A distinction is made between hypotonic, isotonic and hypertonic drinks. With hypotonic drinks, the concentration of dissolved substances in the drink is lower than in the body fluid. This means that the fluid flows very quickly into the body cells and is therefore ideal for a quick supply of fluid. However, hypotonic drinks contain only a few carbohydrates and are therefore only suitable for quenching thirst and not for energy supply. Therefore, they are ideal for recreational athletes. Examples of hypertonic drinks are water and tea without sugar.

Hypotonic sports drinks are better tolerated than isotonic drinks.