistent regardless of the participants' geographical location, sex, baseline physical activity, or age.

    These findings suggest that sudden physical exertion and emotional upset increase the risk of acute MI. However, robust evidence demonstrates that regular physical activity is crucial for preventing cardiovascular disease, including acute MI, especially among inactive people. The authors of this report recommended that clinicians continue to advocate for regular physical exercise and caution patients that intense physical activities could trigger an acute MI in those at risk.

  • Regular moderate-intensity exercise is widely acknowledged for its longevity-promoting effects. However, scientific consensus on the effects of extreme endurance exercise on lifespan is divided. A recent study found that athletes who ran a sub-4-minute mile tend to live longer than the general population.

    Researchers used data from a publicly available database of runners who have successfully run a sub-4-minute mile. They compared the lifespans of 200 of these runners with the life expectancies specific to each athlete’s country of origin.

    They found that about one-third of the sub-4-minute mile runners had died, but those still alive had surpassed their predicted life expectancy by an average of 4.7 years. Interestingly, longevity benefits varied by decade, with those completing the mile in the 1950s, 1960s, and 1970s living longer by 9.2, 5.5, and 2.9 years, respectively, beyond their expected lifespan.

    These findings suggest that high-level endurance training associated with running a sub-4-minute mile may increase longevity. They also challenge the notion that extreme endurance exercise is detrimental and support the benefits of vigorous physical activity for extending lifespan. Learn more about how vigorous exercise and other healthy lifestyle habits promote longevity in this episode featuring Dr. Rhonda Patrick.

  • Pathological increases in the heart’s left ventricle typically arise from diseases or unhealthy behaviors, such as increased sedentary time, and can negatively affect heart function. These changes usually manifest in adulthood and are robust predictors of cardiovascular disease-related death. Physiological increases in the left ventricle, on the other hand, are beneficial adaptations that occur in response to healthy activities, such as moderate-to-vigorous physical activity. These changes promote a stronger and more efficient heart muscle without the adverse effects associated with pathological enlargement. A recent study found that sedentary behavior induces pathological increases in left ventricular mass in children.

    Researchers monitored the health and activity levels of more than 1,600 children enrolled in the Avon Longitudinal Study of Parents and Children from age 11 to 24 years. The children wore accelerometers during waking hours on two or more weekdays and one weekend day at least once during the 13-year study. They underwent echocardiography at the ages of 17 and 24 years.

    At age 11, the children averaged six hours of sedentary time daily, increasing to nine hours by age 24. Cumulative sedentary time contributed to 40 percent of the pathological increase in left ventricular mass during adolescence, regardless of the children’s sex, body weight, or blood pressure. Children who were more sedentary had higher body fat, inflammation, blood pressure, lipid levels, and left ventricular mass, increasing their future cardiovascular risks.

    Conversely, cumulative light physical activity (about three hours daily) reduced pathological increases in left ventricular mass by 49 percent. Each minute of moderate-to-vigorous physical activity induced physiological increases in left ventricular mass of 5 percent.

    These findings suggest that sedentary time in childhood induces pathological changes in the heart’s left ventricle, but light activity can mitigate these harmful effects. Moderate-to-vigorous activity, however, induces beneficial physiological changes. Resistance training is a safe and effective way to boost kids' activity levels. Learn more about kids and resistance training in this clip featuring Dr. Brad Schoenfeld.

  • Gardening is a popular pastime for many people, especially older adults, who benefit from the increased physical activity and mental engagement. A recent study found that people who garden sleep better than those who engage in other exercises or don’t exercise.

    Researchers collected information about the sleep habits of more than 16,000 adults in the U.S. They categorized the participants as gardeners, exercisers, or non-exercisers.

    They found that compared to non-exercisers, gardeners were 42 percent less likely to experience sleep problems, and exercisers were 33 percent less likely. The effects of gardening on sleep were dose-dependent, with sleep problems decreasing as weekly gardening time increased. The benefits of gardening were consistent, even after considering other factors that influence sleep, such as age, sex, education level, and body mass index.

    These findings from this observational study suggest that gardening improves sleep better than other forms of exercise or not exercising. Gardening’s sleep-enhancing effects may stem from increased exposure to natural light during the day, regulating the body’s circadian rhythms and, ultimately, sleep. Learn how light exposure, especially early in the day, influences circadian rhythmicity and sleep in this clip featuring Dr. Satchin Panda.

  • Maintaining muscle mass as we age requires a comprehensive approach encompassing nutrition and regular physical activity. However, many older adults don’t consume adequate dietary protein and may lead sedentary lives, due to injuries, chronic illnesses, or joint problems. A recent study found that older adults who increased their dietary protein intake and engaged in regular exercise showed marked improvements in multiple health and fitness parameters.

    The study involved 97 older adults (average age, 64) with low dietary protein intake (less than 1 gram per kilogram of body weight daily) who had experienced at least one fall in the past year. Half of the participants received a daily serving of a protein-enriched soup (providing 24 to 30 grams of protein) and engaged in one hour of group exercise (aerobic and resistance) each week for 12 weeks. The other half received nutrition education training at the beginning of the study and maintained their normal activity levels.

    At the end of the study, sedentary participants showed improvements in handgrip strength only. However, the participants who consumed the protein-rich soup and exercised regularly showed improvements in waist circumference, walking distance, lower body strength, functional mobility, handgrip strength, nutritional status, serum triglycerides, HDL cholesterol, and DHEA-S.

    DHEA-S (dehydroepiandrosterone sulfate) is a naturally occurring precursor to estrogen and testosterone. These steroid hormones exert anabolic effects by enhancing the bioavailability of insulin-like growth factor-1 in muscles, facilitating muscle growth and repair.

    These findings suggest that increasing dietary protein and activity levels in older adults improves multiple health and fitness parameters. Interestingly, most of the participants in this study were female. Evidence suggests women typically consume less protein than men. In this clip, Dr. Stuart Phillips provides some insights to help older women get sufficient protein to support muscle health.

  • The connection between physical exercise and enhanced cognitive function is well-established. However, the extent of benefit varies markedly depending on the intensity of the physical activity. A recent study found that high-intensity interval training (HIIT) boosted reaction time and cognitive flexibility better than moderate-intensity continuous exercise (MICE).

    The study involved 28 elite male boxers in their mid-twenties. The participants underwent cognitive performance tests and provided blood samples in five scenarios: after an hour of rest, immediately after HIIT, one hour after HIIT, immediately after MICE, and one hour after MICE.

    The blood tests revealed that participants' serum brain-derived neurotrophic factor (BDNF) levels immediately after exercise were considerably higher after HIIT than after rest or MICE. Interestingly, serum levels of S100B and neuron-specific enolase (proteins associated with brain injury) were also higher after HIIT than after rest but were comparable to those after MICE. HIIT and MICE improved cognitive performance, but HIIT was better at improving reaction time and incongruent task assessments (which measure cognitive flexibility).

    These findings suggest that HIIT and MICE elicit beneficial effects on the brain, with HIIT outperforming MICE in certain arenas. These effects may be attributable to increased BDNF, a growth factor known to influence neuronal health and mediate the beneficial cognitive effects associated with exercise. Learn more about BDNF in the Cognitive Enhancement Blueprint, located in the Members' Library.

  • Prolonged sitting is a prominent feature of modern life. Unfortunately, it carries considerable health risks, including impaired glucose metabolism and an increased risk of type 2 diabetes. A recent study found that interrupting prolonged sitting periods with short bursts of activity – especially frequent walks or squats – improves blood glucose levels.

    The study involved 18 men with overweight and obesity who engaged in four different activities on separate days: sitting uninterrupted for 8.5 hours, or sitting interrupted by a single 30-minute walk, ten three-minute walks (every 45 minutes), or ten three-minute squat sessions (every 45 minutes). Researchers assessed the participants' blood glucose levels using continuous glucose monitors and gauged their muscle activity, especially in the quadriceps, hamstrings, and gluteal muscles, using an electromyogram.

    They found that any form of sitting interruption reduced blood glucose levels better than uninterrupted sitting, with the frequent three-minute walks and squat exercises outperforming the single 30-minute walk. Increased muscle activity, particularly in the quadriceps and gluteal muscles, correlated strongly with these improvements.

    These findings suggest that interrupting prolonged sitting with frequent, short bouts of physical activity, especially those that engage the lower body muscles, is more effective in enhancing glycemic control than a single, longer session of activity. Evidence suggests that these short bursts of activity, often called “exercise snacks,” improve cardiorespiratory fitness and markers of immune function. Learn more in this clip featuring Dr. Martin Gibala.

  • Although obesity increases the risk of chronic disease and premature death, especially in those who have type 2 diabetes, exercise may counter some of those risks. However, the time of day a person exercises may influence the extent of risk reduction. A recent study found that moderate to vigorous physical activity in the evening reduced the risk of premature death by 61 percent in people with obesity.

    Researchers asked nearly 30,000 adults with obesity, some of whom (3,000) had type 2 diabetes, how often they engaged in moderate to vigorous physical activity (lasting at least three continuous minutes) and whether they did so in the morning, afternoon, or evening. They tracked the participants' health for about eight years.

    They found that engaging in moderate to vigorous physical activity in the evening reduced participants' risk of premature death from all causes by 61 percent. Afternoon exercise reduced the risk by 40 percent, and morning exercise reduced it by 33 percent. Similarly, evening exercise reduced the risk of cardiovascular disease by 36 percent and microvascular disease by 24 percent. They noted similar risk reductions in those who had type 2 diabetes.

    These findings suggest that moderate to vigorous physical activity reduces the risk of chronic disease and premature death in people with obesity (including those with type 2 diabetes), but evening exercise confers the greatest benefit. Learn more about the health benefits of vigorous exercise in this episode featuring Dr. Rhonda Patrick.

  • Cognitive function typically declines with aging, but evidence suggests physical activity can help mitigate some of these declines. A recent study in mice found that exercise improves memory and spatial learning by inhibiting neuroinflammation, primarily via the actions of irisin, a myokine, and brain-derived neurotrophic factor (BDNF), a growth factor and signaling protein.

    Researchers conducted a two-part study to investigate the effects of regular, low-intensity exercise on cognitive function in mouse models of inflammation-driven memory impairment and microglia (brain immune cell) degeneration.

    First, they assessed the animals' neuroprotective and antioxidant marker levels and subjected them to various memory and behavioral tests. They found that exercise reduced memory problems and cognitive losses by increasing the expression of irisin. In turn, irisin activated BDNF and nuclear factor erythroid 2-related factor 2 (Nrf2), reducing inflammation and blocking the activity of BACE-1, an enzyme critical for amyloid-beta production.

    Then, they studied the effects of irisin on microglia. They found irisin blocked the NF-κB/MAPK/IRF3 pro-inflammatory signaling pathway. It also lowered pro-inflammatory markers while increasing the expression of Nrf2.

    Nrf2 is a cellular protein that activates the transcription of more than 200 cytoprotective proteins that protect against oxidative stress due to injury, inflammation, and normal aging processes. It is an element of the Keap1-Nrf2-ARE biological pathway, a mediator of protective responses to oxidative and electrophilic stressors. Hormetic stressors like exercise, heat exposure, and dietary components trigger Nrf2 activity. Sulforaphane, a compound derived from broccoli, is the most potent naturally occurring hormetic inducer of Nrf2 activity. Learn more about Nrf2 in this clip featuring Dr. Jed Fahey.

  • Physical activity and sleep are essential for human health, and some evidence suggests they work synergistically to promote mental and physical wellness. A recent study found that physical activity improves aspects of sleep, reducing stress levels and improving mood.

    Researchers used wearable sensors and smartphone tracking to monitor heart rates, sleep, activity levels, and mood in 82 healthy adults over six months. They found that people who engaged in low-, moderate-, or vigorous-intensity exercise tended to have more NREM (deep, slow-wave) sleep and less REM (dream) sleep than non-exercisers. They also tended to enter REM sleep sooner. These changes in sleep patterns correlated with better mood, higher energy levels, less stress, and an enhanced perception of having restful sleep.

    These findings support a growing body of evidence suggesting that physical activity and sleep are intrinsically linked. They also highlight the emerging role of wearable technology as a valuable tool in sleep research.

    Wearable sensors and smartphones allow people to monitor their health, fitness, activity, sleep, or mood. Often simply called “wearables,” these devices can transmit information to a physician, researcher, or user in real time, facilitating data collection and allowing the wearer to actively participate in tracking and maintaining their health. Learn more about wearables in this episode featuring Dr. Michael Snyder.

  • Cardiovascular disease claims the lives of nearly 20 million people worldwide every year. Exercise reduces the risk of cardiovascular disease, but experts aren’t sure which form of exercise is optimal for reducing that risk. A recent study found that aerobic exercise alone or combined with resistance exercise is more effective at reducing cardiovascular disease risk than resistance exercise alone.

    The study involved 406 middle-aged adults with high blood pressure and either overweight or obesity. Participants engaged in one of three training regimens – resistance, aerobic, or combined resistance and aerobic – for one hour, three times weekly, for one year. A fourth group remained sedentary. Researchers scored the participants' cardiovascular disease risk based on measures of their systolic blood pressure, low-density lipoprotein (LDL) cholesterol, fasting glucose, and percent body fat before and after the interventions.

    They found that participants who engaged in the aerobic or combined aerobic/resistance regimens showed improved cardiovascular disease risk scores at the one-year point. However, those who engaged in only resistance or were sedentary showed no improvements in their risk scores. When the researchers looked at individual risk factors, they found that all three exercising groups lost body fat, but their systolic blood pressure, LDL cholesterol, and fasting glucose did not decrease.

    These findings suggest that aerobic exercise alone or combined aerobic plus resistance reduces the cardiovascular disease risk profile in people with overweight or obesity. Other evidence indicates that high-intensity interval training (HIIT)’s cardiovascular benefits rival or surpass those of traditional aerobic exercise. Learn more about the benefits of HIIT in this episode featuring Dr. Martin Gibala.

  • High-intensity resistance training, also known as functional training, requires the body to exert considerable effort against weights or resistance. Evidence suggests this type of training confers myriad physical and mental health benefits, including improved metabolic function and mood, particularly in older adults. A recent study found that engaging in a single session of high-intensity resistance training enhanced memory capabilities.

    The study involved 60 young, healthy adults who took memory tests and underwent resting-state functional magnetic resonance imaging of their brains. Then, half of the participants engaged in a single high-intensity resistance training session, while the other half did not. The training involved three resistant exercise sets at 75 to 80 percent of the participants' one-rep max, with one minute of rest between sets and a total duration of under seven minutes. Two days later, both groups repeated the memory tests and brain imaging scans.

    Those who participated in the resistance exercise session exhibited marked improvements in memory recall compared to the non-exercising group. These memory improvements correlated with greater connectivity in the left posterior region of the hippocampus, an area involved in memory.

    The findings from this small study suggest that just one session of high-intensity resistance training has considerable influence on memory, highlighting its potential to promote cognitive health and neural plasticity. Learn more about high-intensity resistance training in this clip featuring Dr. Martin Gibala.

  • A recent study found that older adults who engaged in flexibility (stretching) exercises were 20 percent less likely to die prematurely than those who didn’t stretch.

    The study involved more than 34,000 adults between the ages of 20 and 79 years. Participants provided information about the frequency and duration of their engagement in moderate- and vigorous-intensity aerobic physical activities, including aerobic, resistance, and flexibility exercises. Researchers tracked the participants' health for roughly 10 years and noted any deaths.

    They found that engaging in just flexibility exercises like stretching or yoga five times per week reduced the risk of premature death from all causes by 20 percent and the risk of death from cardiovascular disease by 25 percent.

    Stretching can take three forms – static, dynamic, and proprioceptive neuromuscular facilitation (PNF). Static stretching involves holding a stretch for 10 to 30 seconds, as seen in yoga poses, such as “downward-facing dog.” Dynamic stretching involves active movements, such as arm circles (used in warm-ups without holding the stretch) or elements of Tai Chi. PNF stretching is used primarily in physical therapy for flexibility and rehabilitation.

    A 2014 review found that stretching’s effects vary by context. Dynamic stretching before exercise tends to improve strength, power, speed, and agility, enhancing sprint and agility test outcomes. Integrating dynamic stretching with exercises like front squats may further boost performance, but overdoing it can promote fatigue and hinder results. Although its effects on endurance sports are less certain, dynamic stretching is generally recommended in warm-ups for its benefits in speed and agility-focused activities.

    Some evidence suggests that stretching may be particularly beneficial for older adults and those who are sedentary. For example, a comprehensive meta-analysis found that stretching exercises reduce arterial stiffness, heart rate, and diastolic blood pressure while improving vascular endothelial function in middle-aged and older adults. Stretching may reduce the risk of fall-related injuries in older adults by improving balance.

    An abundance of research consistently singles out aerobic activities, especially at moderate to vigorous intensities, as the premier choice for improving health and extending life, as further supported by this study’s conclusions. However, the findings from this study point to the potential value of flexibility exercises. Although they may not offer the same cardiovascular benefits as aerobic activities, their beneficial effects on overall health are noteworthy. Embracing a diverse exercise regimen that includes aerobic and flexibility training may provide myriad health advantages. Learn more about the benefits of vigorous exercise in this episode featuring Dr. Martin Gibala.

  • Yoga is an ancient Indian practice that engages the mind and body through physical poses, breathing techniques, and meditation. Robust scientific evidence suggests that yoga benefits both mental and physical health. A new study found that Kundalini yoga – a type of yoga that involves specific postures, breathing techniques, and meditation – boosted cognition and memory in older women at risk of developing Alzheimer’s disease.

    The study involved 63 older women who had self-reported memory problems and cerebrovascular conditions – risk factors for Alzheimer’s. About half the women participated in a weekly yoga session, while the other half participated in weekly memory training. Researchers assessed the women’s cognitive function and moods before and after the two interventions. They also measured markers of aging and inflammation in the women’s blood and assessed changes in their brains using magnetic resonance imaging (MRI).

    They found that the women who participated in yoga experienced marked improvements in memory, increased connectivity in the hippocampus, and increased expression of anti-inflammatory and anti-aging markers** compared to those who did memory work only. The MRIs revealed that the brains of the women in the yoga group showed less age-related volume loss.

    Women are at greater risk of developing Alzheimer’s disease than men, partly due to having higher rates of cardiovascular conditions, many of which share risk factors with Alzheimer’s. In addition, the decrease in protective estrogen during menopause may also amplify cognitive declines.

    These findings suggest that Kundalini yoga benefits women at risk for Alzheimer’s disease. Evidence indicates that vigorous exercise can boost cognitive function, too. Learn more in this episode featuring Dr. Martin Gibala.

  • Exercise has profound effects on the brain, stimulating the release of neurotransmitters that enhance mood and cognitive functions. Evidence suggests that regular physical activity can promote long-term improvements in mental health, reducing symptoms of depression and anxiety and fostering a sense of well-being. A recent review and meta-analysis found that exercise, especially intense exercise, is comparable to psychotherapy and drug treatments for depression.

    Researchers analyzed the findings of 218 studies comparing the effects of exercise versus standard treatments or placebos on depression. The various trials included more than 14,000 participants and incorporated different exercise modalities.

    The researchers found that physical activities such as walking, jogging, yoga, strength training, mixed aerobic exercises, and tai chi or qigong moderately reduced depression symptoms compared to standard treatments or placebos. Specifically, walking or jogging markedly reduced depression symptoms, with yoga and strength training also demonstrating notable benefits. Mixed aerobic exercises and tai chi or qigong were also beneficial but to a lesser extent. Notably, exercise intensity was directly linked to the magnitude of depression symptom reduction.

    These findings suggest that exercise is comparable to psychotherapy and drug treatments for depression. However, only one of the studies included in the analysis met the highest standards for quality, creating uncertainty regarding the effectiveness of each exercise type. Sauna use, which mimics many of the physiological effects of exercise, improves mood, too. Learn more in this clip featuring Dr. Rhonda Patrick.

  • Irritable bowel syndrome (IBS) is a digestive disorder characterized by abdominal cramping, gas, diarrhea, and constipation. The condition affects as many as 10 percent of people worldwide and has no cure. A recent study shows that adopting three or more healthy lifestyle behaviors may reduce the risk of IBS by as much as 42 percent.

    The study involved more than 64,000 people enrolled in the UK Biobank database. Researchers collected information about the participants' dietary intake and whether they engaged in any of five healthy lifestyle behaviors: never smoking, getting optimal sleep, engaging in vigorous physical activity, eating a quality diet, and moderating their alcohol intake.

    They found that 11.8 percent of the participants did not practice any of the five critical healthy behaviors; 32.1 percent practiced one, 34.1 percent practiced two, and 21.9 percent practiced three to five healthy behaviors. As participants engaged in more healthy behaviors, their likelihood of developing IBS decreased, with those practicing one healthy behavior having a 21 percent lower risk, those with two healthy behaviors having a 36 percent lower risk, and those engaging in three to five healthy behaviors having a 42 percent lower risk. These findings were consistent across various groups, regardless of age, sex, job status, where they lived, history of gastrointestinal infection, endometriosis, family history of IBS, or other lifestyle habits.

    These findings suggest that adopting multiple healthy lifestyle behaviors, such as not smoking, staying physically active, and getting good sleep, can significantly reduce the risk of developing IBS. Learn more about factors that influence gut health in this episode featuring Dr. Eran Elinav.

  • Women generally have a longer life expectancy than men, a phenomenon often attributed to biological, behavioral, and lifestyle factors. Now, findings from a recent study demonstrate that women achieve greater benefits from equivalent amounts of moderate-to-vigorous activity than men do, reducing their risk of premature death from all causes by 24 percent.

    Researchers asked more than 412,000 healthy men and women in the United States to provide information about their physical activities, including the frequency, duration, intensity, and type. Then, they looked for links between physical activity and the risk of premature death from all causes and cardiovascular disease.

    They found that physical activity reduced the risk of premature death from all causes in women by 24 percent and men by 15 percent compared to inactivity. Interestingly, the reduction in risk seen in men topped out at 19 percent, achieved at about 300 minutes per week of moderate-to-vigorous activity. Women, on the other hand, achieved the same risk reduction at just 140 minutes per week, topping out at 24 percent at 300 minutes. They found similar effects for aerobic and strength training activities, with men reaching their peak benefit from three roughly half-hour sessions per week and women gaining the same benefit from about one strength-training session per week.

    These findings suggest that women can achieve substantial health benefits with shorter workouts than men. They also serve as a powerful encouragement, underscoring how limited time for physical activity can lead to considerable health advantages for women. Learn how to incorporate strength training into your workouts, maximizing your efforts in less time, in this clip featuring Dr. Brad Schoenfeld.

  • Sugar-sweetened beverages encompass a wide variety of drinks, including soft drinks/sodas, sports drinks, energy drinks, and coffees. People who are physically active often consume sugar-sweetened sports drinks to replenish the electrolytes lost during exercise. While this can be beneficial during prolonged, intense physical activities, the added sugar content in many sports drinks might not be necessary for routine exercise or for people engaging in moderate physical activity. A recent study found that for every additional serving of sugar-sweetened beverages consumed daily, the risk of cardiovascular disease increased by 18 percent for physically active people and 12 percent for those who were inactive.

    The study involved more than 105,000 adults enrolled in the Nurses' Health Study and the Health Professionals Follow-up Study who were healthy at the time of enrollment. Researchers gathered information from the participants regarding their physical activity, cardiovascular health, and consumption of sugar-sweetened beverages.

    They found that participants who consumed more than two servings of sugar-sweetened beverages per day were 21 percent more likely to develop cardiovascular disease than those who rarely or never consumed them. For each additional serving of sugar-sweetened beverages consumed daily, the risk of cardiovascular disease increased by 18 percent for people who met physical activity guidelines and by 12 percent for those who did not, indicating that physical activity did not compensate for high sugar-sweetened beverage consumption. Participants who did not meet physical activity guidelines and consumed two or more servings per week of sugar-sweetened beverages were 47 percent more likely to develop cardiovascular diseases than those who were physically active and rarely or never drank them.

    These findings suggest that consuming sugar-sweetened beverages markedly increases a person’s risk for cardiovascular disease. Furthermore, physical activity does not offset this risk. Learn more about the health effects of sugar-sweetened beverages in our overview article.

  • Most cardiovascular health interventions emphasize aerobic exercise, which challenges the heart, lowering blood pressure and increasing cardiac output. However, a recent study found that a combination of aerobic exercise and resistance training provides similar cardiovascular benefits to those of aerobic exercise alone.

    Researchers conducted a randomized controlled trial involving 406 adults with overweight or obesity and elevated blood pressure. They randomly assigned participants to one of four exercise intervention groups: aerobic only, resistance only, a combination of aerobic and resistance, or no exercise. Participants exercised for one hour daily, three times weekly, for one year.

    The researchers found that the participants in the aerobic-only and aerobic and resistance combination groups benefited equally from the one-year intervention, with both groups showing nearly identical improvements in risk profiles. The resistance-only and no-exercise groups did not improve.

    These findings suggest that aerobic exercise alone or combined aerobic plus resistance exercise reduces cardiovascular disease risk in adults with overweight or obesity. Interestingly, resistance exercise can have aerobic effects. Learn more in this clip featuring Dr. Martin Gibala.

  • Regular physical activity can have profound effects on mental health by reducing depression and anxiety. Evidence suggests that cycling to work reduces the risk of premature death from all causes, including cardiovascular disease and cancer. A recent study found that people who cycle to work are also less likely to require mental health medications.

    The study, which took place in Scotland, involved more than 378,000 adult participants living in Edinburgh, Glasgow, and the surrounding areas. Researchers collected data regarding whether the participants cycled to work and if they required a prescription for mental health (anti-anxiety or antidepressant) medications.

    They found that very few commuters cycled to work, with just 4.8 percent of commuters in Edinburgh and 1.85 percent in Glasgow cycling. However, those who did cycle were less likely to have received a prescription for mental health medications than non-cyclists. This difference translated to a 15 percent reduction in mental health prescriptions over five years. Interestingly, men were more likely to cycle and less likely to take mental health medication than women.

    These findings suggest that cycling to work improves mental health and supports public health efforts that encourage commuters who travel shorter distances to consider cycling. Watch this episode in which Dr. Rhonda Patrick talks about her love of cycling for its powerful mood-enhancing effects and describes the compelling science suggesting exercise is a powerful tool for preventing or managing the symptoms of depression and mental illness.

  • The idea that exercise benefits metabolic health is widely accepted. But whether the benefits of exercise are greater depending on when one exercises – morning versus afternoon – is a matter of considerable debate. A recent study shows that morning exercise reduces blood pressure, fasting insulin, and insulin resistance better than afternoon exercise in people with metabolic syndrome.

    Metabolic syndrome is a constellation of conditions characterized by abdominal (central) obesity, elevated blood pressure, elevated fasting plasma glucose, high serum triglycerides, and low high-density lipoproteins. Having metabolic syndrome increases a person’s risk of cardiovascular disease and type 2 diabetes. Roughly one-third of adults between the ages of 20 and 60 have metabolic syndrome.

    The study involved 139 adults with metabolic syndrome who agreed to participate in three supervised high-intensity interval training sessions every week for 16 weeks. About a third of the participants performed their exercise in the morning, a third did so in the afternoon, and a third didn’t engage in any exercise. Researchers measured the participants' body composition, cardiorespiratory fitness, maximal fat oxidation, blood pressure, and blood metabolites before and after the intervention.

    They found that both exercise groups demonstrated greater body fat loss, reduced waist circumference (nearly an inch), and lower diastolic blood pressure than those who didn’t exercise. However, when comparing the morning exercise group to the afternoon group, they found that morning exercise was more effective at reducing systolic blood pressure (4 percent drop vs. 1 percent), lowering fasting insulin (12 percent drop vs. 5 percent), and decreasing insulin resistance (14 percent drop vs. 4 percent).

    These findings suggest that morning exercise boosts cardiometabolic health better than afternoon exercise. The investigators posited that these effects may be related to circadian rhythms, which influence the body’s response to exercise and dietary intake.

    Finding the time or motivation to exercise in the morning may be challenging for many. Fortunately, most experts agree that some exercise is better than none, as long as it’s not too close to bedtime. Learn more in this clip featuring Dr. Rhonda Patrick.

  • Many older adults have generalized anxiety disorder, a persistent feeling of anxiety or dread that interferes with everyday life. Evidence suggests that physical activity alleviates symptoms of anxiety, but scientists don’t know how much activity is optimal. A recent study found that older adults who engaged in regular physical activity were 47 percent less likely to experience symptoms of anxiety than those who engaged in no activity.

    Researchers drew on data from more than 7,600 older adults enrolled in The Irish Longitudinal Study on Ageing (TILDA). They gathered information about the participants' physical activity levels, worry symptoms, and anxiety levels over ten years. They assessed the participants' activity levels and categorized them as having no, low, medium, or high activity levels.

    They found that participants with high activity levels were 31 percent less likely to develop anxiety than those with no activity. However, participants who engaged in even minimal moderate-intensity physical activity – equivalent to just 10 minutes a day, five times a week – were 47 percent less likely to develop anxiety than those with no activity.

    These findings suggest that even a small amount of physical activity has robust effects on mood in older adults, markedly reducing the risk of developing anxiety. They also align with previous research, which found that older adults enrolled in TILDA who met WHO physical activity guidelines were 63 percent less likely to develop generalized anxiety disorder than those who did not.

    Exercise supports the health of pericytes, tiny contractile cells surrounding the brain’s capillaries that regulate vascular blood flow and maintain blood-brain barrier integrity. Pericytes detach from the blood vessels in aging, driving the pathophysiology of neurological dysfunction, vascular dementia, and mood disorders like anxiety. Learn more in this episode featuring Dr. Axel Montagne.

  • Robust evidence supports dietary protein intake to support muscle protein synthesis after resistance training. However, most studies investigating the effects of dietary protein have been conducted in men. A recent study found that a daily protein intake greater than 1.8 grams per kilogram of body weight optimized muscle protein synthesis in trained women.

    Researchers asked 24 young women who regularly engaged in resistance training to engage in two resistance training sessions separated by a four-hour break. After each session, the women consumed 15, 30, or 60 grams of whey protein. These amounts provided the women 1.8, 2.3, and 3.2 grams of protein per kilogram of body weight, respectively. Over 24 hours post-workout, the researchers measured the women’s muscle protein synthesis and blood amino acid levels.

    They found that 15 grams of whey protein had little effect on muscle protein synthesis. However, after consuming 30 or 60 grams of whey protein, the women’s muscle protein synthesis increased, especially in the first eight hours post-workout. Interestingly, there was little difference in muscle protein synthesis between the 30- and 60-gram doses.

    Current dietary guidelines recommend that healthy adults consume 0.8 grams of protein per kilogram of body weight per day. However, this intake level is likely too low for building and maintaining muscle mass. The findings from this study suggest that increasing the recommended amount, ensuring a daily intake of greater than 1.8 grams per kilogram of body weight, will pay the greatest dividends for promoting muscle protein synthesis in trained women. Learn more about the importance of dietary protein in this episode featuring Dr. Stuart Philips.

  • The physical stress of marathon running can promote exercise-induced muscle damage, reducing muscle force production, elevating blood cytokines, and driving systemic inflammation. Consequently, despite having high cardiorespiratory and neuromuscular fitness, marathon runners are susceptible to lower extremity muscle injuries, cardiac dysfunction, and arrhythmia, particularly as running intensity escalates. A recent study shows that supplemental omega-3 fatty acids ameliorate some of the harmful effects of endurance running.

    The study involved 24 male long-distance runners. Half of the runners received 3,000 milligrams (mg) of omega-3s (852 mg EPA; 1,602 mg DHA) daily for three weeks, and the other half took a placebo. After the third week of supplementation, the participants performed a downhill running exercise test. The researchers measured the participants' cardiac markers, inflammatory cytokines, and blood lipids and assessed their Omega-3 Index, a measure of omega-3 concentrations in red blood cell membranes.

    They found that the participants' Omega-3 Indices increased from 3.9 to 4.8, roughly 23 percent relative to baseline when they took supplemental omega-3s. Markers of cardiac injury (troponin and creatine kinase isoenzyme MB) and the inflammatory cytokine TNF-alpha decreased. Participants' HDL cholesterol levels also increased.

    These findings suggest that supplemental omega-3s ameliorate some of the harmful effects of endurance running, possibly due to omega-3s' potent anti-inflammatory properties. Learn more about the health effects of omega-3s in this episode featuring Dr. Bill Harris.

  • Nearly 1.3 billion people worldwide have high blood pressure, the primary risk factor for cardiovascular disease-related death. However, findings from a recent study suggest that greater cardiorespiratory fitness offsets some of the risks associated with having high blood pressure.

    The study involved nearly 2,300 middle-aged men enrolled in the Kuopio Ischemic Heart Disease Risk Factor Study, an ongoing study of heart disease risk factors among men and women living in Finland. Researchers measured the participants' blood pressures (classified as normal or high) and cardiorespiratory fitness levels (classified as low, medium, or high).

    They found that high blood pressure increased a person’s risk of cardiovascular disease-related death by 39 percent, and low fitness increased risk by 74 percent. These findings were consistent even after considering other risk factors, including age, body mass index, cholesterol levels, smoking status, type 2 diabetes, coronary heart disease, physical activity, socioeconomic status, and high sensitivity C-reactive protein (a marker of inflammation).

    Men with high blood pressure and low fitness levels were more than twice as likely to die from cardiovascular disease than those with normal blood pressure and high fitness levels. However, men with high blood pressure and high fitness levels were only 55 percent more likely to die from cardiovascular disease.

    These findings suggest that exercise markedly reduces the risk of dying from cardiovascular disease, even among men with high blood pressure. Interestingly, sauna use also reduces blood pressure and the risk of cardiovascular disease-related death. Learn more in this clip featuring Dr. Jari Laukkanen (one of the authors of this study.)

  • Current exercise guidelines recommend that adults engage in at least 150 to 300 minutes of moderate-intensity aerobic physical activity or 75 to 150 minutes of vigorous-intensity aerobic physical activity weekly to promote cardiovascular health. However, finding the time to exercise often presents challenges, with many people squeezing in a couple of weekend workouts – often called the “weekend warrior” pattern. A recent study found that people whose physical activity occurred over one or two days had similar cardiovascular disease risks as those with more evenly distributed activity.

    Researchers analyzed the accelerometer-based physical activity patterns of nearly 90,000 adults enrolled in the UK Biobank study. They categorized the participants according to three activity patterns: inactive (fewer than 150 minutes), active weekend warrior (150 minutes or more, mostly over one or two days), and active regular (150 minutes or more, spread throughout the week).

    They found that both activity patterns – weekend warrior vs. regular – had comparable effects on cardiovascular disease risk, reducing the risk of atrial fibrillation (22 percent vs. 19 percent), heart attack (27 percent vs. 35 percent), heart failure (38 percent vs. 36 percent), and stroke (21 percent vs. 17 percent).

    These findings suggest that engaging in aerobic physical activity, either regularly throughout the week or in a more condensed pattern during the weekends, reduces the risk of cardiovascular disease. Aerobic exercise strengthens the heart muscle, lowers blood pressure, and reduces inflammation, promoting improved cardiovascular health. Learn how even resistance training can be aerobic in this clip featuring Dr. Martin Gibala.

  • During exposure to temperature extremes or hypoxia (low oxygen levels), cells increase their expression of heat shock proteins to stabilize unfolded proteins and repair damaged ones. This phenomenon, referred to as the heat shock response, occurs at the expense of other cellular proteins to protect the cell. Evidence from a 2016 study suggests that the heat shock response enhances athletic performance in low-oxygen environments characteristic of high altitudes.

    The study involved 21 elite cyclists who engaged in ten 60-minute training sessions in either low-oxygen or hot conditions. Before and after the intervention, they performed a time trial, where researchers tested their tolerance to low-oxygen levels.

    The researchers found that training during heat exposure improved athletic performance nearly as well as low oxygen exposure. Expression of heat shock protein 72 and hypoxia-inducible factor 1-α, a protein that mediates the body’s response to low oxygen levels, increased in both scenarios.

    Heat-shock proteins comprise a large, highly conserved family of proteins that are present in all cells. They play prominent roles in many cellular processes, including immune function, cell signaling, and cell-cycle regulation. Cells maintain a constant level of HSPs to facilitate aspects of the protein synthesis machinery, including assembly, folding, export, turn-over, and regulation. However, stress can upregulate HSP production.

    These findings suggest that training in a hot environment enhances performance in low-oxygen settings. Learn more about heat exposure via sauna use in our comprehensive overview article.

  • A high-protein diet may increase the risk of heart disease, diabetes, and increased body fat, especially in sedentary people. However, a new study in mice demonstrates that resistance training may counter these effects. Mice that ate a high-protein diet and performed resistance exercises gained muscle – not fat – and were more metabolically healthy than sedentary mice on the same diet.

    Researchers fed one group of mice a low-protein diet (7 percent of total calories) and another a high-protein diet (36 percent of total calories). Half of each group performed resistance exercises three times weekly for three months, while the other half remained sedentary. The researchers then compared various parameters, such as body composition, weight, and metabolic indicators, across the different groups.

    They found that the sedentary mice that ate a high-protein diet gained more fat than those on a low-protein diet. However, mice that ate a high-protein diet but engaged in resistance-based training gained muscle mass but not excess body fat. Interestingly, the high-protein-fed mice gained strength faster but, by the study’s end, did not outperform the low-protein group.

