OBJECTIVES: To explore the activitystat hypothesis in primary school children by asking whether more physical activity (PA) in school time is compensated for by less PA at other times. STUDY DESIGN: Observational, repeated measures (four consecutive occasions over a 12-month period). SETTING: South-west England. PARTICIPANTS: A total of 206 children (115 boys, aged 8-10 years) from 3 primary schools (S1, S2 and S3), which recorded large differences in PA during school time. MEASUREMENTS: Total PA (TPA) and its moderate-and-vigorous component were recorded weekly by accelerometry, in school and out of school, and adjusted for local daily rainfall and daylight hours. Habitual PA was assessed by linear mixed-effects modelling on repeated measures. RESULTS: S1 children recorded 64% more in-school PA, but S2 and S3 children compensated with correspondingly more out-of-school PA, so that TPA between the three schools was no different: 35.6 (34.3-36.9), 37.3 (36.0-38.6) and 36.2 (34.9-37.5) Units, respectively (P=0.38). CONCLUSIONS: The PA of children seems to compensate in such a way that more activity at one time is met with less activity at another. The failure of PA programmes to reduce childhood obesity could be attributable to this compensation.
OBJECTIVES: To explore the activitystat hypothesis in primary school children by asking whether more physical activity (PA) in school time is compensated for by less PA at other times. STUDY DESIGN: Observational, repeated measures (four consecutive occasions over a 12-month period). SETTING: South-west England. PARTICIPANTS: A total of 206 children (115 boys, aged 8-10 years) from 3 primary schools (S1, S2 and S3), which recorded large differences in PA during school time. MEASUREMENTS: Total PA (TPA) and its moderate-and-vigorous component were recorded weekly by accelerometry, in school and out of school, and adjusted for local daily rainfall and daylight hours. Habitual PA was assessed by linear mixed-effects modelling on repeated measures. RESULTS: S1 children recorded 64% more in-school PA, but S2 and S3 children compensated with correspondingly more out-of-school PA, so that TPA between the three schools was no different: 35.6 (34.3-36.9), 37.3 (36.0-38.6) and 36.2 (34.9-37.5) Units, respectively (P=0.38). CONCLUSIONS: The PA of children seems to compensate in such a way that more activity at one time is met with less activity at another. The failure of PA programmes to reduce childhood obesity could be attributable to this compensation.
Authors: Allana G LeBlanc; Jean-Philippe Chaput; Allison McFarlane; Rachel C Colley; David Thivel; Stuart J H Biddle; Ralph Maddison; Scott T Leatherdale; Mark S Tremblay Journal: PLoS One Date: 2013-06-14 Impact factor: 3.240
Authors: Lee Smith; Shannon Sahlqvist; David Ogilvie; Andy Jones; Kirsten Corder; Simon J Griffin; Esther van Sluijs Journal: Int J Behav Nutr Phys Act Date: 2012-11-21 Impact factor: 6.457