Hydration and Exercise - Which is Better, Water or Sports Drink?

It has been well established that even a slight dehydration (1-2% loss of bodyweight) can decrease an athletes ability to train and perform to their capacity. If an athlete fails to hydrate serious physiological changes can occur including higher heart rate, higher plasma osmolality, lower blood flow to the skin, and higher core temperature. The performing benefits of drinking plenty of fluid during exercise outweighs the consequences. The one problem that many athletes run into is not knowing the signs that dehydration and what to use to properly rehydrate. There has been numerous research studies recently that have helped clear up that question and have come to the conclusion that certain sport drinks can help rehydrate an athlete much better than water alone.

The Science of Sports Drinks

There are a number of benefits of sports drink over water including:

1. Sports Drinks encourage voluntary fluid intake: since athletes underestimate sweat loss and fluid loss during exercise, a sports drink must taste well and be palatable enough for the athlete to drink. Since electrolytes are lost during sweat, the right balance of electrolytes in a sports drink to drive an athlete to drink and replenish the electrolytes lost. Thirst is driven by sodium concentration, and since sports drinks contain ample amount of sodium it drives the thirst mechanism unlike water that contains no sodium.

2. Sports Drinks encourage fast absorption: to stay well hydrated, fluid must be rapidly absorbed to offset the loss of electrolytes and carbohydrates during exercise. Most sports drinks are formulated to stimulate rapid gastric emptying. If a beverage has the wrong amount of carbohydrates or it is carbonated, much like most soda, it will slow gastric emptying and hydration will not occur as rapidly.

3. Sports Drinks promote rapid rehydration: the key to rapid rehydration is the right electrolyte balance to make sure the osmolality of the blood stays in balance. Sports drinks have been formulated to provide sodium and other electrolytes to rehydrate the body.