For moderate workouts less than one hour, water is all you need because the body has enough stored energy to function safely, Nelson said. Instead of filling up on sports drinks, a healthy post-workout meal is a better choice to replenish lost minerals and nutrients. Sports drinks, however, can be beneficial during grueling physical activity lasting more than one hour because they are a source of carbohydrates that the body needs to replenish, she said. They also will help to rehydrate the body. Be careful, however, because there are 50 calories or more per serving.
Water has no calories.
Drinks such as fitness waters are fortified with vitamins and minerals, however, these substances are not lost during physical activity and are easily found in a healthful diet, Nelson said. If the carbohydrate content of fitness drinks is too high, greater than 8 percent, they can actually inhibit the hydration process by pulling water from the body and into the stomach to dilute them before digestion. There are other red flags. The recent supplement craze has produced dozens of designer drinks possibly containing herbal extracts of questionable benefit. Water is practically free.