    These findings suggest that resistance training can offset the harmful effects associated with a high-protein diet.

    Current recommendations for protein intake for healthy adults – 0.8 grams per kilogram (0.36 grams per pound) of body weight per day – are likely too low for building and maintaining muscle mass. Doubling the recommended amount, ensuring a daily intake of 1.6 to 1.8 grams per kilogram (0.7 to 0.8 grams per pound) of body weight, will pay the greatest dividends for promoting muscle protein synthesis for non-novices. Learn more about the importance of dietary protein in this episode featuring Dr. Stuart Philips.

  • Mitochondrial function and whole-body maximal oxygen uptake – a surrogate measure of metabolic function and health – are closely linked. Exercise boosts mitochondrial function, but some evidence suggests there is an upper limit to exercise’s benefits. A new study demonstrates that the benefits of exercise on mitochondrial function peak, after which the benefits plateau or even drop.

    The study involved 11 healthy adults enrolled in a four-week high-intensity interval training (HIIT) program. The exercise load and duration gradually increased over the first three weeks of training (scaling up to 154 minutes per week) and then decreased for the final week to allow recovery. Researchers measured the participants' glucose tolerance and collected muscle biopsies throughout the intervention. They also assessed continuous blood glucose profiles in world-class endurance athletes.

    They found that after the week with the highest exercise load, the participants' mitochondrial function had declined markedly, impairing their glucose tolerance and insulin secretion. Interestingly, the impaired mitochondrial function coincided with the loss of cellular Nrf2, a protein involved in the body’s antioxidant defense response. In addition, they found that the endurance athletes had worse glucose control than a matched control group.

    The findings from this small study suggest an upper limit to the mitochondrial benefits of HIIT exists, potentially impeding performance and harming health. However, it’s noteworthy that the participants tolerated 90 minutes of HIIT per week and didn’t experience impairments until reaching 152 minutes. One of the unique advantages of HIIT is that a shorter routine can have robust beneficial effects comparable to those of endurance training. Learn more about HIIT in this episode featuring Dr. Martin Gibala.

  • Mental health disorders are rising, affecting more than 970 million people worldwide. While lifestyle behaviors can be beneficial in treating these disorders, drugs are often the primary treatment choice. A recent review found that physical activity reduced symptoms of depression by as much as 43 percent.

    Researchers conducted an umbrella review – an analysis that consolidates findings from multiple systematic reviews, providing a comprehensive overview of the existing evidence. Their analysis included 97 reviews, encompassing 1039 randomized controlled trials (128,119 participants) investigating the effects of physical activity on depression, anxiety, or psychological distress.

    They found that various forms of physical activity, including walking, resistance training, Pilates, yoga, and others, reduced symptoms of depression by 43 percent and anxiety by 42 percent, eliciting faster effects than medication. They observed the most pronounced effects in people with depression, pregnant and postpartum women, healthy people, and those with HIV or kidney disease. For people with depression and anxiety, higher-intensity exercise involving bursts of short and mid-duration activities proved more effective than longer-duration exercises.

    These findings demonstrate that physical activity has marked, beneficial effects on mood and may be an effective intervention for many people. The mechanisms that drive these effects likely include increased expression of neurotrophic factors, increased availability of serotonin and norepinephrine, regulation of the hypothalamic-pituitary-adrenal axis, and reduced systemic inflammation. Learn more about some of these mechanisms in this short video featuring Dr. Rhonda Patrick.

  • Poor sleep negatively affects metabolism, impairing glucose tolerance and increasing the risk of developing type 2 diabetes. Findings from a recent study indicate that HIIT compensates for the harmful effects of sleep loss on glucose tolerance.

    Researchers assigned 24 healthy young men to one of three five-night sleep protocols: normal sleep (eight hours nightly), sleep restriction (four hours nightly), and sleep restriction with HIIT. Researchers collected muscle biopsies to assess muscle protein synthesis before and after the intervention.

    They found that the group with sleep restriction experienced marked reductions in glucose tolerance, mitochondrial respiratory function, and sarcoplasmic protein synthesis. They also experienced altered diurnal skin temperature rhythms. However, sleep-restricted participants who engaged in HIIT did not experience these disturbances.

    The sarcoplasm is the cytoplasm of muscle cells. Sarcoplasmic protein synthesis is crucial for muscle growth, repair, and maintenance, contributing to overall muscle health and function.

    This study was small, but the findings suggest that sleep restriction impairs metabolic function, circadian rhythmicity, and muscle protein synthesis. However, engaging in HIIT during periods of sleep restriction helps counter these effects. Learn more about the benefits of HIIT in this episode featuring Dr. Martin Gibala.

  • Lynch syndrome is an inherited condition linked to increased risks of colorectal and endometrial cancers. While exercise is known to curb the risk of many types of cancer, scientists don’t fully understand its effects on Lynch syndrome. A recent study found that regular exercise reduced inflammation and boosted immune surveillance in people with Lynch syndrome.

    The study involved 21 people with Lynch syndrome. About half of the participants engaged in a 12-month cycling program (three sessions per week, 45 minutes per session), while the others received standard care and a single exercise counseling session. Researchers assessed the participants' cardiorespiratory fitness and measured gene expression in colorectal tissue before and after the intervention.

    They found that participants' oxygen consumption increased and colon and blood inflammatory markers decreased in those who exercised but not in those who received standard care. Gene expression analysis revealed heightened levels of natural killer and CD8 T cells in those who exercised.

    Natural killer (NK) cells and CD8 T cells play critical roles in the immune system’s defense against cancer. They are crucial components of the body’s immunosurveillance mechanism, responsible for identifying and eliminating potentially cancerous cells.

    These findings underscore exercise’s potential to intercept cancer in Lynch syndrome and shed light on its immunological effects in high-risk people. Learn about the differential effects of exercise intensity and duration on the body’s immune response in this live Q&A featuring Dr. Rhonda Patrick.

  • The benefits of physical activity on the brain’s aging process are widely known. Evidence suggests that exerkines, a class of molecules released into the bloodstream in response to exercise, drive many of these benefits. Findings from a recent study in mice found that PF4, an exerkine derived from platelets, promotes the production of hippocampal precursor cells in the brains of older mice.

    Researchers injected PF4 into mice and assessed its effects on hippocampal neurogenesis (the growth of new brain cells). Then they investigated the effects of exercise on blood platelets.

    They found that systemic elevation of PF4 levels mitigated age-related declines in brain regeneration and cognitive function, an effect that was dependent upon hippocampal neurogenesis. They also found that exercise triggered platelet activation, which in turn increased the production of hippocampal precursor cells in the brains of older mice.

    These findings underscore the crucial role of platelets in mediating the rejuvenating effects of exercise on the aging brain. It also sheds light on the potential mechanisms that link physical activity with improved brain health in aging, with possible implications for people who are unable to exercise due to advanced age, mobility issues, or various health conditions.

    Interestingly, heat stress also promotes PF4. In a study involving endurance cyclists exercising in hot conditions, PF4 increased by as much as 150 percent. Sauna use has similar effects on PF4. Learn about other effects of heat stress from sauna use in our overview article.

  • Physical activity is often a fundamental component of weight management strategies. However, some people experience weight loss with physical activity while others do not. A recent study found that differences in the gut microbiome influence the body’s metabolic response to physical activity.

    The study involved 307 healthy men and 209 healthy women enrolled in two long-term cohort studies. Researchers analyzed the participants' gut microbial makeup and assessed their physical activity levels over several years.

    They found that a specific gut microbe called Alistipes putredinis played a crucial role in how physical activity influenced body weight. Participants with higher levels of A. putredinis experienced more weight loss when they increased their physical activity. Conversely, those with lower A. putredinis levels saw less weight loss in response to physical activity. This pattern was consistent for long-term and short-term physical activity and associated with metabolic processes linked to A. putredinis, such as folate transformation and fatty acid metabolism.

    These findings suggest that having a greater abundance of A. putredinis in the gut boosts the positive effects of physical activity on weight management. Interventions aimed at manipulating the gut microbiome could enhance the effectiveness of physical activity in controlling body weight. Learn more about the gut microbiome’s roles in human health in this episode featuring Dr. Eran Elinav.

  • As people age, their total energy expenditure (total calories burned in a day) decreases primarily due to declines in resting metabolic rate and the energy expenditure of physical activity, driving increases in body fat. Strength training increases fat-free mass (muscle mass), offering a promising intervention to offset these declines. A 2001 study found that strength training increased resting metabolic rate in men, regardless of age, by 9 percent.

    The study involved young and older men and women participating in a supervised strength training program three days a week for 24 weeks. Participants maintained their usual diet and body weight throughout the study period. Researchers assessed the participants' resting metabolic rate and energy expenditure of physical activity before and after the intervention.

    They found that strength training increased the participants' resting metabolic rate by 7 percent, regardless of age. However, they observed a gender-related difference, with men experiencing a 9 percent increase in resting metabolic rate, while women did not experience a notable increase. This effect persisted even after adjusting for fat-free mass.

    These findings suggest that strength training increases resting metabolic rate, an effect influenced by gender but not age. Learn more about the benefits of strength training in this episode featuring Dr. Brad Schoenfeld.

  • Type 2 diabetes is a metabolic disorder characterized by skeletal muscle insulin resistance. High-intensity interval training (HIIT) improves skeletal muscle insulin sensitivity, but the demanding nature of traditional HIIT sessions can be daunting for people unaccustomed to regular physical activity. A 2012 study found that reduced-exertion high-intensity interval training (REHIT) improved aerobic capacity and metabolic health in people who were sedentary – a risk factor for developing type 2 diabetes.

    The study involved 29 sedentary young adults. Half the participants engaged in three 10-minute REHIT sessions weekly for six weeks. Each session consisted of low-intensity cycling and one or two brief “all-out” sprints lasting between 10 and 20 seconds. The other half of the participants remained sedentary. Researchers assessed the participant’s aerobic capacity (measured as VO2 peak) and insulin sensitivity before and after their respective interventions.

    Ten of the 15 REHIT participants completed all 18 sessions, indicating high compliance. Aerobic capacity increased by 15 percent in males and 12 percent in females. Insulin sensitivity improved by 28 percent in males but not in females. Participants rated their perceived exertion as “hard” or “somewhat hard.”

    Encouraging regular, balanced exercise that includes cardiorespiratory, strength, and flexibility training can optimize health benefits. However, addressing barriers, such as lack of time or access to formal exercise equipment, is crucial to have widespread effects. The findings in this small study suggest that brief, reduced-exertion high-intensity training improves aerobic capacity and metabolic health in sedentary people despite a low time commitment (just 30 minutes per week) and relatively low effort. Learn more about REHIT and how it differs from HIIT and SIT in this clip featuring Dr. Martin Gibala.

  • The extent to which physical activity influences health outcomes depends on its intensity, with higher-intensity activities contributing to greater reductions in disease and death risk. Evidence suggests that brief episodes of vigorous lifestyle physical activity (VILPA) that are part of people’s daily routines, such as fast walking or stair climbing, are as effective as structured, vigorous exercise at improving health outcomes. A 2022 study found that engaging in three to six minutes of VILPA daily reduced the risk of dying from cardiovascular disease by as much as 49 percent.

    Researchers tracked the physical activity of more than 25,000 non-exercisers – people who did not engage in leisure time physical activity, such as sports – for a week using wrist-worn accelerometers. Then, they monitored the participants' health for approximately seven years.

    They found that participants who engaged in three short bursts of activity (each lasting one or two minutes) daily were 38 to 40 percent less likely to die of cancer or other causes of premature death than those who did not. They were also 48 to 49 percent less likely to die from cardiovascular disease.

    These findings demonstrate that even small amounts of VILPA can markedly reduce the risk of early death, yielding similar benefits to vigorous physical activity performed during structured exercise. VILPA may be a viable strategy for promoting physical activity, especially for people unable or unwilling to engage in structured exercise programs. Incorporating vigorous activities throughout one’s day, with a goal of accumulating several minutes of VILPA daily, can have profound health effects. Learn more about VILPA in this clip featuring Dr. Martin Gibala.

  • Sedentary behavior is associated with an increased risk of many chronic diseases. Evidence suggests that “exercise snacks” – brief, isolated intervals of vigorous exercise, each lasting less than one minute and typically performed multiple times throughout the day – may counter the harmful effects of sedentary behavior. A 2022 study found that vigorous stair-climbing increased participants' peak oxygen uptake by approximately 5 percent.

    The study involved 24 healthy, sedentary young adults. For six weeks, half of the participants engaged in three bouts of vigorous stair climbing (60 steps in a three-flight stairwell) daily, with one to four hours of rest in between, three days a week. The other half did not participate in any training. Researchers measured the participants' peak oxygen uptake and power output before and after the intervention.

    At the end of the intervention, the stair-climbing participants' peak oxygen uptake had increased by approximately 5 percent, and peak power output increased by 12 percent. Participants maintained a consistent rate of perceived exertion of 5, indicating a “hard” level, and their heart rate remained relatively stable at approximately 85 percent of the age-predicted maximum.

    These findings suggest that integrating brief periods of intense exercise into one’s daily routine can improve cardiorespiratory fitness in sedentary adults. They also align with previous research showing that exercise snacks improve insulin sensitivity in people with insulin resistance.

    A key benefit of exercise snacks is that they eliminate the need for specialized equipment and the scheduling of leisure time for structured exercise. They are easily integrated into everyday activities, whether inserting short bursts of activity between tasks or incorporating them into daily routines at home, work, or school. Exercise snacks can also reduce blood glucose levels in people with type 2 diabetes. Learn more in this clip featuring Dr. Martin Gibala.

  • VO2 max – the maximum rate of oxygen a person can consume during exercise – is a robust predictor of a person’s risk for chronic diseases and death. Exercise increases VO2 max, but how well a person responds to exercise training varies considerably and may be influenced by genetics. A 2017 systematic review identified nearly 100 genes that likely influence a person’s VO2 max response to exercise training.

    Researchers reviewed 35 studies investigating genetic variants in the context of supervised aerobic exercise interventions aimed at improving VO2 max. The studies were based on DNA samples from more than 4,200 people of varied genetic makeup.

    The researchers' analysis identified 97 genes that might influence a person’s VO2 max response to exercise training by modulating muscle function and efficiency, electrolyte balance, lipid metabolism, oxidative phosphorylation, energy production, and oxygen delivery. They found that people who responded more favorably to exercise training tended to have more positive response alleles – genetic variants associated with a more favorable or beneficial response to exercise training – in those genes.

    These findings highlight the influence of specific genetic variants on a person’s response to exercise training and their effect on VO2 max improvements. However, the authors cautioned that while most of the articles reviewed in their analysis primarily investigated a single or a limited number of candidate genes or markers, exercise-related traits are intricate and influenced by multiple genes working in concert. Learn how Tabata, a type of HIIT, increases VO2 max in this clip featuring Dr. Martin Gibala.

  • Traditional moderate-intensity continuous exercise training (MICT) promotes cardiometabolic health but requires a considerable time commitment, a factor many people often cite as a reason for not exercising. Evidence suggests sprint interval training (SIT) offers similar benefits for insulin sensitivity and heart health as MICT. A 2016 study found that 12 weeks of SIT improved cardiometabolic health as effectively as MICT – with one-fifth of the time commitment.

    SIT typically involves short bursts of high-intensity exercise followed by low-intensity recovery periods. It is sometimes described as a “sprint from danger” pace, equating to one’s top running speed, executed for five to ten seconds.

    The study involved 27 young, sedentary men who engaged in SIT, MICT, or no exercise (a control group) for 12 weeks. Those who engaged in SIT performed three 20-second high-intensity intermittent exercise sets within a 10-minute cycling session, while those who engaged in MICT performed 50 minutes of continuous cycling exercise at a moderate intensity. Both groups underwent muscle biopsies and body composition analyses before and after the interventions.

    SIT and MICT improved peak oxygen uptake by 19 percent, indicating improved cardiorespiratory fitness. In addition, both groups demonstrated enhanced insulin sensitivity and increased levels of citrate synthase, a marker of muscle mitochondria content.

    Although this was a small study, its findings suggest that SIT can be an effective and time-efficient strategy to improve cardiometabolic health among sedentary people. The findings also underscore the importance of considering alternative exercise strategies that may be more feasible for people with limited time for workouts. Learn more about SIT in this clip featuring Dr. Martin Gibala.

  • Sleep deprivation profoundly affects the human body, negatively influencing cognitive performance, cardiovascular health, and more. Findings from a 2020 study suggest that sleep deprivation impairs muscle protein synthesis, but exercise counters this effect. People who slept only four hours per night but engaged in high-intensity interval training (HIIT) exhibited muscle protein synthesis comparable to those who slept a full night.

    Researchers assigned 24 healthy young men to one of three five-night sleep protocols: normal sleep (eight hours nightly), sleep restriction (four hours nightly), and sleep restriction with HIIT. Researchers collected muscle biopsies to assess muscle protein synthesis before and after the intervention.

    They found that the group with sleep restriction had lower rates of muscle protein synthesis than those with normal sleep and those who combined sleep restriction with HIIT.

    HIIT is a time-efficient strategy to promote cardiovascular fitness and metabolic health. Its flexibility accommodates a wide range of exercises, including walking, running, cycling, and even resistance training, making it accessible to people of different fitness levels and abilities.

    This was a small study, but the findings suggest that sleep restriction reduces muscle protein synthesis, potentially contributing to muscle loss. However, engaging in HIIT during periods of sleep restriction helps maintain muscle protein synthesis, potentially counteracting the adverse effects of sleep loss on muscle mass. Learn more about the benefits of HIIT in this episode featuring Dr. Martin Gibala

    Former FMF guest Dr. Stuart Phillips was a collaborator and participant in this study. Learn more about Dr. Phillips' research in this episode.

  • Current exercise guidelines recommend that adults engage in at least 150 to 300 minutes of moderate-intensity physical activity or 75 to 150 minutes of vigorous-intensity aerobic physical activity (or an equivalent combination of the two) weekly to promote cardiovascular health. However, a 2006 study challenged those recommendations, suggesting that a single weekly bout of vigorous exercise reduced the risk of cardiovascular disease-related death by 40 percent.

    The study involved more than 56,000 people who were free of cardiovascular disease at enrollment. Researchers tracked the participants' health for roughly 16 years to assess their activity levels and risk of death from heart disease or stroke.

    They found that even a single weekly session of intense exercise, lasting 30 minutes or longer, markedly reduced the risk of dying from heart disease or stroke compared to no exercise at all. Interestingly, exercising more frequently or for longer durations each week didn’t provide additional benefits. Another finding was that as men got older, the protective effect of exercise against cardiovascular death became more pronounced. However, this age-related benefit wasn’t evident in women.

    Vigorous-intensity exercise is physical activity that demands a significant and challenging effort, promoting a substantial increase in heart and breathing rates. It requires considerable energy expenditure and typically involves activities like running, cycling at high speeds, or intense aerobics. During vigorous-intensity exercise, a person’s target heart rate is approximately 60 to 85 percent of their maximum heart rate.

    These findings from this observational study suggest that even one vigorous, 30-minute or longer workout a week can have substantial cardiovascular health benefits. Current exercise guidelines may need to be revised to account for the effects of HIIT on cardiorespiratory fitness. Learn more about the health benefits of HIIT in this episode featuring Dr. Martin Gibala.

  • Cardiorespiratory fitness is a measure of the body’s aerobic capacity – the ability to deliver oxygen to skeletal muscles – during sustained physical activity. A 2009 meta-analysis found that people with low cardiorespiratory fitness were 70 percent more likely to die prematurely and 56 percent more likely to experience a heart or cardiovascular disease-related event.

    Researchers evaluated data from 33 studies examining connections between cardiorespiratory fitness and the risk of premature death from all causes (more than 102,000 participants) and combined heart disease and cardiovascular disease events (more than 84,000 participants). They used maximal aerobic capacity, measured in metabolic equivalent (MET) units, to estimate cardiorespiratory fitness. They grouped participants into three categories based on their cardiorespiratory fitness levels: low (<7.9 METs), intermediate (7.9-10.8 METs), and high (≥10.9 METs).

    They found that for each 1-MET increase in maximal aerobic capacity (equivalent to a 1-kilometer per hour increase in running/jogging speed), the risk of death from all causes and heart disease/cardiovascular disease events. Compared to participants with high cardiorespiratory fitness, those with low cardiorespiratory fitness were 70 percent more likely to die prematurely and 56 percent more likely to experience a heart disease/cardiovascular disease event. However, even intermediate cardiorespiratory fitness conferred substantial benefits. Compared to participants with intermediate cardiorespiratory fitness, those with low cardiorespiratory fitness were 40 percent more likely to die prematurely and 47 percent more likely to experience a heart disease/cardiovascular disease event.

    These findings demonstrate that having low cardiorespiratory fitness markedly increases one’s risk of dying prematurely or developing heart or cardiovascular disease. The most accurate way to assess cardiorespiratory fitness involves measuring maximal oxygen uptake, often referred to as VO2 max, during a graded exercise test in a laboratory, clinical, or research setting. However, online calculators, such as the World Fitness Level, can predict VO2 max based on various personal factors. Learn more about VO2 max and the World Fitness Level calculator in this episode featuring Dr. Martin Gibala.

  • Ketones are molecules produced by the liver during the breakdown of fatty acids. Supplemental ketones – referred to as endogenous ketones – are popular among many athletes due to their purported beneficial effects on performance. A new study shows that endogenous ketone supplementation impairs athletic performance in endurance athletes.

    Researchers asked 23 well-trained adult cyclists to consume a ketone supplement (providing 0.35 grams of ketones per kilogram body weight) or a placebo 30 minutes before completing a 20-minute cycling trial on an exercise bike. The participants repeated the cycling trial a week later with the opposite beverage.

    The researchers found that the participants' power output after taking the ketone supplement was 2.4 percent lower than after taking the placebo, regardless of the order in which they performed the two treatments. The cyclists' average heart rate during the trial was lower after taking the ketone ester, but other factors, such as peak heart rate, glucose levels, and perceived exertion, were similar between the two situations. Out of the 22 participants, 11 felt their perceived exertion was greater after taking the ketone ester, seven felt the same in both situations, and four felt less exertion after taking the ketone ester than when taking the placebo.

    Although this was a small study, these findings suggest that exogenous ketone supplementation impairs performance in endurance athletes in a setting of short-duration, high-intensity training. However, some evidence suggests that ketone supplementation enhances performance in extreme settings in which hypoxia may be a factor, such as mountain climbing. Learn more in this clip featuring ketone expert Dr. Dominic D'Agostino.

    Coming soon: an interview with Dr. Martin Gibala, one of the investigators involved in this study.

  • Although inflammation is a critical component of the body’s immune response, excess inflammation drives many chronic diseases, such as autoimmune disorders, cardiovascular diseases, diabetes, and cancer. A new study in mice shows that regular exercise reprograms macrophages, altering how they sense and respond to pathogens and reducing inflammation.

    Macrophages are immune cells that participate in pathogen elimination via phagocytosis. Distinguished by their polarization, “M1” macrophages exhibit a proinflammatory phenotype, while “M2” macrophages exhibit an anti-inflammatory phenotype. A high M1 to M2 ratio indicates inflammation and a chronic disease state.

    Researchers collected macrophages from the bone marrow of two groups of mice – one that had exercised regularly for eight weeks and one that had been sedentary. Then they exposed the macrophages to lipopolysaccharide (a bacterial toxin that induces an acute inflammatory reaction) and assessed the cells' responses.

    They found that macrophages from the exercised mice exhibited decreased activation of NF-κB, the primary transcription factor of M1 macrophages. The macrophages also demonstrated reduced expression of inflammation-related genes, increased expression of M2 macrophage-associated genes, and improved mitochondrial function.

    These findings suggest that regular exercise modulates macrophages' responses to inflammation by enhancing their respiratory capacity and altering gene expression, with potential implications for preventing or treating inflammatory diseases. Read more about the benefits of exercise in our overview article.

  • Aerobic exercise has profound effects on the human body – including the skin. Now findings from a new study suggest that resistance training slows skin aging. Women who engaged in resistance training had thicker, more resilient skin than women who engaged in aerobic exercise alone.

    Researchers compared the effects of aerobic versus resistance training on skin aging in 56 sedentary, middle-aged women. The participants engaged in a twice-weekly supervised exercise program involving either aerobic or resistance training for 16 weeks. The researchers evaluated the participants' skin properties, body composition, and physical capacity before and after the intervention.

    They found that both types of training improved skin elasticity and structure, but only resistance training increased the thickness of the dermis, the inner layer of the skin. Resistance training also increased levels of biglycan, a protein that promotes wound healing and skin resilience via its interactions with collagen. The researchers also noted an increase in the expression of genes related to the skin cells' extracellular matrix.

    These findings suggest that resistance training enhances several aspects of skin health, slowing the effects of skin aging. They also highlight yet another way in which resistance training bolsters health. Learn about other strategies to promote healthy, resilient skin in this Aliquot featuring Dr. Rhonda Patrick.

  • Selective attention – the ability to focus on what’s important and manage distraction – can be elusive. But findings from a new study suggest that exercise enhances selective attention. People who engaged in just a single exercise session before completing a task exhibited better focus and less distraction.

    The study involved 24 healthy adults who participated in two protocols (20 minutes of exercise or 30 minutes of seated rest) on separate occasions. Participants completed a task before and after each protocol that tested their attention to attended versus unattended stimuli. Attended stimuli are things a person needs to focus on; unattended stimuli are those a person should ignore, such as background noise. Researchers measured the participants' brain activity during the task completion.

    They found that participants focused better on the task after a single exercise session than after sitting. However, neither of the protocols influenced the participants' performance on the task. Processing of attended stimuli increased after exercise, while processing of unattended stimuli decreased, suggesting that exercise allocated neural resources to support attention.

    One mechanism that drives the increased focus after exercise may be related to norepinephrine, a neurotransmitter produced in the locus coeruleus. Exercise increases norepinephrine release, which in turn promotes attention and vigilance.

    This was a small study; nevertheless, it supports other evidence suggesting that exercise has potent effects on the brain. Learn more about the effects of exercise in our overview article.

  • A new study finds that exercise maintains critical connections in the brains of older adults while boosting fitness. Older adults who walked regularly performed better on tests of cognitive function and memory and had better cardiorespiratory fitness.

    The study involved 33 older adults (average age, 78 years). Participants walked on a treadmill for 30 minutes a day, four times a week, for 12 weeks and underwent tests before and after the intervention to assess their physical and cognitive performance. In addition, researchers performed functional MRIs to examine the neural connections in their brains.

    They found that participants' cardiorespiratory fitness improved by more than 10 percent. They also demonstrated improvements in cognitive performance, particularly in verbal fluency, verbal learning, and memory. The MRIs revealed that participants experienced increased connectivity between the default mode network and regions of the brain involved in memory.

    The default mode network is a collection of interconnected neural structures involved in attention and focus. Disturbances in default mode network connectivity are associated with poor working memory, reduced performance, and work-related productivity losses.

    Although this was a small study, it supports a growing body of evidence suggesting exercise is a potent strategy for staving off cognitive decline in aging. One contributor to cognitive decline is the loss of blood-brain barrier integrity. Learn how vigorous exercise helps maintain blood-brain barrier integrity as we age in this episode featuring Dr. Axel Montagne.

  • Parkinson’s disease is a neurodegenerative disorder that affects the central nervous system. New research suggests that exercise reduces the risk of developing Parkinson’s disease. Women who regularly engaged in physical activity were 25 percent less likely to develop the disease than inactive women.

    Researchers gathered information about the lifestyles and medical histories of more than 99,000 women and categorized them according to their activity levels. Then, using a statistical method that accounted for the reduced activity that might precede a diagnosis of Parkinson’s disease, they investigated the effects of exercise on Parkinson’s disease risk.

    They found that physical activity levels were consistently lower in women who developed Parkinson’s disease than in those who did not, even up to 29 years before the disease was diagnosed. The difference between the two groups became more pronounced around 10 years before diagnosis. Overall, women with the highest activity levels had a 25 percent lower risk of developing Parkinson’s disease than those with the least activity, even after considering other risk factors.

    These findings suggest that exercise protects women against Parkinson’s disease. The mechanisms that drive this protective effect may be related to exercise’s capacity to regulate key neurotransmitters, promote the release of brain-derived neurotrophic factor (BDNF), ameliorate brain inflammation, and reduce oxidative stress. Interestingly, exercise also benefits people after they have been diagnosed with Parkinson’s disease. Learn more in this clip featuring Dr. Giselle Petzinger.

  • Resistance training builds muscle mass and strength by promoting muscle growth, increasing muscle fiber size, and enhancing the body’s ability to generate force. A recent study shows that omega-3 fatty acids enhance the effects of resistance training on strength gains. Healthy young adults who took fish oil supplements – which are rich in omega-3s – while engaging in a resistance training program showed greater strength gains than those who took a placebo.

    The study involved 28 healthy young adults who engaged in a 10-week resistance training program. Half of the participants took 4.5 grams of fish oil per day (providing 2.275 grams of EPA + 1.575 grams of DHA), while the other half took a placebo. Before and after the intervention, they measured the participants' blood omega-3 concentrations. Using the one-repetition maximum (1RM) method, they also assessed the participants' gains in absolute strength (the total amount of weight lifted ) and relative strength (the comparison of a person’s lifting capacity to their body weight).

    They found that blood omega-3 concentrations increased by 109 percent among the participants who took fish oil, but increased by only 1.3 percent among those who took the placebo. Both groups showed similar increases in lean body mass and decreases in fat mass and body fat percentage. However, those who took the fish oil showed considerable absolute and relative strength gains in the 1RM bench press compared to the placebo group. Absolute strength increased by 17.7 percent in the fish oil group versus 9.7 percent in the placebo group, and relative strength increased by 17.6 percent versus 7.3 percent. Absolute strength gains in the 1RM squat were similar between groups, at 28.8 percent versus 20.5 percent; however, relative strength gains for the 1RM squat were higher in the fish oil group, at 29.3 percent versus 17.9 percent.

    These findings suggest that fish oil supplementation during resistance training enhances muscle strength gains. The study investigators posited that these improvements were due in part to enhanced muscle protein synthesis, aligning with other research demonstrating that fish oil supplementation induced a 50 percent increase in muscle protein synthesis.

    Coming soon: Our next FMF episode will feature Dr. Chris McGlory (one of the authors of this study), whose work focuses on the effects of omega-3 fatty acids on muscle protein synthesis.

  • Changes in brain function and connectivity often occur many years before the clinical manifestation of cognitive impairment and dementia. A new study shows that lifestyle modifications, including exercise, vitamin D intake, and cognitive training, improve functional brain connectivity in older adults with mild cognitive impairment.

    The study involved 120 older adults (ages 60 to 80 years) with mild cognitive impairment. The participants engaged in 30 minutes of cognitive training and 60 minutes of exercise three times a week for 20 weeks. Thirty-eight of the participants received vitamin D supplements, while the remainder received a placebo. Researchers measured the participants' functional brain connectivity using MRI before and after the interventions.

    They found that physical exercise alone, exercise combined with cognitive training, or exercise combined with both cognitive training and vitamin D supplementation increased functional brain connectivity in regions of the brain’s default mode network, including the hippocampus and angular gyrus.

    The default mode network is a collection of interconnected neural structures involved in attention and focus. Disturbances in default mode network connectivity are associated with poor working memory, reduced performance, and work-related productivity losses.

    This study’s findings suggest that lifestyle behaviors, particularly exercise, enhance functional brain connectivity, potentially staving off age-associated cognitive decline. Learn more about the effects of exercise on the brain in this episode featuring Dr. Axel Montagne.

  • Lactate boosts cognitive function in mice, according to a new study. Mice had better spatial working and long-term memory after exercising and receiving supplemental lactate.

    Researchers studied the effects of exercise – with or without supplemental lactate – on cognitive function in mice. The mice engaged in moderate-intensity exercise (about 55 to 60 percent of their VO2 max) five days a week for five weeks. This level of intensity is just below the “lactate threshold” – the point at which lactate builds up in the bloodstream and compromises performance. At the end of the five-week period, they tested the animals' memory skills.

    They found that exercise plus supplemental lactate improved the animals' spatial working and long-term memory. In addition, the expression of various proteins produced in the hippocampus, including FNDC5 (also called irisin) and brain-derived neurotrophic factor (BDNF), increased, suggesting that supplemental lactate augments the beneficial effects of exercise on the hippocampus and subsequent cognitive function.

    Lactate is a compound produced in muscles during exercise via the breakdown of glucose. It is thought to participate in a sort of “lactate shuttle” in which it is transported from the muscles into tissues like the heart and brain, where it is used for energy. Evidence suggests that lactate mediates some of the benefits of exercise on learning and memory via inducing neuronal BDNF expression. Learn more about the lactate shuttle and its effects on the brain in this episode featuring Dr. George Brooks.

  • Greater, more intense physical activity may preserve brain volume – especially in the hippocampus, an area of the brain involved in memory. Physichttps://neurosciencenews.com/physical-activity-neuroprotection-21177/al activity boosts brain health.

    Being more physically active is associated with having larger brain volume, a 2022 study found. The greatest brain-enhancing effects were seen in those who engaged in moderate- to vigorous-intensity exercises.

    The study involved more than 2,500 adults between the ages of 30 and 94 years. The participants wore wrist accelerometers to track their activity levels and underwent brain scans to assess their brain volume, cortical thickness, and gray matter density.

    The scans revealed that physical activity had a marked, dose-dependent effect on the participants' brain health. Those with greater, more intense physical activity levels exhibited larger brain volumes – especially in the hippocampus, an area of the brain involved in memory – than those with lower, less intense levels. However, the beneficial effects of physical activity on brain health were particularly evident when comparing the brain volumes of those who engaged in moderate physical activity to those who were sedentary, suggesting that even small increases in physical activity can boost brain health and reduce brain volume losses associated with aging.

    The beneficial effects of physical activity may be related to exercise-induced production of brain-derived neurotrophic factor (BDNF), a protein that controls and promotes the growth of new neurons. BDNF is active in the hippocampus, cortex, cerebellum, and basal forebrain – areas involved in learning, long term memory, and executive function. Learn more about the brain-boosting effects of BDNF in our comprehensive overview article.

  • Higher cardiovascular fitness delays brain aging and the onset of dementia in women, a 2018 study showed. Women with high cardiovascular fitness levels experienced nearly a decade’s delay in dementia onset than those with moderate fitness levels.

    The study involved 191 middle-aged women. Participants completed a cycling test to gauge their cardiovascular fitness and underwent regular neuropsychiatric testing to determine if they developed dementia during their lifetime.

    Compared to women with moderate cardiovascular fitness levels, women with high cardiovascular fitness levels were 88 percent less likely to develop dementia. However, those with low fitness levels were 41 percent more likely to develop dementia. Higher fitness delayed the onset of dementia by 9.5 years compared to those with moderate fitness.

    Cardiovascular fitness is a measure of how well the heart, lungs, and blood vessels transport oxygen to the muscles during exercise. Exercise contributes to cardiovascular fitness because it exerts robust effects on the cardiovascular system, boosting heart rate, blood pressure, and cardiac output. Interestingly, sauna use exerts similar effects on the cardiovascular system. Learn more in our overview article.

    These findings suggest that cardiovascular fitness protects against dementia in women. Learn more about the effects of cardiovascular fitness on brain health in this short video featuring Dr. Rhonda Patrick.

  • A 2022 study showed that sweating while exercising promoted the excretion of heavy metals. The sweat produced during exercising contained more heavy metals than that produced during low-temperature sauna use.

    The study involved 12 young, healthy young adults. Researchers collected sweat samples from the participants after 20 minutes of either running on a treadmill or sitting in a sauna cabinet (at ~113°F). Then they measured concentrations of the heavy metals nickel, lead, copper, arsenic, and mercury in their sweat.

    They found that engaging in exercise promoted higher concentrations of nickel, lead, copper, and arsenic in sweat, while sitting in a low temperature sauna did not produce such elevated levels. On the other hand, the sweating method did not affect sweat concentrations of mercury.

    Heavy metals are naturally occurring metallic elements that are toxic or poisonous even at low concentrations. Exposures to heavy metals in everyday products such as arsenic in agricultural products, cadmium in cigarette smoke and automobile exhaust, lead in toys, and mercury in dental amalgam and certain types of fish, are common occurrences.

    These findings suggest that sweating through exercising facilitates heavy metal excretion from the body more effectively than a very low temperature sauna. This was a very small study, however, and larger studies are needed to confirm these findings.

    It’s noteworthy that these findings don’t undermine the utility of sauna use to promote heavy metal excretion in sweat. The average person loses 0.6 to 1.0 kilograms of sweat per hour in a typical traditional sauna session, which is typically considerably hotter (158°F to 212°F) than the experimental conditions used in this study. Consequently, sauna use likely induces considerably greater sweat losses than exercise, depending on the conditions and duration.

  • A new study found that regular cycling may slow sarcopenia – the age-related loss of muscle mass and strength. Men who cycled regularly had larger, leaner gluteus muscles than inactive men.

    The study involved two groups of men: 28 who were physically inactive and had not practiced sports for an average of 27 years and 28 who were trained recreational male cyclists, had cycled more than 4,300 miles in the past year, and had been cycling for an average of 15 years. Researchers used magnetic resonance imaging to determine the volume of the participants' gluteus maximus and gluteus medius muscles, which are situated in and around the buttocks, as well as the percentage of fat infiltration within those muscles.

