A look at the components and effectiveness of sports drinks.

The confusion about sports drinks is lessened if the types are understood. Types include: fluid replacers, carbohydrate loaders, and nutrient supplements. The athletic activity and the timing of the consumption of the drink need to complement the type of drink. Fluid replacement is a must before, during, and after activity to maintain heart rate and body temperature. Whether water or a sports drink is consumed is the athlete's choice. The carbohydrate concentration of a fluid-replacing drink should not exceed 10%, which is comparable to the gastric emptying characteristics of water. Glucose, sucrose, and glucose polymers are all well tolerated by athletes during activity, although fructose in high concentrations may not be. Electrolytes are present in drinks to enhance absorption; high levels usually are not needed, except in certain populations.