Tuesday, June 9, 2009

No Place for Alcohol

One of the time-honored, post-match traditions of adult league soccer leagues is to head to the pub and have a pint or two (or three). Many believe that beer and other alcohol-containing drinks actually aid recovery. The argument is that alcohol is a carbohydrate and carbohydrates help replenish energy stores. In fact, some athletes jokingly refer drinking beer as “carbohydrate loading”. Unfortunately, research clearly shows that drinking alcohol after exercise does not aid in recovery. In fact, beer and other adult beverage can dramatically impair the recovery process by affecting muscle damage, energy replenishment and re-hydration.

A new study published in the Journal of Science and Medicine in Sports emphasizes this point. The researchers examined the effect of post-exercise alcohol consumption on markers of muscle damage and soreness. They asked their subjects perform a strenuous bout of exercise which was followed by a meal. One group drank orange juice (control) while the alcohol group drank orange juice mixed with vodka. For this group the total amount of alcohol consumed was equal to 8-9 standard drinks.

At 36 and 60 hours after exercise, muscle force produced by the alcohol group was considerably lower than the control group, 15-20% lower. Those in the alcohol group also reported higher ratings of muscle soreness and the 36 and 60 hour measures. Diminished muscle performance and increased pain, clearly two strikes against alcohol.

The investigators explained that the alcohol consumption after exercise likely magnifies the amount of muscle damage that is typically associated with strenuous activity. The type of muscle damage that leads to muscle soreness typically occurs in several stages (see The Painful Truth About Muscle Soreness). The first occurs during exercise. The second occurs immediately after exercise and the process usually last for several hours. This is the process that seems to be increased by alcohol , possibly through its negative effects on the immune system and inflammation. Whatever the cause, it’s clear from this study that the effects of drinking after exercise can literally be felt for several days.

The conclusion that alcohol is not a good recovery drink is supported by several earlier studies. These studies show that consuming alcohol after exercise adversely affects energy replenishment. Drinking after a match can impair the metabolism of carbohydrates which leads to reduced blood glucose levels and diminished replacement of muscle glycogen. In addition, consuming alcohol-containing drinks typically reduces the intake of other carbohydrates that are essential to recovery. As discussed previously on the Science of Soccer Online (link), restoration of muscle glycogen is possibly one of the most important aspects of recovery. Thus, from metabolic point of view, drinking after a hard match can prevent the muscles from replenishing much needed energy stores. Despite it being a carbohydrate, it actually hinders recovery.

Alcohol is also a potent diuretic that causes fluid loss through urination. It makes sense that drinking after a match can lead to further dehydration. Much of the fluid that is being consumed through alcoholic beverages is also being excreted. Research has shown that anything containing 4% or more alcohol can lead to further dehydration after exercise. By way of comparison, anything other than light beer contains more than 4% alcohol.

So, despite the popular belief that beer and other adult beverages help recovery from exercise, the scientific evidence clearly shows otherwise. Alcohol consumption after strenuous exercise 1) intensifies delayed-onset muscle soreness, 2) impairs muscle glycogen replenishment and 3) hinders re-hydration. So, hoisting a few pints after a hard match can leave the player in poor condition of play the following day. The bottom line... there is no place for alcohol after exercise.

References:

Barnes MJ, Mundel T, Stannard SR (2009) Acute alcohol consumption aggravates the decline in muscle performance following strenuous eccentric exercise. Journal of Science and Medicine in Sports, in press (doi:10.1016/j.jsams.2008.12.627)

Burke LM, Collier GR, Broad EM, Davis PG, Martin DT, Sanigorski AJ, Hargreaves M (2003) Effect of alcohol intake on muscle glycogen storage after prolonged exercise. Journal of Applied Physiology, 95:983-990.

Heikkonen E, Yilkahri R, Roine R, Valmaki M, Harkonen M, Salaspuro M (1998) Effect of alcohol on exercise-induced changes in serum glucose and serum fatty acids. Alcohol Clinical and Experimental Research, 22:437-443.

Shirreffs SM, Maughan RJ (1997) Restoration of fluid balance after exercise-induced dehydration: effects of alcohol consumption. Journal of Applied Physiology, 83:1152-1158.