Estimate how much fluid you lose per hour of exercise so you know how much to drink to stay properly hydrated.
Athletes lose fluid through sweat during exercise, and replacing it at the right rate helps maintain performance and avoid dehydration. Comparing body weight before and after exercise is a simple, well-established way to estimate fluid loss.
Sweat Rate (fl oz/hr) = (Weight Lost (oz) + Fluid Consumed (fl oz)) ÷ (Duration in Hours)
Losing 2 lb (32 oz) of body weight plus drinking 16 fl oz during a 60-minute workout gives a sweat rate of about 48 fl oz per hour.
This is a general fitness estimate, not medical advice. Individual hydration needs vary.
(pre-exercise weight − post-exercise weight + fluid intake − urine output) ÷ exercise duration.
It helps personalize hydration strategy during exercise, since rates vary significantly by individual.
Exercise intensity, ambient temperature, humidity, clothing, and physiology.