Post-exercise hydration: Is beer a better choice than water?
Beer seems to have a lot of the elements necessary for effective post-exercise recovery and rehydration: It contains fluid and carbohydrates, it’s normally consumed with salty snacks, and it helps some athletes relax and unwind after a hard day.
But most beers also have one more important ingredient: Alcohol. And anyone who has had a couple cold ones knows that taking in alcohol with fluid makes you pee! This could be a problem if your goal is rehydration. So luckily, researchers are hard at work carrying out scientific experiments to get to the bottom of this.
In 1997, a pair of world-renowned hydration experts set out to answer the question: How much alcohol can we add to our recovery beverages and still properly rehydrate? The answer, unfortunately, is a bit disappointing: Somewhere between 2 and 4% alcohol. The study they performed had subjects lose 2% body mass through exercise, and then rehydrate with drinks containing 0, 1, 2 and 4% alcohol. They found no increase in urine production with 1 or 2% alcohol, but a significant increase with 4%.
The traditional view is that alcohol suppresses a specific hormone that is responsible for holding onto water in your body. But not every study (there are actually quite a few!) has found this hormone suppression with alcohol intake, so the absolute reason for alcohol’s dehydrating effects are not fully known.
A more recent study gives a bit of hope to post-workout beer enthusiasts. The study had 4 trials. In two trials, athletes arrived to the lab in a dehydrated state (about 2.5% body mass loss). In the other two, they arrived in a hydrated state. In one of the hydrated trials and one of the dehydrated trials, they drank one litre of an alcoholic (4% alcohol) beer over a 30-minute period, while in the other two trials, they were given non-alcoholic beer. Turns out that regardless of whether the drink contained alcohol, the hydrated athletes produced way more urine than the dehydrated athletes! Hydrated athletes produced over one litre of urine in both cases, while dehydrated athletes produced only a couple hundred mL’s, regardless of whether or not there was alcohol in the drink.
So what does this tell us? Well, it seems like the more dehydrated you are, the less it really matters if there’s alcohol in your rehydration drink! It would be interesting to see studies involving higher percentages of alcohol, to see if the body is still able to effectively rehydrate (I’m envisioning some sort of positive correlation between sweat loss and acceptable recovery drink alcohol content). But for now, if you come back from a long run, drenched in sweat and dying of thirst, don’t feel too bad about cracking open a beer or two to rehydrate! Plus the carbohydrate content and generaldeliciousness of beer can’t be discounted!
One last point of caution (sorry): Alcohol intake does seem to slow muscle recovery. In a study just carried out this year, alcohol in about the same amount as a one litre, 4% solution, exacerbated muscle force loss in the days following a hard exercise bout. But half that amount did not seem to have a negative effect.
But most beers also have one more important ingredient: Alcohol. And anyone who has had a couple cold ones knows that taking in alcohol with fluid makes you pee! This could be a problem if your goal is rehydration. So luckily, researchers are hard at work carrying out scientific experiments to get to the bottom of this.
In 1997, a pair of world-renowned hydration experts set out to answer the question: How much alcohol can we add to our recovery beverages and still properly rehydrate? The answer, unfortunately, is a bit disappointing: Somewhere between 2 and 4% alcohol. The study they performed had subjects lose 2% body mass through exercise, and then rehydrate with drinks containing 0, 1, 2 and 4% alcohol. They found no increase in urine production with 1 or 2% alcohol, but a significant increase with 4%.
The traditional view is that alcohol suppresses a specific hormone that is responsible for holding onto water in your body. But not every study (there are actually quite a few!) has found this hormone suppression with alcohol intake, so the absolute reason for alcohol’s dehydrating effects are not fully known.
A more recent study gives a bit of hope to post-workout beer enthusiasts. The study had 4 trials. In two trials, athletes arrived to the lab in a dehydrated state (about 2.5% body mass loss). In the other two, they arrived in a hydrated state. In one of the hydrated trials and one of the dehydrated trials, they drank one litre of an alcoholic (4% alcohol) beer over a 30-minute period, while in the other two trials, they were given non-alcoholic beer. Turns out that regardless of whether the drink contained alcohol, the hydrated athletes produced way more urine than the dehydrated athletes! Hydrated athletes produced over one litre of urine in both cases, while dehydrated athletes produced only a couple hundred mL’s, regardless of whether or not there was alcohol in the drink.
So what does this tell us? Well, it seems like the more dehydrated you are, the less it really matters if there’s alcohol in your rehydration drink! It would be interesting to see studies involving higher percentages of alcohol, to see if the body is still able to effectively rehydrate (I’m envisioning some sort of positive correlation between sweat loss and acceptable recovery drink alcohol content). But for now, if you come back from a long run, drenched in sweat and dying of thirst, don’t feel too bad about cracking open a beer or two to rehydrate! Plus the carbohydrate content and generaldeliciousness of beer can’t be discounted!
One last point of caution (sorry): Alcohol intake does seem to slow muscle recovery. In a study just carried out this year, alcohol in about the same amount as a one litre, 4% solution, exacerbated muscle force loss in the days following a hard exercise bout. But half that amount did not seem to have a negative effect.