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Cross-Sectional Associations of Objectively-Measured Physical Activity and Sedentary Time with Body Composition and Cardiorespiratory Fitness in Mid-Childhood: The PANIC Study.

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Collings, Paul J 
Väistö, Juuso 
Atkin, Andrew J 


BACKGROUND: The minimum intensity of physical activity (PA) that is associated with favourable body composition and cardiorespiratory fitness (CRF) remains unknown. OBJECTIVE: To investigate cross-sectional associations of PA and sedentary time (ST) with body composition and CRF in mid-childhood. METHODS: PA, ST, body composition and CRF were measured in a population-based sample of 410 children (aged 7.6 ± 0.4 years). Combined heart-rate and movement sensing provided estimates of PA energy expenditure (PAEE, kJ/kg/day) and time (min/day) at multiple fine-grained metabolic equivalent (MET) levels, which were also collapsed to ST and light PA (LPA), moderate PA (MPA) and vigorous PA (VPA). Fat mass index (FMI, kg/m2), trunk fat mass index (TFMI, kg/m2) and fat-free mass index (FFMI, kg/m2.5) were derived from dual-energy X-ray absorptiometry. Maximal workload from a cycle ergometer test provided a measure of CRF (W/kg FFM). Linear regression and isotemporal substitution models were used to investigate associations. RESULTS: The cumulative time above 2 METs (221 J/min/kg) was inversely associated with FMI and TFMI in both sexes (p < 0.001) whereas time spent above 3 METs was positively associated with CRF (p ≤ 0.002); CRF increased and adiposity decreased dose-dependently with increasing MET levels. ST was positively associated with FMI and TFMI (p < 0.001) but there were inverse associations between all PA categories (including LPA) and adiposity (p ≤ 0.002); the magnitude of these associations depended on the activity being displaced in isotemporal substitution models but were consistently stronger for VPA. PAEE, MPA and to a greater extent VPA, were all positively related to CRF (p ≤ 0.001). CONCLUSIONS: PA exceeding 2 METs is associated with lower adiposity in mid-childhood, whereas PA of 3 METs is required to benefit CRF. VPA was most beneficial for fitness and fatness, from a time-for-time perspective, but displacing any lower-for-higher intensity may be an important first-order public health strategy. Clinical trial registry number (website): NCT01803776 ( ).



Body Composition, Body Mass Index, Cardiorespiratory Fitness, Child, Cross-Sectional Studies, Exercise, Female, Humans, Male, Motor Activity, Physical Fitness, Sedentary Behavior

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Sports Med

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Springer Science and Business Media LLC
Medical Research Council (MC_UU_12015/3)
Wellcome Trust (074296/Z/04/Z)
British Heart Foundation (None)
Medical Research Council (MC_UU_12015/7)
Medical Research Council (MC_U106179473)
This work has been financially supported by Grants from the Ministry of Social Affairs and Health of Finland, the Ministry of Education and Culture of Finland, the University of Eastern Finland, the Finnish Innovation Fund Sitra, the Social Insurance Institution of Finland, the Finnish Cultural Foundation, the Juho Vainio Foundation, the Foundation for Paediatric Research, the Paulo Foundation, the Paavo Nurmi Foundation, the Diabetes Research Foundation, the city of Kuopio, Kuopio University Hospital (EVO Funding Number 5031343), the Research Committee of the Kuopio University Hospital Catchment Area for the State Research Funding, the UK Medical Research Council [Grant MC_UU_12015/3], the Wellcome Trust [Grant 074296/Z/04/Z], the British Heart Foundation [Intermediate Basic Science Research Fellowship Grant FS/12/58/29709 to KWi], and the UK Clinical Research Collaboration Public Health Research [Grant RES-590-28- 0002].