MET (Metabolic Equivalent of Task)

A unit expressing the energy cost of physical activities relative to resting metabolic rate. Sitting = 1 MET; brisk walking = 3.5 METs; running at 6 mph = 10 METs. Used to estimate calorie burn.

One MET equals the energy you burn sitting still, so a 5-MET activity burns roughly five times that rate. Multiplying an activity’s METs by your weight and duration yields a practical estimate of calories burned.