Even with 7 calories per gram, alcohol is a nutrient which cannot be stored and used by the body as a source of energy. Though there are mixed reviews and opinions on its effects on athletic performance, what is known for sure is that it has a diuretic effect and causes at least 2% dehydration depending on the amount of alcohol consumed. Moreover, it lowers glycogen stores as well as reduces glycogen uptake. Along with its psychological effects like hangover, dizziness, disorientation, headache, alcohol can definitely affect an athlete’s performance.
It has also been proven to reduce muscle protein synthesis when consumed post resistance training which can hamper an athlete’s recovery and in turn, stall the progress. Though alcohol directly doesn’t make you gain fat, it does temporarily reduce fat oxidation to a minimal extent and prolonged habit can increase an athlete’s body fat%. In a study, it was proved that athletes who consume alcohol are two times more prone to injuries as compared to their non-drinking counterparts, a fact which is indirectly linked to a decline in athletic performance.
Now, if the deed is already done, recovering from the hangover can be influenced – a high calorie meal has been shown to reduce the absorption pace of alcohol and in turn reducing the load on the liver. Including some aerobic activity aids in speeding up the process to some extent.
But all said and done, it would be wiser to refrain from consuming alcohol, or at the least limiting it to moderation and at sufficiently large gaps of time, so that it doesn’t hamper your performance.
We have all been or are a part of a group of friends who like to relax and unwind after a hectic weekend with a couple of cold beers or any other alcoholic drinks, and some of us have experienced personally, or known someone who has had terrible hangovers after a night of binge drinking. But the question is, do we understand the actual effects of alcohol on our fitness goals and our health?
Training for hours and hours and still unable to lose that fat? Training hard but unable to achieve those desired results? Alcohol might be the reason. Here’s why you should start thinking about it…
Alcohol metabolism & elimination:
Alcohol, like carbs, fats, and protein, is a nutrient although not a necessary one. With 7 calories per gram, it is a nutrient which cannot be stored and used by the body as a source of energy. Alcohol is absorbed at a faster rate when the body is in a fasted state as compared to fed state thus increasing alcohol concentration levels in the blood.
When ingested in high concentration on fasted state, alcohol bypasses the first phase i.e. through the stomach because of lack of ADH (alcohol dehydrogenase, alcohol digesting enzymes). This puts the load on the liver, and often leads to a slowdown in the oxidation of alcohol.
Alcohol metabolism: Alcohol may get metabolized in the stomach but it lacks the necessary enzymes to metabolize it. Hence, majority of the work is done in the liver as it has greater levels of alcohol metabolizing enzymes (alcohol dehydrogenase). Naturally, there is greater load on the liver in terms of metabolizing alcohol till the time it gets eliminated from the body. This unnecessary burden on the liver may end up causing liver damage in prolonged continuation of this habit.
Age and Alcohol elimination: It’s elimination pace varies from person to person depending on their sex, age, race, and nutrition, though an average person can metabolize around 170 to 240 grams a day depending on their metabolic rate. Women usually eliminate alcohol at a faster rate as compared to men because of their slender frames and lighter lean body mass. It is found that people in their older ages have slower response in elimination of alcohol from their system as compared to someone in their youth. It is also found that speed of elimination of alcohol reduced as the age progressed.
Alcohol metabolism is higher on fed state as compared to a fasted state as it has increased availability of ADH enzymes, increased blood flow in the liver, and because of the enhancement of the shuttling capacity to mitochondria, which is reduced in fasted state. Exercise has also shown to be used as a way to increase the elimination rate of alcohol.
Effects of alcohol on Athletic performance
- Alcohol ingestion impairs maximal post-exercise rates of myofibrillar protein.
In a study done on 8 physically active men, who were divided into 3 groups and were fed with protein, protein + alcohol, and protein + carbohydrates 4 hours post exercise, it was shown that alcohol mixed with either of the nutrients suppressed protein synthesis, anabolic response in skeletal muscle, and may impair recovery as well as affect the progress from the training, and in turn affect performance in the following training session. So, consuming alcohol is certainly not beneficial and is rather detrimental for someone who is looking forward to achieving their fitness goals. 
Alcohol has also been shown to reduce mTOR signaling, which further leads to reduction in muscle protein synthesis and causes delayed recovery. 
- Alcohol ingestion inhibits lipolysis
Lipolysis is the process of burning fats and using them as a source of energy. In a study done on 8 healthy men, it was found that moderate consumption of alcohol (24g) activated DNL pathway which rose from 1% to 8%, decreased adipose release of fatty acids by 53% and decreased whole body lipid oxidation by 73%.
DNL pathway rises on moderate consumption of alcohol and can convert the carbohydrates you consume into fats which is a nightmare for someone who is on a fat loss regime (DNL is a metabolic pathway that converts excess carbohydrates into triglycerides). Consumption of alcohol stops your body from burning fats and has a high chance that the fats and carbs you consume with alcohol are being stored as fats. 
- Alcohol increases insulin resistance:
Binge drinking has been shown to cause insulin resistance. More than 3 drinks causes an insulin spike, disturbs glucose homeostasis, and impairs the nutrient partitioning system. Prolonged habit can cause insulin resistance even when the blood concentration levels go back to normal. Prolonged habit can also increase the risk of metabolic syndrome and type-2 diabetes. 
