Hydration Guidelines, Fluid Replacement During Exercise

Thirst is a late response. Be the time you feel thirsty you are already behind the curve of optimal hydration. Maintaining hydration helps ensure your best performance. Even a loss of 1-2% of body water weight can significantly impact cardiovascular capacity. Here are some steps to ensure optimal hydration before, during, and after exercise:

  • Always be prepared and think about hydrating appropriately at least a day in advance
  • Immediately prior to exercise or during warm-up, drink up to 10 fl oz. of cool water (1 Cup = 8 fl oz.)
  • For exercise under 1-hour of exercise; water is sufficient in replacing fluid lost.
  • For exercise lasting 60-75 min or more; consider drinking a sports drink that will help replenish the sugar and electrolytes lost through sweat and exercise
  • Try to drink ½ cup of a cool sports drink at regular 10 – 15 minutes intervals
  • Be cautious about consuming over 27 oz. of fluid an hour.
  • Most sports drinks on the shelf are too sweet; especially, if you are running or moving on a hot day, or exercising at high intensity. If you buy the regular Gatorade, dilute it by half with plain water
  • For longer durations of exercise, 75-90 min of exercise, increase concentration of ingested glucose, sodium, and potassium
  • Higher sodium concentrations, although possibly may promote rapid intestinal absorption, are not palatable to most athletes (Gatorade may not provide enough Sodium late into exercise and snacks or supplements may be necessary)
  • Small amounts of potassium may facilitate re-hydration of the intracellular fluid compartment, may be included
  • Such a regimen ensures optimal rates of fluid and energy delivery, limiting any dehydration-induced decreases in plasma volume, and maintaining an adequate rate of carbohydrate oxidation late in exercise

*Adapted from the American College of Sports Medicine Guidelines