Comparison of two methods to assess PAEE during six activities in children

CORDER, K., S. BRAGE, C. MATTOCKS, A. NESS, C. RIDDOCH, N. J. WAREHAM, and U. EKELUND. Comparison of Two Methods to Assess PAEE during Six Activities in Children. Med. Sci. Sports Exerc., Vol. 39, No. 12, pp. 2180-2188, 2007. Purpose: The purpose of this study was to compare the accuracy of physical activity energy expenditure (PAEE)-prediction models using accelerometry alone (ACC) and accelerometry combined with heart rate monitoring (HR+ACC) to estimate PAEE during six common activities in children (lying, sitting, slow and brisk walking, hop-scotch, running). Three PAEE-prediction models derived using the current data, and five previously published prediction models were cross-validated to estimate PAEE in this sample. Methods: PAEE was assessed using ACC, HR+ACC, and indirect calorimetry during six activities in 145 children (12.4 +/- 0.2 yr). One ACC and two HR+ACC PAEE-prediction models were derived using linear regression on data from the current study. These three new models were cross-validated using a jackknife approach, and a modified Bland-Altman method was used to assess the validity of all eight models. Results: PAEE predictions using the one ACC and two HR+ACC models derived in the current study correlated strongly with measured values (RMSE = 97.3-118.0 J.min(-1).kg(-1)). All five previously published models agreed well overall (RMSE = 115.6-245.3 J.min(-1).kg(-1)), but systematic error was present for most of these, to a greater extent for ACC. Conclusions: ACC and HR+ACC can both be used to predict overall PAEE during these six activities in children; however, systematic error was present in all predictions. Although both ACC and HR+ACC provide accurate predictions of overall PAEE, according to the activities in this study, PAEE-prediction models using HR+ACC may be more accurate and widely applicable than those based on accelerometry alone.