Sports Injury Rehabilitation & Performance Training

Proper Hydration is Crucial 
for Good Performance

Have you ever been on a long run or bike ride and all of a sudden start feeling a “little off” maybe lightheaded, dizzy or fatigued???  You could be dehydrated.

Proper hydration is crucial for performing at your best.  Approximately 60% of body weight is water, that is if you weigh 150#, 90# is water weight.  If you lose 3% or more of your body weight, that is 4.8# or more for a person weighing 150#, you are dehydrated and performance will decline.    

A quick way to assess if you are properly hydrated is to check the color of your urine.  If it is light yellow, the color of lemonade or straw, you are adequately hydrated.  If it is dark yellow the color of tea you are under hydrated and if it is clear in color you are over hydrated.

Daily hydration need (not including activity) is 0.5 -0.6 times body weight.  A person weighing 150# should consume 75 – 90 oz. of fluid per day or 9 to 11 cups.  All beverages including water, sports drink, milk, juice or watermelon which is 92% water can be counted as part of your fluid intake.  Use drinks that contain caffeine, like coffee and tea, with caution and sparingly as they can act as a diuretic.  Alcohol acts as a dehydrator.  If you drink a beer, drink a glass of water with it.

If you are an athlete or exercise regularly your fluid intake needs to increase.  Most athletes will be adequately hydrated with 80-100 oz. of fluid per day.  An exception where more fluid is needed would be heavier athletes, athletes competing at a high VO2 max percentage and/ or those exercising in severe environmental conditions.

As a general rule of thumb, keep fluid intake at 16 to 24 oz. of fluid per hour, yes…2-3 cups. Most people should not exceed more than 28 oz. of fluid per hour.  It takes time for your body tissues to absorb water.  Don’t just sit down and drink a gallon of water.  You will be better off drinking 4-6 oz every 15 minutes than drinking all at once. In most circumstances, one water bottle per hour will give you the right amount of fluid.

Now just a few more helpful hints:

1.   Train to get fit in the heat.  Heat acclimation and being in shape can reduce fluid and electrolyte loss by up to 50%.  On those first few hot days to help you acclimate cut your workout short, drink extra fluid, use an electrolyte supplement or eat a banana. 

2.   Wear the lightest evaporation-friendly clothing you can afford.  Cotton is not on the list.

3.   Use cold fluids.  Your body absorbs them better than warm fluids.

4.   During the hottest weather conditions, sponge off with cold water and give yourself a short, periodic rest break from race pace.  This will provide heat relief.

5.   Know the symptoms of dehydration.  STOP immediately if you feel lightheaded, dizzy or get the dry chills.  No race or training is worth compromising your health.

July 2012

Submitted by Becky McClure, PT, MOMT

Sports Physical Therapist at LMH South Rehabilitation