Staying Hydrated

Why do I have to drink so much water?

The human body is comprised of approximately 60-70% of the body weight.  Water is essential for many processes in the body, especially those invovled in energy production and digestion.  Water is the main component in blood as well, if there not enough water in the blood, the body tissues will not be get enough blood and nutrients to function properly.  

The average adult requires a minimum of 2.5 Liters or 10 glasses of water a day.  Athletes need more because they lose more water through sweat than a sedentary individual.  In order to cool the body during exercise and hard work, the body will sweat to cool the body through evaporation.  This takes water away from other areas, so more needs be taken in.  Just a 2% decrease in body weight loss during exercise (resulting from sweat loss) will negatively influence performance.

The National Athletic Trainers' Association (NATA) recommends that athletes should begin activity well hydrated; typically they should ingest 17-20 oz of fluid 2 hours before exercise and 7-10 oz 10-20 minutes before exercise.  Urine should be a light yellow color or appear clear.

To rehydrate during exercise, they recommend 7-10 oz every 10-20 minutes, depending on the individual's sweat rate and climate.  Rehydrating immediately after exercise is also important to aid recovery.  For every pound lost during exercise, the individual should consume ~17-20 oz of fluid afterwards.  

Other fluids than water that include carbohydrates and electrolytes, such as Gatorade, are very good at hydrating exercising athletes.  Carbohydrates help speed up the hydration process and electrolytes that are lost in sweat need to be replenished.

Exercising in the heat and not being adequately hydrated can quickly lead to muscle cramps, heat exhaustion, and heat stroke.