Fluid Replacement for Athletes
NATA (National Athletic Trainers Association)
Position Statement
Effects of Dehydration
Dehydration can affect an athlete’s performance in less than an hours of exercise – sooner if the athlete begins the session dehydrated.
Dehydration of just 1-2% of body weight can negatively influence performance.
When dehydration exceeds 2% of body weight, physical work capacity can decrease by as much as 48%.
Dehydration of greater than 3% of body weight increases an athlete’s risk of developing an exertional heat illness (heat cramps, heat exhaustion or heat stroke).
Thirst is not a reliable indicator of either dehydration or fluid needs. Thirst mechanisms do not kick in until an athlete has lost 2% of the body weight as sweat.
Athletes typically replace only 1/3 to 2/3 of sweat losses when they use thirst as a guide.
Warning Signs of Dehydration
1. Thirst
2. Irritability
3. Headache
4. Nausea
5. Dizziness
6. Decreased performance
7. Weakness
8. Cramps
9. Dark urine output
What to Drink During Exercise
Before Exercise
2-3 hours before drink 17-20 oz of water or sports drink
10-20 minutes before drink 7-10 oz of water or sports drink
During Exercise
Every 10-20 minutes drink 7-10 oz of water of sports drink
Encourage athletes to drink beyond their thirst
After Exercise
Within 2 hours drink enough to replace any weight loss from exercise
Approximately 20 oz of water or sports drink per pound of weight loss.
Within 6 hours drink an additional 25-50% more than weight loss from exercise.
What Not To Drink During Exercise
Fruit juices, carbohydrate gels and sodas.
Beverages containing caffeine, alcohol and carbonation are discouraged during activity because they can dehydrate the body by stimulating excess urine production.
