There can be no maximum performance without proper fuel. It is also important to eat well so that you can bounce back from illness quickly. While nutrition education will be an ongoing process during the season, there are a few guidelines that your coaches would like to see you follow. Drink a great deal of water. The biochemistry of muscular contraction simply does not work well unless adequate water is present.
Dehydration occurs long before the swimmer actually feels thirsty.
Most muscle cramps are caused by dehydration. Drink at least three glasses of water per meal in addition to your other beverages. Drink until you are full right before practice. Don't worry, you will use it up very quickly. Water bottles at practice are a great way to get lots of water conveniently.