Total Energy Expenditure Estimated Using Foot–Ground Contact Pedometry

Abstract

Routine walking and running, by increasing daily total energy expenditure (TEE), can play a significant role in reducing the likelihood of obesity. The objective of this field study was to compare TEE estimated using foot-ground contact time (Tc)-pedometry (TEE_PEDO) with that measured by the criterion doubly labeled water (DLW) method. Eight male U.S. Marine test volunteers [27 ± 4 years of age(mean ± SD); weight = 83.2 ± 10.7 kg; height = 182.2 ± 4.5 cm; body fat = 17.0 ± 2.9%] engaged in a field training exercise were studied over 2 days. TEE_PEDO was defined as (calculated resting energy expenditure + estimated thermic effect of food + metabolic cost of physical activity), where physical activity was estimated by Tc-pedometry. Tc-pedometry was used to differentiate inactivity, activity other than exercise (i.e., non-exercise activity thermogenesis, or NEAT), and the metabolic cost of locomotion (M_LOCO), where M_LOCO was derived from total weight(body weight + load weight) and accelerometric measurements of Tc. TEE_PEDO data were compared with TEEs measured by the DLW (²H₂ ¹⁸O) method (TEE_DLW): TEE_DLW = 15.27 ± 1.65 MJ/day and TEE_PEDO = 15.29 ± 0.83 MJ/day. Mean bias (i.e., TEE_PEDO - TEE_DLW) was 0.02 MJ, and mean error (SD of individual differences between TEE_PEDO and TEE_DLW) was 1.83 MJ. The Tc-pedometry method provided a valid estimate of the average TEE of a small group of physically active subjects where walking was the dominant activity.