Athlete and Coach Edition users can save sweat rate and sodium concentration test results to help refine Fueling Targets.
Click the + icon to the right of the Sweat Tests table to add a new test
Enter the date, sport, temperature, sweat rate, sodium concentration, and any notes
Click the edit icon 
next to any test to update or delete it
What is Sweat Rate Testing? #
Sweat rate testing measures how much fluid an athlete loses through sweat during exercise. Sodium concentration testing measures the concentration of sodium in the athlete’s sweat.
- Sweat Rate — fluid lost per hour (oz/hr or L/hr), used to set an athlete’s Fluid target
- Sodium Concentration — sodium lost per unit of sweat (mg/oz or mg/L), used to guide an athlete’s Sodium target
Why It Matters #
Fluid and sodium losses vary significantly from person to person and across conditions — temperature, humidity, and intensity all play a role. A sweat test provides data-driven targets rather than guesswork, helping your athlete dial in hydration more precisely.
Over time, logging tests across different conditions builds a picture of how an athlete’s sweat rate changes — useful for fine-tuning Fluid and Sodium Targets for different environments.
How to Conduct an At-Home Sweat Test #
- Weigh yourself (in the nude) immediately before your workout
- Complete your workout, noting the workout duration, intensity, temperature and humidity, and amount of fluid consumed
- Weigh yourself (in the nude) immediately after your workout, toweling off excess sweat as best as you can
- Calculate pounds of body weight lost during exercise
- Convert to pounds to ounces (16 oz = 1 lb)
- Add back in fluid consumed, in ounces, to measure total fluid loss during exercise
- That number divided by number of hours exercised is your hourly sweat rate under those conditions
Sweat rates vary based on the environment – you can conduct sweat tests in a range of temperature and humidity environments to understand an athlete’s sweat rate in a range of conditions.