Pre-workout recommendations are calculated based on an athlete’s body weight and a one hour time frame leading up to the start time.
Mid-workout recommendations, depending on the information available (biological sex, body weight, exercise duration, air temperature, type of activity, energy expenditure, and Gx patch sweat rate), are calculated using our algorithm. This algorithm uses a 7-factor model to predict each Gx Sweat Patch’s local forearm sweat into a Whole-Body Sweat Rate (WBSR).
Whole-Body Sweat Sodium Concentration (WBSC) is similarly predicted using a model based on local sweat sodium concentration. We then use WBSRs and WBSCs in a sweat profile matching algorithm to predict how much fluid and sodium an athlete will lose during an activity of given length and intensity.
For example, if an athlete’s WBSR is 1,500 mL/h and their workout is 2 hours, a matched workout estimates 3,000 mL lost (1,500 mL * 2 h). If that same athlete’s WBSC is 1,000 mg/L, we estimate 3,000 mg of sodium lost for that exercise (1,000 mg x 3,000 mL).
Post-workout recommendations are calculated based on weigh-in/out values or expected sweat and sodium loss based on a matching sweat profile.
Note that generally some athletes may need gut training to reach the upper end of the recommended range for fluid intake, and should generally drink to their own comfort level.
Similar to training for competition and gradually increasing an athlete’s workload, we recommend slowly increasing the amount of fluid and carbohydrates they consume during practice and games until they are in their target range.