Athletes should consume at least 500 mls of fluid two hours prior to exercise, and 150 to 300 mls during exercise, taken every 15 to 20 minutes.
Sports drinks are appropriate for athletes involved in endurance activities (e.g. marathon, triathlon) or stop-and-go sports (e.g. soccer, sprinting) to replace lost fluids, carbohydrates, and electrolytes.
The most effective sports drinks comprise six per cent to eight per cent carbohydrate. Diluting sports drinks lowers the carbohydrate concentration, thus providing too few carbohydrates for replenishing those lost.