Total energy expenditure estimated using a foot-contact pedometer.
BACKGROUND
Total energy expenditure (TEE) assessment using pedometers provide an easy and less expensive method than doubly labeled water (DLW). This study assessed TEE by a new pedometry method (TEEpedo) compared to the doubly labeled water method (TEEdlw).


METHODS
Shipboard sailors (7 men, age: 23.0+/-3.9 yrs; ht: 180.2+/-6.5 cm; wt: 83.8+/-11.8 kg, and 10 women, age: 24.7+/-4.4 yrs; ht: 165.2+/-8.0 cm; wt: 63.5+/-14.0 kg) (Mean +/-SD) were studied for 8 days. The energy cost of activity was estimated using (a) total body weight, (b) foot-ground contact times [Tc] during running, walking, and non-exercise activity [NEAT], and (c) the known proportion of time spent in each activity category. Resting metabolic rate (RMR) was estimated from lean body mass.


RESULTS
TEEPEDO was calculated as: TEEpedo (MJ) = (1440 x [%Run Time x ((0.0761 x [Total Body Weight/TcRun]) - 7.598) +%Walk Time x ((0.056 x [Total Body Weight/TcWalk]) - 2.938) + (%NEAT Time x 0.1 x [RMR/Minute])] + RMR)/239. This method, explained 79% of the variance of TEEpedo with a 95% confidence interval of +/-0.81 MJ/day, relative to TEEdlw (12.55+/-3.3MJ/day). Mean TEEpedo (12.65+/-3.1 MJ/day) did not differ from mean TEEdlw (p=0.95).


CONCLUSIONS
At TEEs >14 MJ/day, the TEEpedo method underestimated actual TEE, possibly due to unaccounted for upper body exercise. At more moderate TEEs of 9 to 14 MJ/day, the Tc pedometry method provided accurate estimates of TEE.
U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA. william.tharion@na.amedd.army.mil
William J
WJ
Tharion
Miyo
M
Yokota
Mark J
MJ
Buller
James P
JP
DeLany
Reed W
RW
Hoyt
D003903:Deuterium / Q000378:metabolism; D004734:Energy Metabolism; D016552:Ergometry / Q000295:instrumentation*; D015444:Exercise; D005260:Female; D005528:Foot; D006805:Human Experimentation; D006801:Humans; D008297:Male; D008889:Military Personnel; D010103:Oxygen Isotopes / Q000378:metabolism; D012044:Regression Analysis
D010103:Oxygen Isotopes; D003903:Deuterium