What You Should Know About Alcohol and Muscle Growth
If you don’t think alcohol is a common theme in endurance sports, think again. Race bibs often come with drink tickets and beer tents aren’t an uncommon sight at the finish line. And why wouldn’t alcohol be a part of the post-race celebration? It’s a culturally accepted practice to celebrate with a drink and racing is no exception. But, when alcohol creeps in to the daily life of an endurance athlete, what impact does it have on muscle growth and recovery?
Alcohol isn’t Nutrient Dense
Alcohol has 7 calories per gram, but otherwise provides no nutritional benefit. This is why it’s often referred to as a source of “empty calories.” For caloric reference, carbohydrates and protein both contain 4 calories per gram while fat contains 9 calories per gram. Alcohol isn’t stored in the body for energy use unlike the other macronutrients, and its metabolism is prioritized by the liver which impacts the metabolism of other nutrients in the diet. The metabolism of alcohol varies from one person to the next with factors such as body composition, age, and sex all playing a role in the rate of alcohol metabolism. Of note, food intake influences the absorption of alcohol and is one of the reasons why many will recommend eating when drinking versus drinking on an empty stomach because the food slows the absorption of alcohol in the stomach.
Alcohol and Muscle Growth
Endurance athletes work hard to build and maintain muscle. These adaptations are a result of grueling training schedules and proper nutrition to promote muscle repair and maintenance. A shift in body composition that improves lean muscle mass also positively impacts performance. Any practice that inhibits this adaptation is one that most athletes look to avoid.
One of the negative impacts of alcohol is its impact on muscle protein synthesis. In a small study of active males, researchers found that alcohol negatively impacted muscle protein synthesis. This study consisted of three groups - one that consumed whey protein only after the exercise bout, one with protein plus alcohol, and another with carbohydrate plus alcohol. All groups also ate a carb-rich meal at two hours post exercise. The researchers found that muscle protein synthesis was negatively impacted by the intake of alcohol after exercise. This effect continued for the eight hours post exercise with the most significant impact seen in the group that did not consume protein after the exercise session. The researchers conclude:
“…the results of the current study provide clear evidence of impaired recovery when alcohol is consumed after concurrent (resistance, continuous and intermittent high-intensity) exercise even in the presence of optimal nutritional conditions.”
*Note that this study provided 1.5g of alcohol per kg body weight in the post-exercise feeding. For reference, one 12 fl oz beer has approximately 14g of alcohol. The impact of alcohol outside of this quantity cannot be determined based on this study alone.
Should Endurance Athletes Enjoy the Post-Race Beer?
It might go without saying that if you don’t currently drink, there is not benefit to starting. But, if you’re an endurance athlete who enjoys drinking alcohol on occasion then you’re probably wondering when and how much to drink to avoid the impact on muscle growth and maintenance.
First, prioritizing carbohydrates and protein from food after exercise is of primary importance. This is especially true after high intensity or long duration training sessions. Carbohydrate and protein ingestion within two hours after exercise has been shown to promote glycogen synthesis and muscle protein synthesis. This process is vital to recovery and adaptations associated with endurance training. If you’re going to the bar after a long training session then it’s unlikely you’re going to prioritize food over beer. Not to mention, the food choices might be sub-par compared to what you’d normally re-fuel with after exercise. The bottom line: focus on food first before indulging in alcohol.
Second, keep the booze intake to a minimum. Alcohol is a diuretic which can further exacerbate dehydration after exercise. Alcohol can also contribute to excess calorie intake, poor food choices, and poor quality sleep - all which can have a downstream effect on body composition and recovery. The recommendation for daily alcohol intake is no more than two drinks per day for men and one drink per day for women.
Alcohol Alternatives
If you’re looking for alcohol alternatives then look no further than the increasingly popular mocktail. Some have published books of recipes featuring fancy non-alcoholic beverages. I’ve also rounded up a few delicious, lower sugar mocktails from fellow dietitians. Many of these feature kombucha, a fermented beverage that’s a great alcoholic alternative and is even available on tap in many bars and restaurants.
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