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Meaning of MET

Meaning of MET

MET stands for "metabolic equivalent" and is defined as "the ratio of the work metabolic rate to the resting metabolic rate". One (1) MET is the rate at which adults burn kcal at rest: This is approximately 1 kcal per kilogram of body weight per hour (expressed as 1 kcal/kg/hr). Thus, the MET value of "sitting quietly and watching TV" is "1", whereas the MET value of "walking on level ground at moderate pace" is 3.3. In other words, sitting quietly burns 1 kcal/kg/hr whereas walking on level ground at a moderate pace burns 3.3 kcal/kg/hr.

MET values also are defined as "multiples of resting metabolic rate." Thus, sitting quietly watching TV burns no more kcals than are needed for resting whereas walking at a moderate pace burns 3.3 times as many kcals as are needed for resting (or sitting quietly).


The information below comes directly from the Compendium.

Comp Code METS Description
18230 10.0 swimming laps, freestyle, fast, vigorous effort
18240 7.0 freestyle, slow, moderate or light effort
18250 7.0 backstroke, general
18260 10.0 breaststroke, general
18270 11.0 butterfly, general
18290 11.0 crawl, fast (75 yards/minute), vigorous effort
18300 8.0 crawl, slow (50 yards/minute), moderate or light effort
18310 6.0 leisurely, not lap swimming
18320 6.0 sidestroke
18330 8.0 synchronized
18340 10.0 treading water, fast vigorous effort

Using MET Values

To use the MET values directly from the Compendium, you must know the individual's body weight in kg. Since 1 kg = 2.2 lb, weight in lb can be converted to weight in kg by dividing "weight in lbs" by "2.2 lb/kg." Example for 132 lb individual:

132 lb = 60 kg
2.2 lb/kg

The total kcal expended by an individual of a certain body weight (e.g., 60 kg) who engages in a given activity (e.g., butterfly stroke) for a specified length of time (e.g., 45 minutes, which is .75 hr) is calculated by multiplying together 3 numbers:

MET value of activity x body weight in kg x time in hours

For the previous example of swimming butterfly stroke, the calculation and respective total kcal expended is:

11.0 kcal/kg/hr x 60 kg x .75 hr = 495.0 kcal.

Converting MET Values to Use with Body Weight in Pounds (lb).

Any MET value in the Compendium can be converted to provide the kcal expenditure per lb as opposed to per kg. Since 1 kg = 2.2 lbs, simply divide the MET value by "2.2". Example for butterfly stroke (MET value of 11.0):

11.0 = 5.00 (kcal/lb/hr)
To calculate total kcal expended by a 132 lb (60 kg) person who swims butterfly stroke for .75 hr:
5.00 kcal/lb/hr x 132 lb x .75 hr = 495 kcal
Note the answer--total kcal expended by a 132 lb (60 kg) person who swims butterfly for .75 hr--comes out basically the same regardless of whether you are using the actual MET value (kcal/kg/hr) or the converted MET value (kcal/lb/hr).


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