LEWIS G. MAHARAM, MD: Heat stroke has nothing to do with hydration status, and that's another myth. Heat stroke is due to your body revving up and working harder than it's capable of working in the heat that you're running in or working out in. By that I mean your body has a metabolic motor and if you're not trained and your body isn't trained enough to be able to deal with the heat of the environment, then your body temperature rises and you can get heat stroke. Has nothing to do with the amount of fluid on board.
ANNOUNCER: There is also often debate as to which is a better replacement drink: water or sports drinks?
LEWIS G. MAHARAM, MD: Both water and sports drinks are good replacement drinks, but they're used for different things. You use water for any exercise that is less than forty minutes, and forty minutes is the cutoff where you want to go to a sports drink that has added electrolytes and sugar in it to help you to maintain your body energy.
ANNOUNCER: The bottom line for runners is, while our bodies need fluids to function and we should be aware of our hydration needs, experts advise not to overdo it.
LEWIS G. MAHARAM, MD: The takeaway message about hydration is: Too much is harmful, too little isn't that bad. So please drink appropriately, and don't overdrink.