title: Daily physical activity related to aerobic fitness and body fat in an urban sample of children.
abstract: This study evaluates associations between objectively measured daily physical activity vs aerobic fitness and body fat in children aged 8-11 years. A cross-sectional study of 225 children aged 7.9-11.1 years was performed. Abdominal fat mass (AFM) and total body fat (TBF) were quantified by dual-energy x-ray absorptiometry. TBF was calculated as percentage of total body mass (BF%). Body fat distribution was calculated as AFM/TBF. Aerobic fitness was measured by indirect calorimetry during a maximal cycle ergometer exercise test. Daily physical activity was assessed by accelerometers for 4 days and daily accumulation of moderate-to-vigorous and vigorous activity was calculated. Significant relationships (P<0.05) existed for vigorous activity vs ln BF% (r=-0.40), ln AFM (r=-0.35), TBF/AFM (r=-0.22) and aerobic fitness (r=0.38), whereas moderate-to-vigorous activity displayed weaker relationships (-0.22, -0.18, -0.12 NS, and 0.25). Multiple regression analyses with inclusion of possible confounders concluded that vigorous activity was independently related to aerobic fitness and ln BF% or ln AFM. Moderate-to-vigorous activity was only independently related to aerobic fitness. In this population, low daily accumulation of vigorous activity was, already in children aged 8-11 years, associated with more body fat and lower aerobic fitness. A similar relation was not found for daily accumulation of moderate-to-vigorous activity.
authors.affiliation: Department of Clinical Sciences, Clinical Physiology and Nuclear Medicine Unit, Malmö University Hospital, Lund University, Malmö, Sweden. magnus.dencker@skane.se
authors.forename: M
authors.initials: M
authors.lastname: Dencker
authors.forename: O
authors.initials: O
authors.lastname: Thorsson
authors.forename: M K
authors.initials: MK
authors.lastname: Karlsson
authors.forename: C
authors.initials: C
authors.lastname: Lindén
authors.forename: P
authors.initials: P
authors.lastname: Wollmer
authors.forename: L B
authors.initials: LB
authors.lastname: Andersen
mesh_terms: D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000502:physiology*; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods; D009043:Motor Activity; D010809:Physical Fitness / Q000502:physiology*; D012044:Regression Analysis; D013548:Sweden; D014505:Urban Population