Rate of energy expenditure per body mass and unit time, while performing some specific physical activity, compared to a reference. 1 MET is sitting at rest (not sleeping).
It can be used to estimate activity energy expenditure from resting energy expenditure.
It is broadly used to estimate the absolute intensity of a physical activity:
- MET < 1.5: sedentary activity
- 1.5 ≤ MET < 3: light-intensity activity
- 3 ≤ MET < 6: moderate-intensity activity
- MET ≥ 6: vigorous-intensity activity
- MET ≥ 3: moderate-to-vigorous activity
It should be noted that the Compendium of Physical Activities was developed to standardize the assignment of MET values to physical activity types.