Sports drinks are an excellent choice for hydration. Athletes can usually find a flavor they like, and the electrolytes (like sodium chloride) will stimulate thirst, help the body hold onto fluid, reduce the chance of cramping, and possibly improve performance.
Water is fine too, for events lasting up to about two hours.
Avoid any drinks with caffeine or high fructose corn syrup, and no carbonated sodas. “Energy drinks” such as Red Bull contain caffeine and should be avoided.
The athlete should have 12-16 ounces of fluid up until about 30 minutes before the game or practice (remember that most sports drinks come in 20 ounce bottles).
Keep sipping sports drinks or water during the practice or game, about 4 ounces at a time at the end of periods or halftime.
Start re-hydrating within 20 minutes of the conclusion of the game. Research shows that the first 20 minutes are the most efficient time to start refueling. Try to take in 20 ounces; no need to guzzle this down, but once you start drinking try to finish the bottle over the next several minutes.