Fitbod calculates calories burned based on the volume of weight lifted during a workout and duration of the workout. Additionally, Fitbod uses your Weight, Height, Gender, and Age to further refine and improve the calories burned estimation. If you're using an Apple Watch as well, Fitbod will read in heart rate to factor into the calorie calculation.
Weight is a required entry for Calories Burned to be estimated. Input your weight by either connecting Apple Health within the Fitbod app or follow the following instructions to input your weight manually:
Open the Fitbod app
> Log tab
> Settings (top right corner)
> Connected Apps
> Apple Health
> tap on the Weight field to manually enter
For additional information about Fitbod on the Apple Watch and Fitbod + Apple Health, please visit the article Apple Watch + Apple Health.