What is TSS?
- Training Stress Score: VirtualTraining uses several physiological metrics to quantify the training stress of a particular workout or portion of a workout.
- Training Stress Score. In VT software this is an indicator of how hard a workout is. The formula for TSS is:
TSS = [(s x NP x IF) / (FTP x 3,600)] x 100
where 's' is workout duration in seconds, 'NP' is normalized power (or pace in running), 'IF' is intensity factor, 'FTP' is functional threshold power (or pace in running), and '3,600' is the number of seconds in an hour.
NP Normalize Power: An estimate of power that a rider can maintain for the same physiological “cost” if their power output is perfectly constant, rather than variable. Let say that is kind of average Power from one of your Training.
IF Intensity Factor: The ratio of the normalized power to the rider’s threshold power. IF = NP/FTP
And Power (W) is calculated as estimated power based on the user's heart rate.