What Does Science Say About Mixing Alcohol and Exercise?

It probably won’t come as a surprise to you that during the COVID-19 lockdown, there has been a 70 percent rise in the number of people riding their bikes for exercise in the UK, while running is booming in North America. These faster-paced and outdoor sports are seen as a fun, safe way to stay fit while social distancing measures continue.  

While there has been this rise in (outdoor) exercise, there has also been a rise in alcohol consumption. According to the University of Utah, in the US, Alcohol distributors reported a 50 percent increase in the sales of alcohol from one week in March during the 2020 coronavirus outbreak compared to the same week a year ago. Home delivery of alcohol has increased dramatically, and one report notes a 300 percent increase in alcohol sales in March as compared to January. That’s a whole lotta booze, people!

Reading about these exercise and alcohol trends made me wonder how going for more runs and rides, while also consuming more alcohol, affects our endeavors to get and stay fit. Are we better off, worse off, or somewhere in between?

In the past, headlines based on the results of a study called The Effect of Post-Match Alcohol Ingestion on Recovery From Competitive Rugby League Matches, instructed us to stay far away from alcohol if we wanted to maximize our workout results.

For alcohol to impair workout recovery, you need to drink the equivalent of about four to six servings right after you finish exercising.

And sure, this study, and others before it, did show that alcohol can negatively affect your exercise efforts. But what the headlines missed was that for alcohol to impair workout recovery, you need to drink the equivalent of about four to six servings right after you finish exercising. Yes, four to six servings! At that amount, not only will the alcohol hurt recovery but it will also give you lots of empty calories. Not to mention, a lightweight like me would probably do nothing but lie around nursing a hangover the next day.

To give some perspective, in North America, “legal intoxication” is defined as having a blood-alcohol level of 80 mg / dL (17.4 mmol/L) or 100 mg / dL (21.7 mmol/L) or above. This is a different way to look at it than we’re used to. Most of us are more aware of the legal measurement of blood alcohol concentration (BAC) to be 0.08 percent. So try to keep that in mind as we go through the studies since many of them vary in the amount of alcohol that was given to the participants and how it was measured in their blood.

Alcohol before exercise

This is definitely not the way it usually goes. Alcohol is usually how we reward ourselves after we workout, not before. So, with this in mind, there aren’t many studies that looked at alcohol before exercise. But the results of the few studies that do exist are mixed—just like a cocktail!

In one study called Alcohol, Cardiorespiratory Function and Work Performance it was found that ingesting 0.44 and 0.88 ml/kg body weight of 95 percent alcohol half an hour before a progressive cycling test had no effect on exercise performance.

The results of the few studies that do exist are mixed—just like a cocktail!

Then, in terms of strength performance, another study found that a blood alcohol concentration of 140 mg/dL was found to have no effect on isokinetic and isometric knee extension.

But then, another small study of short-distance sprinters and middle-distance runners found that alcohol consumption worsened performance at 1500, 800, 400, and 200 meters, but strangely not at the shorter (but most intense) 100 meters.

So, it appears that alcohol’s effect on sports performance depends greatly on how much you drink. This is not a surprise. We know that alcohol is a central nervous system depressant that also throws us off balance, wreaks havoc on our coordination, and slows our reaction time by varying degrees, depending on how much we drink. 

In fact, a 2010 research paper called Alcohol, Athletic Performance and Recovery suggested that exercise performance is significantly affected at blood alcohol concentrations around 92 mg/dL (20 mmol/L), which is above the legal limit to drive. 

Mixing alcohol and exercise

There are some definite negatives to mixing alcohol and exercise. A study found in PLoS One highlighted one example, which showed that high amounts of alcohol intake can impair protein synthesis (how our muscles repair themselves after exercise). In practical terms, this means chugging a few beers during or after a 10k run on a sunny day may lead to slower recovery of the muscles in your legs.

Chugging a few beers during or after a 10k run on a sunny day may lead to slower recovery of the muscles in your legs.

That same study also showed that when athletes “binged on alcohol” after a killer strength-training workout, their protein synthesis decreased by nearly 40 percent. But again, this is very dose-dependent. When I say these athletes binged, I meant it. They ingested roughly eight shots of vodka mixed (with orange juice) in just three hours!

Alcohol and hydration

Most of us know that alcohol is a diuretic—it increases the water lost from our body as urine. More scientifically, it appears that alcoholic drinks that contain four percent weight/volume (or more) alcohol inhibit the release of a hormone called ADH (antidiuretic hormone or vasopressin).

As you probably guessed from the name, ADH is the opposite of a diuretic. Instead of making you have to pee, it increases the reabsorption of water back into your bloodstream. But when the release of ADH is inhibited, water loss goes up and so does dehydration. That can really inhibit our recovery, even the following day.

But once again, it depends on how much you indulge. An older (but important) study published in the Journal of Applied Physiology, showed that an alcohol dose of less than 0.49 g/kg body weight (three or four standard alcoholic drinks) would not affect rehydration. 

Is beer different?

A study published in the International Journal of Sports Nutrition and Exercise Metabolism discovered that beer’s dehydrating effect could be lessened by adjusting the electrolyte content. By lowering the level of alcohol to 2.3 percent (from the usual five or six percent) and then adding some salt, these crafty brewers found that the electrolyte-enhanced, lower-alcohol beer actually hydrated athletes better than traditional ale.

The researchers were comparing this fancy new beer to traditional beer. This does not mean the modified beer performed better than good old water.