- Leads to increased appetite and cravings:
As proteins, fats, and carbs satiate you, alcohol as a nutrient does the opposite. It increases your appetite and can lead you to go off your structured diet plan and eventually stray you off your course. Logically, therefore, a prolonged alcohol habit can cause obesity too. 
- Effects on aerobic/anaerobic performance:
An athlete is only as good as his/her performance and hydration plays a huge role in it. Dehydration can affect the aerobic endurance and performance as well as the strength of the athlete, as it has been shown that dehydration can reduce the lean body mass of the athlete in turn affecting his 1RM. Reduced hydration levels can even hamper blood flow and supply of nutrients to the muscle and in turn affecting the pump all bodybuilders crave. Since alcohol has diuretic effect, it can cause loss of water by excess urination, and eventually it affects the performance and strength of an athlete. Alcohol reduces cardiovascular capacity as well, which results in poor performance and early failure in cardiovascular activity. It has been shown to cause a drop in aerobic performance by 11%.    
- Reduction/prevention in increasing Androgen receptors content:
Androgen receptors are areas where testosterone attaches to stimulate protein synthesis. Resistance training helps in increasing androgen receptor content leading to increase in protein synthesis which is the key to recovery. Alcohol was found to have an opposite effect on the androgen receptors, it was found that in trained men who were performing squats during this research period, androgen receptor content was significantly reduced in the type 2B fiber predominant rectus femoris, and prevented resistance training-induced increase in androgen receptor content in men who were consuming alcohol as compared to those who weren’t. 
- Neurological effects:
Alcohol is considered to be a depressant and thus reduces central nervous system(CNS) activity. It has been shown to cause loss of memory, impaired stability, reduced balance, increased reaction time, and reduced accuracy of motor skills. It has shown to cause disruptive sleeping patterns and loss of sleep at times. Apart from the immediate effects, hangover caused by alcohol has additional deteriorating effects such as headache, dizziness, stomach ache, and disorientation, which can affect an athlete’s performance in a negative manner. 
- Effect on testosterone production and muscle uptake:
Testosterone is a sex hormone which is predominant in males. Alcohol may not affect testosterone production but it has been shown that it may reduce muscle uptake in turn affecting muscle growth. Testosterone is known to increase muscle mass by increasing muscle protein synthesis, but alcohol impairs its uptake in the muscles, and in turn, affects growth.  
Even though there are studies backing benefits of moderate drinking, as an athlete and as a person following a fitness goal, one should avoid consuming alcohol upon looking at its detrimental effects on health and performance. Alcohol is quite addictive and at times leads to a prolonged habit without being beneficial to health. These health issues are especially applicable to athletes, but have even adverse effects on people following a sedentary/inactive lifestyle. Some of these adversities/health issues can be reversed to a large extent (if not completely) by following a structured diet plan and exercise routine.
Article Credits – Mukund Dawra
Cederbaum, Arthur I. “ALCOHOL METABOLISM.” Clinics in Liver Disease. U.S. National Library of Medicine, Nov. 2012. Web. 04 Feb. 2017.
“Alcohol Ingestion Impairs Maximal Post-exercise Rates of Myofibrillar Protein Synthesis following a Single Bout of Concurrent Training.” PloS One. U.S. National Library of Medicine, n.d. Web. 04 Feb. 2017.
“De Novo Lipogenesis, Lipid Kinetics, and Whole-body Lipid Balances in Humans after Acute Alcohol Consumption.” The American Journal of Clinical Nutrition. U.S. National Library of Medicine, n.d. Web. 04 Feb. 2017.
“Binge Drinking Induces Whole-body Insulin Resistance by Impairing Hypothalamic Insulin Action.” Science Translational Medicine. U.S. National Library of Medicine, n.d. Web. 04 Feb. 2017.
“Alcohol, Appetite and Energy Balance: Is Alcohol Intake a Risk Factor for Obesity?”Physiology & Behavior. U.S. National Library of Medicine, n.d. Web. 04 Feb. 2017.
Barr, Susan I. “Effects of Dehydration on Exercise Performance.” Canadian Journal of Applied Physiology 24.2 (1999): 164-72. Web.
Vella, Luke D., and David Cameron-Smith. “Alcohol, Athletic Performance and Recovery.”Nutrients. MDPI, Aug. 2010. Web. 04 Feb. 2017.
“Chronic Alcohol Intake, Resistance Training, and Muscle Androgen Receptor Content.”Medicine and Science in Sports and Exercise. U.S. National Library of Medicine, n.d. Web. 04 Feb. 2017.
“Alcohol-induced Decrease in Muscle Protein Synthesis Associated with Increased Binding of MTOR and Raptor: Comparable Effects in Young and Mature Rats.” Nutrition & Metabolism. U.S. National Library of Medicine, n.d. Web. 04 Feb. 2017.
Pesta, Dominik H., Siddhartha S. Angadi, Martin Burtscher, and Christian K. Roberts. “The Effects of Caffeine, Nicotine, Ethanol, and Tetrahydrocannabinol on Exercise Performance.” Nutrition & Metabolism. BioMed Central, 2013. Web. 04 Feb. 2017.
“Effect of Testosterone on Muscle Mass and Muscle Protein Synthesis.” Journal of Applied Physiology (Bethesda, Md. : 1985). U.S. National Library of Medicine, n.d. Web. 04 Feb. 2017.
- “Postresistance Exercise Ethanol Ingestion and Acute Testoste… : Medicine & Science in Sports & Exercise.” LWW. N.p., n.d. Web. 04 Feb. 2017.