But what should you be drinking?
Here's some advice from Robert Stelma, supervisor of athletic training services for the Geisinger-Wyoming Valley Human Motion Institute in Wilkes-Barre, Pa.
Water is the best source for fluid replacement and should be your primary beverage when you exercise, Stelma says. However, water alone may not be enough if you're doing intense activity or exercising for more than 45 minutes.
That's when a sports drink may be beneficial, Stelma says. However, the choices may be somewhat confusing.
Choose a sports drink that contains no more than 8 percent carbohydrates. Stay away from carbonated sports drinks or those that contain caffeine or herbal remedies, or those that have more than 8 percent sugar, Stelma says.
All those ingredients could counter the reason you want to use a sports drink, which is to keep your body hydrated as you exercise, Stelma adds.
Some sports drinks containing guarana, caffeine, ephedra, ginseng or taurine make claims that they boost your energy and/or performance. However, Stelma says it's difficult to prove those claims.
"The Food and Drug Administration (FDA) does not evaluate herbal remedies, so their claims, effectiveness and purity of the product are the responsibilities of the manufacturers. This can lead to outrageous claims, and a product that has little or too much of the herbal product," Stelma says.
In the end, no sports drink is going to provide you with a quick fix, he adds. The key to performing and feeling better is a good diet, lots of rest and the right amount of exercise.
For additional insight into sports drinks, Running Times has a guide.