Because I'm sick of KI...

___________________________________________________________________

Fluids during Extensive Exercise
During hard exercise, your muscles can generate 20 times more heat than they do when you are at rest. You dissipate this heat by sweating. As the sweat evaporates, it cools the skin. This in turn cools the blood, which cools the inner body. If you did not sweat, you could cook yourself to death (and I don’t think it’d be very tasty). For this reason, you shouldn’t push yourself beyond your limits in extremely hot weather.

Thirst, as defined by a conscious awareness of the desire for water and other fluids, usually controls water intake. An abnormally high concentration of body fluids triggers the sensation of thirst. When you sweat, you lose significant amounts of water from your blood. The remaining blood becomes more concentrated and has, for example, an abnormally high sodium level. This triggers the thirst mechanism and increases your desire to drink. To quench your thirst, you have to replace the water losses and bring the blood back to its normal concentration.

Unfortunately for athletes, this thirst mechanism can be an unreliable signal to drink. Hence, you should plan to drink before you are thirsty. By the time your brain signals thirst, you may have lost 1% of your body weight, which corresponds with the need for your heart to beat an additional 3-5 times per minute. A 3% loss can significantly hurt your performance. Exercise can blunt thirst, and the mind can override it. You may voluntarily replace less than half of sweat losses. To be safe, always drink enough to quench your thirst, plus a little more.

Muscle Cramps (WEI NING! READ THIS!)
Muscle Cramps are often associated with dehydration. They most commonly occur among athletes who work their muscles to the point of exhaustion. They are likely related to over-exertion, but fluid loss, inadequate conditioning, and electrolyte imbalance may also be predisposing factors. To prevent dehydration-induced cramps, drink more than enough fluids before, during, and after you exercise.

Recovery Fluids
After you finish a hard workout, your top dietary priority should be to replace the fluids you lost by sweating so that your body can get back into water balance. Ideally, you should have minimized dehydration during the event by consuming at least 80% of sweat losses, but that can be hard to do during intense exercise. Hence, the best choices for replacing sweat losses include one or more of the following:

• Juices, which supply water, carbohydrates, vitamins, and potassium
• Watery foods such as watermelon, grapes, and soups that supply fluids, carbohydrates, vitamins and potassium
• High-carbohydrate sports drinks or soft drinks, which supply fluids and carbohydrates (but minimal, if any, vitamins minerals)
• Commercial fluid replacers, which supply fluids, some carbohydrates and sodium, and a few vitamins if fortified with them
• WATER, which tends to be convenient, well-tolerated, and least expensive