Sports Drinks: Handy for Some Workouts, Not All
You can be forgiven if you're drowning in the flood of sports drinks now on the market. Gatorade, Accelerade, and Powerade (not to be confused with PowerBar's line of drinks) all say they can improve exercise performance and keep the athlete's body going. But how, exactly, do they do that? And who really needs them?
During exercise, the main goal of drinking is to rehydrate. Anyone working out for less than about 30 minutes can get by on water, says Mark Haub, director of the Human Metabolism Lab at Kansas State University. For longer workouts, the body's needs depend on the athlete's goals, the intensity of the exercise, and weather conditions, he says, and that's when sports drinks may come in handy. Theoretically, the body can run a long time on nothing more than water, but it doesn't always prompt its owner to drink enough. So drinks like Gatorade have some electrolytes, including sodium, which promote thirst, and some glucose to aid water absorption.
Glucose also provides ready-to-burn fuel for people who are exercising for long periods of time or those exercising more intensely; it might help a runner on an easy, three-hour jaunt or on a fast 10K at maximum effort. "Balance your fluid intake with your fluid loss, and match your intensity with the environmental conditions," says John Seifert, an exercise physiologist at St. Cloud State University in Minnesota. For example, he says, walking usually isn't intense enough to require more than water, but a 90-minute hike in the heat may make a sports drink necessary.
Because the drinks are caloric, people walking 30 minutes three times a week may be best off not fueling up if they're trying to lose weight, says Lauren Antonucci, the owner and director of Nutrition Energy, a sports nutrition and consulting company in New York. "I tell them to limit it to something that's no more than 10 calories a serving," she says.
Other drinks, like Gatorade's recovery shake and PowerBar Performance Recovery, are meant to be taken within an hour or so after finishing a workout. They contain protein, which helps rebuild overworked muscles. "Athletes like to believe that while they're exercising, that's when the benefits are occurring, but actually it's in the recovery, regardless of the form of exercise," says kinesiologist Stuart Phillips of McMaster University in Hamilton, Ontario. In a study published this week, he gave either fat-free milk, a soy protein drink, or a carbohydrate-loaded drink like Gatorade to young men who were new to weightlifting. He found that drinking milk after a strength routine promoted greater lean muscle creation than did drinking either of the alternatives. Something in the milk made it possible to burn more fat and increase lean muscle, says Phillips, whose research was funded by the National Dairy Council.
Antonucci tells her clients to replace fluid, electrolytes, carbs, and a bit of protein after sessions that are 90 minutes or longer. Experts' recommendations may vary to take into account the workout the day before, however. "If you feel like your legs aren't recovering," says Seifert, "take in more carbs and proteins after a workout."
And there is no one-size-fits-all prescription. "The best rule of thumb is practice," says Haub. "Get used to what you need, and be your own guinea pig."