    They found that the inactive group tended to be heavier than the cyclists. They also found that the cyclists had larger gluteus maximus and gluteus medius muscles than the males in the inactive group. On average, the cyclists had 7 percent less fat infiltration in the gluteus maximus and 5 percent less in the gluteus medius than the males in the inactive group.

    Research suggests that physical inactivity promotes muscle fat infiltration and progressive muscle weakness, driving sarcopenia – the age-related loss of muscle tissue. However, exercise and appropriate nutritional support may forestall these muscle losses. Learn how exercise and dietary protein play roles in slowing age-related muscle loss in this episode featuring Dr. Stuart Phillips.

  • People who follow vegan diets generally have weaker bones than omnivores, a new study shows. However, vegans and omnivores who practice resistance training have comparable bone strength.

    The study included 88 healthy adults. About half had followed a vegan diet for five years or more, while the other half had followed an omnivorous diet. Participants provided information about their dietary intake and exercise practices, and researchers assessed their bone microarchitecture – a measure of bone strength.

    They found that, overall, vegans had altered microarchitecture compared to omnivores. However, the bone microarchitecture of vegans and omnivores who practiced resistance training was comparable, suggesting that resistance exercise compensated for dietary differences between the two groups. Interestingly, aerobic exercise alone did not confer a protective effect on bone microarchitecture.

    These findings suggest that resistance training protects against bone loss associated with vegan diets. Aerobic exercise did not appear to confer protection, however.

    Vegan diets are rich in plants and plant-based proteins. People who follow vegan diets often experience more bone loss over time than those who follow an omnivorous diet. Evidence suggests that plant-based proteins – when consumed in sufficient quantities – can support muscle hypertrophy in resistance training, which would in turn support bone health. Learn more in this episode featuring Dr. Stuart Phillips.

  • A new study shows that eating wild blueberries, which are rich in bioactive compounds called anthocyanins, may improve athletic performance. After young men consumed freeze-dried wild blueberries for two weeks, their fat oxidation rates during exercise increased by more than 43 percent.

    During exercise, fats and carbohydrates undergo oxidation, providing fuel for contracting muscles. At lower exercise intensity, the body relies primarily on fat oxidation; at higher intensity, the body shifts more toward carbohydrate oxidation. During endurance training, the body’s carbohydrate stores can deplete, causing fatigue and impairing athletic performance.

    The study involved 11 healthy, aerobically fit men. The men ate 25 grams of freeze-dried wild blueberry powder (roughly equivalent to a cup of fresh blueberries and providing 325 grams of anthocyanins) every day for two weeks. Before and after the intervention, researchers measured men’s fat utilization at 65 percent of their peak oxygen consumption while exercising.

    They found that the men’s fat oxidation increased by 19.7 percent after exercising for 20 minutes, 43.2 percent after 30 minutes, and 31.1 percent after 40 minutes. Conversely, their carbohydrate oxidation decreased by 10.1 percent after 20 minutes, 19.2 percent after 30, and 14.8 percent after 40. The men’s lactate levels were lower, too, likely due to improved blood flow.

    Anthocyanins are polyphenolic compounds that exert antioxidant, anti-inflammatory, and cardioprotective effects, among others. It’s noteworthy that freeze-drying blueberries induces considerable anthocyanin losses. Eating fresh blueberries may provide even greater benefits to athletic performance.

    The findings from this small study suggest that consuming anthocyanin-rich blueberries promotes fat oxidation, thereby enhancing athletic performance. Further studies in larger populations are needed to confirm these effects.

  • A new study shows that engaging in even a few minutes of daily exercise improves memory and cognitive function. Middle-aged adults who engaged in just nine minutes of moderate to vigorous activity daily performed better on tests of memory, planning, and organization than those who engaged in sedentary or light activities.

    Researchers tracked the activity patterns of nearly 4,500 adults over a period of a week. The participants took cognitive tests that assessed their verbal memory and executive function – the ability to plan, monitor, and execute one’s goals.

    People who engaged in moderate to vigorous activity scored higher on the cognitive tests than those who were sedentary or engaged in only light activity. Surprisingly, just nine minutes of moderate to vigorous activity markedly improved cognitive performance versus sedentary activity.

    Physical activity is a broad term that includes exercise, work-related exertion, and even some hobbies. Moderate-intensity physical activities, which include activities like brisk walking, doubles tennis, or raking leaves, increase a person’s heart rate to about 50 to 60 percent of their maximum. Vigorous-intensity physical activities, which include activities like running, swimming, or cycling, increase the heart rate to 70 to 80 percent of one’s maximum.

    Robust evidence demonstrates that vigorous activity maintains the blood-brain barrier, a critical component of brain health and cognitive function. Learn more in this episode featuring Dr. Axel Montagne.

  • Running may be as effective as traditional antidepressant therapies for reducing symptoms of depression.

    A new study found that running was as effective as traditional antidepressant drugs at reducing symptoms of depression. In addition, people who ran had better physical health than those who did not.

    The study involved 141 people with depression. Participants chose which 16-week therapy intervention they preferred: running at least twice a week with a group (96 participants) or taking traditional antidepressant medication (45 participants). They underwent mental and physical health assessments before and after the interventions.

    The two therapies were comparable in terms of reducing depressive symptoms. However, running therapy improved many aspects of the participants' health, including body weight, waist size, blood pressure, heart rate, and heart rate variability.

    Nearly 25 million adults living in the United States take some form of antidepressant medication. Most antidepressants work by altering the brain’s chemistry to affect mood. Side effects of the drugs include nausea, weight gain, decreased libido, and anxiety, among others. Evidence suggests that antidepressants are only about 20 to 30 percent more effective at reducing symptoms of depression than placebo treatments.

    Exercise boosts the production of molecules that enhance mood and promote mental health. Learn more about the mental health effects of exercise in this video featuring Dr. Rhonda Patrick.

  • A new study shows how omega-3 fatty acids increase nitric oxide production – a molecule that supports and enhances athletic performance. Endurance athletes who consumed supplemental omega-3s had higher blood levels of arginine, an amino acid involved in nitric oxide production.

    The study involved 26 men who underwent endurance training for 12 weeks. Half of the men took an omega-3 supplement (approximately 3 grams daily) for the duration of the training, while the other half did not. Researchers measured their Omega-3 Indices and blood amino acid levels before and after the intervention.

    They found that the men who took the supplemental omega-3s had higher Omega-3 Indices than those who did not. These higher indices corresponded with higher blood arginine levels – indirect indicators of increased nitric oxide synthesis and bioavailability.

    Nitric oxide is a molecule produced in the body’s blood vessels and from precursors acquired in the diet via nitrate-containing foods, such as beets and green leafy vegetables. It plays crucial roles in regulating vasodilation, heart rate, and mitochondrial respiration.

    Omega-3s are essential fatty acids that play important roles in cardiovascular health. An abundance of research shows that supplemental omega-3s enhance muscle function and recovery. Learn more about omega-3s in our comprehensive overview article and this episode featuring omega-3 expert Dr. Bill Harris.

    These findings suggest that omega-3 supplementation support nitric oxide production – potentially boosting athletic performance. This was a small study, however, and larger studies are needed to confirm these findings.

  • A new study shows that replacing sedentary time with physical activity improves sleep in women. Women who swapped just one hour of sedentary time or low-intensity activity with moderate- or vigorous-intensity activity slept better and felt more rested.

    Researchers investigated the effects of replacing sedentary time with physical activity. The study involved 683 men and women between the ages of 40 and 64 years. The participants wore accelerometers to gauge their activity levels for one week and reported their sleep quality.

    The researchers found that sleep measures improved when women replaced sedentary behavior or low-intensity physical activity with moderate- to vigorous-intensity physical activity. Interestingly, they found no associations between altering men’s activity levels and sleep quality, highlighting the sex-related differences in response to exercise.

    These findings indicate that engaging in moderate- to vigorous-intensity physical activity improves sleep quality in middle-aged women. They also align with other studies that show that exercise improves sleep. Sleep is essential for human health. Learn more about the benefits of sleep in this episode featuring Dr. Matthew Walker.

  • From the article:

    Current research has shown that (i) increased peripheral lactate levels (following high intensity exercise) are associated with increased peripheral BDNF levels, (ii) lactate infusion at rest can increase peripheral and central BDNF levels and (iii) lactate plays a very complex role in the brain’s metabolism. In this review, we summarize the role and relationship of lactate and BDNF in exercise induced neuroplasticity.

    […]

    Several trials have used blood lactate for the monitoring of exercise intensity. These studies indicate that higher lactate concentrations are associated with increased BDNF plasma and/or serum levels. Furthermore, current evidence indicates that high intensity interval training evokes larger BDNF levels compared to moderate and/or intensive continuous exercise […] Current research indicates that lactate transport from astrocytes to neurons plays a crucial role for memory formation and could be a link between exercise and neuroplasticity. Pharmacological inhibition of MCT 2 irreversibly impairs long-term memory. Van de Hall et al. have shown that lactate uptake in the brain increases from 8% at rest up to 20% during exercise.

  • A new study shows that resistance exercise helps the body’s cells identify and eliminate misfolded proteins – key players in the pathogenesis of many human diseases, including diabetes, atherosclerosis, and neurodegenerative diseases.

    The study involved 30 older adults who engaged in an eight-week resistance training program in which they exercised twice a week. Before and after the exercise intervention, researchers measured changes in the number of key proteins in the participants' blood involved in inflammation, aging, and cellular stress responses.

    They also measured levels of IRE1, a protein that detects stress in the endoplasmic reticulum – a part of the cell that ensures misfolded proteins don’t escape into the body’s circulation or accumulate in the cell. IRE1 must be activated to be effective.

    They found that none of the proteins involved in inflammation, aging, and cellular stress responses were changed after the intervention. However, the ratio of activated IRE1 to inactivated IRE1 was higher among those who engaged in resistance training, suggesting that resistance training supports the identification and elimination of misfolded proteins – yet another way in which resistance training benefits health.

    Resistance training involves pushing or pulling against the resistance of an object, such as weights, bands, or even one’s own body weight. These exercises exert powerful forces on the bones, slowing bone loss and promoting bone accretion. Learn more about resistance training in this episode featuring Dr. Brad Schoenfeld.

  • Six minutes of vigorous exercise increased brain levels of BDNF – a protein that may protect against Alzheimer’s disease and other neurodegenerative conditions – as much as five times more than light exercise, a new study has found.

    Researchers measured BDNF levels after fasting, light exercise, or vigorous exercise in healthy, physically active adults. Participants fasted for 20 hours, engaged in light cycling (90 minutes at 25 percent VO2 max), or engaged in vigorous cycling (six 40-second bursts at 100 percent VO2 max interspersed with 20 seconds of light cycling).

    They found that on average, 90 minutes of light cycling increased serum BDNF levels by approximately 6 percent. However, six 40-second vigorous-intensity cycling bursts increased both plasma and serum BDNF levels four to five times more than light cycling.

    BDNF, or brain-derived neurotrophic factor, is a growth factor that controls and promotes the growth of new neurons and is necessary for the formation and storage of memories and overall cognitive performance. BDNF exerts robust protective effects on crucial neuronal circuitry involved in Alzheimer’s disease. Evidence suggests that endothelial cells that line the blood vessels of the brain release BDNF in response to shear stress – the increase in force that occurs during increased blood flow (as in exercise).

    Interestingly, fasting for 20 hours had no effect on BDNF levels, but it did promote a ninefold increase in ketone delivery to the brain. Evidence suggests that ketones increase blood flow to the brain and improve memory and brain function in certain contexts. Learn more about the brain benefits of ketones in this clip featuring Dr. Dominic D'Agostino.

  • People who regularly engaged in vigorous-intensity exercise were less like to die from cancer, cardiovascular disease, or other causes, according to a new study. Engaging in vigorous-intensity exercise for as little as 54 minutes per week provides optimal mortality reduction – but the catch is that it must be sufficiently vigorous.

    Using wrist-worn accelerometers, nearly 72,000 middle-aged adults enrolled in the UK Biobank study tracked their activity. Researchers monitored the participants' health for approximately six years.

    They found that the participants' risk of dying during the study period varied based on their activity level. The risk of dying among those engaging in no vigorous-intensity activity per week was 4.17 percent; zero to less than 10 minutes, 2.12 percent; 10 to less than 30 minutes, 1.78 percent; 30 to less than 60 minutes, 1.47 percent; and for 60 minutes or more, 1.10 percent. They determined that the “optimal” dose of vigorous-intensity activity was approximately 54 minutes per week, and the “minimal” dose – sufficient to reduce the risk of dying from cancer, cardiovascular disease, or all other causes – was approximately 15 minutes.

    Vigorous-intensity exercise is defined as activity that achieves a heart rate that is 70 to 80 percent of one’s maximum. High-intensity interval training, often referred to as HIIT, is a popular form of vigorous exercise involving short bursts of intense aerobic exercise interspersed with periods of rest or lower-intensity exercise. During a typical HIIT session, exercisers typically achieve 80 to 100 percent of their VO2max (a measure of respiratory function) or maximum heart rate. Most HIIT workouts are brief, lasting just 15 to 30 minutes.

  • From the publication:

    The low-pH environment induced by the metabolic accumulations is known to stimulate growth hormone (GH) secretion, which is known to possibly have an interactive effect toward MPS [muscle protein synthesis]. There is continual debate over the direct hypertrophic actions of GH toward overall MPS. […] The implementation of BFR training in 1 study has been found to elevate GH levels to ∼290. Another study has found that skeletal muscle ischemia coupled with low-intensity resistance exercise through knee extensions acutely increased GH levels, whereas reducing the maximal voluntary contraction. It is known that the implementation of Kaatsu training [blood flow–restricted training] increased the postexercise GH levels 10-fold above the control group with no blood flow–restriction.

    […]

    According to the literature, it is also known that a single bout of low-intensity resistance exercise with blood flow restriction can result in both an upregulation of the anabolic cell signaling mTOR pathway within 3 hours after exercise and a downregulation of the proteolytic transcripts for skeletal muscle at 8 hours after exercise.

    […]

    In accordance with occlusion training, it is known that compared with slow-twitch (ST) muscle fibers, the fast-twitch (FT) fibers are recruited quickly, although the intensity is low. In other words, BFR training can recruit FT fibers without regards to the widely accepted size principle in which ST fibers are recruited first with FT fibers being recruited as intensity progresses. The rationale presented throughout the literature may be due to the hypoxia conditions created by the vascular occlusion through which the additional recruitment of more motor units may take place to compensate for the deficit in overall force development. In addition, the metabolite accumulations throughout the BFR training session may also induce the increased recruitment of FT or higher threshold motor units. Several studies show through the utilization of electromyography (EMG) that during Kaatsu training, there was an increase in the recruitment of FT muscle fibers. Another study that implemented low-intensity vascular occlusion training showed early fatigue of type I fibers due to the lack of delivery in oxygen, thus showing a greater increase in the CSA [ross-sectional area] of type II fibers by 27.6% compared with type I muscle fibers increase of 5.9% during a 2-week training program at 20% of 1RM.

  • From the publication:

    Evidence has demonstrated that 14 days of BFR [blood flow restriction] are more effective than isometric exercise to prevent muscle waste and weakness induced by immobilization and unloading. [repeated blood flow restriction without training vs isometric training vs no intervention]

    […]

    Several randomized controlled trials and meta‐analyses have shown that RT [resistance training] with BFR (RT‐BFR) [usually low intensity, between 20% and 40% of the 1‐RM load] produces similar muscle hypertrophy response to high intensity RT, in different populations.

    […]

    Moderate to high intensity ET [endurance training] promotes significant increases in cardiorespiratory capacity, with no or small improvements in muscle strength and hypertrophy. However, when ET [endurance training] is performed with BFR (ET‐BFR), there is a significant increase in aerobic power (i.e. maximum oxygen consumption VO2max), as well as increases in muscle strength and hypertrophy.

    […]

    BFR approach has been applied to >12 000 people in Japan across different physical conditions, such as cerebrovascular, orthopaedic, cardiac, respiratory, and neuromuscular diseases, as well as obesity, diabetes, and hypertension, with no significant side effects reported on rheological response. From 300 000 training sessions, only 0.055% of practitioners developed venous thrombus, 0.008% developed pulmonary embolism, and 0.008% of the cohort presented rhabdomyolysis.

  • Microbes in your gut may trigger your motivation to exercise, a new study in mice has found. Compounds produced by the microbes signal the release of dopamine – a neurotransmitter produced in the brain that promotes the “runner’s high” and the desire to exercise.

    Researchers analyzed the gut microbial species and the byproducts of their metabolism from nearly 200 mice with diverse genetic backgrounds. They also tracked the animals' daily exercise activity and measured their endurance.

    They found that mice that had certain species of gut microbes – Eubacterium rectale and Coprococcus eutactus – exercised more and had greater endurance than mice lacking these microbes. These two species produce compounds called fatty acid amides, which interact with gut neurons and ultimately activate dopamine-producing neurons in the brain, turning on the brain’s reward circuits and triggering the desire to exercise00394-0.pdf).

    This study in mice reveals a novel way in which the gut microbiome influences human health and behavior. It may also provide evidence to support the use of therapeutic microbial transfer to promote exercise behavior and improve aspects of mood.

  • Microbes in your gut may trigger your motivation to exercise, a new study in mice has found. Compounds produced by the microbes signal the release of dopamine – a neurotransmitter produced in the brain that promotes the “runner’s high” and the desire to exercise.

    Researchers analyzed the gut microbial species and the byproducts of their metabolism from nearly 200 mice with diverse genetic backgrounds. They also tracked the animals' daily exercise activity and measured their endurance.

    They found that mice that had certain species of gut microbes – Eubacterium rectale and Coprococcus eutactus – exercised more and had greater endurance than mice lacking these microbes. These two species produce compounds called fatty acid amides, which interact with gut neurons and ultimately activate dopamine-producing neurons in the brain, turning on the brain’s reward circuits and triggering the desire to exercise.

    This study in mice reveals a novel way in which the gut microbiome influences human health and behavior. It may also provide evidence to support the use of therapeutic microbial transfer to promote exercise behavior and improve aspects of mood.

  • From the article:

    Misra compared 109 female athletes with exercise-induced menstrual irregularities with 50 female athletes with normal menstrual cycles and 39 female non-athletes. All of the study subjects were 14-25 years old and were in a normal weight range. The young women’s eating behavior and mental health was evaluated with self-report assessments and questionnaires.

    Athletes with irregular periods reported a higher drive for thinness and more mental control over their food intake compared with athletes with regular periods and non-athletes. They also had higher mean body dissatisfaction scores than athletes with regular periods.

    Athletes who had irregular menstrual periods were randomly assigned to receive either estrogen replacement through a patch, at a dose that resulted in estrogen levels seen with normal menstrual cycles; a commonly used combined oral contraceptive pill containing estrogen; or no estrogen for 12 months. Athletes randomized to estrogen replacement as a patch also received cyclic progesterone.

    Over one year, the groups that received estrogen showed reductions in drive for thinness, body dissatisfaction and uncontrolled eating, compared with those who didn’t receive estrogen. The patch was the most effective, leading to significant decreases in body dissatisfaction and uncontrolled eating.

    View full publication

  • Resistance exercise reduces symptoms of sarcopenia – age-related muscle loss – in older women, a new study has found. Women who engaged in resistance training saw improvements in muscle size, strength, and function.

    Researchers studied the effects of resistance training in 38 women who were 70 years of age or older. About half of the women engaged in a supervised resistance training program for six months, while the other half did not. The researchers assessed the women’s body composition, strength, and capacity to perform basic fitness tests.

    They found that half of the women who engaged in the resistance training experienced remission of their sarcopenia, demonstrated by increases in muscular mass, decreases in fat mass, and enhanced muscular strength and performance in their arms and legs. The women who trained also performed better on tests of leg function and strength as well as balance.

    Sarcopenia is an age-related condition characterized by a progressive loss of muscle mass and associated strength. Because the condition begins as early as one’s 30s, a person in their 70s may have lost as much as half of their muscle mass.

    This study demonstrates that resistance training rebuilds muscle mass in older women. Having sufficient muscle mass markedly reduces a person’s risk of dying prematurely, and actively challenging those muscles, through regular physical activity and exercise, may extend a person’s life by several years. Learn more in this clip featuring Dr. Stuart Phillips.

  • Scientists have long known that being physically active reduces a woman’s risk of developing breast cancer. But a new study shows that breast cancer survivors who are physically active are as much as 60 percent less likely to die than those who are inactive.

    Researchers tracked 315 women who were breast cancer survivors. The women provided information about the type and duration of their daily physical activities, and the researchers categorized them as being active, moderately active, or inactive.

    They found that compared to breast cancer survivors who were inactive, those who were active were 58 percent less likely to die, and those who were moderately active were 60 percent less likely to die. The protective effects of exercise were seen even after taking into account different cancer treatments.

    Breast cancer is the most common form of cancer (after skin cancer) among women living in the United States. With nearly 290,000 cases diagnosed in 2022, experts expect breast cancer to claim the lives of nearly 44,000 women.

    This study adds to the robust library of scientific literature supporting the role of exercise and physical activity in promoting survivorship among people who have breast cancer. Other evidence suggests that time-restricted eating promotes survivorship, too. Learn more in this episode featuring Dr. Ruth Patterson.

  • Performing eccentric movements – the “lowering” aspect of lifting a weight – pays huge dividends in muscle size and strength, a new study has found. Study participants who lowered weights achieved similar benefits to those who lifted and lowered weights, even though they performed half as many repetitions.

    Researchers asked 53 young adults who did not regularly lift weights to perform one of three variations of a dumbbell curl twice a week for five weeks. The variations included concentric + eccentric (lifting and lowering) movements, concentric (lifting) movements only, or eccentric (lowering) movements only. One group of participants did not perform any exercises. The researchers measured the participants' upper arm muscle thicknesses before and after the intervention.

    They found that all the participants who performed the various exercises saw improvements in muscle size, strength, and force-generating capacity. In particular, muscle thickness increased by an average of 10.6 percent among those who performed concentric + eccentric movements, 9.7 percent among those who performed eccentric movements only, and 2.5 percent among those who did concentric movements only. Interestingly, the total training volume for those performing eccentric movements was roughly half that of the concentric + eccentric group.

    These findings suggest that performing eccentric movements during resistance training benefits muscle growth and strength – with less effort than concentric movements. [Learn more about eccentric and concentric exercises in this episode featuring Dr. Brad Schoenfeld.](LINK)

  • People who regularly engage in high-intensity aerobic exercise have nearly half as many upper respiratory infections as sedentary people, a 2010 study found. Those who engage in high-intensity aerobic exercise also experience fewer and less severe upper respiratory symptoms than those who engage in lower-intensity exercise.

    Researchers tracked the number and severity of respiratory infections during the fall and winter of a single year among more than 1,000 adults. The participants, who were between the ages of 18 and 85 years, provided information about the frequency and intensity of their aerobic physical exercise during the 12-week period.

    The researchers found that those who engaged in aerobic physical exercise five or more times per week reported 43 percent fewer upper respiratory infections than those who were sedentary. Those who engaged in high-intensity exercise reported 46 percent fewer infections than those who engaged in low-intensity exercise. Upper respiratory symptoms were 32 to 41 percent less severe among those who engaged in high-intensity exercise compared with those who engaged in low-intensity exercise.

    These findings suggest that regular aerobic exercise – especially high-intensity exercise – protects against upper respiratory infections. Other research suggests that during aerobic exercise, profound molecular changes occur that enhance the production of beneficial cytokines and other factors that support immune health. Learn more about the effects of exercise on immunity in this clip featuring Dr. Michael Snyder.

  • From the article:

    Gavin and her colleagues recruited 17 overweight-to-obese premenopausal women, all between the ages of 18 and 44 years old. […] Participants performed this [submaximal] exercise both by itself and while the [fat-mobilizing] drugs were being infused. To test the effects of estrogen, the researchers also performed each of these conditions while estrogen was also being slowly infused into participants' fat deposits.

    Results

    The researchers found that estrogen’s effects differed tremendously depending on the fat-mobilizing interventions themselves and where the fat deposit was located. For example, estrogen blunted fat breakdown in the abdomen if it was infused while a particular fat-mobilization drug called isoproterenol was also being infused, but it didn’t have this effect in the buttocks. When a second fat mobilizing drug was given along with the first while participants were at rest, fat breakdown didn’t change any further. However, when both drugs were injected together during exercise or when the volunteers exercised without the drugs, fat breakdown increased in the abdomen, but less so in the buttocks.

    Importance of the Findings

    These results suggest that estrogen has different effects within fat tissue depending on its location. Together, these effects could help maintain premenopausal women’s “pear” shape even in the face of exercise or other signals the body receives to break down fat. They could also help generate some new ideas on how estrogen in fat may influence why postmenopausal women tend to accumulate more fat in the abdomen.

    View full publication

  • High-load resistance training restores bone mineral density in people who have osteoporosis and osteopenia, a 2021 analysis of several studies found. Those who engaged in the training experienced improvements in their motor function and reported few adverse events.

    Researchers analyzed the findings of nine randomized controlled trials involving nearly 500 women and men with either osteoporosis or osteopenia. The various studies examined changes in the bone mineral density of the participants' lower extremities and spine after engaging in resistance training interventions versus not.

    The researchers found that resistance training increased the bone mineral density of the lumbar spine, femoral neck, and total hip. The greatest benefits were obtained in the lumbar spine, an area that is particularly vulnerable to the damaging effects of bone loss.

    High-load resistance training involves using heavier weights and performing fewer repetitions (typically 8 to 12 per set per exercise) than ordinary resistance training. Evidence suggests that high-load resistance training strengthens the lower extremities more effectively than training with lighter loads.

    The findings from this analysis suggest that performing high-load resistance training reverses the bone loss that accompanies osteoporosis and osteopenia. However, the researchers cautioned that the variability in the studies' designs and outcomes and the possibility of publication bias (the tendency to publish only favorable findings) make generalizing their findings difficult.

  • A high-fat, high-sugar diet accelerated normal vascular aging in mice, according to a 2021 study. However, regular, lifelong aerobic exercise maintained vascular health and ameliorated some of the harmful effects of a poor diet.

    Researchers studied the effects of diet and exercise on cardiovascular health in mice that exhibit many of the key features of age-related vascular dysfunction in humans. Starting at the age of three months and continuing until their natural deaths, half of the mice ate a normal diet, while the other half ate a diet that was high in fat and sugar and low in dietary fiber – much like the typical Western diet. Because mice voluntarily run in the wild and in captivity, half of each group of mice was allowed access to a running wheel for exercise, while the other mice were sedentary.

    The researchers found that as the mice aged, they exhibited signs of declining cardiovascular health. In particular, they exhibited impaired endothelium-dependent dilation, a condition that occurs in the early stages of vascular disease and is a precursor to atherosclerosis. This effect was exacerbated by the high-fat/high-sugar diet. However, the researchers found that exercise ameliorated some of the harmful vascular effects of the high-fat/high-sugar diet throughout the lifespan, likely due to lower levels of oxidative stress and inflammation.

    This study in mice demonstrates that aerobic exercise exerts profound protective effects on the cardiovascular system, even in the setting of a poor diet. Learn more about the benefits of aerobic exercise in our overview article.

  • Aerobic exercise improves symptoms of Parkinson’s disease, a comprehensive analysis of several studies has found. The beneficial effects of exercise lasted up to six months post-intervention.

    Researchers analyzed the findings of 20 studies involving 450 people with Parkinson’s disease. The studies, which lasted between three weeks and six months, employed a variety of aerobic exercise interventions, such as treadmill training, walking, cycling, dancing, and others.

    They found that participants who engaged in regular aerobic exercise performed better on tests of mobility, balance, stride/step length, gait velocity, and motor function than those who did not. One of the studies found that the effects on motor function endured up to six months after the intervention ended. Two of the studies showed that exercise also improved the participants' quality of life.

    Parkinson’s disease is a neurodegenerative disorder that is caused by the destruction of nerve cells in the part of the brain called the substantia nigra. It typically manifests later in life and is characterized by tremors, poor balance, and a shuffling gait.

    These findings support the use of exercise as a means to improve many of the symptoms of Parkinson’s disease. Learn more about the importance of exercise in managing Parkinson’s disease in this episode featuring Dr. Giselle Petzinger.

  • Intense aerobic exercise reduces the risk of metastatic cancer by as much as 73 percent, a recent study has found. It does this by reducing the glucose consumption of the body’s internal organs, effectively diverting energy away from the tumor.

    Researchers quantified the proteins present in the internal organs of mice and the plasma of humans and found that exercise alters multiple aspects of metabolism, including glucose uptake, mitochondrial activity, and carbohydrate utilization.

    Then they analyzed data from a long-term study of more than 2,700 adults living in Israel. They found that high-intensity exercise reduced the risk of developing highly metastatic cancer by 73 percent. They observed similar findings in an animal model of melanoma: animals that exercised before they developed cancer were less likely to experience cancer metastasis.

    Evidence suggests that exercise exerts antitumor effects by increasing the body’s insulin sensitivity, reducing sex-steroid hormone levels, and dampening the immune response (and the accompanying inflammation). It also promotes the release of signaling molecules in skeletal muscle, called myokines, which inhibit tumor growth.

    This study demonstrates that exercise markedly reduces cancer risk in humans. Following a time-restricted eating pattern may reduce cancer risk, too. Learn more in this episode featuring Dr. Ruth Patterson.

  • From the publication:

    Patient interest in fertility and testicular size preservation and a desire to avoid lifelong medical therapy with testosterone drives the need to identify non-TTh [non-testosterone therapy] for hypogonadism. Medical therapies that can stimulate endogenous testosterone production include hCG [human chorionic gonadotropin], AIs [aromatase inhibitors], and SERMs [selective estrogen receptor modulators], all of which demonstrate efficacy in increasing serum testosterone levels and good safety profiles. Natural therapies to increase testosterone production include diet and exercise, weight loss, improved sleep, decreasing stress, and varicocele repair. Diet, exercise, and weight loss provide a means to potentially reverse comorbidities that are closely linked to hypogonadism. Improvements in sleep quality and duration and decreasing stress are additional lifestyle modifications that can improve testosterone levels without the need for lifelong medication. Varicocele repair also can increase testosterone levels, although rigorous data supporting its use remain lacking. Patients considering TTh should be counseled on disease modification and the possibility of discontinuing TTh in the future, before initiation of therapy, and the alternatives discussed in this review also should be considered first in appropriate candidates.

    […]

    Diet, exercise, and weight loss

    – 12-wk lifestyle modification program involving aerobic exercise and diet modification significantly increased mean testosterone levels

    – 52-wk program of diet and exercise significantly increased mean serum testosterone levels

    – Individuals who lost 10% of weight between visits showed a significant increase in testosterone levels

    – Weight loss through low-calorie diets or bariatric surgery was associated with significant increases in total testosterone levels

    Improvements in sleep

    – Men with OSA treated with UPPP had significant 3-mo postoperative increases in testosterone levels

    – Restriction of sleep to 5 h/night decreased testosterone levels by 10-15%

    Stress reduction

    – Men with high stress levels had significantly lower serum testosterone levels compared with controls

    – Men with higher work stress had higher than expected incidence of hypogonadism

    Varicocele repair

    – Varicocelectomy significantly increased mean testosterone levels

    – Varicocele repair significantly increased testosterone levels

    – Significantly increased total testosterone levels were found at 12-mo follow-up after varicocelectomy

    – Mean serum total testosterone significantly increased after varicocelectomy

  • From the article:

    But new research shows that Tsimane (“chi-MAH-nay”) men have a third less baseline testosterone compared with men living in the United States, where life is less physically demanding. And unlike men in the U.S., the Bolivian foragers-farmers do not show declines in testosterone with age.

    Maintaining high levels of testosterone compromises the immune system, so it makes sense to keep it low in environments where parasites and pathogens are rampant, as they are where the Tsimane live,” said Ben Trumble, an anthropology graduate student at the University of Washington.

    That men living in the U.S. have greater circulating levels of testosterone represents an “evolutionarily novel spike,” Trumble said. The spike reflects how low levels of pathogens and parasites in the U.S. and other industrialized countries allow men to maintain higher testosterone without risking infection.

    […]

    Despite lower circulating levels of testosterone under normal conditions, the forager-farmers do have something in common with U.S. men: short-term spikes of testosterone during competition.

    Trumble and his co-authors organized a soccer tournament for eight Tsimane teams. The researchers found that Tsimane men had a 30 percent increase in testosterone immediately after a soccer game. An hour after the game, testosterone was still 15 percent higher than under normal conditions. Similar percent increases have been shown in men living in the U.S. or other industrialized nations following sports competitions.

    […]

    “What’s interesting is that in spite of being in a more pathogenic environment, it’s still important to raise testosterone for short-term bursts of energy and competition,” said Michael Gurven, co-author and anthropology professor at the University of California Santa Barbara.

    View full publication

  • From the article:

    To investigate whether testosterone supplementation improves measures of aerobic function ― the peak oxygen uptake and the gas exchange lactate threshold ― Dr. Storer and his colleagues analayzed data from subjects in a larger randomized controlled study of men over age 65 who had low testosterone levels and difficulty performing the usual physical activities of daily living. For 6 months, 28 men in one group received 10 milligrams of testosterone gel and 36 men in a second group received a placebo gel. All subjects completed a cycle exercise test to measure their peak aerobic fitness before and after the 6 month study.

    The men taking testosterone displayed a slight improvement in aerobic fitness while those taking placebo showed a slight decline. This small increase in aerobic capacity in the testosterone group eliminated the expected decrease that men generally experience with natural aging.

    Among the men taking testosterone, the age-related decline in the peak oxygen uptake was 3.4 times less than expected, while the rate of decline among the men taking placebo accelerated to nearly twice the expected rate. The decrease in gas exchange lactate threshold was significantly smaller in the testosterone group than in the placebo group. Longer term studies are needed to evaluate safety and durability of effect.

    View full publication

  • From the publication:

    The effects of creatine and creatine plus β-alanine on strength, power, body composition, and endocrine changes were examined during a 10-wk resistance training program in collegiate football players. Thirty-three male subjects were randomly assigned to either a placebo (P), creatine ( C), or creatine plus β-alanine (CA) group. During each testing session subjects were assessed for strength (maximum bench press and squat), power (Wingate anaerobic power test, 20-jump test), and body composition. Resting blood samples were analyzed for total testosterone, cortisol, growth hormone, IGF-1, and sex hormone binding globulin. Changes in lean body mass and percent body fat were greater (P < 0.05) in CA compared to C or P. Significantly greater strength improvements were seen in CA and C compared to P. Resting testosterone concentrations were elevated in C [creatine group], however, no other significant endocrine changes were noted. Results of this study demonstrate the efficacy of creatine and creatine plus β-alanine on strength performance. Creatine plus β-alanine supplementation appeared to have the greatest effect on lean tissue accruement and body fat composition.

  • From the publication:

    Twenty amateur male swimmers ingested creatine monohydrate (CR) or a matched placebo (PL) for 6 days. All subjects performed 6 days, swimming exercise. The subjects were tested for performance and hormonal responses the day before and after this creatine loading.

    Results. — The mean swimming time of CR group in 50 m was significantly decreased (Beforeperiod: 53.1 ± 3.73 s, after-period: 50.7 ± 2.84 s). Growth hormone and cortisol were not affected by this creatine loading. But, testosterone concentration was significantly greater in CR compared to PL after supplementation period (P < 0.05).

    Conclusions. — Our data suggest that short-term creatine supplementation has improved 50 m sprint performance in amateur swimmer and it seems unlikely creatine loading is hormonally mediated.

  • Aerobic exercise reduces symptoms of anxiety. bmchealthservres.biomedcentral.com

    Aerobic exercise – especially high-intensity exercise – reduces symptoms of anxiety, an analysis of 15 studies shows. These anti-anxiety effects endured for several months after cessation of the exercise.

    Reviewers analyzed data from 15 studies that investigated the effects of low- or high-intensity exercise on anxiety symptoms. All the participants in the studies had some degree of anxiety, with their conditions falling on a spectrum that included anxiety disorders, raised anxiety levels, and raised anxiety sensitivity – a condition in which a person feels anxious about the physical symptoms that often accompany anxiety. People on waiting lists for anxiety treatment who did not exercise served as comparisons.

    They found that participants who engaged in both low- and high-intensity aerobic exercise experienced greater improvements in their anxiety than non-exercising people on treatment waiting lists. High-intensity exercise reduced anxiety symptoms more effectively than low-intensity exercise. The various interventions lasted between 10 weeks and six months, with participants exercising three times a week, on average.

    Multiple mechanisms may be responsible for the anti-anxiety effects of exercise. For example, high-intensity exercise promotes the production of lactate, a byproduct of glucose metabolism that participates in the production of neurotransmitters, such as norepinephrine and serotonin. Low norepinephrine and serotonin levels can drive anxiety and the inability to handle stressful situations. Learn more about lactate and its effects on the brain in this episode featuring Dr. George Brooks.

  • Colon cancer survivors who engaged in moderate-intensity exercise for six months had fewer circulating tumor cells than non-exercising survivors, according to a 2018 study. The researchers attributed these anticancer effects to mechanical stressors that cancer cells experience in the bloodstream during exercise that drive cells to self-destruct.

