The last topic that I want to discuss is exercise. Alcohol and exercise don't seem like they'd be discussed together, but many FoundMyFitness members had questions about how they could enjoy alcohol while also making progress with their fitness. We will cover how exercise could be used to counter alcohol cravings, how alcohol affects exercise performance and recovery, and if exercise actually lessens the damaging effects of moderate alcohol drinking. All of you know that I am a huge fan of exercise. And there's actually some pretty interesting research on the effects of alcohol on exercise performance and recovery. Alcohol is commonly used to socialize after exercise, to celebrate a big achievement, like running a marathon, often along with some good food.

And at this time, most people aren't thinking about optimizing their adaptations or recovery. It's just about having a good time. First, let's talk about alcohol and performance. It's obvious to me that you would not want to have even 1 or 2 drinks right before a workout. There are zero aspects of alcohol that would help improve endurance, strength, or speed. From the evidence that is available on this topic, it seems that alcohol acutely reduces endurance performance, but may not have major impact on strength, even at high doses. What seems to be more relevant is how alcohol impacts recovery from exercise and adaptations to training. Again, there's not a ton of evidence here, but there is some.

So in order to recover properly from exercise and get the most out of training, hydration, refueling, attenuating muscle tissue damage are really important. Consuming alcohol after exercise appears to have a negative effect on hydration status, but only at a dose of nearly 1 gram per kilogram of body weight, which would be around 5 or more standard drinks for most people. At a dose less than 0.5 grams of alcohol per kilogram of body weight, alcohol may not impair rehydration. Whether you should be concerned about alcohol's effect on hydration after exercise probably depends on how soon you'll be engaging in exercise again. It may not be that consequential.

Alcohol also doesn't appear to impair the ability to restore muscle glycogen after exercise, as long as it's consumed with a post-exercise meal that contains carbohydrates. Of course, if an alcoholic drink or 2 displaces some food you might be eating, then this might compromise muscle glycogen replenishment. Alcohol may also be detrimental for recovery from injury. For one, alcohol impacts our immune system in a way that suppresses some pro-inflammatory cytokines, such as TNF-alpha and IL-1-beta and IL-6, and increases levels of some anti-inflammatory cytokines. This might seem like a good thing, but when we're dealing with an acute injury, we actually want an inflammatory response at the site of injury to initiate the healing process.

There is also some research, though very limited, that suggests alcohol may have effects on skeletal muscle blood flow and anabolic hormones like testosterone that are crucial to the healing process. When consumed after a session of exercise, alcohol blunts muscle protein synthesis for as much as 24 hours after. Type 2 muscle fibers, the so-called fast twitch fibers, seem to be more susceptible to the effects of alcohol, at least when looking at studies in rats and when using an extremely heavy dose of alcohol. And lastly, consuming alcohol after exercise has been shown to worsen the declines in muscle performance after muscle-damaging exercise, meaning that greater muscle damage may have been introduced or induced, or that recovery ability is impaired.

Several of these studies have used a very high dose of alcohol that really isn't practical for any person to consume in a safe single setting. So I do think that is worth noting. In addition to negatively affecting recovery, this also means that alcohol consumption could blunt your gains. A study involving physically active males demonstrated that consuming 12 standard drinks after resistance anaerobic training, despite also ingesting 25 grams of whey protein, reduced muscle protein synthesis by 24%. This reduction was even greater at 37% when alcohol was consumed without additional protein. This shows that alcohol, even when paired with optimal amounts of protein, can blunt the anabolic response crucial for muscle repair and growth.

Essentially, alcohol can counteract the benefits of your workout efforts by impairing the body's ability to repair and build muscle tissue. Now, this study was a bit extreme because most people are not going to consume 12 standard alcoholic beverages. However, it is still likely that even small amounts of alcohol can potentially influence recovery processes and protein synthesis, but the extent and significance of these effects would be considerably less than with high levels of alcohol intake. But even a 5 to 10% reduction in protein synthesis after exercise isn't ideal for someone looking to optimize their training response. Higher doses of alcohol after exercise can hinder recovery by promoting a catabolic state, which is not conducive to muscle growth and repair.