But there may actually be other benefits to beer. For example, a 2011 German study found that the polyphenols in beer may assist with immune function during prolonged strenuous exercise.

In this study, the runners who were given a non-alcoholic beer every day for three weeks before and two weeks after their marathon reported fewer incidences of upper respiratory tract infections (which are somewhat common after endurance races) and were up to three times less susceptible to the common cold. This is likely due to the compounds found in the plants used to make beer, which have anti-inflammatory and anti-oxidative effects.

So beer—with its carbohydrates, some added electrolytes, lowered amounts of alcohol, and some smart engineering to add more plant protein—may actually be helpful after exercise. But of course, not many of us have access (or even want access) to this scientifically perfected beery beverage. 

Alcohol and refueling

When we move our bodies—especially when we move vigorously—the glycogen stores in our liver and skeletal muscles are broken down to release glucose. This glucose is then used to fuel muscle contractions which make us perform the movements. When we eat carbs after we exercise, we replenish these glycogen stores. In an oversimplified nutshell, we break down the carbohydrates that we eat into glucose, which then fills our glycogen stores back up. 

Once again, we see that the amount of alcohol matters. And in this case, so do the carbs.

Unfortunately, alcohol may interfere with this process of glycogen replenishment. But a study of cyclists found that glycogen stores were not affected by drinking 1.5 g/kg bodyweight of alcohol with a high-carbohydrate meal. But, when the cyclists drank more alcohol and some of the carbs were replaced with booze, glycogen storage was reduced.

So once again, we see that the amount of alcohol matters. And in this case, so do the carbs. 

Alcohol and exercise recovery

Intense exercise (in particular, resistance training) actually damages and tears our muscle fibers. Then, during the recovery phase, our muscles repair themselves and adapt so they’re stronger and more resilient.

Once again, we see that dose matters.

But as I mentioned earlier, studies have found that alcohol can impair this reaction. One study, in particular, had its subjects complete a whopping 300 eccentric contractions (the most damaging part of the movement) of the quadriceps muscle of one leg before either consuming 1g/kg bodyweight of alcohol or the same amount of orange juice (measured in calories). The subjects who consumed alcohol experienced a severe loss of muscle strength at 30 and 60 hours after the experiment.

Another study called Alcohol: Impact on Sports Performance and Recovery in Male Athletes found that drinking 0.5g/kg bodyweight of alcohol did not affect the athlete’s strength. So, once again, we see that dose matters.

Alcohol and injuries

Recovering from an injury, and returning to your favorite sport, is always excruciatingly slow. We want to do everything we can to speed it along. And Since the various inflammatory and hormonal processes that rebuild tissue and promote healing after an injury can be negatively impacted by high alcohol intake, it’s smart to avoid it altogether.

In a study we looked at earlier, alcohol was shown to lower the acute inflammatory response to tissue injury, which delays recovery. Also, alcohol causes vasodilation (relaxing of the blood vessels), which has been shown to increase swelling and delay healing.

Since the various inflammatory and hormonal processes that rebuild tissue and promote healing after an injury can be negatively impacted by high alcohol intake, it’s smart to avoid it altogether.

Larger amounts of alcohol (1.5g/kg body weight) also inhibit the production of two important repair hormones—testosterone and growth hormone.

Alcohol and sleep

Alcohol is well known to wreck a good night’s sleep, which is the most effective recovery tool we have. 

In a paper called Sleep, Recovery, and Performance: The New Frontier in High-Performance Athletics, lead author Charles Samuels says:

Sleep has been identified by elite athletes, coaches, and trainers as an important aspect of the PER (post-exercise recovery) process, and is thought to be critical for optimal performance.

In a 2005 study on melatonin—a hormone associated with good sleep—it was found that aiding the release of this hormone can help heal skeletal muscle injuries heal faster. That means that a solid night of sleep may help you bounce back from your workouts with less soreness.

Alcohol and muscle growth

To get bigger, muscle cells need to create new proteins faster than they break them down. This process is known as muscle protein synthesis (MPS). In one study, MPS was reduced by 24-37 percent in subjects consuming alcohol after exercise (even if the alcohol was consumed along with protein and carbohydrate).

But again, the subjects in this study consumed a whopping 1.5g/kg bodyweight of alcohol. This equals about ten to thirteen standard drinks. So, I guess the take away is to not go on a bender if you want to pack on muscle.

How much alcohol is ok with exercise?

Following the general health guidelines for alcohol consumption is good for all of us. If we want to truly get all we can from our exercise time, we should ignore the voice in our head telling us we earned that extra drink. 

In her article Rethinking Drinking, the Nutrition Diva had these wise words:

Here in the US, we define moderate consumption as one drink a day for women and two drinks a day for men. Sweden sets the bar lower, France quite a bit higher. According to this latest analysis, however, all of these recommended limits could still put you at increased risk. The only way to reduce your risk of alcohol-related harm to zero is to reduce your consumption to zero. But remember that risk is merely an expression of statistical probability. It does not predict the future.

So my takeaway is that on some days of the week, one or two drinks is fine. But when I am focussed on performing at my absolute best and dedicated to getting the maximum benefit from my exercise program, I will err closer to none.

Although we could definitely use more studies that measure the zone between drinking non-alcoholic beer and a total party binge, it seems pretty clear that if you want to perform at your best, limiting your alcohol consumption is a good idea from a recovery, muscle growth, injury repair, and stamina standpoint.

But it is also clear that the dose, as they say, makes the poison.