Why does the MET list show odd values like "4.3?"

Honesty labels: the Compendium ranges (yoga spans 2.0–6.0 by style and effort) make single values approximations. Where the catalog spans widely, we flag it — pick the option closest to your actual practice, or use the effort selector.

My watch says double this number. Who is right?

Usually the calculator. Consumer wearables estimate from heart rate with population calibrations and err high for most people — validation studies show 20–90% overestimation on energy expenditure for some devices. Heart rate reflects effort, not only energy — that is the leak in the math.

Do heavier people really burn more?

Yes — linearly in the formula, and physically true: moving more mass costs more energy, especially in weight-bearing activity (walking, running). Non-weight-bearing activity (swimming, cycling) scales less steeply. The weight field is doing real work; keep it current.

What about EPOC — the "afterburn"?

Real but small: excess post-exercise oxygen consumption adds ~6–15% of the session's burn, concentrated in high-intensity work. An hour of HIIT nets maybe 30–60 extra kcal afterward. It does not double the number, whatever the class marketing says.

Activity Burn Calculator

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How the activity burn calculator works

The formula

kcal/min = MET × 3.5 × weight(kg) ÷ 200. A MET (metabolic equivalent) is the ratio of an activity's energy cost to resting: 1 MET is sitting quietly (~1.2–1.4 kcal/min for most adults), 5 METs is five times resting. The Compendium of Physical Activities — five decades of measured research — catalogs the MET values for everything from bird-watching to shoveling snow, and this calculator applies them to your weight and time.

Net vs gross — the correction that matters

The formula above computes gross burn (everything during the session). But you would have burned the resting baseline anyway — which for an hour is ~80–100 kcal of "burn" you get for free every hour of life. Net burn subtracts the baseline: that is the number that earns food, and the honest one for energy-balance math. The calculator shows both; the gap is bigger than most people expect for light activities (an hour of walking: ~240 gross, ~160 net).

Reading the results

Steady activities (walking, cycling) track the formula within ±10–20% for most people.
Variable activities (HIIT, team sports) widen the error — the MET value assumes the average participation; your session may be more or less.
The effort-honesty selector exists because "as described" is often optimistic: the person coasting the last third of a spin class burned the 0.9× number.

What burn is worth

An hour of brisk walking nets ~160–200 kcal — a banana, not a pizza. Exercise's real dividends are cardiovascular, metabolic, and mood — the calorie ledger is the smallest account. Track it honestly, then spend it on performance rather than permission.