Moderate alcohol consumption, something equivalent to about 3.5 drinks, raises cortisol levels, a stress hormone that breaks down muscle, but it doesn't significantly alter testosterone. Moreover, alcohol consumption disrupts the activation of mTOR, a key protein in the pathway that stimulates muscle protein synthesis. When the alcohol dose is high, like 7.5 standard drinks for a 70-kilogram male, then it does decrease testosterone production, which is particularly important for males. I've mainly been talking about the acute effects of alcohol, but chronic heavy alcohol consumption is associated with a range of muscle abnormalities, including inflammation, mitochondrial dysfunction, oxidative stress, reduced muscle mass, enhanced protein degradation, and increased autophagy.

However, This may only apply to adults who are heavy chronic drinkers. Overall, it seems that you can still consume light alcohol and reap the benefits of exercise, but it is clear that drinking alcohol will probably reduce exercise recovery and adaptation somewhat when compared to the same exercise regimen without alcohol. There's one more study I want to talk about that looked at the longer-term effects of consuming a moderate dose of alcohol on the improvements in VO2 max after high-intensity interval training, or HIIT. This was known as the BEER-HIT study. For 10 weeks, all of the participants performed high-intensity interval training twice per week. Some of the participants consumed beer, some consumed sparkling water with vodka, and some consumed water or non-alcoholic beer.

Men in the alcohol group consumed 1 standard drink with lunch and dinner on Monday through Friday, and the women consumed 1 standard drink at dinner. All of the groups increased their VO2 max at the end of the study, and there were no differences between the groups indicating that low to moderate alcohol consumption may not get in the way of cardiorespiratory fitness improvements during high-intensity interval training. A final point I'd like to discuss along the lines of exercise and alcohol is the potential of exercise to treat alcohol use disorder and perhaps reverse some of the damage to the brain caused by long-term alcohol use. We've already discussed some of the damaging effects of chronic heavy alcohol use on the brain. They're not good.

If you're a regular listener of my podcast, then you'll be aware of the incredible benefits of exercise on brain health and cognitive function. In fact, many of the ways that exercise benefits the brain are the same pathways by which alcohol damages it. But unfortunately, there hasn't been much research into the interaction between alcohol and exercise. But I do want to bring up a study from 2013 that provided some evidence that regular exercise may protect the brain from some damage related to heavy alcohol consumption. In a group of 60 adults, heavy alcohol consumption was associated with less white matter integrity in 2 specific brain regions.

However, in the participants who reported the average or above average levels of exercise, Alcohol consumption was not related to less white matter integrity. There was one other interesting finding that deserves some attention. In the participants who didn't exercise regularly, there was a strong positive association between alcohol consumption and a loss of control over drinking. And this relationship was not as strong for the participants who engaged in exercise regularly. This would suggest that exercise seems to play an important role in modulating alcohol intake or cravings of alcohol, which is actually well-supported based on some literature as a reason for exercise being incorporated into alcohol treatment programs for over 40 years.

Similar to alcohol, exercise activates brain reward circuitry and may reduce cravings for alcohol. Meta-analyses show that exercise interventions reduce drinking volume among people with alcohol use disorders And even improve their VO2 max. There are many proposed mechanisms as to why exercise might reduce drinking behaviors. Some of these are psychological and include enhancing self-efficacy, reducing stress, promoting social interaction, improving mood, and mitigating symptoms of comorbid depression and anxiety, which are common among adults with alcohol use disorder. Regarding physiological mechanisms, exercise triggers the release of beta endorphins and modulates the endorphin-opioid system. Both of which are involved in pain pathways and reward processing.

