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).
Compendium
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)
2.2
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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