Drinking plenty of fluids is the single, most important thing athletes can do to prevent heat illness. One indicator athletes can use to tell if they are drinking an adequate amount of fluids is the color of their urine. Clear urine means an athlete is drinking an adequate amount of fluids. Yellow urine indicates he or she needs to drink more fluids. Expect yellow urine after a practice session, but it should be clear before practice the following day.
Sports drinks encourage student-athletes to drink more because of the added flavor.
Another advantage of sports drinks over water, is water may actually stimulate urination and cause greater water loss, where sports drinks will not. Finally, water tends to decrease the thirst drive and student-athletes may quit drinking before they are rehydrated. Through the use of a sports drink the thirst drive is maintained and athletes tend to drink more. Many people believe the need for fluid is decreased when one becomes accustomed to the heat. That is not true.