There are many different commercial sports drinks available. They contain varying kinds and amounts of sugars and electrolytes. Whether they offer advantages over plain water depends on the situation. Many times, plain water is all that an athlete needs. When activities last an hour or more, however, some sport drinks may offer advantages both for carbohydrate and electrolyte replacement.
More concentrated solutions can delay fluid absorption.
Also, avoid drinks that contain fructose as the only source of carbohydrate. Fructose may cause upset stomach. Additionally, fructose must first be converted to glucose before it can be used for energy. This conversion delays its use as an energy source. Salt needs can be met by increased use of salt on foods.