But there's also mounting evidence that moderate alcohol consumption offers some real health benefits. Alcohol in moderation has been shown to increase the levels of "good" cholesterol in the bloodstream, preventing "bad" cholesterol from clogging arteries and causing heart attacks. It also relaxes the muscles in the arteries, which lowers blood pressure. Scientists have even shown that some alcoholic beverages help prevent osteoporosis and reduce the risk of Alzheimer's disease.
Red wine drinkers in particular benefit. A Harvard Medical School study found that the cholesterol-fighting antioxidant resveratrol, present only in red wine, produces the same life-lengthening effects as calorie reduction. Other research has determined that red wine is full of flavonoids, which are antioxidants that lower the risk of heart disease. And scientists at the University of California-Davis have recently discovered plant compounds called saponins in wine that block the body's absorption of cholesterol. Nearly half the average daily intake of saponins is present in a single glass of red wine (white wine contains less), and the higher a wine's alcohol content, the more saponins it provides. And if you prefer hops to grapes, there's good news for you, too. British scientists have found that beer drinkers have 30 percent more vitamin B6 in their blood plasma, which prevents the buildup of a chemical that causes heart disease.
But long-distance runners, of course, have to think about hydration and endurance. Are the benefits worth the risks? Maybe. New research suggests that alcohol is not as dehydrating as once thought. "Initially, alcohol can dehydrate you, but over the course of 24 hours, alcohol no longer has a dehydrating effect," says Nancy Clark, R.D., a sports nutritionist in Boston and author of Nancy Clark's Sports Nutrition Guidebook. Still, alcohol can produce up to a three-percent loss of body weight (in fluids) within four hours of consumption, which can have a negative impact on performance and even be dangerous when heat is a factor. Consequently, drinking alcohol in the hours just before a hard run or race is not a good idea. "But as long as runners who are accustomed to drinking wine are drinking extra water and taking in other carbohydrates," says Clark, "one glass of wine with dinner the night before a race doesn't concern me."
You'll notice that Clark says one glass, not one bottle. Moderation is the key to reaping the health benefits of alcohol and avoiding any negative effects on your running. In general that means women should limit their alcohol intake to one drink (equal to five ounces of wine) a day, and men (who tend to be larger than women) two drinks per day. But nutritionists say that because people process alcohol differently, it's not simply the amount you drink. For instance, large, muscular people can usually handle more alcohol than smaller people. Women are more susceptible than men to the effects of alcohol due to hormonal and body-fat differences. Women also tend to have less dehydrogenase, a liver enzyme that breaks down alcohol. And regular drinkers can process alcohol more easily than nondrinkers can. In the end, you need to know how alcohol affects you and your performance--preferably well before race day.
"Running, biking, and swimming are part of my life every day, just like having a glass of wine every night," says Sarah Gott, a competitive amateur triathlete and a winemaker living in Napa Valley. Gott limits herself to one or two glasses of wine or beer a day, and drinks plenty of water to compensate for dehydration, particularly before a big training day or race.
And while a finish-line beer seems like a well-earned reward, it is no substitute for proper refueling. Some runners believe that the high-carbohydrate content of beer will help them recover. But alcohol is a poor source of carbohydrates (a 12-ounce can of beer has only about 11 grams of carbs), and it also interferes with glycogen replenishment, delaying recovery. So hold off on the beer until you've eaten something and had the chance to rehydrate with water or sports drink.
"I don't push nondrinkers to start drinking," says Clark, "but if athletes enjoy alcohol, there are the known health benefits, plus the psychological benefit of slowing down and socializing with friends." We'll drink to that.
Before you pop that cork or beer cap, follow these guidelines to make sure your running performance never suffers
Wait 8--or Even 48
Everyone metabolizes alcohol differently, so you must take into account the way your own body handles alcohol. Some nutritionists advise skipping it for up to 48 hours before a long race, such as a half-marathon or a marathon, to ensure enough time for proper rehydration. Others say one glass of wine with dinner the night before a race shouldn't cause problems as long as you're also taking in plenty of water and carbs.
Before lifting a glass at a postrace party, have a snack high in carbs and with a little protein (a bagel with peanut butter or a turkey sandwich on whole-wheat bread) and rehydrate with 16 to 24 ounces of water or sports drink for every pound of body weight you lost while you were running.
Just Add Water
To combat alcohol's diuretic effect, drink an eight-ounce glass of water for every alcoholic beverage you drink.
Remember to Sleep
A glass of cabernet with dinner may be okay; partying all night at the bar is not. Getting too little sleep before a big training day or race affects balance, sharpness, coordination, and endurance--similar to too much alcohol.
On average, a five-ounce glass of wine has about 100 calories (the same size glass of sweet dessert wine has about 230 calories). A 12-ounce can of beer contains around 140 calories. And a one-ounce serving of spirits like rum, vodka, gin, or bourbon has about 65 to 80 calories--but mix it with juice instead of club soda and that number will rise considerably. A large piña colada can have upward of 300 calories and lots of fat.