To validate the activPAL3 algorithm for predicting metabolic equivalents (TAMETs) and classifying MVPA in 5- to 12-year-old children.


Fifty-seven children (9.2 ± 2.3y, 49.1% boys) completed 14 activities including sedentary behaviors (SB), light (LPA) and moderate-to-vigorous physical activities (MVPA). Indirect calorimetry (IC) was used as the criterion measure. Analyses included equivalence testing, Bland-Altman procedures and area under the receiver operating curve (ROC-AUC).


At the group level, TAMETs were significantly equivalent to IC for handheld e-game, writing/coloring, and standing class activity (P < .05). Overall, TAMETs were overestimated for SB (7.9 ± 6.7%) and LPA (1.9 ± 20.2%) and underestimated for MVPA (27.7 ± 26.6%); however, classification accuracy of MVPA was good (ROC-AUC = 0.86). Limits of agreement were wide for all activities, indicating large individual error (SB: −27.6% to 44.7%; LPA: −47.1% to 51.0%; MVPA: −88.8% to 33.9%).


TAMETs were accurate for some SB and standing, but were overestimated for overall SB and LPA, and underestimated for MVPA. Accuracy for classifying MVPA was, however, acceptable.

van Loo (, Okely, Jones, and Cliff are with the Early Start Research Institute and the Illawarra Health and Medical Research Institute, Faculty of Social Sciences; Batterham is with the Statistical Consulting Centre; Peoples is with the School of Medicine, Faculty of Science Medicine and Health; University of Wollongong, Australia. Hinkley is with the Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Australia. Ekelund is with the Dept of Sports Medicine, Norwegian School of Sport Sciences and with the Medical Research Council, Institute of Metabolic Science, Cambridge, United Kingdom. Brage is with the Medical Research Council, Institute of Metabolic Science, Cambridge, United Kingdom. Reilly and Janssen are with the University of Strathclyde, School of Psychological Science and Health, Glasgow, Scotland, UK