    Researchers assigned 23 stage I-III colon cancer survivors to engage in either 150 or 300 minutes of moderate-intensity exercise (brisk walking) per week for six months or to continue their normal activities. The researchers measured the participants' circulating tumor cells before and after the intervention.

    They found that after six months, both groups of exercisers experienced reductions in their circulating tumor cells, but non-exercisers did not. Exercisers also lost weight and had lower insulin levels.

    Circulating tumor cells are cancer cells that separate from the primary cancer site and appear in the bloodstream, where they can migrate to and establish themselves in other parts of the body – a process known as metastasis. Exercise increases blood flow and exerts tremendous mechanical forces on circulating tumor cells, sensitizing them to apoptosis, a cellular self-destruct mechanism.

    The findings from this small study suggest that exercise reduces the number of circulating tumor cells in cancer survivors. A larger study showed that stage III colon cancer survivors who exercised were 40 percent less likely to experience a recurrence and 63 percent less likely to die from their cancer compared to non-exercisers. Interestingly, time-restricted eating may help reduce the risk of cancer recurrence, too. Learn more in this episode featuring Dr. Ruth Patterson.

  • HIIT suppresses colon cancer cell growth.

    Just a single session of HIIT – high-intensity interval training – reduced the number of colon cancer cells in vitro, a 2019 study found. Researchers attributed the cancer-suppressing effect of HIIT to a transient increase in inflammatory cytokines that occurred shortly after the exercise.

    The study involved 20 male colon cancer survivors. Half of the men performed a single, 38-minute bout of HIIT (at 85 to 95 percent of their maximum heart rate), while the other half performed 12 HIIT sessions over a period of four weeks. Researchers treated cultured colon cancer cells with serum taken from the participants at various time points before and up to seven days after their respective HIIT protocols.

    They found that serum collected immediately after engaging in HIIT reduced colon cancer cell numbers in the cultured cells. HIIT also produced increases in pro-inflammatory cytokines interleukin (IL)-6, IL-8, and tumor necrosis factor. Interestingly, the inhibition of cancer growth was transient, lasting less than two hours post-exercise when inflammatory cytokine levels were high. The serum collected at other time points had no effect on the cancer cells' growth.

    The pro-inflammatory response that normally results from exercise peaks roughly an hour post-exercise. It then begins to subside and is followed by a powerful anti-inflammatory response – an essential process for maintaining an appropriate balance of pro- and anti-inflammatory mediators.

    These findings suggest that transient exercise-induced inflammation slows colon cancer growth, potentially influencing cancer survival. Sauna use mimics many of the physiological effects of exercise and may be suitable for cancer survivors with health or mobility issues that make exercising difficult. Learn more about sauna use in our overview article.

  • From the article:

    The researchers previously showed that two weeks of moderate daily exercise substantially improves regeneration of cut nerves and leads to functional recovery in mice, though different types of exercise are required to produce the effect in males and females. They now report that these beneficial effects of exercise require androgens such as testosterone in both males and females.

    In the study they conducted, they exercised three groups of male and female mice. Nerves of the three groups were cut and surgically repaired. Once group received the drug flutamide, which blocks the androgen receptor. A second group received a placebo treatment. The third group was unexercised. Regenerating nerve fibers in the placebo group grew to more than twice the length of those in unexercised mice in both males and females. In flutamide-treated mice, the effects of exercise were blocked completely in both sexes.

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  • Lactate is a compound that is produced primarily in the muscles via the breakdown of glucose during exercise. It can be “shuttled” from the muscles to various tissues, including the heart, and brain, where it can be used as an energy source. Evidence from a recent study suggests that lactate rejuvenates immune cells that target cancer.

    Specialized immune cells called CD8+ T cells are the primary drivers of anti-tumor immunity. During cancer progression, CD8+ T cells can experience “exhaustion,” a dysfunctional state caused by immune-related tolerance and immunosuppression in the environment surrounding the tumor.

    Researchers injected either lactate or glucose into mice that had cancer. The lactate markedly reduced cancer growth, but the glucose had little effect. They determined that the anti-tumor response was mediated by the CD8+ T cells. Depleting the CD8+ T cells negated lactate’s effect, confirming that lactate promotes anti-tumor immunity through CD8+ T cells.

    They also measured metabolites produced by CD8+ T cells (in culture) that had been treated with lactate. They found that the cells' uptake and subsequent metabolism of lactate increased. In addition, lactate inhibited the activity of histone deacetylases, and in turn, promoted the cells' stemness – the strictly controlled molecular processes that drive stem cell self-renewal and replication.

    These findings suggest that lactate rejuvenates the immune cell populations that target cancer, providing a possible mechanism by which exercise – which increases lactate production – reduces the risk of cancer. Learn more about lactate and the lactate shuttle in this episode featuring Dr. George Brooks.

  • From the article:

    The authors found that in addition to being linked to numerous physical health issues, including cancer and diabetes, systemic inflammation is linked to mental health issues such as depression. Among patients suffering from clinical depression, concentrations of two inflammatory markers, CRP and IL-6, were elevated by up to 50 percent.

    Fagundes said chronic inflammation is most common in individuals who have experienced stress in their lives, including lower socio-economic status or those who experienced abuse or neglect as children. Other contributing factors are a high-fat diet and high body mass index.

    […]

    The study also found that depression caused by chronic inflammation is resistant to traditional therapy methods, but can be treated with activities such as yoga, meditation NSAIDS and exercise.

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  • To optimize children’s physical, social, and emotional well-being, the American Academy of Pediatrics (AAP) recommends that children eat plenty of fruits and vegetables, limit screen time, and regularly engage in physical activity. Findings from a recent study suggest that meeting the guidelines for physical activity and screen time is related to greater executive function in toddlers.

    Executive functions are defined as neurocognitive processes that influence working memory, flexible thinking, and self-control. People with lower executive functioning are more likely to exhibit low academic performance, poor physical health, financial difficulties, and substance dependence than those with higher executive function.

    The study involved 356 toddlers (24 months old) enrolled in the STRONG Kids2 study, an ongoing investigation into how individual biology interacts with the family environment to promote healthy eating habits in young children. The children’s parents completed questionnaires about their child’s diet, physical activity, and daily screen time.

    The investigators found that toddlers that met the AAP guidelines had greater executive function and self-control. They also showed greater evidence of emergent metacognition – the emerging awareness and understanding of their own thought processes, an essential component of the learning process. Toddlers who were physically active every day showed the highest levels of emergent metacognition. Taken together, these findings suggest that less screen time and more physical activity help children develop executive functioning skills.

  • Adolescents who engage in aerobic physical activity tend to have better cardiometabolic health and perform better in school. Unfortunately, most adolescents fall short of recommended physical activity guidelines. Findings from a recent study suggest that aerobic physical activity improves working memory and promotes the production of BDNF in adolescent girls.

    BDNF, or brain-derived neurotrophic factor, is a growth factor that controls and promotes the growth of new neurons. It is active in areas of the brain involved in learning, long-term memory, and executive function. Robust evidence indicates that aerobic exercise increases BDNF concentrations.

    The study involved 16 healthy adolescent girls (average age, 11 years). Half of the girls engaged in three sprint-training sessions for two weeks, while the other half continued their regular physical activities. The investigators measured the girls' metabolic biomarkers, BDNF concentrations, and working memory before and after the intervention.

    They found that compared to the girls who continued their regular activities, the girls who engaged in the two weeks of sprint training performed 2.2 percent better on memory tests, and their BDNF concentrations nearly doubled. Neither group exhibited differences in their metabolic biomarkers. The girls who participated in the sprint training reported enjoying the activities.

    These findings suggest that aerobic exercise programs not only improve cognitive function and increase BDNF concentrations in adolescent girls, but they are also enjoyable. Learn more about the beneficial effects of aerobic exercise in our overview article.

  • Youth sports activities challenge participants and provide opportunities to develop problem-solving skills, discipline, teamwork, and goal setting. Findings from a recent suggest that participating in youth sports promotes the development of grit.

    Grit is typically described as a positive character trait characterized by passion and determination to achieve one’s long-term goals. Evidence suggests that people with more grit are more likely to complete high school, perform better in high-stress military training, and maintain steady employment as adults

    The investigators collected retrospective accounts of sports participation experiences during childhood from more than 3,800 adults. The participants completed a questionnaire to help identify whether they exhibited gritty personality traits. They also answered questions about whether they thought their youth sports experiences influenced their adult work ethic.

    The investigators found that participating in youth sports was associated with having gritty characteristics. Most of the participants thought that their youth sports experiences had a positive effect on their adult work ethic, especially males, Blacks, those with higher socioeconomic status, and those raised in a continuously two-parent intact household. Participants who were involved in youth sports but dropped out tended to exhibit less grit. These findings suggest that youth sports participation promotes the development of grit and positively influences adult work ethic.

  • Aerobic exercise pre-conditions muscles for optimal returns from resistance exercise.

    Skeletal muscle contains a designated population of adult stem cells called satellite cells. These cells are typically inactive, but if the muscle is injured or stressed (as in exercise), they can be recruited to participate in the regeneration of muscle fibers. As such, satellite cells play important roles in muscle maintenance, repair, and hypertrophy, the increase in muscle size that accompanies exercise. Findings from a new study suggest that engaging in aerobic exercise prior to resistance training increases satellite cell numbers and promotes muscle hypertrophy via increased muscle capillarization.

    Muscle capillarization refers to the formation of capillaries in muscle tissue. Capillarization facilitates the delivery of oxygen, nutrients, and various signaling and growth factors to muscle tissues and plays critical roles in muscle maintenance and growth. Previous research indicates that muscle capillarization decreases with age.

    The study involved 14 healthy, recreationally active young adults (average age, 22 years). Using a specially adapted exercise bike that challenged only one leg, participants engaged in 45 minutes of progressively difficult aerobic exercise conditioning three times a week for six weeks. Previous research has demonstrated that six to eight weeks of conditioning is sufficient to promote muscle capillarization.

    Two weeks after completing the conditioning program, the participants began a 10-week resistance training program using both legs and primarily targeting the muscles of the thighs. Immediately after each resistance training session, participants received a whey protein supplement that contained leucine, a branched-chain amino acid that promotes muscle protein synthesis, which is essential for muscle gains. The investigators collected muscle tissue samples from the participants' legs before and after the interventions to assess muscle capillarization, fiber size, and satellite cell content and activity.

    They found that aerobic conditioning promoted muscle capillarization in the conditioned leg, amplifying muscle hypertrophy in response to resistance training. They noted that the number of satellite cells increased in the conditioned leg relative to the non-conditioned one. In addition, they observed a significant relationship between the degree of capillarization and hypertrophy.

    These findings suggest that engaging in aerobic exercise prior to resistance training promotes muscle capillarization, which in turn increases satellite cell numbers and promotes muscle protein synthesis and hypertrophy. Learn about other factors that promote muscle hypertrophy in this episode featuring Dr. Stuart Phillips.

  • Older adults who engage in leisure time physical activities have lower risk of premature death.

    Leisure time physical activity is a broad term that refers to physical activities performed outside work or typical household responsibilities. Examples include exercise, sports, dancing, gardening, and walking. Findings from a recent study suggest that certain leisure time physical activities are associated with a lower risk of death from all causes of premature death, including cardiovascular disease and cancer, in older adults.

    Most public health organizations recommend that adults of all ages should engage in at least 150 minutes of moderate-intensity aerobic physical exercise or at least 75 minutes of vigorous-intensity aerobic physical exercise each week, or an equivalent combination of both. The bulk of the research focused on the benefits of physical activity has been in younger people, the findings of which might not be translatable to older adults.

    The investigators drew on data from 272,500 older adults (average age, 70 years) enrolled in the National Institutes of Health-AARP Diet and Health Study, an ongoing study of associations between diet and cancer. Participants provided information about their demographics, height, weight, smoking status, mood, educational level, and alcohol consumption. They also answered questions about the average amount of time they spent per week during the previous year engaging in cycling, swimming laps, playing racquet sports, playing golf, walking for exercise, jogging or running, and other aerobic exercises. The investigators calculated the participants' average leisure time activity levels in terms of metabolic equivalents, or METs, a measure of the rate of energy expended per unit of time.

    They found that playing racquet sports was associated with a 16 percent reduction in the risk of death from any cause and running was associated with a 15 percent reduction. The other activities conferred protection as well, but to a lesser extent. Achieving the recommended amount of physical activity through any combination of the seven leisure time activities reduced the risk of death by 13 percent. The protective effects of leisure time physical activity were dose-dependent to a degree, with greater duration conferring greater reduction in risk, but levels beyond those recommended showed diminishing returns.

    These findings suggest that older adults who meet physical activity guidelines through leisure time physical activities, especially aerobic activities such as racquet sports or running, have a reduced risk of premature death from all causes. Learn about the benefits of aerobic exercise in our overview article.

  • Exercise boosts mitochondrial function and promotes weight loss among people who struggle to lose weight with dieting alone.

    Most weight loss programs focus on reducing caloric intake. Although this strategy works for many people, a subset of people with obesity are diet-resistant – failing to lose weight even when adhering to a low-calorie diet. Findings from a new study suggest that exercise promotes weight loss in diet-resistant women by boosting mitochondrial function.

    Mitochondria are tiny cellular organelles that produce energy in the presence of oxygen. They are often referred to as the “powerhouses of the cell” because of their role in the production of ATP. Mitochondrial dysfunction, the disruption of normal mitochondrial function that occurs over time, is a driver of many chronic diseases, such as cancer, type 2 diabetes, and cardiovascular disease, and is a hallmark of aging.

    The investigators enrolled 20 women with obesity for the study. Half of the women had exhibited diet resistance when following a 900-calorie-per-day diet, while the other half had exhibited diet sensitivity. Both groups participated in a supervised, six-week exercise program that included both aerobic and resistance exercises, performed three times per week. The investigators assessed the women’s body composition and metabolic markers and collected muscle tissue samples for biopsy.

    They found that at the end of the six-week exercise program, the women who were diet resistant exhibited improved body composition and muscle metabolism and increased numbers of muscle mitochondria. The exercise program elicited only minimal effects in women who were diet sensitive. Interestingly, the diet-sensitive women exhibited risk factors associated with metabolic syndrome, suggesting that diet-sensitive obesity confers a greater risk for cardiometabolic disease.

    These findings demonstrate that exercise promotes weight loss and metabolic health in women with obesity and diet resistance and may confer greater health benefits than rapid diet-induced weight loss. Learn more about the benefits of exercise in our overview article.

  • Exercising 30 minutes a day reduces the risk of a ruptured brain aneurysm.

    Exercise and other forms of physical activity exert profound cardioprotective effects. In fact, people who regularly engage in moderate leisure time physical activity are less likely to develop cardiovascular disease than people who are inactive. Findings from a 2019 study suggest that just 30 minutes of moderate exercise daily reduces the risk of experiencing a ruptured brain aneurysm.

    The bleeding associated with a ruptured brain aneurysm impedes the delivery of oxygen to brain tissue, potentially causing a stroke and impairing cognitive and motor function. Experts estimate that as many as 12 percent of people who experience a ruptured brain aneurysm will die immediately; as many as 45 percent will die within 30 days of the event.

    The study involved more than 65,000 adults enrolled in the FINRISK, an ongoing study of risk factors for chronic diseases among people living in Finland. The investigators collected information about the participants' physical activity, including activities performed during leisure time, commuting, and working. They also reviewed medical records and autopsy registries to identify those who had experienced a ruptured brain aneurysm.

    They found that 543 of the participants experienced a ruptured brain aneurysm during a 42-year period. However, those who engaged in regular physical activity were protected: For every 30-minute increase in weekly leisure-time physical activity, the risk of experiencing a ruptured brain aneurysm decreased by 5 percent. The protective effects of leisure-time activity were observed across all age groups and were particularly strong for smokers. Participants who had an active commute were protected as well, but this protection lessened upon retirement, when they stopped commuting. Interestingly, those who had moderate or high work-related physical activity were 34 to 41 percent more likely to experience a ruptured brain aneurysm.

    These findings suggest that just 30 minutes of moderate leisure-time exercise and physical activity daily exert robust cardioprotective effects, reducing the risk of ruptured brain aneurysm. Learn more about the benefits of exercise in our overview article.

  • Exceeding current exercise recommendations protects against premature death.

    Most public health organizations recommend that adults of all ages engage in 150 to 300 minutes of moderate-intensity aerobic physical exercise or 75 to 150 minutes of vigorous-intensity aerobic physical exercise each week, or an equivalent combination of both. Most adults fall far short of these recommendations, however. Evidence from a recent study suggests that people who exceed current exercise recommendations are less likely to die prematurely than those who exercise less.

    Exercise stresses the human body, eliciting a wide array of protective mechanisms that work together to condition the body for future stressors, a biological phenomenon known as hormesis. Hormesis is a compensatory defense response to a stressor that is disproportionate to the stressor’s magnitude.

    The study involved more than 116,000 adults enrolled in the Nurses' Health Study and the Health Professionals Follow-up Study, two ongoing studies focused on identifying risk factors that drive chronic disease. Twice a year for a period of 30 years, participants provided information about their lifestyles and physical activity, including the intensity and duration. The investigators tracked death rates and causes of death among the participants.

    They found that approximately 47,000 of the participants died during the 30 years of follow-up. Compared to participants who didn’t exercise at all, those who met the moderate-intensity exercise guideline during their lives were 19 to 25 percent less likely to die prematurely. Those who met the vigorous-intensity guideline were 19 to 31 percent less likely to die prematurely.

    However, exercising even more conferred greater protection against premature death. Participants who engaged in 300 to 599 minutes of moderate-intensity exercise each week (double the guideline) were 3 to 13 percent less likely to die prematurely, and those who engaged in 150 to 299 minutes of vigorous-intensity exercise each week (double the guideline) were 2 to 4 percent less likely to die prematurely.

    These findings suggest that meeting or exceeding current exercise guidelines markedly reduces the risk of dying prematurely and underscores the importance of regularly engaging in physical activity. Learn about the many health benefits of aerobic exercise in our overview article.

  • From the article:

    Calculating population attributable risk – the fraction of subarachnoid hemorrhages that can be attributed to a particular trigger factor – the researchers identified the eight factors and their contribution to the risk as:

    -Coffee consumption (10.6 percent)

    -Vigorous physical exercise (7.9 percent)

    -Nose blowing (5.4 percent)

    -Sexual intercourse (4.3 percent)

    -Straining to defecate (3.6 percent)

    -Cola consumption (3.5 percent)

    -Being startled (2.7 percent)

    -Being angry (1.3 percent)

    “All of the triggers induce a sudden and short increase in blood pressure, which seems a possible common cause for aneurysmal rupture,” said Monique H.M. Vlak, M.D., lead author of the study and a neurologist at the University Medical Center in Utrecht, the Netherlands.

    Risk was higher shortly after drinking alcohol, but decreased quickly, researchers said.

    […]

    Although physical activity had triggering potential, researchers don’t advise refraining from it because it’s also an important factor in lowering risk of other cardiovascular diseases.

    “Reducing caffeine consumption or treating constipated patients with unruptured IAs with laxatives may lower the risk of subarachnoid hemorrhage,” Vlak said. “Whether prescribing antihypertensive drugs to patients with unruptured IAs is beneficial in terms of preventing aneurysmal rupture still needs to be further investigated.”

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  • Physical activity is perhaps the most important lifestyle factor in the promotion of heart health because of the beneficial stress it puts on the heart. Sauna bathing puts similar stress on the heart by increasing cardiac output in an effort to cool the body, making it a good choice for people unable to meet exercise guidelines; however, people who combine activities may experience unique benefits. Findings from a report released this month demonstrate the robust beneficial effects of combined physical activity and sauna bathing on cardiovascular fitness and metabolic health.

    Both sauna use and exercise increase pulse and blood pressure, activating a negative feedback loop that lowers blood pressure after the activity is over and for an extended period afterward. Adaptations to the metabolic and mechanical stress of exercise include an increase in heart size and mitochondrial density associated with better cardiovascular output, increased elasticity of blood vessels, and a reduction in white blood cells and inflammation. Previous research shows that sauna bathing provides some of the same benefits; however, because sauna use has just recently moved into the mainstream of clinical research, less is known about its mechanisms of action and effects when combined with exercise.

    The authors recruited 47 participants (average age, 49 years) who did not exercise regularly and were at high risk of cardiovascular disease and randomly assigned them to complete eight weeks of exercise training with or without sauna or no exercise training at all. Participants in the exercise groups completed three days of exercise per week that included a 10-minute warm-up, 20 minutes of weight training, and 30 minutes of aerobic exercise. Participants in the sauna group followed their exercise training with 15 minutes of sauna bathing at 150 degrees Fahrenheit. The temperature of the sauna was increased by 40 degrees Fahrenheit every two weeks as participants acclimated to the heat stress. The participants completed a cardiorespiratory fitness test at the beginning and end of the study during which they peddled an exercise bike at increasing resistance levels to increase heart rate. They also provided blood samples and had their body composition measured.

    Eight weeks of exercise training increased maximal heart rate (measured by VO2max or maximal oxygen intake) and reduced fat mass; however, participants did not experience a significant reduction in blood pressure, arterial stiffness, or total cholesterol compared to the participants who did not exercise. Participants who completed sauna bathing in addition to exercise experienced an even greater increase in maximum heart rate and lower systolic blood pressure (reduction of 8 mmHg in systolic blood pressure and 3 mmHg in diastolic blood pressure) and total cholesterol (12 milligrams per deciliter reduction). Participants in the exercise without sauna group experienced no reduction in systolic blood pressure and only a minor reduction in diastolic blood pressure (0.6 mmHG).

    The findings of this study demonstrate the unique benefits of sauna use in addition to exercise. Future studies with a greater number of participants and more diverse sauna bathing conditions would be valuable additions to this research.

  • Type 2 diabetes is characterized by insulin resistance and chronically elevated blood sugar levels. Weight loss is often part of the primary treatment of type 2 diabetes; however, some weight loss diets may have more insulin-sensitizing effects than others. Findings of one report show that a high protein weight loss diet can reverse prediabetes by increasing insulin-sensitizing hormones.

    Digestion of carbohydrates begins when sweetness receptors in the mouth are activated, leading to the release of insulin and hormones that augment insulin metabolism, such as incretins. In type 2 diabetes, incretins such as glucagon-like peptide (GLP)-1 and glucose-dependent insulinotropic peptide (GIP) are reduced, contributing to insulin resistance and increasing abdominal obesity. Pharmaceutical treatments for type 2 diabetes include GLP-1 activators, which can be effective at reducing blood sugar levels and increasing feelings of satiety after eating. High protein diets (30 percent of calories) have also been shown to enhance incretin signaling, making them an important strategy for treating prediabetes.

    The authors recruited 24 participants who had obesity and prediabetes and randomly assigned them to either a high-carb diet (55 percent carbohydrate, 30 percent fat, 15 percent protein) or a high-protein diet (30 percent protein, 30 percent fat, 40 percent carbohydrate) for six months. The diets were designed to produce a 500 calorie per day deficit so that participants would lose weight. Participants completed an oral glucose tolerance test, during which they consumed 75 grams of glucose (equivalent to the amount of sugar in two 12 ounce cans of soda). The researchers measured blood glucose, insulin, GLP-1, and GIP levels during the test.

    After six months, 100 percent of participants consuming the high-protein diet had remission of their prediabetes, while only 30 percent of participants consuming the high-carb diet experienced remission. Participants in both groups experienced weight loss (about 10 percent of their body weight) and improved insulin sensitivity; however, the participants consuming the high-protein diet had higher levels of GLP-1 and GIP and larger reductions in insulin resistance. Importantly, participants consuming the high-protein diet had increased lean muscle mass, while participants in the high-carb protein lost muscle mass.

    These results demonstrate that high protein diets may be an effective strategy for improving insulin sensitivity and reducing type 2 diabetes risk. Learn more about high-protein diets and how to implement them in our new interview with Dr. Stuart Phillips.

  • Urolithin A, a compound derived from walnuts and pomegranates, restores aging muscles.

    Mitochondria are the key organelles responsible for cellular energy production. Mitochondrial dysfunction, a hallmark of aging, occurs over time as reactive oxygen species damage vulnerable mitochondrial membranes and energy production becomes less efficient. A consequence of mitochondrial dysfunction is the loss of muscle mass and strength. Findings from a recent study suggest that urolithin A, a compound derived from walnuts and pomegranates, promotes mitophagy, increases muscle strength, and improves performance.

    Urolithin A is a metabolic byproduct of ellagic acid, a bioactive compound found in walnuts and pomegranates. Bacteria in the human gut break down ellagic acid to produce urolithins. Scientists have identified about 20 urolithins, but the most studied of these is urolithin A, which exerts potent anti-cancer and anti-inflammatory properties.

    Mitophagy is a type of autophagy, an intracellular program involved in the disassembly and recycling of unnecessary or dysfunctional cellular components, that selectively targets mitochondria. It helps ensure that the body’s cells are metabolically efficient and ultimately serves as a trigger for mitochondrial biogenesis, the process by which new mitochondria are produced. Failures in mitophagy are associated with several chronic diseases, including cardiovascular disease, kidney disease, and Alzheimer’s disease

    The study involved 88 healthy adults (40 to 65 years old) who had overweight. The investigators randomly assigned two groups of the participants to receive either 500 or 1,000 milligrams of urolithin A daily for four months. Another group received a placebo. Before and after the intervention, the investigators measured the participants' muscle strength, aerobic endurance (VO2 max, peak oxygen consumption), physical performance, and markers of inflammation, mitochondrial function, and mitophagy.

    They found that compared to participants who took the placebo, the participants who took the urolithin A supplement exhibited a roughly 12 percent increase in muscle strength following the intervention. The participants who took the urolithin A also showed improvements in aerobic endurance, physical performance, and mitochondrial function and had higher levels of proteins involved in mitophagy and mitochondrial metabolism in their muscle tissue.

    These findings suggest that urolithin A increases muscle strength, improves performance, and promotes mitophagy and mitochondrial function. Walnuts are excellent sources of urolithin A. See the story below to read about how eating walnuts reduces the risk of premature death and promotes longevity.

  • Hydrolyzed collagen and resistance exercise promote tendon hypertrophy and muscle strength.

    Tendons are dense connective tissues that attach muscles to bones. They have been described as “mechanical bridges,” responsible for transmitting the energy of muscles to joints and bones to facilitate movement. Tendons undergo anabolic, mechanical, and hypertrophic (growth) changes in response to exercise. Findings from a recent study suggest that collagen peptides, also known as hydrolyzed collagens, and resistance exercise synergistically promote tendon hypertrophy and muscle strength.

    Collagens are the primary structural proteins in many of the body’s connective tissues, including tendons. They are characterized by a triple helix arrangement that forms a sturdy, resilient structure, composed of approximately 1,300 to 1,400 amino acids, the most abundant of which are glycine, proline, and hydroxyproline. Collagen peptides are derived by breaking down collagen into smaller amino acid chains (called peptides) by thermal or enzymatic means.

    The randomized, placebo-controlled study involved 27 healthy males (average age, 26 years) who participated in a 14-week resistance training program. Half of the participants received 5 grams of supplemental collagen peptides (rich in glycine, proline, and hydroxyproline, among others) daily. The other half received a placebo. The investigators measured physical, functional, and strength characteristics of the participants' Achilles tendons and associated muscle groups before and after the intervention.

    They found that both groups experienced improvements in tendon stiffness and muscle strength. However, the cross-sectional area (a measure of hypertrophy) of the Achilles' tendons in the group that took the collagen peptides increased 11 percent versus only 4.7 percent in the group that took the placebo. In addition, the associated muscle groups of the collagen-supplemented group exhibited a 7.3 percent increase in strength, compared to a 2.7 percent increase in the placebo group.

    These findings suggest that collagen peptides, also known as hydrolyzed collagen, improve tendon stiffness, enhance tendon hypertrophy, and promote muscle strength in response to resistance exercise. Learn more about hydrolyzed collagen in our overview article.

  • Air pollution negates some of the beneficial effects of vigorous-intensity exercise.

    Components present in air pollution – a mixture of toxic chemicals, gases, and particulate matter – can cross biological barriers, including the blood-brain barrier. Exposure to air pollutants is associated with poor health outcomes and an increased risk for both acute and chronic diseases. A recent study suggests that air pollution negates some, but not all, of the beneficial effects of vigorous-intensity aerobic exercise.

    Robust evidence demonstrates that vigorous-intensity aerobic exercise (defined as activity that achieves a heart rate that is 70 to 80 percent of one’s maximum) benefits brain health. For example, vigorous-intensity aerobic exercise appears to activate the endocannabinoid system to promote motor sequence memory and learning. Other evidence suggests it improves mood.

    The study involved 8,600 adult participants enrolled in the UK Biobank study. Participants wore wrist accelerometers to track their physical activity. They also underwent magnetic resonance imaging (MRI) to assess their structural brain volumes and identify the presence of white matter hyperintensities – areas of the brain that show up as distinct white areas on MRIs and indicate cerebral small blood vessel disease. The investigators estimated the participants' exposure to air pollution based on where the participants lived.

    The investigators found that the more physically active participants were, the less their brains showed evidence of shrinkage, and the fewer white matter hyperintensities they exhibited – an effect roughly equivalent to being three years younger. Participants who were exposed to more air pollution exhibited greater brain shrinkage than those with less exposure – about the amount observed in one year of normal aging. However, participants who exercised the most and had the most exposure to air pollution demonstrated no evidence of more brain shrinkage, but they exhibited more white matter hyperintensities, especially if they engaged in vigorous-intensity aerobic exercise.

    These findings support earlier studies that demonstrate the beneficial health effects of vigorous-intensity exercise on the brain but suggest that exercising in areas where air pollution is high negates some of these benefits. The authors recommended that because most air pollution comes from vehicle exhaust, people should exercise in areas far from heavily trafficked roads.

  • Cardiorespiratory fitness helps prevent age-related brain volume losses.

    The brain loses about 5 percent of its volume every decade after the age of 40 years, likely due to the death of neurons in the gray matter. These losses contribute to age-related cognitive decline and loss of neuroplasticity, the brain’s ability to change and adapt to new exposures. Findings from a 2020 study suggest that having greater cardiorespiratory fitness helps prevent age-related brain volume losses.

    Cardiorespiratory fitness is a measure of the body’s aerobic capacity – the ability to deliver oxygen to skeletal muscles – during sustained physical activity. Poor cardiorespiratory fitness, along with dyslipidemia, family history, hypertension, age, cigarette smoking, diabetes mellitus, obesity, and physical inactivity, increases a person’s risk for cardiovascular disease and death. The most accurate way to assess cardiorespiratory fitness involves measuring maximal oxygen uptake, often referred to as VO2 max, during a graded exercise test in a laboratory, clinical, or research setting.

    The study involved more than 2,000 healthy adults (average age, 52 years) who were enrolled in a larger, ongoing study. The investigators measured the participants' cardiorespiratory fitness, assessed via VO2 max while riding on an exercise bike. They collected the participants' demographic data, and they measured their brain volumes via magnetic resonance imaging scans.

    They found that participants with greater cardiorespiratory fitness tended to have greater gray matter and total brain volumes. They also had more clusters of gray and white matter tissue in brain areas responsible for cognitive function rather than movement. These findings held true even when taking the participants' ages, education levels, smoking status, blood pressure, and body weights into consideration.

    These findings suggest that having greater cardiorespiratory fitness ameliorates some of the brain volume losses associated with aging and underscore the importance of exercising throughout the lifespan. Learn more about the health benefits of exercise in our overview article.

  • Aerobic exercise influences many aspects of human health, including brain health. For example, exercise promotes the release of brain-derived neurotrophic factor, better known as BDNF, a cell-signaling protein that influences the formation, growth, survival, and development of neurons. Findings from a 2020 study suggest that exercise intensity determines which parts of the brain are affected during a workout.

    Exercise intensity is defined as how hard the body works during exercise. During low-intensity aerobic exercise, a person’s heart rate is typically maintained at a steady pace of about 50 percent of its maximum ability, and workouts last for at least 30 minutes. During high-intensity aerobic exercise, a person’s heart rate is typically 75 percent of its maximum ability or higher. For example, high-intensity interval training, often referred to as HIIT, is a popular form of high-intensity exercise involving short bursts of intense aerobic exercise interspersed with periods of rest or lower-intensity exercise. During a typical HIIT session, exercisers typically achieve 80 to 100 percent of their VO2max (a measure of respiratory function) or maximum heart rate. Most HIIT workouts are brief, lasting just 15 to 30 minutes.

    The study involved 25 healthy male athletes who engaged in both low-intensity and high-intensity aerobic exercise sessions on a treadmill. The sessions lasted for approximately 30 minutes and were separated by at least two days. The participants underwent a battery of tests to determine their mental state, cognitive performance, and attention. Before and after the exercise sessions, they underwent resting-state functional magnetic resonance imaging (rs-fMRI), a technique that characterizes the functional connectivity of neuronal networks when the brain is at rest.

    The investigators found that the participants' moods improved after both exercise intensities. However, the rs-fMRIs revealed that the different intensities affected different parts of their brains. The low-intensity exercise turned on the activity of brain networks involved in cognitive function and attention processing. On the other hand, the high-intensity exercise turned on networks involved in mood and emotions and turned off networks involved in motor function.

    These findings suggest that differing exercise intensities affect different parts of the brain during exercise and underscore the importance of varying workout programs. Learn more about the effects of aerobic exercise on health in our overview article.

  • Exploiting the “gravitostat,” a novel homeostatic mechanism that regulates body weight, promotes weight loss.

    Having overweight or obesity increases a person’s risk of developing many chronic diseases. But losing weight loss is challenging, partly due to homeostatic mechanisms that regulate body weight. Findings from a 2020 study suggest that exploiting a novel homeostatic weight-regulating mechanism called the gravitostat promotes weight loss in humans.

    The concept of the gravitostat first emerged in 2017, when scientists implanted small weights into the abdomens of mice and found that the animals’ food intake decreased, promoting weight loss and improving glucose tolerance. They suggested that the gravitostat regulates weight via a negative feedback system involving bone cells called osteocytes. Because osteocytes can sense changes in bone strain, the investigators proposed that increasing the animals’ body weight activated a biological sensor that communicated with the osteocytes of weight-bearing bones to drive changes in eating behaviors and subsequent weight loss.

    In the 2020 study, the investigators conducted a randomized controlled trial involving 69 adults with mild obesity (body mass index of 30-35). About half of the participants wore a heavy weighted vest (11 percent of their body weight) for eight hours every day for three weeks, while the other half wore a light vest (1 percent of their body weight). Before and after the intervention, the investigators weighed the participants and analyzed their body composition using bioelectrical impedance.

    They found that participants who wore the heavy vest lost an average of 1.37 percent more bodyweight than those who wore the light vest, translating to about 3.5 pounds. Those who wore the heavy vests also lost fat mass and gained fat-free mass. These findings suggest that the gravitostat regulates body weight in humans and exploiting it provides a possible strategy for losing weight.

    Overcoming other aspects of bodyweight homeostasis might still prove challenging, however. Research from Dr. Eran Elinav’s lab suggests that metabolic parameters normalize with weight loss, but characteristics of the microbiome remain unchanged. In other words, the microbiome holds a memory of past obesity that promotes weight regain. Preclinical studies indicate that repeated weight cycling shifts gut microbes to a configuration with an altered ability to metabolize flavonoids — compounds that usually help promote the burning of excess energy by adipose tissue. Learn more in this clip featuring Dr. Eran Elinav.

  • From the article:

    If the person’s brain responds sensitively to the hormone, a significant amount of weight can be lost, unhealthy visceral fat reduced, and the weight loss can be maintained over the long term. However, If the person’s brain responds only slightly or not at all to insulin, the person only loses some weight at the beginning of the intervention and then experiences weight regain. Over the long term, the visceral fat also increases.

    […]

    Since the insulin action in the hypothalamus is crucial for the regulation of peripheral energy metabolism, the researchers also investigated how insulin sensitivity in this area of the brain is related to the distribution of body fat. For this purpose, they examined a cross-sectional cohort of 112 participants. The analysis of the data showed that people with high insulin sensitivity in the hypothalamus form little visceral fat. However, insulin sensitivity has no influence on the mass of subcutaneous fat.

  • From 2005.

    From the article:

    To better understand the effects of differing amounts of exercise, the researchers studied 175 overweight sedentary men and women who were beginning to show signs of lipid problems. They were randomized into one of four groups: no exercise, low dose/moderate intensity (equivalent of 12 miles of walking per week), low dose/vigorous intensity (12 miles of jogging per week) or high dose/vigorous intensity (20 miles of jogging per week).

    […]

    “On the other hand, participants who exercised at a level equivalent to 17 miles of jogging each week saw significant declines in visceral fat, subcutaneous abdominal fat and total abdominal fat,” Slentz continued. “While this may seem like a lot of exercise, our previously sedentary and overweight subjects were quite capable of doing this amount.”

    Specifically, those participants exercising at the highest level saw a 6.9 percent decrease in visceral fat and a 7 percent decrease in subcutaneous fat.

  • From the article:

    According to a new study by researchers at Wake Forest Baptist Medical Center, the way to zero in and reduce visceral fat is simple: eat more soluble fiber from vegetables, fruit and beans, and engage in moderate activity.

    The study found that for every 10-gram increase in soluble fiber eaten per day, visceral fat was reduced by 3.7 percent over five years. In addition, increased moderate activity resulted in a 7.4 percent decrease in the rate of visceral fat accumulation over the same time period.