It seems that high levels of beta-endorphins released during exercise can substitute for alcohol consumption and reduce one's desire to drink. There's also dopamine, which is increased during acute exercise and sustained during chronic exercise training. The rewarding effects of alcohol consumption are associated with the dopamine pathway, and therefore exercise might be one way to reduce the susceptibility to alcohol use. There's one final and super interesting pathway that I want to discuss related to exercise and alcohol, and it's a pathway that involves the exercise hormone or exocrine called fibroblast growth factor 21, or FGF21. During exercise, FGF21 is released by our liver and muscles, and it can cross the blood-brain barrier and bind to receptors in the hypothalamus.

It plays a role in many of the beneficial responses to exercise, like improved glucose uptake, Insulin sensitivity, lower blood cholesterol levels, and reductions in body weight. FGF21 also alters dopamine signaling. While exercising increases FGF21, one of the most potent triggers for FGF21 release is alcohol intoxication. FGF21 actually acts as a negative feedback mechanism to decrease subsequent alcohol intake through a liver-brain signaling axis. Even more fascinating in my opinion is the fact that FGF21 also protects against alcohol intoxication. If we could find a way to translate the potent anti-alcohol effects of FGF21 to humans, this could have, in my opinion, some major implications. There is some evidence that FGF21 may have a therapeutic potential for alcohol use disorders.

Studies in humans have found that single nucleotide polymorphisms in genes involved in FGF21 signaling lead to greater alcohol consumption. In animals, FGF21 tells the brain whether to drink more alcohol. Mice who can't release FGF21 drink more alcohol, and increasing FGF21 decreases alcohol consumption, even when given, given as a drug. When an analog of FGF21 was administered to mice and monkeys who were addicted to alcohol, their alcohol consumption decreased by Increasing FGF21 levels thus appears to be a strategy to decrease the preference for alcohol across species. How does this relate to exercise? Well, exercise is one of the most potent ways to naturally increase FGF21 because it's an extra kind released during physical activity.

Endurance exercise, specifically cycling at 70% of VO2 max, increased FGF21 levels by almost 4-fold over baseline levels 1 hour after exercise. FGF21 levels don't increase after resistance training. However, endurance exercise is better for increasing FGF21 levels because it results in a higher metabolic demand compared to resistance training. This leads me to believe that high-intensity interval training or HIIT may also offer an especially potent benefit for alcohol use disorder due to its benefits on FGF21. But also because of the well-known effects of vigorous exercise on brain-derived neurotrophic factor, or BDNF, which you have all heard me talk about in several previous podcast episodes.

BDNF is thought to be one of the main transducers of the antidepressant effects of exercise and could likely complement the effects of FGF21 and other exercise-induced hormones and neurotransmitters to influence alcohol consumption. But until this has all been studied in randomized controlled trials, I can't make any strong conclusions. Let's summarize the influences of alcohol on exercise and exercise on alcohol consumption. Alcohol at a dose of 1 gram per kilogram of body weight impairs exercise recovery. Because this would equate to 5 or more drinks in one sitting for most people, you may not need to be concerned if you're just having 1 or 2 drinks after exercise. But I would certainly avoid high-volume alcohol consumption after exercise.

But of course, really at any time, if your goal is to optimize recovery and adaptations to exercise. If you are going to consume alcohol after exercise, make sure you are consuming adequate protein, at least 25 to 30 grams, and carbohydrates along with it. Replacing food calories with alcohol is the worst thing to do if optimal recovery is your goal, because remember, alcohol is empty calories. It seems advisable based on my view of the literature to abstain from alcohol while you are trying to heal from an injury related to exercise. As there are certainly no benefits to consuming it at this time, just like you wouldn't want to drink when you're trying to recover from an illness or infection.

There is also some compelling mechanistic evidence that exercise may affect the brain in such a way that it reduces cravings for alcohol and leads to less alcohol consumption. Exercise has been used in treatments for alcohol use disorder for almost half a century and seems based on some studies in humans to be effective for reducing alcohol consumption among heavy drinkers. In many ways, engaging in exercise activates the same reward pathways that alcohol does. Finally, engaging in regular exercise may offer some protection against some of the negative effects of chronic alcohol use on the brain. But this is not to say that you should use exercise as an excuse to consume more alcohol.