Guide
How many calories does exercise actually burn
A plain guide to MET-based calorie estimates, why the numbers vary so much, and what post-workout eating does to the picture.
The MET formula gives a rough order of magnitude
Calorie burn during exercise is estimated using MET values — multiples of resting metabolic rate. Running at a moderate pace has a MET of around 9–10; walking has a MET of around 3.5. Multiply the MET by your weight in kg and the duration in hours to get an approximate kcal figure. The result is a rough guide, not a laboratory measurement.
Individual variation is significant
The same exercise at the same duration burns different calories in different people depending on fitness level, efficiency, intensity, terrain, and metabolic rate. A trained runner uses fewer calories per mile than a beginner because the movement is more efficient. MET values average across a population and miss these differences.
Post-workout eating often cancels more of the deficit than people realise
Exercise often increases appetite, and the reward psychology of a completed session makes food feel more justified. A 400-calorie snack after a 40-minute run can absorb most of the calorie deficit. The net figure is useful because it shows the actual energy picture, not just the effort.