First: alcohol doesn't affect everyone equally
The effects of alcohol on a person depend on the amount consumed and individual tolerance. Some studies show that a small amount of certain kinds of alcohol (namely red wine) may have a protective effect on the cardiovascular system, but even a few drinks can nullify your hard work by erasing the effects of your workouts, reducing your endurance, and compromising your mental fortitude. Bottom line, keep track of the number of drinks you have, and how you feel during, the morning after, and in the following days to get an idea of your personal tolerance.
The effects of alcohol on muscle development and recovery
Muscle health is the key to successful athletic performance, and science shows that alcohol can rob you of your hard work in the weight room. Here’s why:
It impairs muscle growth
Not only does working out under the influence increase your likelihood of injury, but it can also impede muscle growth. Long-term alcohol use diminishes protein synthesis, resulting in a decrease in muscle growth. Even short-term alcohol use can affect your muscles.
It dehydrates your body
If you want to optimize your athletic performance, then you want your recovery from sore muscles to be as fast as possible. Alcohol has been shown to slow this process because it is a powerful diuretic, which can cause dehydration and electrolyte imbalances. And when dehydrated, an athlete is at a greater risk for cramps, muscle pulls, and muscle strains.
It prevents muscle recovery
Getting enough rest is essential to building bigger and stronger muscles. However, because drinking alcohol negatively affects your sleep patterns, your body is robbed of a chemical called human growth hormone (HGH) when you drink.1 HGH plays an integral role in building and repairing muscles, but alcohol can decrease the secretion of HGH by as much as 70 percent. Additionally, binge drinking can reduce serum testosterone levels. Decreases in testosterone are associated with decreases in lean muscle mass and muscle recovery, which can impair performance.
It depletes your energy
After alcohol is absorbed through your stomach and small intestine and moves into your cells, it can disrupt the water balance in your body. And an imbalance of water in your muscle cells can hamper their ability to produce adenosine triphosphate (ATP), which is the essential fuel for all cells, including those in our muscles. A reduction in your body’s ATP can result in a lack of energy and loss of endurance.
It slows reaction time
Lastly, even small amounts of alcohol can result in a slowed reaction time and decreased hand-eye coordination. Not only can this impair performance, but a slowed reaction time can increase your risk for injury.
The effects of alcohol on memory
Performing your best often involves learning plays or strategies for an event. Alcohol impairs the functioning of the hippocampus, a part of your brain which is vital to the formation of memories. If you can’t form new memories, you can’t learn and store information.
Creating memories is a complex process that takes a long time, and many memories are established even when you’re not actively thinking about them. In fact, the majority of memory formation happens when you sleep. Alcohol disrupts the sequence and duration of your sleep cycle (even if you drink up to six hours before you go to sleep), which reduces your brain’s ability to process and store important information, including key performance notes.
The effects of alcohol on nutrition
It can't be used as energy
We tend to think that only carbohydrates, protein, and fat can provide energy (in the form of calories). But actually, that's not a comprehensive list – alcohol has 7 calories per gram (about halfway between the calorie value of carbs and fat). But unlike calories from the food we eat, your muscles are unfortunately not able to use alcohol calories for fuel.
Alcohol calories are not converted to glycogen, a form of stored carbohydrates, and are consequently not a good source of energy for your body during exercise. Your body instead converts the energy from alcohol into fatty acids and stores them in our fat tissue. As a result, alcohol consumption increases fat storage and can adversely affect your percentage of body fat.
It inhibits nutrient absorption
Alcohol itself is devoid of vitamins and minerals, and therefore is extremely limited in its nutritional value. But beyond that, it also keeps your body from absorbing these nutrients from other sources:
Thiamine (vitamin B1)
Thiamine is involved in metabolizing the food we eat into fuel as well as the formation of hemoglobin. Because vitamin B1 plays a role in metabolizing carbohydrates, it is essential for optimal performance.
Vitamin B12 helps maintain healthy red blood and nerve cells. Because alcohol prevents b12 from being used in key processes in your body, chronic excess alcohol consumption may contribute to b12 deficiency symptoms, which manifest as anemia.
Folic acid is a part of a coenzyme involved in the formation of new red blood cells. A deficiency in folic acid can result in a reduced VO2max, which can negatively affect your endurance.
Zinc plays an important role in the process of energy metabolism. Alcohol depletes your body’s zinc resources, which can result in a reduction in endurance.
The effects of exercising with a hangover
Hangovers are actually caused by alcohol toxicity, dehydration and the toxic effects of congeners (or the byproducts of fermentation) that are present in most alcoholic drinks. If you’ve ever experienced a hangover, you’ve probably felt the symptoms of nausea, soreness, depression, and headaches that frequently coincide... with a proclamation to never drink alcohol again. The symptoms can lead to decreased athletic performance and have been known to decrease aerobic performance capacity by as much as 11%. So, if you have a lingering hangover, it’s best not to exercise, as it can increase your risk of injury and further dehydrate you.
The verdict on alcohol's effects on performance
If you’re physically active, take the above points into consideration with how drinking will affect your athletic performance. If you choose to drink, avoid anything excess of low-volume drinking (ex. a single glass of red wine) for 48 hours before your event, and be sure to rehydrate and eat before consuming alcohol post-exercise.