title: Role of physical activity in bone health in peripubertal boys.
abstract: BACKGROUND
  The aim of the present cross-sectional study was to investigate the relationship of physical activity level to bone mineral parameters in 11-13-year-old boys.
  
  
  METHODS
  In total, 264 boys, divided into normal weight (n = 154) and overweight (n = 110), participated in this study. Physical activity was measured via 7 day accelerometry and bone mineral parameters using dual-energy X-ray absorptiometry.
  
  
  RESULTS
  In overweight boys, vigorous physical activity was associated with total bone mineral density (BMD), total bone mineral content (BMC), while moderate-vigorous physical activity MVPA was associated with femoral neck BMD. In normal weight boys, however, only vigorous physical activity was associated with femoral neck BMD. When the normal weight group was divided into tertiles according to MVPA, femoral neck BMD was higher in the highest tertile compared to the lowest tertile. No other significant differences were found in bone mineral parameters according to the tertiles of MVPA.
  
  
  CONCLUSIONS
  In overweight peripubertal boys, physical activity is more associated with bone mineral parameters compared to normal weight subjects. In addition to vigorous physical activity, moderate physical activity has a significant impact on bone mineral parameters in overweight subjects.
authors.affiliation: Faculty of Exercise and Sport Sciences, Centre of Behavioural, Social and Health Sciences, University of Tartu, Tartu, Estonia.
authors.forename: Arturs
authors.initials: A
authors.lastname: Ivuškāns
authors.forename: Toivo
authors.initials: T
authors.lastname: Jürimäe
authors.forename: Evelin
authors.initials: E
authors.lastname: Lätt
authors.forename: Jaak
authors.initials: J
authors.lastname: Jürimäe
authors.forename: Priit
authors.initials: P
authors.lastname: Purge
authors.forename: Meeli
authors.initials: M
authors.lastname: Saar
authors.forename: Katre
authors.initials: K
authors.lastname: Maasalu
authors.forename: Jarek
authors.initials: J
authors.lastname: Mäestu
mesh_terms: D000293:Adolescent; D015519:Bone Density; D001842:Bone and Bones; D002648:Child; D003430:Cross-Sectional Studies; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D050177:Overweight / Q000503:physiopathology; D011627:Puberty
keywords: accelerometry; bone mineral density; boy; dual-energy X-ray absorptiometry; physical activity