Coaches Update Yourself on Hydration as Summer Begins

June 4, 2018

Excerpts from the NCSS PREPARE Course

It is important for everyone to begin activity in a state of proper hydration. Maintaining normal and proper hydration (euhydration) of those involved in athletics is critical in the athlete’s performance as dehydration (loss of body water) can lead to a decrease in athletic performance and ability. The loss of body water can also make one more susceptible for developing heat and cold-related illnesses. Having a proper plan for monitoring and maintaining proper levels of hydration in those involved in athletics is critical in minimizing these potential catastrophic negative effects of dehydration. DEHYDRATION – IT CAN HAPPEN FASTER THAN YOU THINK!

  • In less than one hour of physical activity, an athlete may become dehydrated. Health and performance will suffer.
  • Dehydration of just 1-2% of body weight (only 0.6-1.2 lbs. for a 60 lb. athlete, 1.2-2.4 lbs. for a 120 lb athlete, and 2.0-4.0 lbs for a 200lb. athlete) can negatively influence performance.
  • Dehydration of greater than 3% of body weight substantially increases an athlete’s risk of heat illness.
  • During physical activity, most athletes drink only enough fluid to replace 50% of what was lost.
  • Thirst should not be used as a guideline.
–          Once an athlete is thirsty, he or she has already started to become dehydrated.
  • Before participating, have a rehydration plan for all athletes.

Monitoring Your Level of Hydration


  • Measuring your level of hydration can be easily accomplished through monitoring the color of your urine, frequency of urination and measuring your weight.
  • Other more scientific means of monitoring your level of hydration are available (i.e. refractometer, and urine osmolality).
  • Posting a urine color chart in bathrooms is a helpful way for everyone to monitor their hydration status during activity and competition.

Urine Hydration Status Chart

What to Drink and What Not to Drink
  • People are more likely to consume fluid when it is readily available
  • What to drink:
–          Fluid palatability is influenced by several factors (temperature, sodium content and flavoring)
–          Temperature 15 and 21* C (59°F-70°F)
–          Fluid that is easily and readily available
–          Fluid that taste good
  • What not to drink:
–          Fruit Juice, Carbohydrate Gels, Sodas, Sports drinks with a carbohydrate concentration greater than 8%, caffeine, alcohol, energy drinks

Fluid Replacement guidelines
  • Before Activity:
–          Individuals should slowly drink beverages (5-7 mL·kg) per body weight at least 4 hours before exercise/training (i.e. 60-lb athlete would need to consume 22.36 fl oz-31.31 fl oz)
  • 500-600 mL (17-20 fl oz) 2-3 hours before activity
  • 200-300 mL (7-10 fl oz) 10-20 minutes before activity
–          If the individual does not produce urine, or the urine is dark or highly concentrated, she/he should slowly drink more (3-5 mL·kg ,about 2 hours before the event)
–          Consuming beverages with sodium (20-50 mEq.L) and/or a small amount of salted snacks or sodium-containing foods at meals will help stimulate thirst and retain consumed fluids
  • During Activity:
–          The rate of fluid consumption is based largely on the hydration status prior to the start of activity and based upon the amount of fluid lost during activity
–          The goal is to prevent excessive dehydration (>2% body weight loss from water deficit)
  • During intense exercises, the rate of sweating can be 1 to 2.5L/H (2-5 lbs) of body weight per hour
–          200 to 300 mL (7-10 fl oz) every 10-20 minutes should be consumed during activity
  • Unfortunately, the volume of fluid that most athletes drink voluntarily during exercises replaces only about 50% of body-fluid loss during activity
  • Care is particularly important in activity lasting 3-hours and longer

Carbohydrate-based sports beverages are sometimes used to meet carbohydrate needs, while attempting to replace sweat, water, and electrolyte loss (6-8%)

–          After Activity:
–          The goal is to replace any fluid and electrolyte deficit
–          Pre-activity weight should be attained within 2 hours of the conclusion of activity
–          Replacing the deficit
  • 1 pound = 16 ounces
  • 1 KG = 1 Liter
–          Consume normal fluid and nutrients following activity
–          If there is significant deficit following activity (hydration & nutrition) consider more snacks and regular hydration following your post activity meal