What do leading health and nutrition organizations say about getting proper hydration?

"Drinking fluids is essential to life. Water is the most abundant substance in the human body, but also one of the most forgotten nutrients … Fluids can come from many sources, including foods, water, milk, juice an soft drinks in moderation."

American Dietetic Association
Straight Facts About Beverage Choices
http://www.eatright.org/nfs0901.html

"Proper Hydration is extremely important during exercise … Adequate fluid intake for athletes, even the recreational kind, is essential to comfort, performance and safety. The longer and more intensely you exercise, the more important it is to drink plenty of fluids."

About© The Human Internet
Fluid Fuel for Athletes
http://sportsmedicine.about.com/library/weekly/aa011599.htm

Based on available evidence, the American College of Sports Medicine makes the following general recommendations on the amount and composition of fluid that should be ingested in preparation for, during, and after exercise or athletic competition:

1. Eat a high carbohydrate, low fat diet & drink adequate fluids between exercise sessions. (Plain water or fluids WITHOUT sugar, caffeine or alcohol are the best.)
   
2. Drink 17 oz. (2+ cups) of fluid 2 hours before exercise.
   
3. Drink every 15 minutes during exercise.
   
4. Keep drinks cooler than air temperature & close at hand.
   
5. If you exercise for more than 60 minutes, you may benefit from a sports drink containing carbohydrate, but not more than 8 % concentration.
   
6. Take 30 to 60 grams of carbohydrate per hour to delay fatigue & fuel muscle contractions.
7. Inclusion of sodium, ingested during exercise lasting longer than an hour, may enhance palatability, and therefore encourage athletes to
   drink enough.

http://sportsmedicine.about.com/library/bl_acsm_fluid.htm

DEHYDRATION SEVERELY IMPACTS ATHLETIC PERFORMANCE AND ENDURANCE
A well-hydrated athlete always functions at a higher level than one who exercises in a dehydrated state. If an athlete is dehydrated by just 4.3 percent, performance drops by 22 percent, according to the textbook, Exercise Physiology.