Lifting and cardio have one thing in common. They both can make the brain look younger.

Two recent randomized studies show exercise doesn't just improve a few brain regions, it reduces estimated “brain age."

In older adults, resistance training led to roughly a 1–2 year reduction in brain age gap.

And in early-to-midlife adults, a year of moderate-to-vigorous aerobic training produced about a one-year advantage compared to a no-exercise control group.

Whether you choose to prioritize getting stronger in the gym or elevating your cardiorespiratory fitness with aerobic exercise training (or, ideally, both), you can be confident that you're changing your neurochemistry and the physical structure of your brain, helping it appear (and hopefully perform) like a younger version of itself.

Today's newsletter will break down these studies, discuss the "brain age gap" (and why it matters), and explore a few of my favorite non-exercise strategies for reducing brain aging.

Lifting heavy has brain benefits

Both of the studies we'll talk about today used machine-learning models trained on large imaging datasets to estimate how “old” a brain appears based on patterns in MRI data. The key metric is the gap between chronological age and predicted brain age (often called the brain age gap, BAG, or brain-predicted age difference, brain-PAD). 

A negative value means the brain appears younger than expected (that's good); a positive value means older (not so good). It’s not a literal reversal of aging, but it’s a compelling biomarker because it rolls a huge amount of brain information into a single, interpretable number.

The first study followed 309 adults aged 62–70 who were randomized to one of three groups for a full year: heavy resistance training, moderate-intensity resistance training, or a control group who didn't exercise. Brain outcomes were assessed at baseline, immediately after the year-long intervention, and again one year later (a 2-year follow-up timeline).

People in the heavy training group did supervised, machine-based, full-body lifting 3 times per week, progressing through roughly 70–85% of estimated 1 repetition max (1RM) with sets in the 6–12 rep range (leg press, chest press, knee extensions, low rows, curls, calf work, hip abduction, plus core work). Moderate training did a more home-friendly circuit style using bodyweight/bands, completing 1 supervised + 2 home sessions per week with higher reps (about 10–18 for 2–3 rounds) at around 50–60% of their estimated 1RM.

After one year, estimated brain age dropped by about 1.4 years in the groups who exercised. And a year later (after the intervention had ended), the effect was still there, with reductions approaching ~2 years relative to baseline:

• Heavy training reduced brain age by 1.4 years at 1 year and 1.84 years at 2 years.

• Moderate training reduced brain age by 1.39 years at 1 year and by 2.26 years at 2 years

• The control group experienced no meaningful change in their brain age.

That persistence suggests this isn’t just a short-lived effect of being mid-training. Something about a year of exercise may leave a longer-lasting imprint on brain network organization. Just think about what years or even decades of training is doing on a neurological level.

The authors also used resting-state connectivity to estimate brain age, and found that the benefits weren't confined to one network, but rather, spanned distributed connections across frontal, temporal, subcortical, and cerebellar systems. In other words, this was a global improvement in neural connectivity rather than localized changes, and heavy training showed greater functional connectivity vs. controls, with many changes in the prefrontal cortex and other regions involved in executive control and motor function.

One of the more intriguing details of the study was that in the moderate training group only, greater improvements in leg strength tracked with larger reductions in brain age. Those who got stronger saw greater reductions in their brain age gap (the same thing wasn't observed in the heavy training group, for whatever reason). In any case, it suggests the benefits of strength training on the brain aren't purely about lifting the heaviest loads possible.

The change in brain age gaps in each training group at baseline, 1 year, and 2 years (A) and the relationship of the change in brain age to changes in leg strength in the full sample and in each intervention/control group (C I, II, III, and IV).

Brain age improves after endurance training

The second trial zoomed out to earlier adulthood, recruiting 81 healthy adults aged 26–58 and randomizing them to either 12 months of moderate-to-vigorous aerobic exercise or a control group. The exercise prescription targeted about 150 minutes/week, with intensity set around 60–85% of heart rate reserve.

One of the biggest takeaways from this study is that even before the training started, fitness level already correlated with a younger-looking brain. People with higher cardiorespiratory fitness at baseline tended to have a lower (better) brain-PAD. Each ~7 mL/kg/min increase in relative VO₂peak was associated with a nearly 2-year lower brain-PAD.

After 12 months of training:

• The exercise group had a 0.60 years decrease in brain-PAD.

• The control group had a 0.35 years increase (a slight worsening).

So the between-group separation was roughly ~1 year.

Aerobic training also improved VO₂peak modestly (+1.6 mL/kg/min in exercisers while controls drifted down), yet there was an interesting twist—improvements in VO₂peak didn’t statistically explain the brain-age improvement, and neither did changes in body composition, blood pressure, or BDNF (which didn’t meaningfully change overall).

So what’s going on? Exercise moved the brain-age metric even when the usual candidate mediators didn’t budge. That doesn’t mean fitness, cardiometabolic risk factors and BDNF aren't important, but it may mean that in this specific case, the key biology wasn’t captured by the chosen mediators.

I actually find this particular result reassuring. It suggests that exercise (movement), rather than improvements in aerobic fitness, risk factors, or BDNF per se, is driving the improvements in brain age.

