Metabolic equivalent: one size does not fit all.

Details

Serval ID
serval:BIB_5877704EFE08
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Metabolic equivalent: one size does not fit all.
Journal
Journal of Applied Physiology
Author(s)
Byrne N.M., Hills A.P., Hunter G.R., Weinsier R.L., Schutz Y.
ISSN
8750-7587 (Print)
ISSN-L
0161-7567
Publication state
Published
Issued date
09/2005
Volume
99
Number
3
Pages
1112-1119
Language
english
Notes
Publication types: Clinical Trial ; Controlled Clinical Trial ; Journal Article
Publication Status: ppublish
Abstract
The metabolic equivalent (MET) is a widely used physiological concept that represents a simple procedure for expressing energy cost of physical activities as multiples of resting metabolic rate (RMR). The value equating 1 MET (3.5 ml O2 x kg(-1) x min(-1) or 1 kcal x kg(-1) x h(-1)) was first derived from the resting O2 consumption (VO2) of one person, a 70-kg, 40-yr-old man. Given the extensive use of MET levels to quantify physical activity level or work output, we investigated the adequacy of this scientific convention. Subjects consisted of 642 women and 127 men, 18-74 yr of age, 35-186 kg in weight, who were weight stable and healthy, albeit obese in some cases. RMR was measured by indirect calorimetry using a ventilated hood system, and the energy cost of walking on a treadmill at 5.6 km/h was measured in a subsample of 49 men and 49 women (26-45 kg/m2; 29-47 yr). Average VO2 and energy cost corresponding with rest (2.6 +/- 0.4 ml O2 x kg(-1) x min(-1) and 0.84 +/- 0.16 kcal x kg(-1) x h(-1), respectively) were significantly lower than the commonly accepted 1-MET values of 3.5 ml O2 x kg(-1) x min(-1) and 1 kcal x kg(-1) x h(-1), respectively. Body composition (fat mass and fat-free mass) accounted for 62% of the variance in resting VO2 compared with age, which accounted for only 14%. For a large heterogeneous sample, the 1-MET value of 3.5 ml O2 x kg(-1) x min(-1) overestimates the actual resting VO2 value on average by 35%, and the 1-MET of 1 kcal/h overestimates resting energy expenditure by 20%. Using measured or predicted RMR (ml O2 x kg(-1) x min(-1) or kcal x kg(-1) x h(-1)) as a correction factor can appropriately adjust for individual differences when estimating the energy cost of moderate intensity walking (5.6 km/h).
Keywords
Adolescent, Adult, Age Factors, Aged, Algorithms, Body Composition/physiology, Calorimetry, Indirect/methods, Energy Metabolism/physiology, Female, Humans, Male, Middle Aged, Oxygen Consumption/physiology, Physical Exertion/physiology, Reproducibility of Results, Sensitivity and Specificity, Sex Factors, Walking/physiology
Pubmed
Web of science
Create date
21/01/2008 13:08
Last modification date
20/08/2019 14:12
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