MET reflects the oxygen consumption during rest and sitting. It is 3,5ml O2 /kg body weight/min. The metabolic equivalent is used to determine the energy expenditure during the maximum load. The metabolic equivalent in custo diagnostic is calculated as follows:
a) Treadmill exercise test:
v = max. Speed in miles per hour
: metabolic equivalent
MET is the ratio of oxygen consumption on load to oxygen consumption on resting. The oxygen consumption at rest is 3.5 ml per kg per minute.
The MET value for bicycle and treadmill will be differently calculated:
for Ergometer:
L = Load in Watt and
G = Weight in kg,
the formula applies:
MET = 1 + (12 * L) / (3.5 * G)
Thereby is the oxygen consumption 3,5 ml/kg per minute in resting, 12*( Load/kg) is the additional oxygen consumption ml/kg and per minute on stress.
This leads to the formula above.
Source:
Rost, R. & Hollmann, W. (1982): Stress tests in practice ( German: Belastungsuntersuchungen in der Praxis. Publisher: Georg Thieme, Stuttgart, New York. 164 p.
In other words, the formula is:
MET = 1 + (L / G) * 3,428
Note: other authors use a slightly different factor. (for example Jonathan Myers: MET = 1 + (L / G) * 3,486)
for Treadmill ergometry:
v = Speed in Meter per Minute and
m = Slope in % applies
a) Walking (<= 4.3 miles per hour)m = slope in%
MET = 1 + (v * 26.8 * (0.1 + m * 0.018)) : / 3.5
b) Bicycle exercise test:
L = max. Load in Watts
thereby is
v * 0.1 the relative oxygen consumption in horizontal direction and
v * m * 0.018 is the relative oxygen consumption in vertical direction
b) Running (> 4.3 miles per hour)G = weight in kg
MET = 1 + (12 * L): (3.5 * G(v * (0.2 + m * 0.009)) / 3.5
thereby is
v * 0.2 the relative oxygen consumption in horizontal direction and
v * m * 0.009 the relative oxygen consumption in vertical direction
(Source: ACSM)