ZHANG, K., F. X. PI-SUNYER, and C. N. BOOZER. Improving Energy Expenditure Estimation for Physical Activity. Med. Sci. Sports Exerc., Vol. 36, No. 5, pp. 883–889, 2004.
Purpose: The purpose of this study was to validate the Intelligent Device for Energy Expenditure and Activity (IDEEA) for estimation of energy expenditure during a variety of activities. An additional aim was to improve the accuracy of the estimation of energy expenditure of physical activity based on second-by-second information of type, onset, and duration of activity.
Methods: This study included two tests: a mask calorimetry test with 27 subjects [age = 33.7 ± 13.8 (mean ± SD) yr; BMI = 24.8 ± 4.8 kg·m−2] and a respiratory chamber calorimetry test with 10 subjects (age = 32.9 ± 12.4 yr; BMI = 26.1 ± 5.6 kg·m−2). In the mask test, the subjects performed activities (sitting, standing, lying down, level treadmill walking, and running at different speeds) for 50-min durations. For the chamber test, subjects lived in the metabolic chamber for 23 h and performed three exercise sessions to compensate for the confined environment.
Results: The results showed significant correlations (P < 0.0001) between energy expenditure estimated by IDEEA and energy expenditure measured by the calorimeters with an accuracy >95%. After corrections for the decrease in sleeping metabolic rate, the estimation accuracy for the chamber test was increased by 1–96.2%, whereas the estimation accuracy for nighttime activity was significantly improved by 4–99%.
Conclusion: IDEEA provides a suitable method for estimating the energy expenditure of physical activity. It provides both instantaneous and cumulative estimates of energy expenditure over a given period.