Use of a Two-Regression Model for Estimating Energy Expenditure in Children.

• Autores: Scott E. Crouter, David R. Bassett, Magdalene Horton
• Localización: Medicine & Science in Sports & exercise: Official Journal of the American College of Sports Medicine, ISSN 0195-9131, Vol. 44, Nº. 6, 2012, págs. 1177-1185
• Idioma: inglés
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• Resumen

  • The purpose of this study was to develop two new two-regression models (2RM), for use in children, that estimate energy expenditure (EE) using the ActiGraph GT3X: 1) mean vector magnitude (VM) counts or 2) vertical axis (VA) counts. The new 2RMs were also compared with existing ActiGraph equations for children. Methods: Fifty-seven boys and 52 girls (mean +/- SD: age = 11 +/- 1.7 yr, body mass index = 21.4 +/- 5.5 kg[middle dot]m-2) performed 30-min supine rest and 8 min of six different activities ranging from sedentary behaviors to vigorous physical activity. Eighteen activities were split into three routines with each routine performed by 38-39 participants. Seventy-seven participants were used for the development group, and 39 participants were used for the cross-validation group. During all testing, activity data were collected using an ActiGraph GT3X, worn on the right hip, and oxygen consumption was measured using a Cosmed K4b2. All energy expenditure values are expressed as METRMR (activity V[spacing dot above]O2/resting V[spacing dot above]O2). Results: For each activity, a coefficient of variation was calculated using 10-s epochs for the VA and VM to determine whether the activity was continuous walking/running or an intermittent lifestyle activity. Separate regression equations were developed for walking/running and intermittent lifestyle activity. In the cross-validation group, the VM and VA 2RMs were within 0.8 METRMR of measured METRMR for all activities except Sportwall and running (all P > 0.05). The other existing ActiGraph equations had mean errors ranging from 0.0 to 2.6 METRMR for the activities. Conclusions: The new 2RMs for use in children with the ActiGraph GT3X provide a closer estimate of mean measured METRMR than other currently available prediction equations. In addition, they improve the individual prediction errors across a wide range of activity intensities. (C)2012The American College of Sports Medicine