5 Hydration Do's and Dont's

They told us to "just do it," so we're doing it. Hiking, biking, mountain climbing -- you name it. But as the weather heats up, dehydration can be a big problem. You've got to drink something, and enough of it, or you risk heat stroke or another heat-related illness.

One friend thinks nothing of bicycling 70 miles -- over some pretty grueling hills -- with a water bag on his left shoulder, a squirt-bottle of honey on his right, and a few snacks at break times. Gives him plenty of fuel and hydration, he says.

Another friend -- a tennis fanatic -- swears by berry-flavored Gatorade, even though he dilutes it. "I think it gives me a competitive edge," he says.

The fact is, a sports drink may be your best choice if you're an intense athlete. A new study shows that athletes can stave off fatigue 37% longer if they drink sports drinks -- the kind with electrolytes and carbohydrates in them. They also run faster, have better motor skills, and are mentally sharper, says the study, which appears in the April issue of Medicine & Science in Sports & Exercise.

But these days, there's more than plain old Gatorade on the store shelves. Sports drinks, energy drinks, bottled waters, fitness waters -- who's to know? We don't all sweat like pigs when we exercise. To help you sort it all out, WebMD contacted a number of sports nutritionists and developed this list of do's and don'ts:

1. Don't Drink Caffeine Drinks

Soft drinks are never a good option during sports. "They have no electrolytes, so they really don't replenish what the body needs," says Chris Carmichael, who heads a training company for personal coaches in Colorado Springs, Colo. He's also the personal coach of four-time Tour de France winner Lance Armstrong.

"Sports drinks help you sustain energy or recover from your workout," he tells WebMD. "Soft drinks are really poor at doing either of those."

Like soft drinks, the so-called energy drinks such as Red Bull "have huge amounts of caffeine -- which can be a diuretic and can even have a laxative effect," says Leslie Bonci, MPH, RD, director of sports nutrition at the University of Pittsburgh Medical Center. This can worsen the dehydration often experienced with heavy exercise.

2. Do Consider Sports Drinks During Intense Workouts

When you exercise heavily, you lose water and salts in your sweat. Gatorade was an advance over water because it added a number of electrolytes that were lost in sweat, says Steven Zeisel, MD, PHD, chairman of nutrition at the University of North Carolina in Chapel Hill.

Today's true sports drinks are still the classic Gatorade -- packed with the electrolytes potassium, magnesium, calcium, and sodium to provide energy during intense workouts -- as well as competitors such as Cytomax, Allsport, and Accelerade.