    […]

    Researchers found that increased soluble fiber intake was associated with a decreased rate of accumulated visceral fat, but not subcutaneous fat.

    “There is mounting evidence that eating more soluble fiber and increasing exercise reduces visceral or belly fat, although we still don’t know how it works,” Hairston said. “Although the fiber-obesity relationship has been extensively studied, the relationship between fiber and specific fat deposits has not. Our study is valuable because it provides specific information on how dietary fiber, especially soluble fiber, may affect weight accumulation through abdominal fat deposits.”

  • A low-glycemic index Mediterranean diet and aerobic exercise corrects gut microbial imbalance in people with fatty liver disease.

    Non-alcoholic fatty liver disease, or NAFLD, is a syndrome that encompasses multiple states of liver dysfunction, including steatosis (fatty liver), nonalcoholic steatohepatitis, and cirrhosis. It is the most common liver chronic liver condition among people living in the United States, affecting roughly 90 percent of people with obesity, or about 25 percent of the overall population. A dominant feature of NAFLD is dysbiosis, an imbalance in the types and numbers of microbes in the gut. Findings from a recent study suggest that eating a low-glycemic index Mediterranean diet and engaging in aerobic exercise restores gut microbial balance in people with NAFLD.

    Glycemic index refers to a value (between 0 and 100) assigned to a defined amount of a carbohydrate-containing food based on how much the food increases a person’s blood glucose level within two hours of eating, compared to eating an equivalent amount of pure glucose, which has a value of 100. Whereas eating high glycemic index foods induces a sharp increase in blood glucose levels that declines rapidly, eating low glycemic index foods generally results in a lower blood glucose concentration that declines gradually.

    The Mediterranean dietary pattern is rich in foods that have a low glycemic index, including fruits, vegetables, olive oil, legumes, fish, and poultry. Previous research demonstrated that a Mediterranean diet in conjunction with aerobic exercise improves measures of NAFLD but did not identify the mechanism that drove these improvements.

    The current study involved 109 adults (average age, 53 years) who had been diagnosed with NAFLD. The investigators randomly assigned the participants to receive one of six interventions: low glycemic index Mediterranean diet; aerobic exercise program (with or without the low glycemic index Mediterranean diet); combined aerobic exercise and resistance training program (with or without the low glycemic index Mediterranean diet); or no intervention. The investigators collected stool samples from the participants and sequenced the microbial populations in the samples.

    They found that compared with other dietary/exercise interventions, a low-glycemic index Mediterranean diet in conjunction with aerobic exercise exerted robust effects on the participants' gut microbial population. These effects corrected the participants' dysbiosis and promoted increases in populations of microbes that benefit gut health, including Akkermansia, Firmicutes, and Ruminococcaceae.

    These findings suggest that dietary measures in conjunction with exercise have favorable effects on the gut microbiota of people with NAFLD, providing insights into the mechanisms that drive improvements in disease status. Evidence from cell culture studies suggests that berberine, a bioactive dietary compound, provides protection against NAFLD. Read our overview article to learn more about berberine.

  • Exercise activates the endocannabinoid system to promote learning and memory formation.

    Scientists have identified robust links between physical exercise and brain health. Some of the mechanisms that drive the beneficial effects of exercise on the brain include increases in brain volume and connectivity, improved blood flow, enhanced synaptic plasticity, and increased neurogenesis – the formation of new neurons. Findings from a 2020 study suggest that moderate- to vigorous-intensity exercise improves motor sequence memory via endocannabinoid action on the hippocampus.

    Motor sequence memory involves learning predefined sequences of interrelated motor actions, such as playing the piano or dancing. The hippocampus interacts with various neural networks to support the formation of motor sequency memory.

    Endocannabinoids are small lipid molecules produced in the body that bind to cannabinoid receptors in the central and peripheral nervous systems. Endocannabinoids regulate many physiological processes, including movement control, pain processing, brain development, and learning and memory. The two major endocannabinoids in the body are anandamide and 2-arachindonyl glycerol.

    The study involved 15 healthy adults (average age, 23 years) who had at least fair respiratory fitness, as measured via VO2 max. Participants completed a serial reaction time task (a widely used measure of learning and memory) before and after three conditions: moderate-intensity exercise, vigorous-intensity exercise, and rest. Prior to performing the task, participants consumed a standardized carbohydrate-rich breakfast. During the task, the investigators measured the participants' behavior, brain activity, and circulating anandamide (endocannabinoid) levels.

    They found that vigorous-intensity exercise markedly improved motor sequence memory compared to rest. Moderate-intensity exercise also improved motor sequence memory, but to a lesser degree. The improvements coincided with increased levels of the endocannabinoid anandamide and enhanced hippocampal activity.

    These findings suggest that vigorous-intensity exercise promotes motor sequence memory and learning and underscore the benefits of exercise on cognitive function. Learn about the beneficial effects of aerobic exercise in our overview article.

  • Lifelong exercise protects older adults from losing muscle mass and function with age.

    With age, muscles shrink in size and lose strength, a process called sarcopenia that can increase frailty and reduce the quality of life for older adults. In people with sarcopenia, muscle fibers contain fewer satellite cells (i.e., muscle stem cells) and progressively lose their connections to nerves, a process called denervation. Findings of a new report show that lifelong exercisers have more youthful muscles that resist denervation.

    Satellite cells are stem cells that proliferate, fuse together, and form the long tubular structures than comprise muscle fibers. Satellite cells are necessary for muscle repair and growth after exercise, a process called hypertrophy, due to their connection with cells that produce growth factors and deliver nutrients. Previous research demonstrates that exercise interventions that last several weeks can reverse muscle denervation in older adults with frailty; however, the preventive effects of lifelong exercise have yet to be investigated.

    The authors recruited 15 moderately active young men (average age, 26 years), 16 older men who were lifelong exercisers (average age, 73 years), and 15 older men who lived a sedentary lifestyle (average age, 73 years). On their first visit to the lab, participants completed a bout of heavy resistance training on only one side of their body so that the researchers could compare the effects of exercise and sedentary behavior in each person. The researchers also measured maximum muscle strength and body composition and collected a blood sample. Participants provided another blood sample two days and six days after the exercise challenge and provided a muscle biopsy sample six days after.

    Lifelong exercisers had muscles that were more resistant to fatigue during exercise compared to sedentary young and older adults. Compared with sedentary older adults, lifelong exercisers had more satellite cells in their muscles connected to type 2 myofibrils, which are important for fast-twitch muscle movement, but no difference in connection to type 1 slow-twitch myofibrils. Muscles from lifelong exercisers also expressed high levels of mRNA for acetylcholine receptors, which are necessary for preventing denervation.

    These results show that lifelong exercisers maintained a more youthful muscle profile due to increased connections with muscle- and nerve-supporting satellite cells. People who started life with a sedentary lifestyle can still reap the longevity-promoting benefits of exercise. Starting a new aerobic exercise habit, even at age 70, cuts heart disease death in half.

  • From the article:

    “Over the years, studies have found that restricting calories slows aging and increases longevity – however the mechanism of this effect has remained elusive” Dr. Verdin said. Dr. Verdin, the paper’s senior author, directs the Center for HIV & Aging at Gladstone and is also a professor at the University of California, San Francisco, with which Gladstone is affiliated. “Here, we find that βOHB – the body’s major source of energy during exercise or fasting – blocks a class of enzymes that would otherwise promote oxidative stress, thus protecting cells from aging.”

    […]

    Normally HDACs keep a pair of genes, called Foxo3a and Mt2, switched off. But increased levels of βOHB block the HDACs from doing so, which by default activates the two genes. Once activated, these genes kick-start a process that helps cells resist oxidative stress. This discovery not only identifies a novel signaling role for βOHB, but it could also represent a way to slow the detrimental effects of aging in all cells of the body.

  • From the article:

    “Our team found that high salt consumption lowered levels of circulating beta hydroxybutyrate. When we put beta hydroxybutyrate back in the system, normal blood pressure is restored,” said Dr. Bina Joe, Distinguished University Professor and chair of UT’s Department of Physiology and Pharmacology and director of the Center for Hypertension and Precision Medicine. “We have an opportunity to control salt-sensitive hypertension without exercising.”

    The effects may be microbiome mediated. Read the following excerpt from discussion in a Cell spotlight:

    Changes in the microbiota, specifically a decrease in Lactobacillus spp., in rats fed a high-salt diet have also been implicated in drivingthe progression of hypertension. The authors found that Lactobacillus spp. and Proteobacteria were reduced and Prevotella spp. were increased by a high-salt diet. The changes in the microbiota were associated with a decrease in gluconeogenesis and ketone metabolism, which was not restored by supplementation with 1,3-butanediol. Interestingly, after 1,3butanediol treatment, Proteobacteria and Prevotella shifted back toward the low-salt relative abundance and also correlated with an increase in protective Akkermansia levels.

  • Endurance and resistance training are associated with distinct hormonal signatures Exercise is widely accepted to be beneficial to our health. Research finds it to have a positive dose-dependent impact on factors varying from cognitive function and bone strength to all-cause mortality and metabolic health. But does the specific mode of exercise make a difference? A 2018 study suggests that resistance and endurance exercise engage largely distinct hormonal responses in the body. It also highlights endurance training as a particularly useful tool for engaging biochemical signals that can help combat substance addiction.

    To compare resistance and endurance training, researchers recruited ten healthy young men (average age 24 years) to participate in a cross-over study. This meant that each participant engaged in both forms of exercise, with half randomly selected to first perform a one-hour endurance training session before “crossing over” to one resistance training session after a 6-to-12-day rest period. The other half of the participants followed the reverse order.

    Training sessions were individually tailored to ensure equivalent levels of physiological stress across participants. For instance, resistance training sessions required participants to complete five sets of 10 reps for each exercise, at resistance levels corresponding to 90 percent of their 10 rep maximum capacity. The endurance training sessions were designed to make participants work at 70% of their VO2max(i.e. maximum oxygen uptake capacity). Importantly, participants exercised 10 hours after receiving controlled meals to prevent nutritional factors from interfering with hormone levels in their blood, which was drawn immediately before and at several timepoints after exercise.

    The experiment revealed some surprising insights into the hormonal pathways engaged by the two forms of exercise. Shortly after resistance training, participants had lower plasma levels of fibroblast growth factor 19 (FGF19) – a protein secreted by the small intestine and implicated fighting metabolic disease by stimulating the formation of metabolically active brown fatty tissue and increasing sensitivity to the satiety hormone leptin. The drop in FGF19 shortly after resistance exercise is somewhat counterintuitive given robust links between strength training and metabolic health. It raises questions about a potential long-term rebound increase following recovery, which our team looks forward to seeing explored in future studies.

    Endurance exercise engaged a distinct biochemical pathway. It caused a near-triple increase in the pancreatic hormone glucagon, which stimulates the release of glucose and fatty acids into the blood. This glucagon spike was followed by an increase in plasma fibroblast growth factor 21 (FGF21) – a metabolic regulator implicated in processes ranging from fatty acid oxidation and ketone body production to the regulation of appetite for addictive substances like alcohol. The findings suggest that endurance and resistance training are associated with distinct hormonal and metabolic benefits, and that endurance exercise in particular may be a helpful strategy in combating addiction.

    Link to full study

  • From the abstract:

    Cardiorespiratory fitness and muscle strength were measured before and after supplementation through maximal treadmill tests and dynamometry, respectively. Wilcoxon tests were used to compare intragroup results and the Mann-Whitney test to examine intergroup differences. There was an increase in the serum concentration of vitamin D in participants who ingested the supplementation. Cardiorespiratory fitness improved after supplementation through increases in the values of maximum oxygen consumption of 28% (p < .001). Muscle strength in left hand grip increased 18% in participants who received the supplement (p = .007). Sixty days of cholecalciferol supplementation improved cardiorespiratory fitness and upper limb muscle strength.

  • Liver-derived hormone FGF21 dramatically reduces appetite for alcohol Researchers believe that humans first encountered alcohol long before we learnt how to control the process and make it ourselves – through the consumption of fermented fruit. One plausible result of this long history of alcohol exposure is that we have evolved a suite of biological mechanisms for detoxifying and regulating our appetite for alcohol, which may be useful for developing new treatments for alcohol use disorder. Now, a recent randomized controlled trial suggests that the liver-derived hormone fibroblast growth factor 21 (FGF21) is a candidate treatment capable of altering the reward system of the brain and profoundly reducing alcohol intake in primates.

    The researchers carried out their study in vervet monkeys – a species that parallels human populations in containing a mix of alcohol avoiders, moderate consumers, and heavy consumers who will drink to the point of intoxication. Twenty monkeys were selected based on having at least a slight interest in consuming alcohol. The researchers then quantified each individual’s preferred alcohol intake level by monitoring their behaviours when the animals received four hours of daily access to a bottle of 10% ethanol solution alongside plain tap water.

    After a baseline observation period of nine days, monkeys were randomly selected to receive a daily injection of either a sterile saline solution (placebo) or a pharmacological analog of the liver hormone FGF21 for a total of 16 days.

    The FGF21-mimicking drug was found to produce a 50 percent reduction in alcohol consumption, without influencing the monkeys’ intakes of food or water. Looking into the effects of FGF21 in the brain, the researchers uncovered that both FGF21 and its synthetic analog increased the transmission of signals to a specific group of brain cells in the nucleus accumbens – a hotspot of the brain’s reward system. These cells were distinguished by the presence of specifically D2-type dopamine receptors, which have been strongly implicated in reigning in impulsive and repetitive consumption of other substances like sugar. Human variants in the D2 receptor gene have also been linked to greater risk of alcohol dependence.

    The findings suggest that FGF21 serves as a regulatory message between the liver and the brain’s impulse control circuits, and that boosting this signal may aid in the treatment of substance addictions.

    -Link to full publication.

  • Just 20 minutes of exercise daily reduces heart disease risk in older adults. The benefits of regular physical exercise on cardiovascular health are well established. However, most studies investigating the benefits of exercise have been conducted in younger adults rather than older ones, for whom cardiovascular disease risk is greatest. Findings from a recent study demonstrate that 20 minutes of exercise daily reduces the risk of cardiovascular disease in older adults.

    The authors of the study drew on data from the Progetto Veneto Anziani, a long-term cohort study of more than 3,000 older adults (65 years and older) living in northern Italy. They identified participants with cardiovascular disease based on information gleaned from medical exams or hospital records. Every five years (at 65, 70, 75, 80, and 85 years of age), the authors assessed the participants' physical activity levels based on information provided in questionnaires.

    The risk of cardiovascular-related events or premature death was lower among older adults who were physically active. Men, in particular, were half as likely to experience a cardiovascular event if they were physically active. The effects of exercise were dose-dependent, with 20 minutes of moderate- to vigorous-intensity exercise daily providing the greatest benefits, especially when performed earlier in one’s later years, between the ages of 70 and 75 years. Exercising more than 40 minutes daily provided no additional benefits.

    Although the authors of this study did not differentiate between the effects of different types of exercise, their findings demonstrate that aerobic exercise is particularly beneficial for cardiovascular health. Learn more about aerobic exercise in our overview article.

  • Curcumin is the principal bioactive compound present in the yellow spice turmeric. An abundance of scientific evidence indicates that curcumin has antioxidant, anti-inflammatory, anticancer, and neuroprotective properties in humans. Findings from a 2019 study suggest that curcumin improves exercise tolerance in mice with heart failure via its activation of Nrf2.

    Heart failure, commonly referred to as the end stage of heart disease, affects more than 26 million people worldwide. Exercise intolerance is a common feature of heart failure and is typically attributed to low ejection fraction – a measure of ventricular efficiency. A critical driver of low ejection fraction is oxidative stress.

    Nrf2 is a cellular protein that regulates the expression of antioxidant and stress response proteins via participation in the Keap1-Nrf2-ARE biological pathway. Nrf2 activates the transcription of cytoprotective proteins that protect against oxidative stress due to injury and inflammation.

    The study investigators gauged the effects of curcumin in mice that had heart failure with reduced ejection fraction and in mice with healthy hearts. A subset of the mice received daily curcumin supplementation, while the others did not. The investigators measured the animals' heart function via echocardiogram, assessed their exercise performance on a treadmill, and measured the expression of Nrf2 and its target proteins in their muscles.

    They found that both groups of mice that received curcumin (including those with healthy hearts) had improved exercise capacity compared to those that did not receive the compound. They also found that Nrf2 expression and antioxidant proteins increased in the mice with heart failure that received curcumin.

    These findings suggest that impaired Nrf2 drives oxidative stress in skeletal muscle in those who have heart failure with low ejection fraction. Curcumin counters these effects by upregulating antioxidant defenses in skeletal muscle, likely mediated by Nrf2 activation. Many plant-based dietary compounds induce Nrf2 activity, including sulforaphane, a compound derived from broccoli and broccoli sprouts. Learn more about Nrf2 and sulforaphane in this episode featuring Dr. Jed Fahey.

  • From the article:

    In a new study published in the scientific Journal of Clinical Investigation – Insight, the researchers show that cardio training on an exercise bike causes three times as large an increase in the production of the hormone FGF21 than strength training with weights. FGF21 has a lot of positive effects on metabolism.

    […]

    Endurance training on a bicycle has such a marked effect on the metabolic hormone that we know ought to take a closer look at whether this regulation of FGF21 is directly related to the health-improving effects of cardio exercise. FGF21’s potential as a drug against diabetes, obesity and similar metabolic disorders is currently being tested, so the fact that we are able to increase the production ourselves through training is interesting', Christoffer Clemmensen elaborates.

  • From linked article:

    The researchers gave the monkeys a two-bottle choice between water and ethanol, and administered one group an analog of FGF21 to see what effect it had. Sure enough, the test monkeys drank 50 percent less alcohol than the control group. Similar tests in mice also saw a 50-percent reduction in alcohol consumption after being given either human FGF21 or an analog. Interestingly though, the mice and monkeys still chose the ethanol just as often as before, but they drank far less each time.

    Fibroblast growth factor 21 happens to be modulated by aerobic exercise:

    In a new study published in the scientific Journal of Clinical Investigation – Insight, the researchers show that cardio training on an exercise bike causes three times as large an increase in the production of the hormone FGF21 than strength training with weights. FGF21 has a lot of positive effects on metabolism.

  • Breast cancer is the most common form of cancer among women, with roughly 237,000 cases diagnosed in the United States each year. Nearly one-fourth of women with breast cancer will die within 15 years of diagnosis. Findings from a 2014 study indicate that running reduces the risk of death from breast cancer.

    Most public health organizations recommend that adults of all ages engage in at least 150 minutes of moderate-intensity exercise or at least 75 minutes of vigorous-intensity exercise each week, or an equivalent combination of both. Most adults fall far short of these recommendations, however.

    Data from epidemiological, clinical, and mechanistic studies suggest that exercise reduces the risk of cancer-related death. However, scientists are unsure about how much or what type of exercise is best. Running and walking are both aerobic forms of exercise, but they differ in intensity, with running categorized as vigorous, and walking categorized as moderate. The authors of the study investigated whether running and walking differed in their effects on breast cancer-related death risk.

    The authors drew on data collected in the National Runners' and Walkers' Health Study, a long-term assessment of the health benefits associated with running and walking. They compared death rates among 272 runners and 714 walkers who had previously been diagnosed with breast cancer, taking age, race, menopause, family history, breastfeeding and oral contraceptive use into account. They quantified the intensity of the women’s activity as metabolic equivalents, or METs, a measure of the rate of energy expended per unit of time.

    Over a nine-year period, the risk of death from breast cancer was 49 percent lower among women who ran or walked 1.8 to 3.6 MET-hours per day and 68 percent lower for 3.6 MET-hours per day, when compared to less active women. Among runners only, the risk of death from breast cancer was 14 percent lower among women who ran 1.07 to 1.8 MET-hours per day, 87 percent lower for 1.8 to 3.6 MET-hours per day had a, and 95 percent lower for 3.6 hours or more per day, when compared to those who ran for less than 1.07 MET-hours per day.

    The findings indicate that running promotes greater survival among women who have had breast cancer. The authors noted that the amount of exercise that provided the greatest protection exceeded current guidelines, suggesting that breast cancer survival could be increased by engaging in greater exercise doses than recommended. Other behaviors that may promote breast cancer survival include dietary modifications, especially time-restricted eating. Learn more about the effects of time-restricted eating on breast cancer survival in this clip featuring Dr. Ruth Patterson.

  • 40-60 minutes 3x per week:

    • Systolic blood pressure: 134 ± 4 vs. 119 ± 3 (after)
    • Diastolic blood pressure: 85 ± 2 vs. 75 ± 1 (after)

    From the article:

    At baseline, the overweight/obese men had significantly lower total, free and bioavailable testosterone level than normal weight men. All of the study volunteers completed a 12-week aerobic exercise plan that entailed 40-60 minutes of walking or jogging on one to three days per week.

    […]

    I think decrease in body mass is one of the factors for increasing serum testosterone levels,“ said Hiroshi Kumagai, lead researcher on the study. "However, the degree of weight loss is small, and we found that the increase in vigorous physical activity was independently associated with the increase in serum testosterone levels. So, it seems the increase in physical activity, especially vigorous physical activity, is the main factor for increasing serum testosterone levels.”

  • From the article:

    It was known that the protein PGC-1a1 (pronounced PGC-1alpha1) increases in skeletal muscle with exercise, and mediates the beneficial muscle conditioning in connection with physical activity. In this study researchers used a genetically modified mouse with high levels of PGC-1a1 in skeletal muscle that shows many characteristics of well-trained muscles (even without exercising).

    These mice, and normal control mice, were exposed to a stressful environment, such as loud noises, flashing lights and reversed circadian rhythm at irregular intervals. After five weeks of mild stress, normal mice had developed depressive behaviour, whereas the genetically modified mice (with well-trained muscle characteristics) had no depressive symptoms.

    Eliminating the neurotoxic effects of kynurenine:

    The researchers discovered that mice with higher levels of PGC-1a1 in muscle also had higher levels of enzymes called KAT. KATs convert a substance formed during stress (kynurenine) into kynurenic acid, a substance that is not able to pass from the blood to the brain. The exact function of kynurenine is not known, but high levels of kynurenine can be measured in patients with mental illness.

  • Current public health guidelines recommend that adults engage in muscle-strengthening activities such as resistance training at least twice a week. Research indicates that resistance exercise provides a wide range of health benefits, including increased muscle mass and strength, greater bone density, and improved mood. Findings from a 2019 study also suggest that resistance exercise reduces the risk of the number one killer worldwide: cardiovascular-related disease and death.

    The study involved more than 12,000 adults (average age 47 years) who were enrolled in the Aerobics Center Longitudinal Study - an ongoing prospective investigation of links between exercise and cardiovascular health. Participants underwent a comprehensive examination that included collection of a detailed medical history, assessment of cardiovascular and metabolic health parameters, and information-gathering about the participants’ resistance exercise habits.

    They found that participants who engaged in resistance exercise one to three times (or a total of up to 59 minutes) per week were 40 to 70 percent less likely to experience a cardiovascular disease-related event than those who never engaged in resistance exercise. Engaging in resistance exercise more than four times (or more than an hour) per week did not confer any additional protection. The authors' analysis indicated that the decreased risk was due in part to resistance exercise’s effects on lowering body mass index, a known risk factor for cardiovascular disease.

    These findings suggest that resistance exercise promotes cardiovascular health. Aerobic exercise is also important for cardiovascular health. Learn about the cardiovascular benefits of aerobic exercise in our overview article.

  • Curcumin is the principal bioactive compound present in the yellow spice, turmerice. An abundance of scientific evidence indicates that curcumin exerts antioxidant, anti-inflammatory, anticancer, and neuroprotective properties in humans. Findings from a 2019 study suggest that curcumin improves exercise tolerance in mice with heart failure via its activation of Nrf2.

    Heart failure, commonly referred to as the end stage of heart disease, affects more than 26 million people worldwide. Exercise intolerance is a common feature of heart failure and is typically attributed to low ejection fraction – a measure of ventricular efficiency. A critical driver of low ejection fraction is oxidative stress.

    Nrf2 is a cellular protein that regulates the expression of antioxidant and stress response proteins via participation in the Keap1-Nrf2-ARE biological pathway. Nrf2 activates the transcription of cytoprotective proteins that protect against oxidative stress due to injury and inflammation.

    The study investigators gauged the effects of curcumin in mice that had heart failure with reduced ejection fraction and in mice with healthy hearts. A subset of the mice received daily curcumin supplementation, while the others did not. The investigators measured the animals' heart function via echocardiogram, assessed their exercise performance on a treadmill, and measured the expression of Nrf2 and its target proteins in their muscles.

    They found that both groups of mice that received curcumin (including those with healthy hearts) had improved exercise capacity compared to those that did not receive curcumin. They also found that Nrf2 expression and antioxidant proteins increased in the mice with heart failure that received curcumin.

    These findings suggest that impaired Nrf2 drives oxidative stress in skeletal muscle in mice that have heart failure with low ejection fraction. Curcumin counters these effects by upregulating antioxidant defenses in skeletal muscle, likely mediated by Nrf2 activation. Many plant-based dietary compounds induce Nrf2 activity, including sulforaphane, a compound derived from broccoli and broccoli sprouts. Learn more about Nrf2 and sulforaphane in this episode featuring Dr. Jed Fahey.

  • From the article:

    In mice, the scientists showed that learning ability was passed onto the next generation by epigenetic inheritance. When Fischer and co-workers exposed mice to a stimulating environment in which they had plenty of exercise, their offspring also benefited: compared to the mice of a control group, they achieved better results in tests that evaluate learning ability. These rodents were also found to have improved synaptic plasticity in the hippocampus, a region of the brain important for learning

    Both mental and physical activity of the parents matter:

    The researchers also found that miRNA212 and miRNA132 accumulated in the brains and sperm of mice after physical and mental activity. It was previously known that these molecules stimulate the formation of synapses in the brain, thus improving learning ability. Through the sperm, they are transmitted to the next generation. “Presumably, they modify brain development in a very subtle manner improving the connection of neurons. This results in a cognitive advantage for the offspring,” says Fischer.

  • Older adults were asked to complete twice-weekly aerobic and strength training for 12 weeks. Some participants were advised to consume a healthier diet during the exercise training. Other participants were given two grams of omega-3-rich oil from Calanus finmarchicus. The investigators also evaluated a control group of participants who did not exercise, change their diet, or take the supplement. The investigators measured the activity of sirtuin enzymes 1, 3, and 5 in the blood.

    All three groups who completed the exercise training had significant increases in the activity of sirtuin enzymes 1 and 3. Participants who completed the exercise training and also followed a healthy diet plan had the greatest increase in sirtuin activity compared to the control group. The activity of sirtuin enzyme 5 did not change significantly for any group.

    The authors stated that their report is the first to demonstrate the effects of chronic exercise and healthy eating on sirtuin activity.

  • Disorders like atrial fibrillation and other rhythm disorders may be particularly advantaged by improvements to calcium management induced by HIIT:

    “The interval training also significantly improved the rats' conditioning. After the training period, their fitness level was actually better than that of the untrained rats that hadn’t had a heart attack,” says Stølen.

    […]

    “We found that interval training improves a number of mechanisms that allow calcium to be pumped out of the cells and stored more efficiently inside the cells. The leakage from the calcium stores inside the cells also stopped in the interval-trained rats,” says Stølen.

    The effect was clear when the researchers tried to induce ventricular fibrillation in the diseased rat hearts: they only succeeded at this in one of nine animals that had completed interval training. By comparison, they had no problems inducing fibrillation in all the rats with heart failure who had not exercised.

  • Effect of aerobic exercise on cancer in mice:

    Training mice regularly on a wheel (the mouse version of a treadmill) decreased the growth of multiple types of tumors, including skin, liver, and lung cancers. Furthermore, mice that exercised regularly had a smaller chance of developing cancer in the first place. The beneficial effects of running went beyond tumor formation and growth, extending to cancer-associated weight loss, a process termed cachexia that is seen in cancer patients. Mice that exercised regularly showed no signs of cancer-associated weight loss in the researchers' lung cancer mouse model.

    Myokine signaling from the muscles:

    The researchers say that, the production of adrenaline results in a mobilization of immune cells, specifically one type of immune cell called a Natural Killer (NK) cell, to patrol the body. These NK cells are recruited to the site of the tumor by the protein IL-6, secreted by active muscles. The NK cells can then infiltrate the tumor, slowing or completely preventing its growth. Importantly, the researchers note that injecting the mice with either adrenaline or IL-6 without the exercise proved insufficient to inhibit cancer development, underlining the importance of the effects derived only from regular exercise in the mice.

  • From the article:

    “We have shown that interval training does not have to be ‘all out’ in order to be effective,” says Professor Martin Gibala. “Doing 10 one-minute sprints on a standard stationary bike with about one minute of rest in between, three times a week, works as well in improving muscle as many hours of conventional long-term biking less strenuously.”

    HIT means doing a number of short bursts of intense exercise with short recovery breaks in between. The authors have already shown with young healthy college students that this produces the same physical benefits as conventional long duration endurance training despite taking much less time (and amazingly, actually doing less exercise!) However, their previous work used a relatively extreme set-up that involved “all out” pedaling on a specialized laboratory bicycle. The new study used a standard stationary bicycle and a workload which was still above most people’s comfort zone -about 95% of maximal heart rate – but only about half of what can be achieved when people sprint at an all-out pace.

  • From the article:

    Exercise may play a role in reducing the growth of colon cancer cells according to new research. The study found that after a short session of high intensity interval training (HIIT), growth of colon cancer cells was reduced, and this also increased indicators of inflammation.

    […]

    “We have shown that exercise may play a role in inhibiting the growth of colon cancer cells. After an acute bout of HIIT there were specific increases in inflammation immediately after exercise, which are hypothesised to be involved in reducing the number of cancer cells.

    This suggests that a physically active lifestyle may be important in tackling human colorectal tumours. We would now like to look at how these changes in growth occur and understand the mechanisms by which biomarkers in the blood can impact cell growth."

  • From the article:

    Researchers from the Morrison laboratory discovered that forces created from walking or running are transmitted from bone surfaces along arteriolar blood vessels into the marrow inside bones. Bone-forming cells that line the outside of the arterioles sense these forces and are induced to proliferate. This not only allows the formation of new bone cells, which helps to thicken bones, but the bone-forming cells also secrete a growth factor that increases the frequency of cells that form lymphocytes around the arterioles. Lymphocytes are the B and T cells that allow the immune system to fight infections.

    When the ability of the bone-forming cells to sense pressure caused by movement, also known as mechanical forces, was inactivated, it reduced the formation of new bone cells and lymphocytes, causing bones to become thinner and reducing the ability of mice to clear a bacterial infection.

  • From the article:

    Muscle tissue can remodel itself, which is one reason why exercise becomes easier when we do it regularly, Lessard says. Over time, aerobic exercise such as running or swimming can alter muscle fibers to become more efficient at using oxygen during exercise. “We also grow new blood vessels to allow more oxygen to be delivered to the muscle, which helps to increase our aerobic fitness levels,” she says.

    The scientists propose that high levels of blood sugar may prevent muscle remodeling in part by modifying the “extracellular matrix” proteins in the space between the muscle cells, where blood vessels are formed.

    Adapting to aerobic exercise as though it were strength training:

    The scientists found that these JNK pathway signals were getting crossed in the hyperglycemic mice, by activating pathways associated with strength training, even though the mice were performing aerobic exercise. “As a result, the muscles of hyperglycemic animals have bigger fibers and fewer blood vessels, which is more typical of strength training, rather than aerobic training,” Lessard says.

  • From the article:

    Researchers found that aerobic exercise increased thinking skills. From the beginning of the study to the end, those who did aerobic exercise improved their overall scores on executive function tests by 0.50 points, which was a statistically significant difference from those who did stretching and toning, who improved by 0.25 points. […] “Since a difference of 0.5 standard deviations is equivalent to 20 years of age-related difference in performance on these tests, the people who exercised were testing as if they were about 10 years younger at age 40 and about 20 years younger at age 60,” Stern said.

    Increased thickness of the outer layer of the brain in the left frontal area:

    “Since a difference of 0.5 standard deviations is equivalent to 20 years of age-related difference in performance on these tests, the people who exercised were testing as if they were about 10 years younger at age 40 and about 20 years younger at age 60,” Stern said.

  • From the article:

    The study recruited 125 amateur cyclists aged 55 to 79, 84 of which were male and 41 were female. The men had to be able to cycle 100 km in under 6.5 hours, while the women had to be able to cycle 60 km in 5.5 hours.

    […]

    The cyclists also did not increase their body fat or cholesterol levels with age and the men’s testosterone levels also remained high, suggesting that they may have avoided most of the male menopause.

    More surprisingly, the study also revealed that the benefits of exercise extend beyond muscle as the cyclists also had an immune system that did not seem to have aged either.

    An organ called the thymus, which makes immune cells called T cells, starts to shrink from the age of 20 and makes less T cells. In this study, however, the cyclists' thymuses were making as many T cells as those of a young person.

  • From the article:

    The scientists discovered that after completing the endurance training program, the structure of many enhancers in the skeletal muscle of the young men had been altered. By connecting the enhancers to genetic databases, they discovered that many of the regulated enhancers have already been identified as hotspots of genetic variation between individuals – hotspots that have been associated with human disease.

    The scientists speculate that the beneficial effects of exercise on organs distant from muscle, like the brain, may largely be mediated by regulating the secretion of muscle factors. In particular, they found that exercise remodels enhancer activity in skeletal muscle that are linked to cognitive abilities, which opens for the identification of exercise training-induced secreted muscle factors targeting the brain.

  • From the article:

    Developing endurance means being able to sustain an aerobic activity for longer periods of time. As people become more fit, their muscles shift from burning carbohydrates (glucose) to burning fat. So researchers assumed that endurance is a function of the body’s increasing ability to burn fat, though details of the process have been murky. Previous work by the Evans lab into a gene called PPAR delta (PPARD) offered intriguing clues: mice genetically engineered to have permanently activated PPARD became long-distance runners who were resistant to weight gain and highly responsive to insulin – all qualities associated with physical fitness. The team found that a chemical compound called GW1516 (GW) similarly activated PPARD, replicating the weight control and insulin responsiveness in normal mice that had been seen in the engineered ones.

    […]

    Mice in the control group could run about 160 minutes before exhaustion. Mice on the drug, however, could run about 270 minutes – about 70 percent longer. For both groups, exhaustion set in when blood sugar (glucose) dropped to around 70 mg/dl, suggesting that low glucose levels (hypoglycemia) are responsible for fatigue.

  • “Sport-related concussion is a public health problem, particularly in adolescents.

    Male and female adolescent athletes (aged 13–18 years) presenting within 10 days of sport-related concussion were randomly assigned to individualized sub-symptom threshold aerobic or stretching exercise at least 20 min daily, for up to 4 weeks after injury.

    On survival analysis, controlling for sex, site, and mean daily exercise time, patients assigned to aerobic exercise were more likely to recover within 4 weeks after injury compared with those assigned to stretching exercise, with a 48% reduced risk of persistent post-concussive symptoms (hazard ratio for stretching vs aerobic exercise of 0·52 [95% CI 0·28–0·97], p=0·039).

    This multicenter study found that early treatment with sub-symptom threshold aerobic exercise safely speeds recovery from sport-related concussion and reduces the risk for persistent post-concussive symptoms, an important result given the impact of delayed recovery on adolescent quality of life."

  • Aging drives an array of physiological, functional, and mental changes in the human body. It is the primary risk factor for many chronic diseases in humans, including cancer, Alzheimer’s disease, and cardiovascular disease. Findings from a 2020 study suggest that exercise reverses some of the harmful effects of aging on the brain.

    Scientists have identified strong links between regular physical exercise and brain health. Some of the mechanisms that drive the beneficial effects of exercise on the brain include increases in brain volume and connectivity, improved blood flow, enhanced synaptic plasticity, and increased neurogenesis – the formation of new neurons.

    The intervention study involved 206 healthy, cognitively intact middle-aged and older adults (average age, 66 years) with low physical activity levels. The participants engaged in a supervised aerobic exercise program three days per week, gradually increasing from 20 to 40 minutes over a period of six months. They also completed an unsupervised exercise session one day per week during the six-month period. The authors of the study assessed the participants' cognitive performance, cerebrovascular function, and overall fitness on three separate occasions over a period of 12 months.

    After completing the six months of exercise, the authors of the study noted that the study participants improved by nearly 6 percent on measures of working memory, flexible thinking, and self-control. They improved by nearly 2.5 percent on tests of verbal fluency, comparable to abilities seen in person five years younger. Blood flow to the brain increased by nearly 3 percent, suggesting that cerebrovascular function is a critical aspect of maintaining or improving memory and verbal skills.

  • From the article:

    The study involved restricting mice from using their hind legs, but not their front legs, over a period of 28 days. The mice continued to eat and groom normally and did not exhibit stress. At the end of the trial, the researchers examined an area of the brain called the sub-ventricular zone, which in many mammals has the role of maintaining nerve cell health. It is also the area where neural stem cells produce new neurons.

    Limiting physical activity decreased the number of neural stem cells by 70 percent compared to a control group of mice, which were allowed to roam. Furthermore, both neurons and oligodendrocytes – specialized cells that support and insulate nerve cells – didn’t fully mature when exercise was severely reduced.