Brain-PAD (A) and VO2 peak (B) at baseline and 12 months in the exercise and control group.

In one of my recent Q&A sessions, I share my thoughts on the new Neurocode brain scan for early detection of cognitive decline, including:

• Are blood-based biomarkers useful for detecting early cognitive decline?
• What is the Neurocode brain scan?
• The three biomarkers the test uses—p-Tau 217, GFAP, and Nfl

Listen to member Q&A #62 with Dr. Rhonda Patrick

Other strategies to reduce brain age

While exercise may be one of the most potent levers we can pull to influence brain aging, it’s not the only one. 

A growing body of research (much of which I’ve covered over the years) suggests that other lifestyle and nutrition interventions can shift MRI-based brain age metrics in a favorable direction (you can find a complete archive of brain-related content on our Brain topic page).

• One of the most consistent dietary patterns linked to healthier brain aging is the Mediterranean diet—and especially a “green-Med” variant higher in polyphenols—which has been associated with a more favorable brain age signature and lower markers of neurodegeneration, with effects that appear to be partly mediated by improvements in blood glucose regulation.¹

• Metabolic health shows up as a recurring theme. In one study, weight loss—even as little as ~1% of body weight—combined with improvements in liver fat and reductions in visceral/deep subcutaneous fat was associated with up to a ~9-month reduction in brain age, particularly among those who lowered intake of processed foods, sweets, and sugar-sweetened beverages.²

• Sleep matters too—and not just subjectively. Better overall sleep health (earlier chronotype, 7–8 hours per night, and fewer issues like insomnia, snoring, or excessive daytime sleepiness) has been linked to a younger brain age gap, with evidence suggesting part of that relationship may be explained by inflammation-related pathways.³

• Intermittent fasting, specifically the 5:2 diet, was reported to slow the pace of brain aging by about 2.5 years on average, outperforming a healthy calorie-restricted diet in one analysis.⁴ (I covered this paper in last week’s newsletter on fasting and cognition)

On the flip side, a couple of the usual suspects show up in the expected direction:

• Smoking and more frequent alcohol intake (daily or almost daily use) are associated with accelerated brain aging and worse brain structure/function.⁵

• Vitamin D deficiency has been associated with an “older” brain age, and lower vitamin D levels were linked—within the same study—to lower overall brain and gray matter volume.⁶

There are also a few interventions I find particularly intriguing—even though they don’t yet have large, definitive trials using brain-age endpoints. Omega-3s (DHA/EPA) support blood–brain barrier integrity, and higher omega-3 status is repeatedly associated with better brain health and lower dementia risk in observational datasets. I still consider omega-3s one of the most practical nutritional strategies to support a “youthful” brain, even as we wait for more direct intervention evidence using brain-age clocks.

Creatine is another one to watch. Emerging evidence suggests that higher doses (on the order of 10–20 grams per day in some protocols) can increase brain creatine stores, support brain energy metabolism, and may improve cognition in contexts of high brain energy demand or stress—mechanistically, a plausible way to bolster resilience against age-related energetic constraints.

And then there’s sauna/heat exposure, which has been on my radar for more than a decade. The brain data here are still largely observational, but they’re hard to ignore: in Finnish cohort studies, frequent sauna use (4–7 sessions per week) has been associated with substantially lower dementia risk compared to less frequent use. It’s one reason I think we should take heat exposure seriously as a brain-health tool, especially since, in some ways, it may be the closest thing we have to an “exercise mimetic,” even if it’s not a substitute for exercise.

Final thoughts

I’ve always said the main reason I exercise is for the brain. That’s still true—even as I’ve learned (through reading the literature and through conversations with so many brilliant podcast guests) just how wide-ranging the “whole-body” benefits really are.

For most of us, the brain benefits feel subjective. A hard workout leaves you sharper, more alert, more capable of focusing deeply (at least it does for me). But these studies suggest that what we call a “feeling” may actually be the nervous system adapting, reorganizing, strengthening connections, and shifting the brain toward a younger functional signature over time.

The results of the studies discussed today are just one more reason to stop treating cardio and strength as competing choices. If you’ve followed me for any length of time, you already know my answer to the question, “Should I do cardio or weights for health and longevity?” is the least satisfying—and most correct—answer: BOTH.

We don’t get to opt out of the basics. Without aerobic exercise, we can’t build (or maintain) a strong heart, a high VO₂max, and the kind of mitochondrial capacity that helps us generate energy efficiently for decades. 

And without resistance training, we can’t preserve the muscle mass, strength, and power that protect us from frailty and sarcopenia as we age (protein helps, but it's really training that moves the lever).

What I appreciated most about the two studies covered today is that they don’t crown a winner. They don’t argue that lifting is superior to cardio, or vice versa. Instead, they make the much more important point that a year of structured training—either resistance training or aerobic exercise—can measurably shift brain aging in a favorable direction.

If there is one word I’d use to describe the relationship between exercise and brain health, it's "consistent."

Moving is one of the best things we can do to enhance and maintain brain health throughout life. And the competition really isn't close.

Warm regards

— Rhonda and the FoundMyFitness team