Alcohol seems to have a large effect on exercise. Its effect depends on whether it is taken before or after exercise. It affects fat metabolism. It also seems to negate the positive effects of exercise. Understanding how alcohol effects exercise is vital for anyone who wants to lose weight, increase fitness or build muscles.
Drinking and Exercise
In a study published in the Journal of Alcohol Clinical and Experimental Research, researchers asked volunteers to do 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
Effect on Carbohydrate and Fat Metabolism
Drinking immediately before a workout inhibited the exercise induced increase of blood sugar. It also caused a decrease in blood glucose levels during recovery from the workout. Exercise during hangover also resulted in decreased blood glucose levels during the recovery period.
Drinking before or after a workout 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 levels of circulating glucose and thus affecting glycogen repletion. The researchers also stated that alcohol also disrupted fat metabolism during the recovery phase after a workout.
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 use 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 a workout. When taken before a workout, 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 a workout (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. Alcohol’s presence 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 a workout. 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 drinking 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 drank after a workout.
The longer-sustained cortisol response as a result of drinking after resistance training could resulted in an accentuated catabolic effect. The researchers concluded that the effect may hinder muscle-building and hinder strength levels during a resistance training program.
Alcohol’s Effects on Exercise Recovery
Recovery from exercise is a very important part 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 ideal 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.
Effect of Alcohol on Exercising
Based on the scientific research available, it makes a lot of sense not to mix alcohol and exercise. It is also important for people trying to exercise to know what effect drinking has on the body. Besides the calories, it also halts fat metabolism. What would be wiser is to abstain from drinking until one’s fitness goals are met.