  • From the article:

    “We found that monkeys who exercised regularly at an intensity that would improve fitness in middle-aged people learned to do tests of cognitive function faster and had greater blood volume in the brain’s motor cortex than their sedentary counterparts,” Dr. Cameron said. “This suggests people who exercise are getting similar benefits.” For the study, the researchers trained adult female cynomolgus monkeys to run on a human-sized treadmill at 80 percent of their individual maximal aerobic capacity for one hour each day, five days per week, for five months.

    […]

    “Monkeys that exercised learned to remove the well covers twice as quickly as control animals,” Dr. Cameron said. “Also, they were more engaged in the tasks and made more attempts to get the rewards, but they also made more mistakes.

    […]

    When the researchers examined tissue samples from the brain’s motor cortex, they found that mature monkeys that ran had greater vascular volume than middle-aged runners or sedentary animals. But those blood flow changes reversed in monkeys that were sedentary after exercising for five months.

  • From the article:

    Participants were enrolled in a supervised aerobic exercise program held three days a week. As they progressed through the program, they increased their workout from an average of 20 minutes a day to an average of at least 40 minutes. In addition, people were asked to work out on their own once a week.

    Researchers found that after six months of exercise, participants improved by 5.7% on tests of executive function, which includes mental flexibility and self-correction. Verbal fluency, which tests how quickly you can retrieve information, increased by 2.4%.

    […]

    Before and after six months of aerobic activity, the participants' average peak blood flow to the brain was measured using ultrasound. Blood flow rose from an average of 51.3 centimeters per second (cm/sec) to an average of 52.7 cm/sec, a 2.8% increase. The increase in blood flow with exercise was associated with a number of modest but significant improvements in aspects of thinking that usually decline as we age, Poulin said.

  • A growing body of evidence indicates that exercise supports cognitive health throughout the lifespan, even into one’s later years. Scientists don’t fully understand the mechanisms that drive the beneficial effects of exercise, but some studies suggest that it increases brain volume, while others suggest that it reduces the brain’s toxic burden. Findings from a recent study suggest that exercise maintains synapses in the brains of older adults.

    Synapses are junctions between neighboring neurons, where the exchange of electrical signals and neuronal communication occurs. Synaptic formation and integrity are necessary for the establishment and maintenance of the brain’s neural networks and the precision of its circuitry. The loss of synapses promotes the collapse of neural networks important for memory and cognition and drive the dementia associated with Alzheimer’s disease. Key players in synaptic integrity are synaptic proteins, which play critical roles in neurotransmission and neuronal development.

    The investigators drew on data from the Rush Memory and Aging Project, an ongoing study of aging and Alzheimer’s disease among older adults. More than 400 older adults participated in the study. They wore activity monitors to track their movement and exercise throughout the day for up to 10 days. They also agreed to donate their brains upon their death for postmortem evaluation, during which the investigators measured the presence of synaptic proteins in the participants' brain tissue.

    They found that older adults who exercised regularly had higher levels of synaptic proteins in their brains. The proteins were present in multiple brain regions, including areas involved in memory and cognitive function, and were highest when activity levels were measured within two years of death, suggesting that without sufficient exercise, the proteins diminished over time.

    These findings suggest that exercise preserves synaptic integrity via enhanced production of synaptic proteins, potentially providing protection against Alzheimer’s disease. Learn how exercise affects other aspects of brain health in this episode featuring Dr. Giselle Petzinger.

  • Exercise oncology is an emerging branch of medicine that studies the application of exercise medicine in the treatment of cancer. Although there is a strong base of epidemiological research that supports a relationship between increased physical activity and decreased cancer severity and death, the molecular mechanisms that underlie this relationship require further research. Findings of a recent report identify myokines that suppress tumor growth in patients with prostate cancer.

    Myokines are molecules released from muscle cells that signal to non-muscle tissues that the body is physically active. Studies in non-human animals have shown that myokines such as oncostatin M, decorin,, and interleukin (IL)-6 suppress cancer growth; however research in humans is lacking.

    The investigators recruited 10 men (average age, 73 years) with prostate cancer who were undertaking androgen deprivation therapy, which includes drugs that block the action of testosterone and other male hormones. Participants completed 12 weeks of exercise training that included three sessions-per-week of supervised resistance training and daily self-directed moderate-to-vigorous physical activity. The investigators measured the participants' muscle strength, body composition, and serum myokine concentration before and after the exercise training intervention. They also grew prostate cancer cells in vitro, exposed them to serum from participants taken before and after exercise training, and observed the effects on cancer cells directly.

    Participants lost about six pounds of fat and eight pounds of total body weight during the intervention period. Participants significantly increased their strength, measured during the leg press (57 pound increase) and chest press (16 pound increase). Serum concentrations of oncostatin M increased by 82 percent while other myokines did not increase or could not be measured. Finally, prostate cancer cells incubated with serum taken post-exercise training reduced cancer growth by 22 percent compared to serum taken prior to exercise training.

    These results show that exercise induced the expression of myokines with tumor-suppressing ability in patients with prostate cancer. Future research is needed to refine the prescription of intensity, frequency, and type of exercise in cancer treatment.

  • The euphoria known as a “runner’s high” is caused by activation of the endocannabinoid system, a complex signaling system that regulates energy metabolism, inflammation, pain, and brain biology. The gut microbiota, which coordinates its activity with the brain and immune system, also modulates energy metabolism and inflammation and brain functions such as mood and cognition. Findings of a new report suggest that the endocannabinoid system is involved in communication between the gut and the immune system.

    The gut microbiota, the community of microorganisms that live in the digestive tract, consume nutrients from the diet that are not absorbed by the host and produce multi-purpose compounds such as short chain fatty acids (SCFA). Previous research has demonstrated that some strains of bacteria that produce SCFAs modulate the number of cannabinoid and opioid receptors in the gut. A dysregulated endocannabinoid system and gut microbiota may increase the risk of inflammatory bowel disease, irritable bowel syndrome, and obesity; however, [exercise may improve microbiota and gut health.](​​https://www.hindawi.com/journals/omcl/2017/3831972/)

    The authors collected baseline data from a group of 78 participants (age, greater than 45 years) with osteoarthritis who were part of a separate trial. They also collected data from a group of 40 additional adults. Participants provided a stool sample for the measurement of cannabinoids and cannabinoid metabolites, inflammatory markers, and SCFAs. They also sequenced the bacterial DNA contained in the stool sample to identify the types of bacteria present.

    The researchers found that endocannabinoid concentrations in the stool increased as levels of SCFAs, SCFA-producing bacteria, and overall microbiota diversity increased. Higher endocannabinoid levels were associated with higher levels of inflammation-resolving cytokines such as interleukin-10 and lower levels of pro-inflammatory cytokines such as interleukin-6 and tumor necrosis factor-alpha. Using a statistical model, the researchers found that endocannabinoid levels mediated the relationship between SCFA and inflammatory markers. This means that the relationship among these three variables is stronger than the relationship between SCFA and inflammatory markers alone.

    These results demonstrate that endocannabinoids facilitate some of the anti-inflammatory effects of SCFAs and that the endocannabinoid system modulates the immune system through activity of the gut microbiota.

  • Cancer is the second leading cause of death among people living in the United States, having claimed the lives of more than 600,000 people in 2020. Lifestyle behaviors, such as poor dietary habits, smoking, and physical inactivity, are key drivers of many cancers. Findings from a recent study suggest that more than 46,000 cancer deaths could be prevented every year if people met current physical activity guidelines.

    Physical activity is a broad term that describes both daily activities, such as gardening, doing household chores, or mowing the lawn, and classical forms of exercise, such as running, swimming, cycling, or boxing. Public health guidelines recommend that adults engage in at least 150 to 300 minutes of moderate-intensity physical activity or 75 to 150 minutes of vigorous-intensity aerobic physical activity (or an equivalent combination of the two) weekly. They also recommend that adults engage in muscle-strengthening activities such as weight lifting at least twice weekly. These recommendations are based on robust evidence that regular physical activity supports a healthy immune system (a critical factor in cancer prevention), reduces chronic inflammation, and helps the body maintain healthy levels of hormones such as insulin and estrogen, which can drive certain types of cancers if unbalanced.

    The authors of the study analyzed self-reported physical activity data for more than 550,000 adults who participated in the National Health and Nutrition Examination Survey. They obtained age-, sex-, and state-specific cancer incidence data from the United States Cancer Statistics database and ranked cancer incidence by site, such as the breast, colon, or other site.

    Their analysis revealed that more than 46,000 new cancer cases each year – roughly 3 percent – were likely attributable to physical inactivity, even after taking age, sex, race, and ethnicity into account. Inactivity-related cancer rates varied considerably by geographical location, with the lowest rates in northern and western states (especially Utah, Montana, Wyoming, Washington, and Wisconsin) and the highest rates in southern states (especially Kentucky, West Virginia, Louisiana, Tennessee, and Mississippi). The most common form of cancer associated with physical inactivity was stomach cancer; the least common was bladder cancer.

    These findings support those of previous studies demonstrating that physical activity plays a key role in reducing the risk of many types of cancer. Narrowing the findings to the state level can help state and community-level public health authorities design appropriate cancer prevention and control programs, potentially reducing the cancer burden nationwide.

  • Traditionally, governments and public health authorities have placed a high emphasis on recommending physical activity as a means of combating weight gain and obesity. Yet, randomized controlled trials have found exercise alone to have a relatively modest effect on body weight, yielding weight loss averages in the order of 4 to 11 pounds (2 to 5 kilograms) in people with overweight and obesity. Some researchers have posited that metabolic adaptation causes the body to compensate for energy burned during exercise by reducing the baseline metabolic rate and ultimately “canceling out” some of the exercise-induced calorie deficit. Findings from a recent study indicate that much of the effort of exercise is lost to energy compensation, especially among people with excess bodyweight.

    The researchers’ analysis revolved around energy expenditure data collected in a cohort of more than 1,700 healthy adults, excluding those involved in competitive sports training or were pregnant or breastfeeding. They focused on three measures: baseline energy expenditure (i.e., the energy required to fuel basic functions such as respiration, tissue repair, and immune defense, minus any physical activity), total energy expenditure (i.e., total calories burned over the same period of time), and physical activity expenditure (inferred by subtracting baseline from total energy expenditure).

    Looking at the relationships between the three types of energy expenditure, the researchers corroborated what many smaller studies have suggested. That is, the more energy a person used during physical activity, the more their baseline metabolism slowed down to avoid a calorie deficit. The result of this adaptation is that total energy expenditure is approximately 28 percent lower on active days than might be expected given the number of calories burned during physical activity.

    This metabolic compensation was independent of the participants' sex or age. However, it was significantly affected by fat mass and body mass index (BMI), as individuals in the 90th percentile of BMI recouped approximately 49 percent of calories burned through physical activity by lowering their baseline metabolism.

    These findings suggest that exercise may be a considerably less effective weight loss tool for people with overweight or obesity. They also raise interesting questions about causality, such as whether people who have overweight are better metabolic “compensators” because of their high level of adiposity (which may have hormonal and signaling properties conducive to this form of adaptation) or whether they become overweight because they start out life by being better “compensators” and are more likely exceed their baseline metabolic needs with food. The possibility of innate differences in compensation receives some support from evidence for significant ethnic disparities in baseline metabolism. It is worth mentioning that exercise benefits human health independently of potential weight loss, through effects such as improved endothelial cell function, neurogenesis, glucose regulation, and inflammation.

  • Epidemiological data indicate that regular exercise not only reduces the risk of developing cancer, but it also improves survival among people who have been diagnosed with cancer. Two theories have emerged to explain exercise’s tumor-suppressive effects. Whereas one theory suggests that exercise acts via direct physical effects on tumor cells, the other theory suggests that it acts via indirect effects related to the tumor microenvironment. Findings from a recent study suggest that myokines suppress tumor growth.

    Myokines are cell-signaling proteins produced in muscles during exercise. Evidence indicates that myokines exert direct anti-inflammatory effects on visceral fat and muscles. They also participate in metabolic pathways involving fat oxidation and glucose uptake – critical factors in tumor survival.

    The intervention study involved 10 prostate cancer patients (average age, 73 years) who were undergoing androgen deprivation therapy, a common treatment for prostate cancer that often decreases muscle mass and increases fat mass. The patients engaged in a 12-week exercise program that included resistance and aerobic activities. The patients took a protein supplement that provided 40 grams of protein immediately after each exercise session to promote muscle protein synthesis. The authors of the study assessed the patients' body composition via dual-energy X-ray absorptiometry and measured their muscle strength via the one-repetition maximum method. Before and after the intervention, they measured the patients' fasting blood glucose; serum concentrations of myokines, including oncostatin M (which exibits anti-cancer effects); and prostate cell number and growth rate.

    They found that at the end of the intervention, the patients' fat mass, percent body fat, and body weight had decreased, but their lean mass and strength increased. Concentrations of oncostatin M and prostate cancer cell number and growth rate decreased.

    These findings suggest that exercise exerts anti-tumor effects via the actions of myokines produced in exercising muscles. They also underscore the importance of remaining physically active throughout the lifespan. Learn how exercise, in conjunction with fasting, may work synergistically to benefit health in this episode featuring Dr. Mark Mattson.

  • Sleep is essential for both mental and physical health. Not getting enough sleep increases a person’s risk of developing many chronic illnesses, including cardiovascular disease, kidney dysfunction, hypertension, diabetes, stroke, obesity, and depression. More than a third of all adults living in the United States don’t get enough sleep. Findings of a recent analysis suggest that high intensity exercise does not impair sleep.

    Exercise and sleep are intrinsically linked. Evidence suggests that people who exercise tend to fall asleep more quickly and have better quality sleep than non-exercisers. However, sleep experts often caution against engaging in high intensity exercise less than three hours before bedtime to prevent sleep impairment due to exercise’s effects on circadian rhythmicity as well as other effects.

    The authors of the analysis reviewed data from 15 studies involving 194 healthy adult participants who engaged in high-intensity exercise before bedtime versus non-exercisers. The participants, who were between the ages of 18 and 50 years, reported regular, good sleep quality.

    When exercisers completed an acute bout of high-intensity exercise one-half hour to four hours before bedtime, their rapid eye movement sleep decreased, compared with non-exercisers, but no other significant sleep changes occurred. Similarly, engaging in regular high-intensity exercise in the evening two to four hours before bedtime did not disrupt sleep.

    These findings suggest that high-intensity exercise before bedtime does not impair sleep onset or quality. Many factors influence sleep onset and quality, however, including room temperature and light exposure. Learn more about these factors in this episode featuring sleep expert Dr. Matt Walker.

  • Exposure to high heat while sauna bathing causes mild hyperthermia – an increase in the body’s core temperature – that induces a thermoregulatory response to restore homeostasis and condition the body for future heat stressors. These adaptations to high temperatures involve increased production of brain derived neurotrophic factor (BDNF), a promoter of neuroplasticity, and irisin, a biomarker of exercise. Findings of a new report demonstrate that whole-body hyperthermia increases BDNF and irisin in healthy young adults.

    Whole-body hyperthermia is a therapeutic strategy used to treat various diseases, including cancer and depression. Previous research has shown that use of a hyperthermia chamber increases BDNF to a greater extent than light intensity exercise. Some research has suggested that BDNF production is stimulated by irisin, a hormone secreted from muscle in response to exercise. Irisin may mediate some of the beneficial effects of exercise and sauna use in humans, but additional research is needed.

    The authors recruited 20 male participants (average age, 22 years) and assessed their baseline heat tolerance using a hyperthermia protocol. Participants reclined in a hyperthermia chamber while the researchers increased the temperature of the chamber by 50 degrees F every ten minutes until the participant reached their personal heat threshold. Next, participants completed ten hyperthermia sessions tailored to their baseline conditioning, during which the hyperthermia chamber was set to a temperature of 150 to 175 degrees F. Following a three-week wash-out period, they completed ten sham treatments over two weeks, during which the hyperthermia chamber was set to a temperature of 75 to 77 degrees F.

    Participants had an average core body temperature of 102 degrees F at the end of each whole-body hyperthermia treatment. Following ten whole-body hyperthermia treatments, participants had a significant increase in circulating irisin levels (6.3 micrograms per milliliter) compared to their baseline levels (5.0 micrograms per milliliter) and compared to their irisin levels following the sham treatment (5.4 micrograms per milliliter). Whole-body hyperthermia treatment also significantly increased BDNF levels (28.3 picograms per liter) compared to baseline (25.9 picograms per liter).

    In healthy young adults, ten whole-body hyperthermia significantly increased irisin and BDNF levels. The authors noted that future studies should explore the effects of whole-body hyperthermia on adipose tissue, which also produces irisin.

  • Aging causes brain changes that impair cognitive function, even in people who do not have Alzheimer’s disease or dementia. However, lifestyle factors like diet and exercise have significant influence over the rate of cognitive decline. Previous research has shown that exercise improves brain health and cognitive function during aging. A new report details the role of the muscle hormone irisin in the neuroprotective effects of exercise

    Irisin, a type of myokine, is a hormone secreted from muscle in response to exercise. Previous research has shown that irisin may mediate some of the beneficial effects of exercise on the brain by stimulating the production of brain-derived neurotrophic factor (BDNF), a growth factor that increases neuroplasticity. Irisin is a fragment of the prohormone FNDC5, which is attached to the membranes of muscle cells. During exercise, irisin is cleaved from FNDC5 and circulates throughout the body to induce adaptations to exercise.

    The authors used mice of varying ages who lack the genes necessary to produce FNDC5, called knock-outs, and genetically-normal mice, called wild-type. Both groups of mice completed exercise testing to measure balance, grip strength, endurance, and motor coordination; a water maze test to measure spatial learning ability and memory; and an open field test to measure locomotor activity levels, anxiety, and willingness to explore. In order to study the effects of irisin supplementation, the investigators conducted a second experiment in which they administered exogenous (i.e., made outside the body) irisin to a strain of mice who develop an Alzherimer’s-like dementia at an early age due to loss of FNDC5 function. The investigators measured structural and psychological changes in the brain throughout both experiments.

    Both knock-out and wild-type mice exercised the same amount during testing. However, unlike the wild-type mice, knock-out mice did not show exercise-induced improvements in spatial learning and memory. Aged knock-out mice had more cognitive decline than wild-type mice and were less likely to prefer novel objects, a behavior associated with loss of function in the hippocampus, the brain region most associated with memory loss in dementia. Indeed, aged knock-out mice showed abnormal neuronal activation patterns in the dentate gyrus, a structure within the hippocampus that contributes to memory formation.

    In contrast to knock-out mice and sedentary wild-type mice, wild-type mice who exercised had increased dendritic complexity and length in the dentate gyrus. This demonstrates the ability of exercise to improve neuronal structure and function in brain areas associated with memory through mechanisms involving irisin. Regular injections with exogenous irisin significantly improved performance on spatial learning and memory tasks in mice with Alzheimer’s-like dementia compared to untreated mice. These improvements may have been caused by dampening of overactive glial activity, leading to reduced inflammation.

    Taken together, these data suggest that irisin is essential for mediating the beneficial effects of exercise on cognitive function. The authors concluded that these data also demonstrate the efficacy of exogenous irisin administration in regulating cognitive function in mice with Alzheimer’s-like dementia, providing support for future use of irisin therapies in humans with dementia.

  • The question of why muscles grow after exercise seems to have a simple answer - they grow by repairing themselves from the damage exercise causes. However, this theory does not explain the loss of muscle mass that occurs after long periods of rest or in microgravity environments such as those encountered in space. Authors of a new report suggest that muscle growth is regulated by structures within muscle cells that sense changes in mechanical force.

    Muscle fibers lengthen and shorten in cycles to create muscle movement. Fast muscle fiber cycling is utilized during the fight or flight response, generating nearly instantaneous motion. Over periods of several days, muscles regulate their growth based on the number of these contraction cycles. But how muscles “know” how much they have been used has yet to be elucidated.

    The sarcomere is the smallest structural unit of striated muscle (i.e., skeletal and cardiac muscle) and is composed of thin actin and thick myosin filaments, which slide against each other to create the force needed for contraction and relaxation. Titin is a protein at the core of the myosin filaments that changes shape when force is applied. Force “opens” the titin protein structure, exposing a molecular site for phosphorylation (i.e., adding a phosphate group). This phosphorylation initiates a signaling cascade that results in changes to gene expression that affect long-term growth and atrophy of skeletal muscles.

    The authors created a mathematical model to explain the mechanism of the mechanosensing function of titin. The model was divided into three parts. The first part of the model characterized the opening of the titin protein structure in response to force. The second part of the model characterized the creation and degradation of signaling molecules that are downstream in the signaling cascade initiated by titin phosphorylation. The third part of the model characterized how muscle cells compensate for the depletion of short-term adenosine triphosphate (ATP) energy stores that results from energy production through oxidative phosphorylation.

    From the modeling calculations, the authors found that titin acts as a mechanosensitive switch that is put under extreme force during resistance exercise (e.g., weight lifting) and less force during endurance exercise (e.g., jogging). The model also explained that titin phosphorylation geometrically inhibits the function of ribosomes, the cell structures that build proteins. Following exercise, some protein synthesis in the muscle is inhibited; however, after a lag of days or weeks, repeated exercise increases the rate of ribosome gene expression and synthesis. Building on this information, the model yielded that these alterations in protein synthesis are ultimately responsible for muscle hypertrophy following exercise and muscle atrophy following extended rest.

    The authors noted that this important research may identify targets for future therapies that prevent the loss of muscle mass that occurs with age and with diseases such as cancer and HIV.

  • Time-restricted eating involves restricting the timing of food intake to certain hours of the day (typically within an 8- to 12-hour time window) without an overt attempt to reduce caloric intake. Increasing the amount of time spent fasting each day has been used to treat metabolic diseases such as type 2 diabetes and high cholesterol, increase muscle mass, decrease fat mass, and improve exercise performance. Findings of a recent report demonstrate the beneficial effects of time-restricted eating on exercise performance in power athletes.

    Increasing muscle mass and decreasing fat mass is an important goal for many athletes because increasing their strength-to-mass ratio improves performance. While time-restricted eating is one strategy to improve body composition, previous research has shown that other types of intermittent fasting (e.g., religious fasting during Ramadan) decrease power output and endurance. Another study involving intermittent fasting with caloric restriction found similar deficits in athletic performance. The effects of long-term time-restricted eating without caloric restriction are unknown.

    The researchers recruited healthy young males who were currently practicing a power-sport at least three times per week and had been practicing for at least three years. Twelve participants (average age, 22 years) completed four weeks of time-restricted eating and four weeks of a standard meal pattern in random order with two weeks of wash-out in between. During the time-restricted eating period, participants consumed all of their food within an eight-hour window. The researchers measured body composition using X-ray and athletic performance using the Wingate test, a cycling challenge that measures power and total work.

    Time-restricted eating produced a significant increase in total work (a measure of force over a set distance) and average power output (a measure of work over time). These improvements translated to a one second reduction in sprinting time. The participants achieved this change after four weeks of time-restricted eating, but not after one week. Time-restricted eating did not improve peak power, endurance, or body composition.

    Time-restricted eating, along with regular training, improved exercise performance in athletes. Given that the difference between the current and former 400 meter running world records is only 15 hundredths of one second, the one second decrease in sprinting time produced by time-restricted eating is meaningful.

  • Nearly two-thirds of adults living in the United States have high blood pressure, defined as having a systolic pressure of 130 mm Hg or higher or a diastolic pressure of 80 mm Hg or higher. Aerobic exercise is one of the most effective strategies for maintaining healthy blood pressure, but fewer than 40 percent of adults meet current exercise guidelines. Findings from a new study suggest that high-resistance inspiratory muscle strength training improves blood pressure.

    High-resistance inspiratory muscle strength training is a form of resistance exercise that strengthens the muscles involved in breathing. The technique involves inhaling forcefully via the mouth through a portable, hand-held device that provides resistance against the inhalation. The frequency of training, number of repetitions, and amount of resistance vary based on the participant’s needs and respiratory health.

    The study involved 36 healthy adults (ages 50 to 79 years) who had high systolic blood pressure. Half of the participants performed high-resistance inspiratory muscle strength training (five sets of six breaths, with one minute of rest between sets) for six weeks. The other half performed sham breathing exercises against very little resistance. The study investigators measured various biomarkers associated with stress and cardiovascular health in the participants' blood. They measured the participants' resting blood pressure at four time points (screening, baseline, end‐intervention, and follow‐up) and measured ambulatory pressure via a portable monitoring device every 20 minutes during the day and every 60 minutes at night over a 24-hour period. They also measured flow‐mediated dilation, an indicator of vascular endothelial function. They treated endothelial cells with plasma drawn from the participants before and after the intervention to assess the bioavailability of nitric oxide, a key signaling molecule in the cardiovascular system.

    When participants performed with high-resistance inspiratory muscle strength training, their resting systolic blood pressure decreased from an average of 135 mm Hg to an average of 126 mm Hg. Similarly, their diastolic blood pressure decreased from an average of 79 mm Hg to an average of 77 mm Hg. Their 24-hour systolic blood pressure decreased, and their arterial flow‐mediated dilation improved by approximately 45 percent. The sham training had no effects on blood pressure or flow-mediated dilation. Participants who performed high-resistance inspiratory muscle strength training exhibited decreases in C‐reactive protein (a biomarker of inflammation) and improvements in other markers associated with cardiovascular function. Nitric oxide bioavailability increased in both groups but was 10 percent higher among those who performed high-resistance inspiratory muscle strength training.

    These findings suggest that high-resistance inspiratory muscle strength training demonstrates promise as a lifestyle strategy to lower blood pressure. Another lifestyle behavior that reduces blood pressure is sauna use. Learn more about sauna use in our overview article.

  • Depression is characterized by mood alterations, such as increased sadness and irritability, and physiological changes, such as decreased sleep, appetite, and sexual desire. Previous research has reported a relationship between increased muscle strength and lower depression risk in older adults. Findings of a recent study detail the relationship between muscle strength and depression risk in young adults.

    Cytokines are proteins that participate in cell-signaling. Pro-inflammatory cytokines are increased in depression and contribute to the dysfunction of neurotransmission, hippocampal neurogenesis, and stress-related nervous system activation. Skeletal muscle cells secrete a number of pro-inflammatory cytokines, such as interleukin (IL)-6, IL-8, and IL-15. A previous study demonstrated a relationship between lower levels of inflammation in adolescents with increased muscle strength and decreased body fat, but the study did not measure depression risk.

    The authors included 600 female participants without depression (average age, 19 years) in their analysis who were part of a larger observational study of physical fitness and health in Chinese college students. Participants completed a survey to measure depression symptoms and a physical exam including the use of a dynamometer to measure grip strength, a proxy for total skeletal muscle strength. The authors collected these measures at baseline and at a one-year follow-up. They classified participants into one of four categories based on the amount of grip strength they gained over the one-year study period.

    At the one-year time point, about 11 percent of participants reported depressive symptoms. Participants who gained the most grip strength over the one-year study period had a 66 percent lower risk of depression compared to participants who gained the least grip strength. Participants with the greatest gains in grip strength tended to be younger and smoke less at baseline than participants with the least gains in grip strength. Finally, gains in grip strength were significantly related to body mass index (BMI) at baseline. Underweight, defined as a BMI less than 18.5, was more common in participants with the lowest gains in grip strength (43 percent), while overweight, defined as a BMI greater than 25, was more common in participants with the greatest gains in grip strength (23 percent).

    The authors concluded that increased grip strength is associated with a lower risk of depressive symptoms in young adults.

  • Chronic sleep deprivation, a risk factor for cardiovascular and Alzheimer’s diseases, is common among adults in industrialized nations, with many reporting less than seven hours of sleep each night during the workweek. Acute sleep deprivation impairs cognitive function, working memory, attention, and executive function, increasing the rate of mistakes made while driving, at work, and at home. A recent report details the effects of aerobic exercise on cognitive function following a night of sleep deprivation.

    Sleep deprivation has been shown to decrease brain oxygen saturation, contributing to cognitive impairment. However, previous research has demonstrated that aerobic exercise increases blood flow to the prefrontal cortex, activating key brain regions that improve cognitive function. Enhanced blood flow to the brain during exercise increases oxygen saturation in brain tissue and improves energy metabolism.

    In this study, the researchers recruited 12 participants (average age, 21 years) and measured their baseline maximum aerobic capacity while riding a stationary bicycle. On a separate study visit, participants completed cognitive testing and answered questionnaires before and after cycling for 20 minutes at 60 percent of their maximum aerobic capacity. Participants wore an electrode cap on their heads during exercise to measure electrical activity in the brain. They completed this study visit twice in random order, once after a full night of rest and once following a night of total sleep deprivation.

    Sleep-deprived participants reported feeling sleepier and performed significantly worse on cognitive tests prior to exercise. Following exercise, both sleepiness and cognitive function were improved in both groups, although cognitive scores were still comparatively worse in the sleep-deprived group. Under both rested and sleep-deprived conditions, blood flow to the prefrontal cortex increased within 12 minutes of initiating exercise and was maintained until the end of exercise. However, the researchers did not find a relationship between oxygenation levels and cognitive function, so whether exercise-induced brain oxygenation had a beneficial effect on cognitive function is unclear.

    The authors concluded that exercise corrects the cognitive impairment induced by sleep deprivation, although future research is needed to identify the best exercise protocol to maximize the benefits on brain oxygenation following sleep deprivation.

  • Aerobic exercise provides many health benefits, including a reduced risk of cardiovascular, metabolic, and other chronic diseases. Some of these benefits are due to adaptations in skeletal muscle that arise from the repair of cellular damage produced by the demand of exercise. One team of researchers aimed to determine the effects of antihistamines on muscle adaptation following acute and chronic high intensity interval training, often referred to as HIIT.

    Histamine is an organic molecule that acts as a neurotransmitter in the brain and spinal cord, while also regulating gut and immune function. Much of the research surrounding histamine is in relation to its effects in allergies and inflammation; however, recent research has demonstrated the role of histamine as a mediator of exercise-induced physiological responses. Histamine release is stimulated by exercise and promotes increased blood circulation, which may be important for facilitating muscle adaptation.

    The investigators conducted two phases of research including a randomized cross-over study of antihistamines and their effect in acute exercise and a double-blind, placebo-controlled, randomized study of chronic exercise training and antihistamine use. Participants in the acute exercise trial completed two exercise sessions on separate days. On one day, they took an antihistamine one hour prior to aerobic exercise and on the other day they took a placebo treatment. The researchers measured heart rate during exercise and blood pressure, heart rate, and arterial blood flow in the thigh before and after exercise.

    In the placebo group, blood flow in the thigh was increased by approximately threefold 15 minutes following exercise and remained 50 percent higher two hours following exercise. However, post-exercise blood flow was significantly reduced in participants who took an antihistamine (about 35 percent). Histamine treatment did not alter blood pressure or heart rate before or after exercise compared to the placebo group.

    For the study on chronic exercise, participants completed six weeks of high intensity interval training, which consisted of three weekly sessions of cycling. Half of the participants took an antihistamine one hour prior to exercise and the other half took a placebo. The researchers measured maximum exercise capacity by having participants exercise to exhaustion and measuring their oxygen output. They measured metabolic health by having participants complete an oral glucose tolerance test in which they consumed 75 grams of glucose (the amount of sugar in about two cans of non-diet soda) and had their blood glucose measured over two hours. They assessed vascular function by using ultrasound to measure the rate of blood flow in the thigh. Finally, the researchers took muscle biopsies from the thigh of participants in order to measure muscle adaptation.

    Over the six weeks of training, resting heart rate tended to decrease in the placebo group but not in the antihistamine group, indicating a blunting of exercise-induced adaptation. Peak power output during exercise also increased in both groups; however, this increase was significantly greater in the placebo group (12 percent increase) compared to the antihistamine group (7 percent increase). The time to exhaustion also improved significantly with training in the placebo group (81 percent increase) compared to the antihistamine group (31 percent increase). Training improved glucose tolerance significantly in the placebo group (26 percent increase), but this effect was blocked in the antihistamine group (1 percent increase). Finally, participants in the placebo group experienced a 37 percent improvement in vascular function while those in the antihistamine group experienced a 14 percent decrease in vascular function. Maximal blood flow during exercise also increased due to training in the placebo group only.

    In conclusion, antihistamine use blunted the functional adaptations in exercise capacity, whole-body glycemic control, and vascular function produced by exercise. Histamine activity is necessary for the integrative exercise training response in humans, potentially related to increases in blood flow.

  • Exercise training provides a wide range of physiological benefits that help maintain cardiovascular health. Although most people acknowledge the benefits of exercise, many people do not exercise, often due to the time commitment involved in regular training. A recent review describes the cardiovascular benefits associated with short-duration high-intensity interval training.

    High-intensity interval training, often referred to as HIIT, is a popular form of exercise involving short bursts of intense aerobic exercise interspersed with periods of rest or lower-intensity exercise. A classic example of HIIT is combining sprints (high-intensity) with jogging (low-intensity). During a typical HIIT session, exercisers typically achieve 80 to 100 percent of their VO2max (a measure of respiratory function) or maximum heart rate. Most HIIT workouts are brief, lasting just 15 to 30 minutes.

    An abundance of research has demonstrated that short bouts of HIIT improves cardiorespiratory fitness, metabolic function, and body composition, among other effects, even in the absence of clinically significant weight loss. The mechanisms that drive these effects are thought to be related to improvements in muscle tissues' oxidative capacity, enhanced insulin response, and improvements in heart function (specifically, left ventricle ejection fraction) and vascular compliance (an indicator of blood vessel elasticity and storage capacity).

    Short bouts of HIIT elicit many of the same health benefits that longer bouts of HIIT or traditional forms of exercise (sometimes to a greater extent) and are considered safe, even for inactive people. The authors of the review posit that such types of activity offer a means to improve cardiometabolic health in inactive people, requiring little time commitment and modest effort.

  • Exercise puts a demand on skeletal muscle cells to produce energy at a faster rate than at rest. To do this, the body increases the delivery of fats to the muscle mitochondria while increasing the mitochondrial capacity to metabolize fats, a process called beta-oxidation. Researchers of a new study aimed to illuminate the cellular mechanisms of mitochondrial fat metabolism following moderate intensity aerobic exercise.

    Mitochondria are cellular structures responsible for the production of energy in the form of adenosine triphosphate (ATP). The inner membrane of mitochondria possess a series of enzymes called the electron transport chain. These enzymes transfer electrons from carbohydrates and fats (as well as proteins and nucleic acids to a lesser extent) to the final enzyme in the chain that produces ATP. Electron transfer flavoprotein is an enzyme in this chain that transfers electrons from fats, specifically. The authors of this report have previously presented data demonstrating an increase in electron transfer flavoprotein activity in mice after aerobic exercise training.

    The investigators recruited fifteen healthy sedentary adults (average age, 28 years) with a normal body mass index. Participants completed one hour of cycling at 65 percent of their maximum aerobic capacity on one day and rested the next day. The researchers collected biopsies from the participants' thigh muscle after they had rested and 15 minutes after they exercised. They analyzed the muscle mitochondria for the abundance of electron transfer flavoprotein activity and for the metabolism of fats and nonfat fuel sources.

    Following exercise training, mitochondrial metabolism of fats and non-fat sources increased, although this relationship was not statistically significant. Also noted was a six percent increase in hydrogen peroxide, which is a byproduct of fat metabolism that damages cells. Although fat metabolism increased, the authors reported no increase in electron transfer flavoprotein activity abundance.

    They authors concluded that just one session of moderate intensity aerobic exercise in sedentary adults increases energy metabolism of both fats and non-fat sources. They suggested future research would include a larger sample of participants.

  • The circadian rhythm is controlled by a central clock in the brain and by peripheral clocks in skeletal muscle, adipose tissue, and other organs. Together, these clocks coordinate the expression of genes related to a variety of metabolic processes with daily light, eating, and activity cycles. New research suggests that exercising in the afternoon maximizes metabolic benefits due to circadian-driven cycles.

    While light is the main driver of the central circadian clock in the brain, peripheral clocks are responsive to a number of environmental signals such as eating and exercise. When these activities are out of sync with normal light/dark cycles, as seen with shift work, metabolic dysfunction occurs. Previous research in humans has reported severely impaired glucose and insulin regulation with circadian disruption.

    The investigators recruited a group of 32 males (average age, 58 years) who had type 2 diabetes or were at risk for developing type 2 diabetes. Participants completed 12 weeks of combined aerobic and resistance training in the morning (8 a.m. to 10 a.m.) or afternoon (3 p.m. to 6 p.m.). The researchers measured insulin tolerance, body composition, and exercise performance before and after the intervention.

    Participants who exercised in the afternoon improved their insulin sensitivity by 34 percent, while insulin sensitivity in the morning group improved only 3 percent. The afternoon group also experienced a significantly greater reduction in fasting glucose levels, fat mass, percent body fat, and exercise performance. Although it wasn’t statistically significant, afternoon exercise also tended to improve glucose output from the liver, another marker of metabolic health.

    The authors concluded that exercising in the afternoon improved insulin tolerance, body composition, and exercise performance to a greater extent than morning exercise in those with metabolic dysfunction. The authors speculated that circadian cycles in skeletal muscle or cycles in body hormone levels may be the cause of this effect, although further research is needed to fully understand the impact of exercise timing on metabolism.

    Link to full study. Learn more about the importance of circadian rhythms in this episode featuring expert Satchin Panda.

  • Coffee contains a wide range of bioactive compounds that influence human health. Evidence suggests that coffee consumption reduces the risk of cardiovascular disease-related deaths and certain types of cancer. Findings from a new study suggest that caffeine in coffee improves fat metabolism when consumed prior to exercise.

