Staying hydrated during exercise

It's that time of year when high temperatures and humidity combine to increase risks of dehydration.  Even low levels of dehydration lead to stress on the cardiovascular system (loss of blood volume), rising body core temperature, muscle cramps and heat exhaustion. 

Consuming fluids prior to and during exercise will help you to avoid the problems of dehydration.  This will allow you to train harder and longer.  Excessive thirst, infrequent urination, dark colored urine, dry skin and muscle cramps are symptoms of dehydration and a call to take action.

For exercise lasting less than 60 minutes, plain water will work to hydrate the body.  Drinking too much water right before exercise will leave you feeling bloated.  Consume water up to 24 hours prior to exercise, 30 to 60 minutes before the exercise session and every 20 to 30 minutes during exercise.  In this way the body can gradually absorb water and integrate it into all of the body's cells.  The electrolytes you lose in sweat (sodium, potassium, chloride) will be replenished from eating a balanced diet.

During longer exercise sessions and extended periods of working in hot environments, extra care will be needed.  Studies show that athletes will consume more fluid when drinks are flavored (containing small amounts of carbohydrates).  Having ready access to a sports drink, (the most popular and well researched is Gatorade) before, during and after exercise can dramatically reduce dehydration. 

You can meet your body's fluid needs in a variety of ways throughout the day.  Consuming juice, tea, lemonade, soup, sports drinks, fruits or low fat chocolate milk are some good choices.  Alcohol in any form can interfere with good hydration and muscle recovery.  Caffeine acts as a mild diuretic so be careful not to consume too much.

There are other ways to avoid dehydration.  Most important is to gradually acclimate to hot weather.  A well-conditioned athlete sweats sooner (to cool the body effectively) but loses electrolytes more slowly.  Exercise early in the morning.  Wear light clothing and protect your head from the sun with a cap.  Weigh-in before and after exercise.  Any weight loss is fluid loss.  This will help you gauge the need to rehydrate.  Generally one pound lost requires 16 ounces of fluid to replace it.