# metabolic equivalent, or MET

The ratio of the metabolic rate of the average person while seated and resting, to the metabolic rate of a particular person while performing some task. The symbol MET comes from metabolic equivalents of task. It is commonly used in medicine to express metabolic rates measured during a treadmill test. Two definitions of the MET are met with, essentially equivalent:

• 1 MET is equivalent to a metabolic rate consuming 3.5 milliliters of oxygen per kilogram of body weight per minute.
• 1 MET is equivalent to a metabolic rate consuming 1 kilocalorie per kilogram of body weight per hour.

In a treadmill test, actually measuring METs requires that the person being tested wear a mask in order to measure his or her oxygen consumption (and the carbon dioxide exhaled). However, METs are often estimated on the basis of other factors.

METs can be converted to kilocalories consumed per minute: kcal/min = METs × body weight in kilograms ÷ 60.

Oxygen consumption in liters per hour = METs × body weight in kilograms ÷ 0.21

METs calculator

Some METs for various activities:

METs Activity
2 walking at 2 miles per hour
5 walking at 4 miles per hour, level firm surface
8 jogging at 6 miles per hour
12.5 very vigorous effort on a stationary bike
16 skin diving

## resources

G.A. Brooks, T.D. Fahey and T.P. White.
Exercise Physiology: Human Bioenergetics and its Applications (2nd ed.).
Mountain View, CA: Mayfield Publishing Company, 1995.

A very full listing of energy expenditures in various activities is given by:

B. E. Ainsworth.
The Compendium of Physical Activities Tracking Guide.
Prevention Research Center, Norman J. Arnold School of Public Health, University of South Carolina (January 2002).
Available online at http://prevention.sph.sc.edu/tools/docs/documents_compendium.pdf

A page on the history and use of Ainsworth's publication is at

http://prevention.sph.sc.edu/tools/compendium.htm