    Caffeine is an alkaloid compound with potent stimulatory effects. Evidence indicates it improves performance in both endurance and resistance exercise. Some of these effects may be due to caffeine’s capacity to decrease the perception of effort and increase the neural actions on muscle fibers.

    The triple-blind, placebo-controlled, crossover trial involved 15 healthy men (average age, 32 years) who were endurance trained but not regular consumers of caffeine. The men cycled on a stationary bike while slightly increasing the resistance every minute until they reached exhaustion. The test was performed four times, either in the morning (8 a.m.) or afternoon (5 p.m.), with each test separated by seven days. Thirty minutes prior to exercising, the men ingested either anhydrous caffeine powder from green coffee beans (3 milligrams per kilogram of bodyweight) or a placebo. The authors of the study monitored the men’s heart rate, maximal fat oxidation (and the exercise intensity at which it occurs), and respiratory function (VO2 max) during the exercise test.

    They found that maximal fat oxidation and the intensity at which it occurs exhibited a diurnal pattern, with higher values seen when the men exercised in the afternoon rather than in the morning. Caffeine potentiated the diurnal effect, increasing the men’s average maximum fat oxidation by nearly 11 percent in the morning and 29 percent in the afternoon. Caffeine also increased the exercise intensity at which the fat oxidation occurred by 11 percent in the morning and by 13 percent in the afternoon.

    These findings suggest that caffeine improves fat oxidation in endurance athletes and these effects are influenced by a diurnal rhythm. Consuming caffeine in the morning maximized fat oxidation to a degree similar to that seen without caffeine in the afternoon. It is important to note that while caffeine intake may improve fat oxidation, intake late in the day can impair sleep, potentially negating some of the beneficial effects of exercise. Learn more about the effects of caffeine on sleep in this clip featuring sleep expert Dr. Matthew Walker.

  • Just one night of sleep deprivation can impair arterial function, and chronically poor sleep increases the risk of developing cardiovascular disease. Conversely, high intensity interval exercise can improve multiple markers of heart health. In this report, researchers tested the effects of exercise on flow mediated dilation, a measure of vascular function, in sleep-deprived participants.

    Flow mediated dilation is a measure of how wide an artery expands in response to increased blood flow. Meals high in fat normally cause dysfunction in blood vessels, impairing their ability to dilate. Previous research reports that high intensity exercise improves flow mediated dilation following a meal.

    Fifteen healthy active men (average age, 31 years) completed three nights of sleep for this study. The first night, participants slept a full eight hours and ate a high-fat test meal the next morning. The second night, participants slept a full eight hours, then performed high intensity interval training before eating. The third night, participants slept three and one half hours or less, then performed the same exercise and ate the same meal. The researchers measured flow mediated dilation at multiple time points.

    After comparing the post-meal flow mediated dilation following a full night of sleep and a full night of sleep plus exercise, the authors found that exercise improved arterial function. Impressively, the benefit of exercise remained following a night of sleep deprivation. Flow mediated dilation rates were similar between exercise conditions regardless of sleep duration the night before.

    The authors concluded that high intensity exercise improves artery function and that these benefits remain even after a night of sleep deprivation. However, they recommended that people get a full night of sleep before strenuous exercise to get the most benefit.

  • For optimal health, adults of all ages should engage in at least 150 minutes of moderate intensity physical exercise or at least 75 minutes of vigorous intensity physical exercise each week, or an equivalent combination of both. Findings from a new study show that engaging in moderate-to-vigorous intensity exercise in middle age improves cerebrovascular health later in life.

    The study involved an ethnically and racially diverse group of more than 1,600 adults (average age, 54 years). The authors of the study assessed the participants' moderate-to-vigorous intensity exercise levels based on interviews at the beginning of the study (when they were in middle age) and 25 years later. They classified the participants' exercise levels as none, low, middle, or high. The participants underwent magnetic resonance imaging studies to assess cerebrovascular health and measure white and gray matter volumes.

    Roughly one-third (39 percent) of the participants were classified as having moderate-to-vigorous intensity exercise levels during mid-life, and one-third (34 percent) were classified as having low levels. Those who had high exercise levels (about two-and-a-half hours per week) had greater intact white matter volume but not gray matter in late-life. Those who exercised more were 32 percent less likely to have experienced a lacunar infarct (a type of stroke) compared to those who engaged in no exercise.

    These findings suggest that exercise in middle age throughout older age is protective for the brain and underscore public health messaging for people of all ages to engage in more physical activity.

  • Exercise and other forms of physical activity elicit a wide range of beneficial health effects, including improvements in glucose tolerance and mitochondrial function. Findings from a new study suggest that high-intensity exercise compensates for the harmful effects of sleep deprivation.

    Sleep is critical for our mental and physical well-being. Sleep deprivation increases our risk of developing many chronic illnesses, including cardiovascular disease, kidney dysfunction, hypertension, diabetes, stroke, obesity, and depression. More than a third of all adults living in the United States report regular short sleep duration.

    The intervention study involved 24 healthy young men between the ages of 18 and 40 years. The study’s investigators placed the men into one of three groups: normal sleep (eight hours per night, for five nights); sleep restriction (four hours per night, for five nights); and sleep restriction/exercise (four hours per night, for five nights plus three high-intensity interval exercise sessions on a cycle ergometer). They assessed the participants' glucose tolerance, mitochondrial function, sarcoplasmic protein synthesis (a proxy for mitochondrial protein synthesis), and skin temperature before and after the intervention. Sarcoplasmic protein synthesis and skin temperature fluctuate in a diurnal manner due to circadian rhythms, which are altered with poor sleep.

    The men who experienced sleep restriction had reduced glucose tolerance and mitochondrial function. They also exhibited reduced amplitude of diurnal rhythms. However, the men who experienced sleep restriction but engaged in high-intensity exercise did not exhibit any of these effects.

    These findings demonstrate that high-intensity exercise may counteract the harmful effects of sleep deprivation and suggest that clinicians should recommend exercise to patients who experience poor sleep as a means to improve metabolic health.

  • Exercise exerts a wide range of beneficial effects on the human body that influence cardiovascular, metabolic, and overall health. The molecular mechanisms that drive these effects are not widely understood, however. Findings from a new study provide insights into the molecular cardiometabolic response to acute exercise.

    The study involved 471 adults (average age, 54 years) enrolled in the Framingham Heart Study, a long-term, ongoing study of cardiovascular disease risk among people living in Framingham, Massachusetts. The authors of the study measured levels of 588 metabolites in blood drawn from the participants before and immediately after ergometric cardiopulmonary exercise testing. They replicated these methods in a second group of 783 participants.

    The authors noted changes in 508 of the metabolites. In particular, they observed changes in metabolites implicated in cardiometabolic risk, including reduced levels of those involved in insulin resistance and increased levels of metabolites associated with lipolysis, nitric oxide bioavailability, and adipose browning – the process by which white adipose tissue converts to brown adipose tissue, increasing energy expenditure and improving glucose and lipid metabolism. These changes were diminished among participants with a higher BMI, suggesting that obesity (or the metabolic disturbances that accompany it) may block the benefits of exercise.

    These findings provide insights into the molecular mechanisms that drive the widespread cardiometabolic benefits of exercise and support public health recommendations to engage in regular physical activity.

  • Exercise is a critical component of public health recommendations to prevent cancer. A growing body of scientific research demonstrates that engaging in exercise after a cancer diagnosis can improve outcomes, but the mechanisms that mediate these effects are not fully characterized. Findings from a new study demonstrate that exercise alters the metabolism of cytotoxic T cells to improve their ability to attack cancer cells.

    Cytotoxic T cells play key roles in the body’s immune response. They destroy malignant cells by triggering apoptosis – a type of cellular self-destruct mechanism that rids the body of damaged or aged cells.

    The authors of the study placed mice with cancer into one of two groups. Half of the mice exercised on a treadmill, but the other half remained inactive. They transferred cytotoxic T cells from the mice that exercised into the inactive mice. Then they isolated T cells, blood, and tissues from the exercising mice. Finally, the authors injected both groups of mice with antibodies that would destroy the animals' cytotoxic T cells.

    The mice that exercise exhibited slower cancer growth and reduced death rates than those that remained inactive. The inactive mice that received the cytotoxic T cells from exercised mice showed marked improvements in their disease status. The exercising mice had high blood levels of lactate, which altered the T cells' metabolism and increased the cells' activity. Destroying the animals' cytotoxic T cells negated the beneficial effects that the exercise had in terms of cancer growth and survival.

    Taken together, these findings suggest that exercise alters cytotoxic T cells to mediate exercise-induced cancer suppression. Treatment protocols that incorporate exercise might improve outcomes by activating the immune system.

  • Military members often face unique mental and physical demands that require optimal performance under challenging conditions. A recent study demonstrated that exercise and a nutritional supplement providing components present in the Mediterranean diet optimize performance in a group of active duty military members.

    The Mediterranean dietary pattern is rich in fruits, vegetables, olive oil, fish, and poultry. Nutrients provided in the diet include phospholipids, omega-3 polyunsaturated fatty acids, carotenoids (lutein, folate, and polyphenols), and vitamins B, C, D, and E. Robust evidence indicates that these nutrients improve cardiovascular and metabolic health and support cognitive function.

    The randomized, placebo-controlled intervention study involved 148 active duty military members between the ages of 18 and 45 years. About half of the participants engaged in a supervised fitness program and took a nutritional supplement; the remainder engaged in the fitness program but took a placebo. The fitness program included resistance, aerobic, flexibility, and core strength exercises and lasted 45 minutes per session, five times per week, for 12 weeks. The nutritional supplement, which was provided in the form of a beverage, contained beta-hydroxy beta-methylbutyrate, lutein, phospholipids, DHA (an omega-3 fatty acid), and vitamins. Participants consumed two 8-ounce servings of the beverage every day for the duration of the study. The authors of the study measured the participants' nutritional biomarkers (in blood) and assessed their physical and cognitive performance before and after the study.

    At the end of the study, the participants who consumed the nutritional supplement showed greater improvements in physical and cognitive performance than those who consumed the placebo. In particular, those who took the nutritional supplement showed improvements in power, strength and endurance, mobility and stability, heart rate and lean muscle mass as well as episodic memory, fluid intelligence accuracy, executive function reaction time, and processing efficiency.

    These findings suggest that targeted fitness programs that incorporate nutritional support enhance physical and cognitive performance.

  • People living with two or more chronic diseases – a condition known as multimorbidity – are more likely to take multiple medications, have more frequent and longer hospital stays, and die prematurely than those with only one chronic disease. Multimorbidity is common among older adults.60240-2/fulltext) Findings from a recent meta-analysis suggest that exercise benefits people with multimorbidity.

    Evidence indicates that exercise increases muscle strength, improves cardiovascular and metabolic health, and boosts mood by reducing visceral fat mass and activating a wide range of anti-inflammatory processes in the body. A key feature of many chronic diseases is inflammation, but exercise may disrupt inflammation to elicit its beneficial effects.

    The authors of the meta-analysis reviewed data from 23 randomized controlled studies that investigated the health effects of exercise in people with multimorbidity, defined as having two or more chronic health conditions (arthritis of the knee or hip, hypertension, type 2 diabetes, depression, heart failure, ischemic heart disease, or chronic obstructive pulmonary disease). The study participants were between the ages of 50 and 80 years. The average duration of the studies was 12 weeks and included a variety of exercise protocols, including aquatic exercise, strength training, aerobic training, and tai chi, performed two to three times per week.

    The analysis revealed that exercise therapy interventions improved physical fitness (determined by walking distance and speed) and decreased symptoms of anxiety and depression, especially among younger adults. The interventions didn’t increase knee, arm, or back pain, or falls and fatigue. Study participants who engaged in regular exercise were less likely to be hospitalized, develop pneumonia, or experience extreme fatigue.

    These findings suggest that exercise exerts beneficial effects on people with multimorbidity and serves as a viable option in managing their conditions.

  • Exercise has well-established health benefits, such as reducing the risk of cardiovascular disease and cancer. However, long term strenuous exercise can put stress on the bones. Findings from a recent study suggest that supplementation with ubiquinol during strenuous exercise provides benefits for bone health and energy metabolism.

    Ubiquinol, a bioactive compound that exerts antioxidant properties, is the reduced form of coenzyme Q10. It is found in foods such as beef liver, tuna, and broccoli and is also available as a dietary supplement.

    Previous research has demonstrated that ubiquinol positively affects performance during low-intensity physical activity. The current study investigated whether supplementation would affect performance and mitigate bone pathologies during vigorous exercise.

    The randomized, double-blind placebo-controlled trial involved 100 healthy and well-trained male firefighters. The authors of the study provided participants with a daily supplement containing either 200 milligrams ubiquinol or a placebo for two weeks. The participants performed two bouts of vigorous exercise, separated by a 24-hour rest period, and provided blood samples before, during, and after the exercise sessions.

    The blood samples revealed that supplementation increased biomarkers of bone formation, including parathyroid hormone and osteocalcin. The authors also observed increased levels of the transcription factor PGC-1α, and the hormones insulin, leptin, and noradrenaline, which they suggest may benefit skeletal muscle and mitochondrial function, providing a competitive advantage during training or recovery.

    These findings suggest that ubiquinol supplementation can support bone formation and skeletal muscle function during high-intensity exercise.

  • Depression, often referred to as major depressive disorder in the clinical or research setting, is characterized by profound sadness, fatigue, altered sleep and appetite, and feelings of guilt or low self-worth. Although pharmaceutical treatments for depression are available, many people with depression do not respond to the medications. A new study demonstrates that aerobic exercise benefits people with depression, especially those whose symptoms are more severe.

    Previous research has demonstrated that aerobic exercise reduces depressive symptoms, but scientists aren’t sure what mechanisms drive the improvements. Two areas of interest are reward processing (the brain’s response to rewarding stimuli) and cognitive control (the ability to concentrate and make decisions).

    The intervention study involved 66 young adults (average age, 20 years) who had major depressive disorder. About half of the participants completed an eight-week program of moderate-intensity aerobic exercise, while the remainder completed an eight-week program of light stretching. The authors of the study tracked the participants' depressive symptoms throughout the study and assessed their reward processing and cognitive control before and after the intervention.

    They found that aerobic exercise reduced the participants' depressive symptoms better than light stretching. Neither form of activity had an effect on reward processing or cognitive control. However, participants whose depressive symptoms were more severe and scored high in terms of reward processing were more likely to respond to the aerobic program as opposed to the stretching program.

    These findings demonstrate that incorporating aerobic exercise programs into treatment protocols for people with depression might be beneficial in reducing depressive symptoms. Learn more about the growing body of evidence supporting the use of exercise in preventing and treating depression in this podcast featuring Dr. Rhonda Patrick.

  • Current public health guidelines recommend that adults engage in regular physical activity for optimal health. Findings from a new study suggest that a combination of both aerobic and strength activities reduces the risk of death from all causes as well as specific causes.

    According to the guidelines, adults should engage in at least 150 minutes of moderate-intensity aerobic physical activity or at least 75 minutes of vigorous-intensity aerobic physical activity each week, or an equivalent combination of both. They should also engage in muscle-strengthening activities of moderate or greater intensity on two days or more each week.

    The population-based cohort study, which involved nearly 480,000 adults, drew on data from the National Health Interview Survey, an ongoing, cross-sectional survey of people living in the United States. The study participants reported how much leisure time aerobic and strength physical activity they engaged in each week. Then the authors of the study categorized them as having insufficient activity, aerobic activity only, strength activity only, and both aerobic and strengthening activities, based on the guidelines.

    The authors found that the participants who engaged in recommended amounts of aerobic or muscle-strengthening activity had a lower risk of death from all causes, and these benefits were even greater if they engaged in both types of activities. They noted similar reductions in risk of death from cardiovascular disease, cancer, and chronic lower respiratory tract diseases.

    These findings suggest that adherence to public health guidelines for exercise reduce the risk of disease and death and provide support for interventions to improve compliance.

  • Exercise improves cognitive function and reduces the risk neurodegenerative diseases such as Alzheimer’s disease. Some of these benefits are mediated by brain-derived neurotrophic factor (BDNF). Findings from a 2012 study showed that regular exercise improved cognitive function and increased BDNF levels, but a genetic variant in BDNF influenced the degree of these effects.

    BDNF is a protein that acts on neurons in the central and peripheral nervous systems. A single-nucleotide polymorphism (SNP) in the gene that encodes BDNF causes a substitution of the amino acid valine (Val) by methionine (Met) in the BDNF protein. This genetic variant, known as Val66Met, alters exercise-driven release of BDNF and affects learning, memory, and emotion.

    The intervention study involved 75 sedentary, healthy, young adults between the ages of 18 and 35 years. The participants took memory tests and mental health surveys before and after engaging in their randomly assigned respective activities: no exercise; four weeks of exercise with exercise and a test on the last day; four weeks of exercise, without exercise on the final test day; or a single bout of exercise on the last test day.

    The participants who engaged in exercise showed improvements in memory and experienced lower levels of perceived stress, but only if they exercised for four weeks including the final day of testing. Participants who engaged in a single bout of exercise showed no changes in memory performance and demonstrated higher perceived stress levels. The authors of the study noted improvements in the participants' memory only if they did not carry the Val66Met variant, suggesting that the associated reduction in BDNF release attenuated some of the cognitive benefits of exercise. They also noted that the improvements in cognitive function were not correlated to improvements in mental health.

    These findings suggest that the variable effects of exercise on brain function are related to a genetic variant that influences the production of BDNF.

  • The circadian rhythm is the body’s 24-hour cycle of biological, hormonal, and behavioral patterns that, when disrupted, has profound implications for human healthspan. Findings from a recent study suggest that a single bout of exercise can reset the circadian clock in the skeletal muscles of mice.

    The circadian clock coordinates gene expression in nearly all cells in a time-dependent manner. Cues from the environment, known as zeitgebers, can alter the circadian clock in a process known as entrainment. Light acts as the primary zeitgeber, but activity, stress, and eating also affect circadian timing. Exercise affects body temperature, heart rate, and many other metabolic parameters and might also entrain the circadian clock.

    The current study investigated whether exercise would act as a zeitgeber for the circadian clock in the skeletal muscles of mice. Transgenic mice completed a sixty-minute bout of moderate‐intensity exercise at different times during their rest or active periods. The authors of the study observed that mice exercised during their typical rest period exhibited a shift in the muscle circadian clock. However, mice exercised during their active phase showed no effects on the circadian rhythm.

    To factor out the hormonal and temperature effects of exercise, the authors developed an in vitro model system using time‐synchronized rodent muscle cells. They subjected these cells to an electrical current, to simulate muscle contractions, and measured the expression of known molecular clock‐related genes. The authors found that electrical stimulation altered the expression of clock genes, and shifted the circadian clock in a pattern similar to that observed in the mouse model system.

    Taken together these findings suggest that a single bout of exercise can alter the circadian clock — making it a true zeitgeber. The specific effect of exercise on the circadian clock depends on the time when it is performed. While further studies are needed to determine if these findings translate to humans, the authors propose that shift workers might benefit from timed exercise to offset some of the negative effects of circadian disruption.

  • From the article:

    For these experiments, the researchers injected the BDNF gene or protein in a series of cell culture and animal models, including transgenic mouse models of Alzheimer’s disease; aged rats; rats with induced damage to the entorhinal cortex; aged rhesus monkeys, and monkeys with entorhinal cortex damage.

    In each case, when compared with control groups not treated with BDNF, the treated animals demonstrated significant improvement in the performance of a variety of learning and memory tests. Notably, the brains of the treated animals also exhibited restored BDNF gene expression, enhanced cell size, improved cell signaling, and activation of function in neurons that would otherwise have degenerated, compared to untreated animals. These benefits extended to the degenerating hippocampus where short-term memory is processed, one of the first regions of the brain to suffer damage in Alzheimer’s disease.

    […]

    “In this series of studies, we have shown that BDNF targets the cortical cells themselves, preventing their death, stimulating their function, and improving learning and memory. Thus, BDNF treatment can potentially provide long-lasting protection by slowing, or even stopping disease progression in the cortical regions that receive treatment.”

  • From the article:

    Results of study, published in the journal Experimental Biology and Medicine, show that the BDNF response to acute high-intensity interval exercise was greater than continuous moderate-intensity exercise in obese subjects when compared to normal-weight subjects. Similarly, although acute high-intensity interval exercise induced greater blood lactate and plasma cortisol levels than continuous moderate-intensity exercise, obese subjects produced less blood lactate, but showed no difference in cortisol than normal-weight subjects.

    These findings suggest that acute high-intensity interval exercise may be a more effective protocol to upregulate BDNF expression in an obese population, independent of increased lactate and cortisol levels.

  • From the article:

    Lunghi and Sale put 20 adults through this test twice; in one deprivation test, participants with one eye patched watched a movie while relaxing in a chair. In the other test, participants with one eye patched exercised on a stationary bike for ten-minute intervals during the movie. The results were clear: brain plasticity was enhanced by the exercise.

    “We found that if, during the two hours of eye patching, the subject intermittently cycles, the perceptual effect of eye patching on binocular rivalry is stronger compared to a condition in which, during the two hours of patching, the subject watches a movie while sitting on a chair. That is, after physical activity, the eye that was patched is strongly potentiated, indicating increased levels of brain plasticity.”

  • β-hydroxybutyrate production consequent to exercise induces within the muscle the activities of a key promoter involved in the production of brain-derived neurotrophic factor.

    From the article:

    Studies have shown that BDNF levels in the brains of people with Alzheimer’s or Huntington’s disease are, on average, half that of people without either brain-damaging disease.

    Among the key findings of the current study was that a ketone, a chemical naturally produced in the liver called beta-hydroxybutyrate (DBHB), triggers biological reactions that activate the BDNF gene to produce more of its protein. DBHB has long been known to build up in the body and brain with exercise. Ketones are “by-product” chemicals made when animals break down fat as an alternative energy source after having drained more readily available sugar stores during exercise.

    Specifically, Chao says, the researchers found that DBHB prevents other proteins in the brain known as histone deacetylase complexes, or HDACs, from suppressing BDNF production by altering the environment of the BDNF gene.

  • From the article:

    The team evaluated blood levels of BDNF before and after a three-month program of aerobic exercise in 15 overweight or obese men and women. The seven men and eight women, ages 26 to 51, worked out on a treadmill and bicycle. They were asked about their calorie intake and told to continue eating their usual number of calories. The participants were unaware that one of the study’s objectives was to evaluate changes in food intake.

    At the end of the study, the subjects had decreased BMI, waist circumference, and blood pressure, the data showed. They also reported consuming fewer calories than at the beginning of the study. Over the three months, BDNF levels greatly increased. This higher the concentration of BDNF, the less the subject’s intake of calories and the greater the weight loss, Araya said.

    Thus, it is possible that increases in BDNF suppress appetite, she said. They did not test appetite suppression directly, but some past studies have shown that aerobic exercise suppresses appetite.

  • Exercise elicits a wide range of physiological changes in the body that improve multiple aspects of cardiovascular, neurological, and metabolic health. The molecular mechanisms that drive these improvements are not well understood. Findings from a new study suggest that an acute bout of aerobic exercise alters more than 9,000 distinct molecules in the human body to positively influence health.

    The study involved 36 adults between the ages of 40 and 75 years. The average body mass index among the participants was 28, which is considered overweight. Their steady-state blood glucose levels ranged from 86 to 220 milligrams per deciliter, suggesting a wide range of insulin resistance, from very low to very high.

    The authors of the study collected blood samples from all the participants before exercise and two, 15, 30, and 60 minutes afterward. They collected fasting blood samples from 15 of the participants the morning after the exercise protocol to assess inter-day variability. One group of participants engaged in an acute bout of aerobic exercise on a treadmill for eight to 12 minutes at their maximum capacity. A control group of 14 participants did not perform any exercise.

    Analysis of the participants' blood before and after exercise revealed that an acute bout of aerobic exercise induced extensive changes in 9,815 molecules, including proteins, lipids, genes, immune markers, and many others, that correlate with a person’s aerobic fitness.

    The authors of the study suggested that their findings could lay the groundwork for the development of a simple blood test that measures fitness in the future.

  • A growing body of research demonstrates that exercise has beneficial effects on brain health. N-acetyl aspartic acid (NAA) is a compound found in the central nervous system that serves as a biomarker of neuronal health and energy production. Findings from a new study indicate that lower body fat and higher cardiorespiratory fitness are positively correlated with NAA levels.

    Cardiorespiratory fitness is a measure of the body’s ability to deliver oxygen to skeletal muscles during sustained physical activity. It is commonly measured by VO2 max, a person’s maximum rate of oxygen consumption while under maximal physical stress. Cardiorespiratory fitness is linked with lower body fat composition.

    The study involved 290 healthy young adults (average age, 24 years). Each of the participants' body composition and cardiorespiratory fitness were assessed. Then the participants underwent magnetic resonance spectroscopy (MRS) to assess their NAA levels.

    The MRS scans revealed that participants with less body fat and higher levels of cardiorespiratory fitness had higher levels of NAA in the white matter of their brains. This association was driven primarily by a participant’s whole-body total percent fat, suggesting that body fat might have negative effects on brain health. Exercise exerts a wide range of beneficial effects on brain health. Watch this podcast featuring Dr. Rhonda Patrick in which she describes how exercise might be useful in treating or reducing the risk of depression.

  • Poor blood flow to the brain, a common feature of aging, is associated with an increased risk of stroke and cognitive dysfunction. A recent study demonstrated that exercise improves brain blood flow and improves cognitive function in older adults.

    The intervention study involved 206 healthy, cognitively intact middle-aged and older adults (average age, 66 years) with low physical activity levels. The participants engaged in a supervised aerobic exercise program three days per week, gradually increasing from 20 to 40 minutes over a period of six months. They also completed an unsupervised exercise session one day per week during the six-month period. The authors of the study assessed the participants' cognitive performance, cerebrovascular function, and overall fitness on three separate occasions over a period of 12 months.

    After completing the six months of exercise, the authors of the study noted that the study participants improved by nearly 6 percent on measures of working memory, flexible thinking, and self-control. They improved by nearly 2.5 percent on tests of verbal fluency, comparable to abilities seen in person five years younger. Blood flow to the brain increased by nearly 3 percent, suggesting that cerebrovascular function is a critical aspect of maintaining or improving memory and verbal skills.

  • Mild cognitive impairment and memory loss often precede the development of Alzheimer’s disease, a neurodegenerative disorder characterized by progressive memory loss, spatial disorientation, cognitive dysfunction, and behavioral changes. Aerobic exercise has been shown to improve memory function in older adults. Findings from a new study suggest that exercise improves cerebral flood flow in regions of the brain involved in memory.

    The prospective clinical trial involved 30 older men and women (average age, 66 years) with mild cognitive impairment. Half of the participants engaged in a supervised aerobic exercise 25 to 30 minutes per session for three times per week, gradually increasing to 30 to 40 minutes per session for three or four times per week. The other half of the participants engaged in stretching only. At the end of the 12-month study period, the authors of the study assessed the participants' memory function, cardiorespiratory fitness, and cerebral blood flow.

    The participants who took part in the exercise program exhibited marked improvements in memory function and cardiorespiratory fitness. They also demonstrated increased blood flow to the anterior cingulate cortex region of their brains, an area associated with empathy, impulse control, emotion, and decision-making.

    Interestingly, the exercising group showed reduced blood flow to the posterior cingulate cortex, an area of the brain associated with internally directed thought and the default mode network. The posterior cingulate cortex is highly sensitive to age-related cognitive decline, Alzheimer’s disease, and dementia. The authors of the study suggested that once this area of the brain is affected by cognitive impairment, exercise can’t forestall further impairments. Instead, the exercise-induced changes in blood flow indicate a compensatory mechanism to shift brain activity to other regions.

    These findings suggest that exercise can forestall the effects of age-related cognitive decline. Many older adults are unable to participate in exercise due to physical limitations, however. Sauna use is an exercise mimetic that induces the activity of heat shock proteins, a class of proteins that provide protection against neurodegenerative conditions like Alzheimer’s disease. Learn more about the exercise-like effects of sauna use in our overview article.

  • Dementia, a form of cognitive decline that interferes with normal daily living, affects approximately 50 million people worldwide. Findings from a recent study suggest that regular physical exercise can reduce the risk of developing dementia.

    Dementia commonly occurs in older age and is characterized by a progressive loss of memory, executive function, and reasoning. Approximately 70 percent of all dementia cases are due to Alzheimer’s disease. Previous research has demonstrated that the incidence of dementia is influenced by non-modifiable risk factors, such as increasing age, ethnicity, and the presence of a genetic variant known as APOE4.

    Researchers are less certain about modifiable factors that may alter dementia risk, including health behaviors such as exercise. The current retrospective cohort study investigated which individuals developed dementia and the factors associated with its incidence.

    The study involved 206,073 people over the age of 50 years who were enrolled in the Health Check Ubon Ratchathani Project in Thailand. The authors of the study questioned participants about their medical and personal history, including the use of medications and exercise habits. Six years later, investigators reviewed the participants' electronic medical records for the incidence of physician‐diagnosed dementia. They found that a lack of physical exercise was associated with an increased risk of developing dementia in a dose-dependent manner. Exercising three to five days per week reduced the risk of dementia by 37 percent as compared to no physical exercise, while exercising more than five days per week reduced dementia risk by 59 percent.

    These findings suggest that physical exercise at least three days a week can reduce the risk of developing dementia. Further clinical trials with longer follow-ups are needed to confirm the impact of lifestyle factors on dementia risk.

  • Breast cancer is one of the leading causes of death among women living in the United States, claiming the lives of approximately 41,000 women each year. Findings from a new study suggest that regular physical activity can reduce the risk of developing breast cancer.

    The Physical Activity Guidelines for Americans recommend that adults engage in at least 150 to 300 minutes of moderate-intensity, or 75 to 150 minutes of vigorous-intensity aerobic physical activity each week. Moderate-intensity exercises include brisk walking, light cycling, or playing doubles tennis. Vigorous-intensity exercises include jogging, hiking, rigorous cycling, or playing basketball, soccer, or singles tennis. Data indicate that fewer than 23 percent of Americans achieve recommended levels of activity.

    The questionnaire-based study assessed the lifestyles of 1,340 women with breast cancer at multiple times throughout survivorship, including before, during, and after treatment. Women who met the guidelines before and after treatment were 55 percent less likely to have their cancer return and were 68 percent less likely to die from their cancer. But even if a woman didn’t start exercising until after her treatment began, she was likely to experience benefits, with a 46 percent lower risk of her cancer returning and a 43 percent lower risk of dying. These findings underscore the importance of engaging in regular activity as a means to reduce the risk of cancer recurrence and death and suggest that a breast cancer diagnosis can provide an impetus to begin exercising.

  • Sugar-sweetened beverages (SSBs) are among the leading contributors to sugar intake among people living in the United States. Consumption of a single SSB induces acute endothelial dysfunction – the inability of the cells that line the blood vessels to maintain vascular tone and regulate blood flow and inflammation. A recent study found that exercise counteracts the harmful effects of regular SSB consumption in healthy young men.

    High sugar intake is associated with several chronic diseases, including diabetes, kidney disease, and cardiovascular disease. Some evidence suggests that consumption of sugar-sweetened beverages is associated with abnormal blood lipid levels.

    The study involved 22 healthy young men who were not regular exercisers. Three times a day for seven days, the men drank a beverage containing 75 grams of glucose (a type of sugar) – roughly equivalent to consuming a typical, large-sized sugar-sweetened soft drink. They ate their regular diet throughout the study period. On five of the seven days, half of the participants engaged in a 45-minute supervised exercise protocol on an exercise bike at 60 to 65 percent of their maximal heart rate.

    The authors of the study found that the young men’s endothelial function was impaired in the non-exercising group following a week of SSB consumption, compared to their baseline function. However, the subjects who engaged in regular aerobic exercise did not experience impairments in endothelial function, suggesting that exercise offset some of the deleterious effects of regular sugar consumption.

    Interestingly, sauna use elicits many of the beneficial effects of exercise. In fact, some evidence suggests that waon therapy, a form of thermal treatment commonly used in Japan, improves endothelial function in patients with ischemic heart disease. Read more about the benefits of waon and other thermal treatments in this overview article about sauna use.

  • Cardiorespiratory fitness is a measure of the body’s aerobic capacity – the ability to deliver oxygen to skeletal muscles – during sustained physical activity. Poor cardiorespiratory fitness, along with dyslipidemia, family history, hypertension, age, cigarette smoking, diabetes mellitus, obesity, and physical inactivity, increases a person’s risk for cardiovascular disease and death. Findings from a new study indicate that cardiorespiratory fitness measured by submaximal testing predicts risk for deaths from all causes.

    The most accurate way to assess cardiorespiratory fitness involves measuring maximal oxygen uptake, often referred to as VO2 max, during a graded exercise test in a laboratory, clinical, or research setting. The sheer logistics of measuring VO2 max in large groups of people present challenges, however. Submaximal exercise testing, which typically involves completion of a standardized exercise or task using a treadmill or bicycle, is a viable option in these settings.

    The study involved more than 58,000 people between the ages of 40 and 69 years who were enrolled in the UK Biobank Prospective Study. The authors of the study categorized the participants according to their level of risk based on the participants' age, sex, medical history, and biochemical indicators. Then the participants underwent submaximal exercise testing using a stationary exercise bicycle.

    The results of the submaximal exercise testing revealed a linear relationship between cardiorespiratory fitness and the risk of death. In fact, submaximal exercise testing served as a highly reliable predictor of death, even beyond conventional risk factors, especially among people with few risk factors.

  • Acute respiratory distress syndrome (ARDS) is a severe form of acute lung injury, characterized by rapid breathing, shortness of breath, and a low blood oxygen level. It occurs in as many as 17 percent of all COVID-19 cases and can lead to respiratory failure and death. Findings presented in a recent review suggest that extracellular superoxide dismutase (EcSOD), a potent antioxidant enzyme produced by the muscles during exercise, can reduce the risk of developing ARDS.

    A critical feature of the pathogenesis of ARDS is an excessive immune response that leads to increased production of reactive oxygen species and pro-inflammatory mediators in the lungs. Evidence indicates that EcSOD is highly expressed in lung tissues, where it inhibits many of the pathological features of ARDS and acts as a scavenger of superoxide. Loss of EcSOD activity in mice markedly increases risk of death due to ARDS, however.

    An abundance of evidence demonstrates that even a single session of exercise can boost EcSOD production in muscles. Taken together, these findings suggest that exercise could provide protection against ARDS by upregulating EcSOD production.

  • Vitamin C is essential for the synthesis of carnitine, a compound required for fatty acid oxidation – the utilization of fatty acids as energy – commonly referred to as “fat burning.” Carnitine deficiency is associated with fatigue and poor exercise tolerance. Findings from a new study suggest that high dose vitamin C improves fatty acid oxidation.

    The two-part clinical study involved 22 men and women between the ages of 18 and 38 years. Fifteen of the participants had marginal vitamin C blood levels (less than 34 micromoles per liter) and seven had adequate vitamin C blood levels (greater than 34 micromoles per liter).

    In the first part of the study, all of the participants completed a 60-minute treadmill walk at 50 percent of their VO2 max. Fat utilization during the treadmill walk was 25 percent lower among participants with marginal vitamin C status, suggesting that vitamin C status affects fuel utilization during exercise.

    In the second part of the study, the participants' vitamin C levels were depleted over a period of four weeks. Then they took either 500 milligrams of vitamin C or a placebo every day for four additional weeks. At the end of the eight-week period, the average blood vitamin C levels in the supplemented group were 41.7 micromoles per liter, but average levels among the depleted group were 9.7 micromoles per liter. Fatty acid utilization in the supplemented group was approximately four times greater than the vitamin C depleted group. Poor fatty acid oxidation during exercise was related to higher levels of fatigue.

    These findings suggest that low vitamin C status is associated with poor fatty acid oxidation during exercise and may explain why some people are unsuccessful when trying to lose weight.

  • Exercise benefits many aspects of cognitive function. Evidence suggests that children who engage in physical activity typically perform better in school. Findings from a 2011 study showed that exercise improved cognitive function in overweight children.

    The intervention study involved 171 sedentary, overweight children between the ages of 7 and 11 years old. The authors of the study enrolled the children into one of three programs: a “low dose” 20-minute exercise program, a “high-dose” 40-minute exercise program, or a control (sedentary) program. The exercise programs were provided on school days only, for approximately three months. None of the children received any additional tutoring beyond their normal lessons. At the end of the intervention, the children took standardized cognition and achievement tests. Twenty of the children underwent functional MRI (fMRI) testing.

    The results of the standardized tests demonstrated that exercise improved the children’s cognitive function in a dose-dependent manner. Intelligence scores increased among the children in the exercising groups, especially among those in the high dose (40-minute) group, whose scores increased approximately 3.8 points. No improvements were observed among those in the control group.

    Analysis of the fMRIs revealed that the exercising children exhibited higher levels of activity in their prefrontal cortex, an area of the brain associated with complex thinking, decision making, and social behavior – indicators of improved cognitive skills.

    These findings suggest that exercise can benefit children’s cognitive performance and underscore the importance of physical activity programs in schools.

  • From the article:

    “According to Dr. Kliziene, the stability of lumbar segments is an essential element of body biomechanics. Previous research evidence shows that in order to avoid the lower back pain it is crucial to strengthen the deep muscles, which are stabilising the lumbar area of the spine.

    […]

    The static positions are to be held from 6 to 20 seconds; each exercise to be repeated 8 to 16 times.

    […]

    As soon as 4 weeks in lumbar stabilisation programme, it was observed that the cross-section area of the multifidus muscle of the subjects of the stabilisation group has increased; after completing the programme, this increase was statistically significant. This change was not observed in the strengthening group. Moreover, although both sets of exercises were efficient in eliminating lower back pain and strengthening the muscles of the lower back area, the effect of stabilisation exercises lasted 3 times longer - 12 weeks after the completion of the stabilisation programme against 4 weeks after the completion of the muscle strengthening programme."

  • Exercise-induced bronchoconstriction – a narrowing of the airways in response to exercise – occurs in as much as 10 percent of the general population and up to 50 percent in some fields of competitive athletics. Findings from a meta-analysis suggest that vitamin C might reduce the incidence of exercise-induced bronchoconstriction.

    Previous research demonstrated that vitamin C can triple respiratory tissue levels within an hour or two of a single oral dose of 1 or 2 grams. This local increase in vitamin C concentration appears to protect against acute increases in airway oxidative stress. In addition, vitamin C inhibits the production of prostaglandins and leukotrienes, biological compounds that participate in the pathogenesis of exercise-induced bronchoconstriction.

    In addition, vitamin C halved the incidence of the common cold among people experiencing heavy short-term physical stress – an indication that vitamin C might also have other effects on people experiencing heavy physical exertion.

    The authors of the current conducted analyses of nine studies that investigated varied aspects of the effects of vitamin C on exercise-induced bronchoconstriction. Three placebo-controlled studies analyzed the relative exercise-induced decline in forced expiratory volume, or FEV1, (a measure of respiratory capacity) with or without a vitamin C. They found that doses ranging between 0.5 and 2 grams of vitamin C reduced FEV1 decline by half. Similarly, five studies investigated the effects of vitamin C supplementation on respiratory symptoms after short-term heavy physical work and found that incidence was halved. One study investigated the duration of respiratory symptoms in young male swimmers and also found that incidence was halved.

    The authors noted that a variety of factors might influence whether and to what degree vitamin C affects respiratory function during exercise, including the type of activity and the conditions under which it is performed, among others.

  • Exercise reduces the risk of developing cancer and improves the quality of life among cancer survivors. A recent study shows that exercise reduces the harmful effects observed among men about to undergo androgen-deprivation therapy (ADT) for prostate cancer.

    Prostate cancer is the most common form of cancer among men living in the United States. The first line of treatment for prostate cancer is commonly ADT, which involves the surgical or pharmaceutical suppression of serum testosterone levels. Side effects of ADT include body fat increases, muscle mass losses, and changes in cardiopulmonary and metabolic fitness.

    The study involved 50 men who were about to start ADT. Half of the men engaged in supervised aerobic and resistance exercise twice a week for an hour for a three-month period, followed by three months of unsupervised exercise. The other half, which served as a control group, maintained their regular activity levels. The authors of the study assessed the men for changes in fat mass, biomarkers, cardiopulmonary fitness, energy levels, and quality of life at the three- and six-month time-points in the study.

    At the three-month point, the men who had engaged in the exercise program did not see reductions in body fat, but they did demonstrate improvements in their respiratory fitness and energy levels. After the exercise program ended, the exercising men had improved quality of life and reduced markers of cardiovascular disease risk, compared to the control group. These findings suggest that low-risk interventions such as exercise can benefit men about to undergo ADT.

  • An abundance of scientific evidence demonstrates that exercise benefits physical health and improves cognitive function in people of all ages. A new study has found that aerobic exercise improves brain glucose metabolism and executive function in older adults who are at risk for Alzheimer’s disease.

    Impaired brain glucose uptake and metabolism are pathological hallmarks of Alzheimer’s disease, and their manifestation typically precedes the onset of clinical symptoms. Impaired brain glucose uptake also plays a causal role in tau tangle formation, another hallmark of Alzheimer’s disease.

    Executive function involves higher-level cognitive skills that include working memory, flexible thinking, and self-control. A person who experiences loss of executive function may have problems with planning, organization, flexible thinking, social behavior, decision making, emotional control, and concentration.

    The randomized, controlled, exercise intervention involved 23 cognitively normal, sedentary adults between the ages of 45 and 80 years old who had a family history or genetic risk for Alzheimer’s disease. Eleven of the participants engaged in a moderate-intensity exercise program in which they walked on a treadmill three times per week for 26 weeks. The remaining participants made no changes to their physical activity levels.

    At the end of the study, the participants who engaged in the exercise program experienced improved cardiorespiratory fitness and improved brain glucose metabolism in the posterior cingulate cortex region of their brains. They also spent less time engaged in sedentary activities compared to those who did not change their activity levels. Furthermore, the adults who exercised demonstrated improvements in their executive functioning. Other recent research suggests that aerobic exercise, especially if it includes high-intensity interval training, has the potential to enhance memory in older adults.

    Taken together, these findings suggest that lifestyle modifications that include exercise may be beneficial in improving cognitive function in people at high risk for Alzheimer’s disease. Interestingly, sauna use mimics the effects of exercise and may be useful in reducing Alzheimer’s disease risk. Learn more in this clip featuring sauna expert Dr. Jari Laukanen.

  • An abundance of scientific data demonstrates that regular exercise improves overall physical health. Findings from a new study demonstrate how different exercise intensities influence brain function.

    The study involved 22 young men (average age, 27 years) who exercised regularly. Each of the men completed questionnaires and underwent tests to assess their mood, mental health, and cognitive function. Then the men engaged in either low or high intensity exercise (relative to each individual’s fitness level) on a treadmill for 30 minutes, with the two exercise periods separated by several days. The low-intensity exercise was performed at 35 percent under the lactate threshold (the point at which an increase in blood lactate concentration of 0.4 mmol/l above the baseline is observed). The high-intensity exercise was performed at 20 percent above the lactate threshold.

    Although both forms of exercise improved the men’s reported moods, resting state functional magnetic resonance imaging provided insights into how the different exercise intensities influenced brain function. Whereas low-intensity exercise activated brain networks involved in cognition control and attention processing, high-intensity exercise activated networks involved in mood.

    These findings support other data indicating that exercise benefits brain health and suggest that exercise may be a promising modality for use in improving cognitive function and in treating mood disorders.

  • Public health officials and healthcare providers commonly recommend exercise as a strategy to prevent or manage the symptoms of type 2 diabetes, but the cardiometabolic response to exercise is variable. Whereas exercise improves insulin sensitivity and promotes cardiovascular health in most adults (responders), exercise exerts a paradoxical effect in which metabolic health is compromised in as many as 69 percent of adults (non-responders). Findings from a recent study suggest the variable effects of exercise in people with prediabetes may be due to alterations in gut microbial fermentation.

    Microbial fermentation is the process by which gut bacteria break down and utilize carbohydrates in the gut. The metabolites produced during microbial fermentation include short-chain fatty acids and branched-chain amino acids, which are absorbed and used by the host. Short-chain fatty acids improve symptoms of diabetes, but branched-chain amino acids have the converse effect

    The study involved both humans and mice. The human study included 39 overweight or obese men with prediabetes who were between the ages of 20 and 60 years. Participants were randomized to engage in either sedentary activities or supervised exercise training for 12 weeks. They maintained their usual diet throughout the study period. At the end of the 12-week period, fecal microbial samples from two of the participants (responders and non-responders) were transplanted into obese mice.

    The results demonstrated that the responders' microbiota displayed increased production of short-chain fatty acids, whereas those of the non-responders displayed increased production of brain-chain amino acids. Fecal microbial transplantation from responders mimicked the effects of exercise on alleviation of insulin resistance in the mice, but fecal transplants from the non-responders did not. These findings may augment and facilitate clinical management of symptoms of diabetes.

  • Endurance exercise, such as long-distance running, swimming, and cycling, improves metabolism and reduces the risk of disease and death, especially from cardiovascular-related conditions. A new study found that marathon running, in particular, improves cardiovascular health by reversing age-related aortic stiffness.

    The aorta is the largest artery in the human body. It delivers oxygenated blood from the heart to peripheral tissues. Aortic stiffness, or inelasticity, is a hallmark of aging and cardiovascular disease. Alterations in the mechanical properties of the aorta drive aortic stiffness.

    The study involved 138 healthy adults who participated in a 6-month training program for a marathon. The study participants were between the ages of 21 and 69 years who ran between 6 and 13 miles per week.

    Measures of the participants' aortic blood pressure and aortic stiffness provided estimates of their biological “aortic age.” Post-training measures revealed that training reduced systolic and diastolic aortic blood pressures by 4 mm Hg and 3 mm Hg, respectively, translating to approximately four years of chronological age. Men and older marathon runners saw the greatest improvements in their cardiovascular health, compared to younger or female runners.

  • Severe energy deficit, such as would occur during dieting or prolonged hospitalization, promotes skeletal muscle losses. A recent study demonstrated that exercise mitigates some of these losses by inhibiting the induction of autophagy.

    Autophagy is a highly conserved cellular defense mechanism that sequesters protein aggregates, pathogens, and damaged or dysfunctional organelles into vesicles called autophagosomes and then delivers them for destruction. The primary goal of autophagy is to allow the cell to adapt to changing conditions and external stressors, including energy deficit.

    The study involved 15 overweight or obese men between the ages of 30 and 50 years. In the first phase of the study, the participants ate a very low-calorie diet consisting solely of sucrose or whey protein and engaged in endurance exercise consisting of 45 minutes of arm exercises and eight hours of walking for four days. This diet/exercise protocol created an energy deficit of approximately 5,500 calories per day. In the second phase, they ate a control diet and engaged in limited exercise for three days.

    At the end of each phase, participants provided muscle biopsies for analysis, which revealed that severe energy deficit induced autophagy in skeletal muscle, but endurance exercised inhibited this induction, especially in the lower extremities. Interestingly, dietary intake of protein had little effect in preserving muscle mass.

    The authors of the study proposed that exercise may sensitize the skeletal muscle to the anabolic signals that inhibit autophagy induction during energy deficit. These findings underscore the importance of exercise during dietary restriction, especially during prolonged hospital stays, to prevent or reduce skeletal muscle losses.

  • Exercise and other forms of physical activity elicit a wide range of beneficial health effects. Findings from a large study in Sweden suggest that physical activity reduces the risk of depression.

    The observational study involved more than 395,000 people who were followed over a period of 21 years. The study participants were either skiers who partook in Vasaloppet, an annual long-distance cross-country ski race held annually in Sweden (physically active), or non-skiers (physically inactive). Vasaloppet skiers typically exercise a minimum of four hours weekly and have a high level of physical fitness.

    The findings indicated that physical activity was associated with a 50 percent lower risk of developing depression during a 10-year period compared to physical inactivity. Adjustments for age, sex, and education did not alter the results.

    Some have suggested that the association between higher level of physical activity and lower risk of depression might be an artifact of reverse causation. For example, people with depression – especially those whose condition is undiagnosed – might be less likely to engage in physical activity. However, Mendelian randomization studies and data from molecular, genetic, and interventional trials suggests that the relationship is indeed causal.

    Check out our in-depth video covering exercise and depression, including data from randomized controlled trials, Mendelian randomization trials, mechanistic studies, and even ideal exercise parameters.

    An easy take-home message: Aerobic exercise at 70 to 80 percent of maximum heart rate for 40 minutes or more may be critical for boosting brain-derived neurotrophic factor (BDNF) – a growth factor that controls and promotes the growth of new neurons.

  • Cardiorespiratory fitness is a measure of the body’s ability to deliver oxygen to skeletal muscles during sustained physical activity. Findings from a new study suggest that higher cardiorespiratory fitness may increase the brain’s gray matter.

    Gray matter contains the cell bodies, dendrites, and axon terminals of neurons in the brain. Loss of gray matter is associated with cognitive decline and memory loss – hallmarks of dementia. Physical inactivity promotes gray matter losses and is a major risk factor for dementia.

    The new study involved more than 2,100 adults between the ages of 21 and 84 years living in Germany. The authors of the study assessed the participants' cardiorespiratory fitness based on peak oxygen uptake during exercise on a stationary bike. They also measured the participants' gray matter and total brain volume using magnetic resonance imaging (MRI).

    The MRI analysis revealed that for a single standard deviation increase in peak oxygen uptake, gray matter volume increased by more than 5 cubic centimeters in regions associated with emotion, memory encoding, learning, and decision making. These findings suggest that physical activity that promotes cardiorespiratory fitness might be a means to prevent dementia associated with gray matter losses.

    Sauna bathing is an exercise mimetic and promotes many of the cardiovascular benefits associated with exercise. Dr. Rhonda Patrick describes some of these effects in this podcast.

  • Breast cancer is one of the leading causes of death among women living in the United States, claiming the lives of approximately 41,000 women each year. Being overweight or obese increases a woman’s risk of developing breast cancer. Findings from a new study indicate that women who lose weight after the age of 50 years and keep the weight off have reduced risk of developing breast cancer.

    More than two-thirds of women living in the United States are overweight or obese. Excess body fat increases a person’s risk for developing type 2 diabetes, a known risk factor for cancer. Body fat also alters hormone levels, which may increase the risk of developing hormone-sensitive cancers, such as breast cancer. In addition, body fat secretes a wide array of pro-inflammatory substances that damage DNA and inhibit apoptosis.

    The study involved more than 180,000 women who were 50 years of age and older from cohorts of 10 different prospective studies. The women were weighed three times over a period of 10 years. Those who lost weight and kept it off had a lower risk of breast cancer than women who did not lose weight.

    Among women who lost 4 to 10 pounds, 10 to 20 pounds, or 20 or more pounds, risk decreased by 13 percent, 16 percent, and 26 percent, respectively. Among women who lost 20 or more pounds but gained a portion of the weight back, risk was reduced by 23 percent.

    These findings point to the importance of public health interventions that promote weight loss among women as a means to reduce cancer risk.

  • Maintaining a healthy weight requires balancing energy intake with expenditure. A variety of elements influence how physically active we are, including genetic, cultural, and environmental factors. Evidence from a new study suggests that epigenetic changes in agouti-related proteins may regulate voluntary exercise behavior in mice.

    Agouti-related proteins are neuropeptides produced primarily in the hypothalamus. They regulate appetite, metabolism, and energy expenditure.

    Epigenetic changes are biological mechanisms that regulate gene expression (how and when certain genes are turned on or off). DNA methylation – the addition of methyl groups to the nucleotide bases of DNA – is a common epigenetic change. Previous research has shown that DNA methylation influences hypothalamic development in mice at specific time points early in life.

    In this study, transgenic mice that lacked the enzymes that facilitate DNA methylation in agouti-related proteins developed a sedentary phenotype later in life. This was manifested by low energy output in the form of voluntary exercise, with the transgenic mice running roughly half the distance on exercise wheels as their wild type counterparts.

    These findings point to the complexity of identifying ways to motivate people to exercise as a means to regulate body weight.

  • Cognitive decline and associated memory loss are common features of aging, affecting approximately 16 million people living in the United States. A recent study found that high-intensity interval training improves memory in older adults.

    The study involved 64 sedentary older adults between the ages of 60 and 88 years who were randomized to participate in 12 weeks of high-intensity interval training, moderate continuous training, or stretching (which served as the control group). Each of the participants' memory and executive functions were assessed before the training began.

    The participants in the high-intensity group performed four intervals of high-intensity exercise on a treadmill for four minutes, followed by a period of recovery. The participants in the moderate continuous group performed a single set of moderate-intensity aerobic exercise for approximately 50 minutes.

    At the end of the study period, participants who engaged in high-intensity exercise performed better on memory tests than those who engaged in moderate continuous training or stretching only. The participants who saw the greatest fitness gains also saw the greatest memory improvements. Both high-intensity interval and moderate continuous exercise improved executive function in the participants.

    These findings suggest that aerobic exercise, especially if it includes high-intensity interval training, has the potential to enhance memory in older adults.

  • Approximately 322 million people – more than 4 percent of the global population – currently live with depression, the most common mental health condition worldwide. Scientific evidence indicates that roughly one-third to one-half of the risk for developing depression is due to genetic influences. A new study suggests that physical activity may reduce the risk of developing depression, even among people who are genetically predisposed to the condition.

    The study was based on genomic data and lifestyle surveys collected from the electronic health records of nearly 8,000 people enrolled in a large healthcare system in the United States. Findings from the study indicated that for every additional four hours of physical activity per week – roughly 35 minutes per day – the risk of having a new episode of depression were reduced by 17 percent. The protective effects of physical activity against depression were observed with both high- and low-intensity activities, including aerobic exercise, dance, yoga, and stretching.

    The FMF team put together a video covering the clinical and mechanistic evidence explaining why exercise may help prevent and treat depression. The video also presents evidence from Mendelian randomization studies showing that people who are genetically predisposed to depression are not less likely to engage in physical activity.

  • Public health experts recommend that people get at least 150 minutes of moderate to vigorous physical activity, such as walking, running, or cycling, each week for optimal health. Running, in particular, is associated with improved aerobic fitness and cardiovascular function. A recent meta-analysis found that running, even for short periods, reduced the risk of mortality from all causes, especially cardiovascular- and cancer-related deaths.

    The authors of the study analyzed data from 14 studies of six prospective cohorts involving more than 230,000 people. The cohorts were followed over a span of 5 to 35 years. The data were adjusted for sociodemographic factors, other physical activity besides running, body fatness, health status, and unhealthy lifestyle habits such as smoking, alcohol consumption, and poor diet.

    They found that running was associated with a 27 percent lower all-cause mortality, 30 percent lower cardiovascular mortality, and 23 percent lower cancer mortality. Even the smallest amount of time spent running (less than 50 minutes per week) was linked to a significant reduction in all-cause mortality.

  • Exercise promotes the uptake of glucose into muscle cells and increases insulin sensitivity. Other physical adaptations occur during exercise, as well, including increased muscle mass, decreased fat mass, and improved mitochondrial function. Previous research has demonstrated that training in the fasted state promotes greater glucose tolerance and insulin sensitivity and induces higher fatty acid oxidation compared to training in the fed state. A recent study bolsters these findings, demonstrating that exercising before eating breakfast may enhance some of the beneficial effects of exercise.

    The six-week, single-blind, randomized, controlled trial involved 30 overweight or obese men who engaged in moderate-intensity cycling either before or after eating a high-carbohydrate, mixed-macronutrient breakfast. The men exercised for three, 30-minute sessions the first week and progressed to three, 50-minute sessions over the remaining weeks.

    The men who exercised before eating had nearly 2-fold higher whole-body lipid utilization rates as well as decreased carbohydrate utilization compared to the men who exercised after eating. The effects were sustained throughout the entire six-week study period. These findings suggest that exercising before eating breakfast burns more fat, improves insulin sensitivity, and increases glucose uptake into muscle tissue compared to exercising after eating breakfast. Exercising after eating may blunt these effects, however.

  • Limiting food intake and engaging in exercise are highly effective strategies for weight loss. People who are obese are often sedentary, however, due to physical limitations and a lack of motivation to exercise. Compelling findings from a new study in mice suggest that ghrelin, a hormone linked to appetite, may increase motivation to engage in exercise.

    Ghrelin, which is produced primarily in the stomach, stimulates appetite, increases food intake, and promotes fat storage in mice and humans. It is often referred to as the “hunger hormone” and is linked to reward-driven behavior. Previous studies have shown that ghrelin administration increases activity in mice in anticipation of food.

    The current study involved mice that were fed on a time-restricted eating schedule (twice daily) versus mice that were allowed to eat freely throughout the day. Both groups of mice ate roughly the same amount of food each day. The mice that were fed on the time-restricted schedule were more motivated to engage in voluntary exercise and ran on an exercise wheel for longer periods. The increase in the animals' activity corresponded to increases in ghrelin levels. Conversely, inhibiting ghrelin attenuated the animals' motivation to exercise.

    Hunger-related behaviors such as increased activity are essential to animals in the wild or human hunter-gatherers because they must forage and seek out or hunt for food. Tapping into these ancient hormonally-driven behaviors may help resolve modern-day concerns of obesity and lack of exercise. However, a small study in humans demonstrated that time-restricted eating decreased morning levels of ghrelin (and subsequently appetite), so more studies on the effects of time-restricted eating and ghrelin in humans are needed.

  • Age-related skeletal muscle mass and strength is a leading cause of the functional decline and loss of independence in older adults. Resistance training exercise is a highly effective strategy for maintaining or building muscle mass. A new study suggests that metformin, a drug commonly used to treat type 2 diabetes, blunts the effects of resistance training.

    Metformin is in a class of drugs called biguanides, which act by decreasing liver gluconeogenesis (the production of glucose in the liver), decreasing glucose uptake in the gut, and increasing overall glucose utilization by improving insulin sensitivity in skeletal muscle and fat tissue. Scientific evidence suggests that metformin modulates aging processes to improve healthspan and extend lifespan in multiple organisms.

    The present study involved 94 healthy men and women aged 65 years and older who were randomized to take either a 1,700-milligram dose of metformin daily (a typical dose prescribed for diabetes and prediabetes) or a placebo for 14 weeks. The participants also performed supervised resistance training for the duration of the study. At the end of the study, participants who took the placebo exhibited greater gains in lean body mass and thigh muscle mass than those who took metformin.

    Although metformin is a safe and effective treatment for type 2 diabetes, these findings underscore concerns about the possible negative effects of metformin use in healthy older adults.

  • Primate hearts are uniquely adapted to meet their species-specific physical activity needs. Whereas chimpanzee hearts are adapted to relatively low levels of activity interspersed with short bursts of resistance activities, the human heart has adapted to allow humans to engage in low- to moderate-intensity endurance activities to facilitate the acquisition and preparation of food. Findings from a new study suggest that human heart health is dependent upon moderate-intensity endurance exercise, and its absence likely contributes to hypertensive heart disease.

    The structure and function of the heart’s left ventricle are critical to heart health. Left ventricular dysfunction sets in motion a cascade of compensatory mechanisms that promote organ-level structural changes and elicit system-level hormonal adaptations, including hypertension. It is widely recognized as the end-stage of heart failure.

    The authors of this study compared the blood pressures and left ventricular function and structure of chimpanzees and humans. They found that the human left ventricle amplifies cardiac output, a measure of the amount of work the heart performs in response to the body’s need for oxygen. This adaptation facilitates endurance activities and is not present in chimpanzees. They also found that lack of endurance activity changes the shape of the human heart to reflect more of a chimpanzee-like heart.

    These findings suggest that human heart health is dependent upon regular low- to moderate-intensity activities that challenge the heart.

  • A small randomized placebo-controlled trial finds the blood pressure-lowering effect of exercise was diminished by 61% during the first hour of recovery, and completely abolished 2 hours after exercise when participants were given antibacterial mouthwash.

    Part of the blood-pressure-lowering effect of exercise has to do with increased levels of nitrate and subsequently nitric oxide which causes vasodilatation. When antibacterial mouthwash was given to the participants, their blood nitrite levels did not increase after exercise. It was only when participants used the placebo that nitrite levels in blood raised, suggesting that oral bacteria may play a role in nitrate levels in the circulation at least over the first period of recovery after exercise.

    The antibacterial mouthwash used was 0.2% chlorhexidine. This was a small trial (23 participants) so no definitive conclusions can be made but these results are interesting and should be further explored.

  • A new study proposes exercise as a potential primary mode of treatment for mental health disorders ranging from anxiety, depression to schizophrenia, and acute psychotic episodes.

    This small trial included ~100 patients in the medical center’s inpatient psychiatry unit and included a 60-minute structured exercise and nutrition education programs into their treatment plans. The psychotherapists surveyed patients on their mood, self-esteem, and self-image both before and after the exercise sessions to gauge the effects of exercise on psychiatric symptoms.

    Approximately 95% of patients had improved mood after exercise.

    There have been several other intervention studies showing that exercise improves mood in people with depression, improves psychosis in people with schizophrenia, and improves anxiety. The hope of this new study is that psychiatric facilities will incorporate exercise programs as a part of therapy.

  • Exercising while fasted induces adaptations to mitochondria in muscle and adipose tissue including increased fatty acid metabolism that is blunted by pre-exercise feeding (meta-analysis of 46 clinical studies).

    Exercising in a fasted state increased the release of fatty acids stored in adipose tissue and the use of them for energy in muscle and adipose tissue (ie. fat burning). It also increased the use of intramuscular triglycerides over glycogen in muscle tissue. Exercise while fasted also caused mitochondria to increase gene activity in genes related to fatty acid metabolism making them more efficient as using fat for energy. These adaptations were blunted by pre-exercise feeding.

    Pre-exercise feeding did enhance performance in long-duration exercise (> 60 minutes) but had no effect on aerobic training shorter than 60 minutes. Pre-exercise feeding also slightly enhanced anaerobic exercise (ie. run until exhaustion) but had no effect on high-intensity interval training.

  • Hey everyone,

    I am a type 1 diabetic in my early 20’s and wanted to reach out to this community for any helpful info on type 1 nutrition and exercise. A few months ago I had an epiphany and realized it was time to get on top of my health. Over the past few months I have lost almost 30 pounds now only weighing 190, and getting my HbA1c to 7. While there is always conversations about type 2 diabetes, the same cannot be said for type 1. Specifically I want to know how excercise effects blood sugar in T1’s. For my whole life my blood sugar has always gone extremely low during workouts. Know I often find my blood sugar raising after workouts.
    I am also curious what diets/lifestyles you all think would be most successful for type 1’s. I have followed a fairly low carb diet and cut out breads and refined sugars. I have really tried to intermitten fast, but it can be difficult due to low blood sugars. Any other tips and suggestions would be fantastic. Thanks, Jacob

  • Abstract:

    Purpose of review - We systematically appraised randomized controlled trials proposing exercise to influence cognition in older adults to (1) assess the methodologic quality using Cochrane criteria; (2) describe various exercise dose measures and assess their relationship with improved cognitive performance; and (3) identify consistent patterns of reported effects on cognition.

    Recent findings: There was overall good methodologic quality in all 98 included studies. The assessment of the relationship between improved cognition and various measures of exercise dose (session duration, weekly minutes, frequency, total weeks, and total hours) revealed a significant correlation with total hours. Improvements in global cognition, processing speed/attention, and executive function were most stable and consistent.

    Summary: We found that exercising for at least 52 hours [over the course of 6 months is the minimum amount needed] is associated with improved cognitive performance in older adults with and without cognitive impairment. Exercise modes supported by evidence are aerobic, resistance (strength) training, mind–body exercises, or combinations of these interventions.

  • Full Title: Exercise training-induced modification of the gut microbiota persists after microbiota colonization and attenuates the response to chemically-induced colitis in gnotobiotic mice

    Summary: Exercise reduces the risk of inflammatory disease by modulating a variety of tissue and cell types, including those within the gastrointestinal tract. Recent data indicates that exercise can also alter the gut microbiota, but little is known as to whether these changes affect host function. Here, we use a germ-free (GF) animal model to test whether exercise-induced modifications in the gut microbiota can directly affect host responses to microbiota colonization and chemically-induced colitis. Donor mice (n = 19) received access to a running wheel (n = 10) or remained without access (n = 9) for a period of six weeks. After euthanasia, cecal contents were pooled by activity treatment and transplanted into two separate cohorts of GF mice. Two experiments were then conducted. First, mice were euthanized five weeks after the microbiota transplant and tissues were collected for analysis. A second cohort of GF mice were colonized by donor microbiotas for four weeks before dextran-sodium-sulfate was administered to induce acute colitis, after which mice were euthanized for tissue analysis. We observed that microbial transplants from donor (exercised or control) mice led to differences in microbiota β-diversity, metabolite profiles, colon inflammation, and body mass in recipient mice five weeks after colonization. We also demonstrate that colonization of mice with a gut microbiota from exercise-trained mice led to an attenuated response to chemical colitis, evidenced by reduced colon shortening, attenuated mucus depletion and augmented expression of cytokines involved in tissue regeneration. Exercise-induced modifications in the gut microbiota can mediate host-microbial interactions with potentially beneficial outcomes for the host. KEYWORDS: exercise, microbiome, gut, microbiota, colitis, germ-free, transplant, colonization inflammation, voluntary wheel running

  • Exercise causes acute elevation of IL-6 which reduces postprandial blood glucose levels and insulin secretion by delaying gastric emptying in men with type 2 diabetes.

    IL-6 is a cytokine with both negative and positive effects. Chronic elevation of IL-6 reflects ongoing inflammation and is linked to type 2 diabetes and atherosclerosis. In contrast, acute elevation of IL-6 from exercise inhibits inflammatory cytokines and stimulates the production of anti-inflammatory cytokines in humans.

    To learn more about the role of exercise-induced IL-6, the postprandial inflammatory response and their effects on the brain…check out my interview with Dr. Charles Raison. This episode has a timeline, transcript, summary, and glossary to help find and understand the talking points.

    Charles Raison, MD podcast: https://www.foundmyfitness.com/episodes/charles-raison

  • Eating a healthy diet, regular exercise (at least 30 minutes or more per day of moderate to vigorous exercise), maintaining a healthy body weight, not drinking too much alcohol (up to about one 5-ounce glass of wine per day for women, or up to two glasses for men), and not smoking during adulthood may add more than a decade to life expectancy.

    There was also a dose-response relationship between each individual healthy lifestyle behavior and a reduced risk of early death and the combination of all five healthy behaviors was linked with the most additional years of life.

    Women who maintained all five of these healthy habits gained, on average, 14 years of life, and men gained 12 years, compared with those who didn’t maintain healthy habits over the 30-year study period.

    Those individuals that maintained the healthiest lifestyles were 82% less likely to die from cardiovascular disease and 65% less likely to die from cancer compared with those with the least healthy lifestyles.

  • Phthalates were 35% higher in participants who had eaten out the previous day compared with those who ate at home.

    Phthalates are ubiquitous in plastic products yet I have not phthalates listed on consumer product labels. Unfortunately, I’m not sure if it is required to be listed.

    In 2013, a randomized trial with five families that involved dietary replacement with organic foods that lacked plastic packaging found that phthalates increased 2000% during the trial because the chemical was found in organic imported spices and dairy products.

    Other studies have found that phthalates are excreted through sweat suggesting that forced perspiration such as from exercise and/or using a sauna or other types of heat stress may be a good way to eliminate these potentially harmful compounds.

    Link to 2013 phthalate trial: https://www.nature.com/articles/jes20139

    One excretion study: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3504417/

  • Stem cell therapy is a type of cell therapy where stem cells are introduced into the damaged tissue to treat the disorder or the injury. Mesenchymal stem cells (MSCs) are used in most stem cell therapy. They’re non-hematopoietic cell precursors initially found in the bone marrow, but actually present in many other tissues. Mesenchymal stem cells (MSCs) in culture are adherent, proliferating, and capable of multilineage differentiation into several tissues of mesenchymal origin, such as bone marrow stroma, adipose tissue (body fat), bone, cartilage, tendon, skeletal muscle and etc.

    So Why is Stem Cells Therapy Good for Anti Aging?

    In short, stem cells therapy was heavily emphasised to have the capacity to repair, renew and replace damaged tissue is a good anti aging treatment.

    As shown below are the functions of Mesenchymal stem cells (MSCs) therapy: - Help facilitate growth of new blood vessels, a process known as angiogenesis which leads to improved blood flow in tissue - An anti-inflammatory effect which fastens wound healing - After aiding wound healing, it helps in reducing size of scarred tissue such as infected cardiomyocytes (heart cells) or wound to joint injury - Repair of damaged tissue which then leads to renewal of healthy tissue - Relief if symptoms related to any chronic diseases - Vast improvement in the immune system against disease - Better digestion and elimination of constipation - More flexible joints and discs - Improvement in skin elasticity and thickness - Reducing facial pigmentation, and adding a glow to your skin - Diminishing fine lines and wrinkles - Improving skin complexion - Tightening and shrinking open pores - Removing dark circles


    No more joints problems, no more constipation, better appearance, overall human health improves!

    The list is non-exhaustive when it comes to stem cells therapy. All these benefits brought by stem cells therapy are exactly the definition of anti aging if not reviving old age.

    Visit more information on: http://stemfinitycord.co/

  • FTA:

    The research team studied 93 men with biopsy-proven prostate cancer who had elected not to undergo conventional treatment for reasons unrelated to this study. The participants were randomly divided into either a group who were asked to make comprehensive changes in diet and lifestyle or a comparison group who were not asked to do so.

    […] After one year, the researchers found that PSA levels (a protein marker for prostate cancer) decreased in men in the group who made comprehensive lifestyle changes but increased in the comparison group. There was a direct correlation between the degree of lifestyle change and the changes in PSA. Also, they found that serum from the participants inhibited prostate tumor growth in vitro by 70 percent in the lifestyle-change group but only 9 percent in the comparison group. Again, there was a direct correlation between the degree of lifestyle change and the inhibition of prostate tumor growth.

    Participants in the lifestyle-change group were placed on a vegan diet consisting primarily of fruits, vegetables, whole grains, and legumes supplemented with soy, vitamins and minerals. They participated in moderate aerobic exercise, yoga/meditation, and a weekly support group session.

  • Telomeres are tiny caps on the ends of chromosomes that protect our DNA from damage. They get shorter every year and are a biological marker for aging. Exercise is one of the most robust ways to slow telomere attrition and someone that is very physically active may have a biological age that is even 10 years younger than their chronological age. In this study, a high level of exercise was defined as 30 minutes of jogging per day for 5 days a week for women and 40 minutes per day for men. Get out there and sweat!

    FTA:

    Exercise science professor Larry Tucker found adults with high physical activity levels have telomeres with a biological aging advantage of nine years over those who are sedentary, and a seven-year advantage compared to those who are moderately active. To be highly active, women had to engage in 30 minutes of jogging per day (40 minutes for men), five days a week.

    “If you want to see a real difference in slowing your biological aging, it appears that a little exercise won’t cut it,” Tucker said. “You have to work out regularly at high levels.”

  • http://www.ncbi.nlm.nih.gov/pubmed/26174323

    Wow, first, thank you so much for putting this 20-page report together!!

    Unfortunately, it creates a dilemma for me and I suspect others who strength train before work. I need to wait a full hour before taking a cold shower (per Wim Hof protocol)?

    Another option for me is to wake up earlier and swim after my strength training to cut into the hour a bit before cold showering. That’s tough as well though: the water at my pool’s gym is cold to replicate competition temperatures. I’m not sure how cold that is, but perhaps it would not be cold enough to trigger these negative consequences to strength and muscle gains. [Note: I swim for cardio due to a herniated disc; so no running, and the elliptical does little to build up wind imo.]

    What a bummer. Any suggestions? The pubmed abstract doesn’t discuss temperatures, but CWI often means pretty darned cold! Would I be fooling myself if I dismiss it as not applicable to my current weight-lifting-to-cold-shower protocol?

  • This 20-page report explains how cold shock is a type of hormesis, which is a description of a type of stress that, in the right doses, is enough to shock the body and kick off adaptive processes and response mechanisms that are hardwired into our genes, and, once on, are able to create a resilience that actually exceeds what was needed to counter the initial stimuli. Rhonda discusses how cold exposure increases norepinephrine up to 5-fold in the brain and what the temperature and duration needed to do this are, how norepinephrine has an effect on mood, vigilance, focus, and attention, how cold exposure increases cold shock proteins including one in the brain that repairs damaged synapses and in muscle prevents atrophy, how cold-induced norepinephrine lowers inflammation and pain by decreasing the levels of 3 inflammatory mediators, how chronic cold shock may increase immune cell numbers and particularly a type of immune cell that kills cancer cells, how cold exposure increases metabolic rate, the number of mitochondria, and the burning of fat, what the effects of different cold exposure temperatures and timing are on athletic performance, recovery time, and muscle mass, and the differences between various types of cold shock modalities, including cold water immersion and whole body cryotherapy.

  • From the article:

    BHB is a metabolite produced by the body in response to fasting, high-intensity exercise, caloric restriction, or consumption of the low-carbohydrate ketogenic diet. Dixit said it is well known that fasting and calorie restriction reduces inflammation in the body, but it was unclear how immune cells adapt to reduced availability of glucose and if they can respond to metabolites produced from fat oxidation.

    Working with mice and human immune cells, Dixit and colleagues focused on how macrophages – specialized immune cells that produce inflammation – respond when exposed to ketone bodies and whether that impacts the inflammasone complex.

    The team introduced BHB to mouse models of inflammatory diseases caused by NLP3. They found that this reduced inflammation, and that inflammation was also reduced when the mice were given a ketogenic diet, which elevates the levels of BHB in the bloodstream.

  • FTA:

    Freshly secreted sweat has little odor, because the long-chain fatty acids the axillaries secrete are too big to be volatile, says first author, Chris Callewaert of Ghent University, Belgium. Bacteria break these, as well as hormones and sulfur compounds, down to waftable sized, odoriferous molecules.

    On the clothes, the main culprit bacteria are micrococci, says Callewaert. “They are known for their enzymatic potential to transform long-chain fatty acids, hormones, and amino acids into smaller—volatile—compounds, which have a typical malodor.”

    Staphylococci, however, do not create the same odor (but do not grow on polyester as well):

    Staphylococci, which inhabit both axillary skin and adjacent textiles (the latter with much less diversity), create a normal, non-malodorous body odor, he says.