There's absolutely no benefit to being dehydrated. (See Warning Signs of Dehydration.) For athletes, fluid intake is the most important nutrition consideration. Research has shown that a loss of body weight of just one percent (1.5 pounds in a 150-pound athlete) can adversely affect a person's ability to cope with stress. A loss of two percent of body weight can impair athletic performance. To achieve optimal performance, athletes must be adequately hydrated.
It is difficult to maintain proper hydration during exercise, which is why I recommend setting up a daily hydration schedule. Following a hydration schedule will ensure you are properly hydrated before activity begins. Get started with this basic fluid plan, suitable for most athletes. Then tailor it to your activity level, drinking as much as you need.
In the morning. Start your day by drinking 8 ounces of water first thing. Space out your intake throughout the day, aiming for one glass every hour.
Two hours before exercise. Drink at least two cups (16 oz.) of fluid. Drinking two to three hours before exercise allows enough time for fluid to be lost through urine before exercise begins.
30 minutes before exercise. Drink five to 10 ounces of fluid. There is no benefit to chugging fluid in an attempt to stay hydrated. Although everybody is different, the body can only absorb fluid so fast, and you do not want to have extra fluid sloshing around in your stomach when it is time to start your activity.
Right before exercise. Check your weight.
Every 15 minutes during activity. Try to drink a half to a full cup of fluid. The goal is to consistently replace fluid lost during activity. Drink four to eight ounces every fifteen minutes, or sixteen to thirty-two ounces over an hour, without overloading the body and causing GI distress. Remember: One gulp is about one ounce, so aim for four to eight gulps of fluid every 15 minutes.
After activity. Re-weigh yourself and compare it to your pre-practice weight to find out how much water you lost during exercise. Drink 20 to 24 ounces of fluid for every pound of body weight lost.