Shape Calendar

Training Load Calculator

The HRSS calculation uses the following steps:

  1. Calculate Heart Rate Reserve (HRR) at FTP: (FTP HR - Min HR) / (Max HR - Min HR)
  2. Calculate 1hr FTP TRIMP: HRR@FTP * 0.64 * e^(gender factor * HRR@FTP) * 60
  3. Calculate exercise TRIMP: Duration * HRR * 0.64 * e^(gender factor * HRR)
  4. Calculate HRSS: (Exercise TRIMP / 1hr FTP TRIMP) * 100

Gender factor is 1.92 for males and 1.67 for females.