Drinking beer as a post-race drink does not seem like a smart choice considering alcohol is a diuretic and can have dehydrating effects, slowing recovery. Beer does have a higher water content and a lower alcohol content compared to other types of alcohol, 4-5% alcohol by volume versus 40% for most types of liquor. A recent study found that there was no difference in recovery from dehydration with just water or with 660 milliliters of beer (just under two 12-oz beers) followed by a lot of water, and was seen as just as effective. The study did look as body composition, plasma volume, muscle damage and inflammation. Non-alcoholic beer has been shown to reduce inflammation in marathon runners, though it is not known if regular beer would have the same results.
So what should you do to rehydrate properly after exercising? Try and drink at least 16 ounces of fluid for every pound of sweat lost (you can do this by weighing yourself before and after). Replace electrolytes, mainly sodium, if you are sweating a lot. Eat a small snack or meal afterwards to replenish these sodium levels. If you do drink a beer or two after a race, followed by plenty of water or non-alcoholic fluids, there should not be much difference in your recovery. Remember to consume alcohol in moderation, approximately 1 drink per day for women, and 2 drinks per day for men.