Staying well hydrated helps regulate body temperature, transport fuel to exercising muscles and carry away waste products. If you sweat heavily and fail to replace fluid losses, you can hurt your health as well as your performance.

For most exercisers, water does a good job of replacing sweat losses. For athletes who exercise hard for more than 60 to 90 minutes, consuming a sports drink during exercise can both delay dehydration and boost energy. Experiment during training to learn which flavors of sport drinks settle best in your stomach.

Replenishing daily fluid loss.
• On a daily basis, make sure you drink enough fluid by monitoring the volume and color of your urine. The first morning urine should not be dark and smelly!
• You should have to urinate every two to four hours throughout the day. It should be a light lemonade color. Note: Vitamin pills can darken the color of urine, so pay attention to the quantity. If the urine is concentrated and scanty, you need to consume more water, juice and other fluids.
• You can learn how much fluid to drink by weighing yourself naked before and after a hard workout. Losing one pound (16 ounces) equates to losing one pound of sweat. During training, practice drinking enough to replace most of what you lose.
• The goal is to lose no more than 2% of your body weight (3 pounds for a 150-pound athlete).

Preparing for hard exercise.
• The day before hard training or a game, drink extra water, juice or other fluids to ensure your body is well-hydrated.
• The morning of the event, drink about 16 ounces (16 gulps) of fluids up to two hours prior to the start. This allows enough time for you to urinate out the excess before starting to exercise.
• Five or ten minutes before start-time, “tank up” on another 8 to 16 ounces (8 to 16 gulps) of water or sport drink.

Fluids during hard exercise.
• Prevent dehydration early in the event by drinking adequate fluids before you get thirsty! By the time you feel thirsty, you will have lost one percent of your body weight (1.5 lbs. sweat for a 150-pound athlete). Your heart will need to beat 3 to 5 more times per minute. That is tiring!
• By knowing your sweat rate, you can drink to match your sweat losses. For example, if you lose 1 pound (16 ounces)/hour, you should target 4 ounces of water, sport drink or diluted juice every 15 minutes.

Fluids after hard exercise.
• Drink to quench your thirst, and then drink a little more. You may not feel thirsty, but your body might still be under-hydrated. Keep drinking until you need to urinate!
• Chocolate milk is an excellent recovery fluid. It offers water (to rehydrate), carbs (to refuel muscles), protein (to repair muscles) and sodium (to retain fluid). Drinking 12 to 20 ounces of chocolate milk within the hour after exercise is a better recovery choice than a sports drink.

Sodium replacement.
• Sweat contains small amounts of sodium (an electrolyte) that helps keep your body in fluid balance. You are unlikely to deplete your body’s sodium stores, except under extreme circumstances like exercising for more than three hours in the heat. In that case, you want to consume salty foods or fluids before, during and after exercise.

• The little bit of sodium in sport drinks does not replace the sodium lost in sweat. Rather, it enhances water retention, which delays dehydration. To replace sodium, add salt to your food, eat pretzels, soup, cheese and other salty foods both before and after exercise.