What this tool does
You enter class or session length and how hard the work intervals actually were. The MET applies to the whole clock time you type — so include rest if it was inside the hour.
How it works
Circuit and vigorous interval work in the Compendium clusters around 8–12 MET. Afterburn (EPOC) is usually tens of calories, not hundreds. We do not invent a huge EPOC bonus.
Formula and methodology
kcal ≈ MET × kg × hours. We do not add a speculative afterburn term.
How to interpret the result
20 minutes hard for 70 kg at 10 MET is 10 × 70 × 1/3 ≈ 233 kcal gross. A “1,000 calorie HIIT” ad is marketing. The session still counts; it does not rewrite TDEE by itself.
Example
80 kg, 25 minutes, hard 10 MET: 10 × 80 × 25/60 ≈ 333 kcal. Very hard 12 MET on the same clock is 400 kcal. Neither is a large pizza.
Common mistakes
- Logging the full hour for a 25-minute class plus stretching selfies.
- Eating back “afterburn” you cannot measure.
- Doing HIIT daily and wondering why sleep and lifts died.
When this estimate may be off
- The class was mostly coaching and setup.
- You have a clinical condition that makes high-intensity work inappropriate — ask a clinician.