title: [Association of physical activity with bone mass in premenarche Chinese girls].
abstract: OBJECTIVE
  To assess the association of physical activity with bone mass in premenarche girls.
  
  
  METHODS
  Bone mineral density (BMD) and bone mineral content (BMC) at the whole body, femoral neck, Ward triangle and L1-L4 spine were measured using dual-energy X-ray absorptiometry (DXA) in 194 premenarche girls (10 +/- 1, year). Physical activity and dietary calcium intakes were assessed by using frequency questionnaire and diary.
  
  
  RESULTS
  It was found that BMD and BMC were significantly and positively associated with weight-bearing physical activities (WBPA) (P < 0.01), total physical activities (TPA) (P < 0.01) rather than non-weight-bearing physical activity (P > 0.05) at all the studied bone sites (P < 0.01). Both BMC and BMD were tending to a better increase of WBPA. When WBPA increases from 227 to 415 (kcal/d), mean BMC and BMD were increased in 17.5%-29.0% and 8.8%-17.1%, respectively.
  
  
  CONCLUSIONS
  It should be helpful for premenarche girls to improve bone mass by increasing physical activities, especially weight-bearing physical activities.
authors.affiliation: Faculty of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Wang
authors.forename: Yu-ming
authors.initials: YM
authors.lastname: Chen
authors.forename: Xin-cai
authors.initials: XC
authors.lastname: Xiao
authors.forename: Yi-xiang
authors.initials: YX
authors.lastname: Su
mesh_terms: D015502:Absorptiometry, Photon; D015519:Bone Density; D002648:Child; D002681:China; D005260:Female; D005272:Femur Neck / Q000000981:diagnostic imaging; D006801:Humans; D009043:Motor Activity; D011627:Puberty