LeBron James sweats it out with the Heat — and drinks a gallon of water a day during the playoffs to make sure he's well-hydrated. (You probably shouldn't drink that much; water intoxication can be lethal.) But for those of us who chose not to take our talents to South Beach, knowing what and how much to drink isn't so simple.

First, you hear, "Drink eight 12-ounce glasses of water a day." Then reports say that's nonsense. On TV, ads trumpet the virtues of sports drinks, while new research gives them the thumbs down. (Some Gatorade has brominated vegetable oil — not good for the thyroid.) You hear coffee dehydrates you. Wait, now it doesn't. It's enough to drive you to drink!

Well, we've got an oasis of good advice on hydration.

Why hydration matters: Good hydration helps prevent constipation, exercise-related asthma, elevated blood glucose, and and protects against heart damage. Mild dehydration (a 1 1/2 percent loss of normal water volume) reduces energy, affects mood, and hampers memory.

How much you should drink: About 22 percent of the water you consume comes from food. The rest — about 50 to 60 ounces a day — should come from liquids such as coffee, tap water, and juices with pulp.

What you should drink: Unless you are exercising in hot weather, avoid sports drinks and liquids with added sugar (especially high fructose corn syrup) and drink only as much coffee as your nerves and stomach can handle (less than five cups won't dehydrate). The rest? Good old pulp-filled fruit and vegetable juice, and lots of water.


© 2013 Michael Roizen, M.D. and Mehmet Oz, M.D.
Distributed by King Features Syndicate, Inc.