Hydration: 5 Hydration Do's and Dont's (cont.)

If you're exercising intensively in the morning, "A sports drink is better than being on empty," says Bonci. "Most people find they do better if they have something, but it can be solid or liquid form."

While you're exercising: "Thirst is not a good indicator at all," says Bonci. "If you're thirsty, you're already dehydrated."

Drink something every 15 to 20 minutes, if possible: Since that's not possible in all sports, you may have to drink more before you exercise, so you have enough in your body.

Don't try something new before competition: "That's a recipe for disaster," Bonci tells WebMD. The body needs to get used to new fluids, so do it really, really gradually."

Don't drink sports drinks during couch-potato hours. "Those extra calories!"

Don't drink fruit juices before exercise: "They're a very, very concentrated form of carbohydrate," advises Bonci. "That means you might get an upset stomach or a laxative effect. You'll be running, but not necessarily on the field."

Originally published April 19, 2002.

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