What is load?
Updated November 1, 2026
Load is one number for how hard a workout was on your body, based on how long and how intense it was. An hour at your threshold scores 100.
How Shape scores a workout
Shape uses the first formula your workout has the data for, in this order:
- Power (TSS). Rides with a power meter and your FTP set. Standard math every platform agrees on. Try the TSS calculator.
- Pace (rTSS). Runs with a recorded distance and your threshold pace set. Preferred over heart rate for running, which lags on short sessions.
- Heart rate (HRSS). Any sport with heart rate data, using your max, resting and threshold HR. Try the heart rate load calculator.
When none of them apply
The workout has no load. Shape leaves it blank rather than guessing. Add your numbers in Settings → Performance to enable it.
When you add a workout by hand, you can pick a load from how hard it felt, using the same math from duration and intensity. Try the relative effort calculator.
Planned workouts
Shape estimates their load from the type of workout, so name it in the description: “race”, “recovery”, “intervals”. If the estimate is off, edit the load in the workout details.
Where it goes
The Today page turns load into fitness, fatigue and form, and a load ratio that flags when you’re ramping faster than your base supports. How fitness, fatigue and form work.