How does an isotonic beverage work?

Question

anonymous · Answer

The main purpose of an isotonic beverage is fluid retention and re-hydration of the body, as opposed to energy provision, though a lot of modern isotonics do provide additional glucose support for energy, usually the main carbohydrate ingredient will be of a glucose variety. 

The higher the carbohydrate levels in a drink the slower the rate of stomach emptying. Isotonic drinks with a carbohydrate level of between 6 and 8% are emptied from the stomach at a rate similar to water. Electrolytes, especially sodium and potassium, in a drink will reduce urine output, enable the fluid to empty quickly from the stomach, promote absorption from the intestine and encourage fluid retention.

anonymous · Answer

It helps with regulating your water, sodium and potassium homeostatic mechanism, allowing you to stay hydrated during exercise.