title: Osteogenic effects of a physical activity intervention in South African black children.
abstract: OBJECTIVE
  To determine whether a weight-bearing physical activity intervention improves measures of bone density, size and strength in a pre- and early pubertal cohort of black South African children.
  
  
  METHODS
  Twenty two school children (9.7±1.1 years) were cluster randomised into an exercise (EX; n=12) and control (CON; n=10) group. EX children performed a weight-bearing exercise program for 20 weeks. CON children continued their regular activities. Whole body DXA and tibial peripheral QCT scans were obtained. Urine was analysed for concentrations of cross-linked N-telopeptides of Type I collagen (NTX).
  
  
  RESULTS
  Changes in 4% volumetric BMD, area and strength were greater in EX than CON. At the 38% site, change in bone area and density was greater in EX than CON. The greater change in periosteal circumference in the EX groups also resulted in a greater change in cortical thickness of the tibia compared to the CON group. NTX concentration was lower in the EX group than the CON group after the intervention.
  
  
  CONCLUSIONS
  This study documents for the first time the beneficial response of trabecular and cortical bone of black children to a weight bearing exercise intervention.
authors.affiliation: Exercise Laboratory, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: R M
authors.initials: RM
authors.lastname: Meiring
authors.forename: L K
authors.initials: LK
authors.lastname: Micklesfield
authors.forename: I
authors.initials: I
authors.lastname: Avidon
authors.forename: J A
authors.initials: JA
authors.lastname: McVeigh
mesh_terms: D015502:Absorptiometry, Photon; D044383:Black People; D015519:Bone Density; D001846:Bone Development / Q000502:physiology*; D002648:Child; D024042:Collagen Type I / Q000652:urine; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D055070:Resistance Training / Q000379:methods*; D013019:South Africa; D013977:Tibia / Q000033:anatomy & histology; D016896:Treatment Outcome
chemical_list: D024042:Collagen Type I