Water vs. Sports Drinks - Triathlon Week

sfricks · 09-28-2006, 03:12 PM

Dear Dr. Mirkin: Should I drink water or a sports drink when I exercise?

Drinks that contain salt and sugar are better than just plain water during exercise, unless you are also eating foods. A study from the Medical College of Georgia shows that tennis players have lower body temperatures when they drink fluid with electrolytes and sugar, rather than just plain water (British Journal of Sports Medicine, May 2006). Higher body temperatures during exercise slow you down and tire you earlier.
More than 80 percent of the energy that supplies your muscles is lost as heat. Less than 20 percent drives your muscles. So during exercise, your heart has to cool your body by pumping hot blood from your muscles to your skin, as well as pumping oxygen-rich blood to your muscles. If you heart has difficulty serving both functions, it cannot pump enough hot blood from muscles and your temperature rises.
You do not have to take sports drinks to protect yourself from high body temperature. During exercise, you need energy, salt and water and your body doesn't care how it gets these nutrients. Eating any salted food with water or any beverage you like will supply your body as efficiently as sports drinks.