Feasibility of the Tritrac R3D Accelerometer to Estimate Energy Expenditure in Youth.

The purpose of this study was to determine whether an equation could he developed to predict energy expenditure from Tritrac output, body mass, stature, and age in youth. The participants were 308 young people. 8 18 yrs of age, similarly dispersed across ages and genders. Stature (cm) and body mass (kg) were measured. Participants completed 10 mm of nine activities, ranging from light to vigorous intensity. Simultaneous measures of Tritrac vector magnitude counts (VMAG) and oxygen uptake (Cosmed K4h²) were obtained. Mixed model analysis using VMAG, sex, age, stature, and body mass fit well, and all variables were significant (p < .012). The model concordance correlation was R_c= .812; standard deviation = 305 mI/mm. A slightly less complex model was also adequate: VO₂ (mI/min) (0.32 VMAG) + (6.97 cm) + (6.19 kg) 858; standard deviation = 306 mI/min; R_c =809. These results indicate that the Tritrac R3D can he used with some success to assess energy expendi- ture in 8- to 1 8-yr olds. [ABSTRACT FROM AUTHOR]