Water makes up about 60 percent of your body weight.
With every system in your body depending on water, it is imperative
to have adequate fluid intake. Proper hydration is especially
important during exercise to maintain physical comfort, safety and
optimum performance. Studies have revealed that a loss of two or
more percent of an individual's body weight due to perspiration is
directly linked to a drop in blood volume. This will make the heart
work harder to move the blood around the body and may result in
dizziness, cramps and fatigue.
How much water do you need?
Fluid intakes for athletes vary considerably due
to the individuality of perspiration rates and specific fluid losses
and hydration levels. In addition, the right amount of fluid to
drink will depend on the length and intensity of the exercise,
climate (temperature and humidity) and location (altitude,
pollution, etc). Here are a few tips to help monitor your hydration
Monitor urine volume and color. This will
assist in the monitoring of adequate fluid intake. You are most
likely hydrated if you have a large amount of light colored, diluted
urine and dehydrated if you urine is dark colored and concentrated.
Weight before and after exercise. After
exercise, any weight loss is usually from fluid loss. Drink to
replenish this loss. Any weight gain after exercise may mean you are
drinking more than you need.
Eight 8-ounce glasses of water a day. An
easy approach to water intake is the "8 x 8 rule" - drink
eight 8-ounce glasses of water a day.
16 ounces of fluid per hour of exercise.
During exercise, one rule of thumb is to drink about 16 oz during
every hour of workout. More intense workouts may require more, more
intense climates may require more; the key is to remember to drink
during your workouts to stay hydrated and not necessarily wait until
you are finished.
Note: all fluids (even coffee, juice and sodas)
count toward the daily total. While this approach is not supported
by scientific evidence, many people use this basic rule as a
guideline for how much water and other fluids to drink.
Even apart from the above approaches, if you drink
enough fluid so that you rarely feel thirsty and produce 1.5 liters
(6.3 cups) or more of colorless or slightly yellow urine a day, your
fluid intake is probably adequate.