For a 20 to 30 minute exercise, water works well to avoid dehydration. Take a cup of water one-half hour before exercise and at least a cup immediately after exercise. Electrolytes can be found in most sports drinks. These are simply minerals. Minerals help maintain fluid levels in the body.
Any mineral can be an electrolyte.
The main ones are sodium, potassium, and chloride. Most people can replenish the electrolytes lost during exercise with their normal diet. For example, the same amount of sodium that is in one glass of a sports drink is in a glass of milk. Performance is enhanced and endurance is prolonged by drinking sports drinks. Drink 3 to 6 ounces every 15 to 20 minutes during exercise sessions that are longer than 30 minutes.