Isotonic drinks are designed to replace fluids lost by sweating and to replenish energy levels in the body through their carbohydrate content in the form of concentrated glucose.
Apart from assisting in the body’s rehydration and energy levels to compete optimally, Isotonic drinks contain electrolytes. Electrolytes are essentially salts which aid the osmosis of fluid absorbed into the working muscles. These essential salts are lost during sweating.
Isotonic drinks are useful sports supplements and are often used by athletes to allow them to train longer and more effectively than consuming water alone.