Excerpts from the NCSS PREPARE Course
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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
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
– 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
– 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