代谢当量商（Metabolic Equivalent of Task, MET）是一种进行生物活动时的一种生物学特性，可以用于计算从事某一类活动时的代谢水平。
本条目中未有特别说明的，一律指人类活动。
英语百科
Metabolic equivalent 代谢当量
The Metabolic Equivalent of Task (MET), or simply metabolic equivalent, is a physiological measure expressing the energy cost of physical activities and is defined as the ratio of metabolic rate (and therefore the rate of energy consumption) during a specific physical activity to a reference metabolic rate, set by convention to 3.5 ml O2·kg·min or equivalently: