Keep fluid intake during exercise between 16-28 ounces per hour.
FACT: In general, most athletes, under most conditions, will satisfy hydration needs with a fluid intake in the range of 20-25-ounces/hour - roughly the equivalent of a standard size small or large water bottle. Lighter athletes and/or athletes exercising in cool weather conditions may only require an intake of 16-18 ounces/hour. Larger athletes and/or athletes exercising under very hot and humid conditions are the ones that can consider a fluid intake in the range of 28 ounces/hour, perhaps up to 30 ounces/hour in extreme conditions. It's important to remember that regular fluid intake over 30-34 ounces hourly significantly increases the potential for serious performance and health problems.