5 Quick Hydration Facts:

Thirst is not a great indicator of fluid needs.
Sweat rates vary from athlete to athlete dependent on a multitude of different factors (Genetics, training status, heat acclimatization).
Sodium and Potassium are the two most important electrolytes within your body. You’ll lose sodium to potassium in a ratio between 3:1-5:1. Repletion of these two electrolytes is of utmost importance.
Typical athlete’s sweat rates range anywhere between losing .5 liters/hour to 2.0 liters/hr.
Ideally, an athlete will want to consume a sports drink that is 6-8% carbohydrate by volume. Anything less will passively pass through the stomach too quickly, anything more will stay in the stomach and actually inadvertently cause dehydration.

To find out your sweat rate, download our Sweat Rate Calculator (Excel)

Conditions That Increase Sweat Loss:

Air Temperature: Higher temperatures= greater sweat loss
Intensity: The harder your workout, the more you perspire
Body Size & Gender: Larger people sweat more. Generally speaking, men sweat more than women.
Duration: The longer the workout, the greater the fluid loss
Fitness Level: Well-trained athletes sweat more than less trained

Disclaimer:
The George Mason University Sports Nutrition web site provides information about food and human nutrition. The information found in this web site is not intended for medical self-diagnosis, treatment, counsel, or as a substitute for the care of a licensed health care professional.