A lot of people do not realize how alcohol affects the various processes in the body. Understanding how alcohol affects metabolism is vital for anyone who wants to lose weight, increase fitness or build muscles.
Alcohol Consumption and Exercise
In a study published in the Journal of Alcohol Clinical and Experimental Research, researchers asked volunteers to perform an exhaustive ergometer exercise in 3 different scenarios.
- Scenario 1 – Consuming alcohol after exercising
- Scenario 2 – Consuming alcohol before exercising and thus being in an intoxicated state
- Scenario 3 – Exercising during a hangover
How Alcohol Affects Carbohydrate and Fat Metabolism
Alcohol intake immediately before exercise inhibited the exercise induced increase of blood sugar. It also caused a decrease in blood glucose levels during recovery from exercise. Exercise during hangover also resulted in decreased blood glucose levels during the recovery period.
Alcohol consumption before or after exercise inhibited the post exercise increase in free fatty acids concentration in the blood. This was not seen during hangover, when blood alcohol concentration had already reached zero.
Alcohol Interfered with Fat and Carbohydrate Metabolism
The researchers concluded that alcohol interferes with the metabolism of carbohydrates during and after anaerobic exercise. Alcohol decreases the availability of circulating glucose and thus affecting glycogen repletion. The researchers also stated that during recovery from exercise, alcohol also disrupts fat metabolism during the recovery phase.
Disruption in Carbohydrate Metabolism Also Disrupts Glycogen Uptake in Muscles
Alcohol affects carbohydrate metabolism by inhibiting liver glucose output during exercise (Scandinavian Journal of CLininal and Laboratory Investigation) and decreases muscle glucose uptake (Journal Metabolism). Muscle glycogen breakdown is also increased at rest and its pattern of utilization is modified during exercise according to the muscle-fibre-type composition (Scandinavian Journal of Clininal and Laboratory Investigation).
Alcohol therefore has a major effect on metabolism during exercise. When taken before exercise, it reduces glucose production by the liver. As such there is insufficient glucose available for the hungry muscles. There was also disruption in glycogen metabolism when alcohol was taken after exercise (Journal of Applied Physiology).
During rest, muscles should be filling its glycogen stores. Glycogen is broken down by the body and used as fuel during strenuous exercises and needs to be replenished. Instead the presence of alcohol causes the muscles to increase glycogen breakdown. This is attributed to the lower amounts of blood glucose and the body thus trying to regulate blood sugar levels. This is a major interference with muscle recovery. This is especially so for those who have done strenuous exercises such as interval training or weight resistance training. After strenuous exercise, one would want to quickly replenish glycogen stores
Reduced glycogen stores reduces exercise intensity and decreases time to exhaustion during the next workout.
Alcohol’s and Exercise and its Effect on Testosterone and Cortisol
Another interesting study published in the Journal of Alcohol Clinical and Experimental Research. It investigated the effects of alcohol consumption on testosterone when consumed before and after exercise. It also examined the effects of exercising during a hangover. The researchers concluded that alcohol and exercise prolonged the depressant effect of alcohol on testosterone secretion.
A study published in the Journal of Applied Physiology examined the hormonal effects of alcohol consumption after doing resistance exercises. The researchers found that alcohol did not increase circulating cortisol concentration above that caused by just doing resistance exercises without consuming alcohol. They did find however that alcohol appeared to have a more prolonged elevated cortisol effect in resistance trainers who consumed alcohol after exercise.
The longer-sustained cortisol response as a result of consuming alcohol after resistance training could result in an accentuated catabolic effect. The researchers concluded that the effect may hinder muscle building and increased strength during a resistance training program.
Alcohol’s Effects on Exercise Recovery
Recovery from exercise is a very important component that is often overlooked. A body that recovers faster is able to perform at its optimum strength and endurance levels more easily. The easier you recover, the easier it is to push to a higher gear in your next workout.
In a study published in the Journal of Applied Physiology, researchers concluded that the effect of drinking alcohol after exercise for glycogen recovery remained unclear. They postulated that alcohol may displace carbohydrate intake from optimal recovery. In simpler terms, alcohol calories may replace the carbohydrate calories usually eaten after exercise leading to improper recovery.
Alcohol’s Effects on Hydration and How it Affects Exercise
According to Burke’s Complete Guide for Food for Sports and Performance, hydration is an important element often overlooked. Proper hydration before, during, and after exercise is extremely important to create an optimal environment for building muscles and losing fat. It is also critical for achieving peak energy levels as well as for transporting and absorbing nutrients. Another role of proper hydration is removing toxins and by-products from the body.
Someone who is thirsty may have already lost 1- 2% of body weight through dehydration according to a study review in the Journal Medicine and Science in Sports and Exercise. Performance could be compromised by 10 to 20% at this level.
According to a study published in the Journal of Applied Physiology, drinks with more than 4% alcoholic content can cause the body to lose 3% more body fluid within a 4-hour period. This leads to quicker dehydration.
Increased Cardiovascular Strain
Alcohol consumption before exercise increases cardiovascular strain during exercise by increasing heart rate.
Alcohol and Exercise
Based on the scientific research available, it makes a lot of sense not to mic exercise and alcohol. It is also important for people trying to exercise to know what effect alcohol has on the body. Besides alcohol and calories, it also halts fat metabolism. What would be wiser is to abstain from alcohol until one’s fitness goals are met.
Further reading;
- Alcohol’s Effects on Weight Loss – Part 1
- Alcohol’s Effects on Weight Loss – Part 2
- Alcohol’s Effect on Testosterone and How it Affects Fat Loss
- Effect of Alcohol on Male Sexuality
Tags: alcohol and weight loss, alcohol and exercise, alcohol’s effect on exercise, alcohol and exercise recovery, alcohol and dehydration, dehydration and exercise, exercise and hydration, alcohol, exercise and testosterone, post exercise alcohol consumption, pre exercise alcohol consumption, exercising during hangovers, hangover exercise, alcohol and cortisol, exercise and cortisol, alcohol and glycogen repletion, alcohol and glycogen levels, glycogen and alcohol, glycogen, alcohol and fat metabolism, alcohol and carbohydrate metabolism
All images courtesy of stock.xchng

{ 8 trackbacks }
{ 0 comments… add one now }