Rehydration is crucial in sports performance. Human Maximum Performance requires adequate hydration prior to, during, and following exercise. Any event lasting more than twenty five minutes involving intense physical exertion and/or sweating requires hydration. Obviously, marathoners and long distance runners need to hydrate at a higher level than someone exercising for an hour. But athletes like basketball players, in many instances, don’t think hydration is important and they rely on their thirst instincts to control water intake. This can be a huge mistake which leads to performance failure. Athletes cannot wait until they experience thirst to hydrate because body systems that regulate thirst cannot be trusted to trigger cravings for liquid. If an athlete waits until he gets thirsty to hydrate his body, it may be too late. “Already too late” means sports performance will definitely be impaired.
Hydration begins with carbohydrates and water. The human body has to store 2.7 grams of water for every 1 gram of glycogen stored. The most important factor of a sports drink is the glycemic response of the drink and the amount of water ingested. Athletes need 85-95 ounces of extra water available for a strenuous athletic event. That’s not water ingested, but body stores of available water from carbohydrate hydration and water loading.
Your water or sports drink should be ingested cold. Water below 50 degrees F (10 degrees C) is absorbed faster than room temperature water. Do not use carbonated water, soft drinks, sodas or other carbonated beverages when hydrating or during exercise. Hydration guidelines apply to athletes that sweat profusely during an athletic event or athletes that partake in heavy exercise or endurance events.
Coffee, Caffeine, and Hydration
Clinical studies show that coffee, caffeinated soda, and caffeinated sports drinks are beneficial to sports performance. Contrary to popular belief, properly formulated coffee drinks do not increase dehydration, nor do they require athletes to drink more water. Researchers at the Center for Human Nutrition in Omaha collected urine and blood samples in subjects to test various fluid regimens (2001) to ascertain if equal amounts of water vs. caffeinated beverages caused fluid imbalances or deficits. Results: The subjects remained in the same state of hydration no matter which beverage they drank. Coffee drinks, sports drinks, and sodas containing caffeine and high glycemic sugars, such as sucrose, corn syrup, honey, or maltodextrins can imbalance blood glucose levels, thus causing impaired sports performance. Sports drinks and coffee beverages that contain caffeine must also contain low glycemic carbohydrates, and preferentially, chromium, in order to prevent reactive hypoglycemia.
Hydration Guidelines
 Carbohydrate Hydration – Load up on low GI carbohydrates 6-7 days prior to athletic event.
Prehydration – Hydrate with water/sports drinks two days prior to athletic event.
You need to build bladder-comfort levels prior to the event or you will be stopping frequently to urinate. 2-4 hours prior to the event drink an 8-ounce glass of water every 10-15 minutes.
Pre-Exercise – Stop drinking water 20 minutes before the start of the athletic event so stomach contents can empty.
During Exercise – Drink 5-10 ounces of fluid every 15 to 20 minutes. Sip, do not gulp.
Following Exercise – Drink 16 ounces (2 cups) of fluid per pound of body weight lost during exercise. Drink extra water for 12 hours following the athletic event. Immediately following the event, drink 4 large glasses of water (64 ounces) or 32 ounces of a low glycemic sports drink and 32 ounces of water. Eat 100 grams of carbohydrates within 4 hours of end of event.
What Not to Drink
 Drinks with Carbohydrate (CHO) concentrations of greater than eight percent should be avoided.
Fruit juices, CHO gels, sodas, and sports drinks that have a CHO greater than six to eight percent are not recommended during exercise as sole beverages.
Beverages containing caffeine, alcohol, and carbonation are not to be used because of the high risk of dehydration associated with excess urine production, or decreased voluntary fluid intake.