title: Increasing weight-bearing physical activity and calcium intake for bone mass growth in children and adolescents: a review of intervention trials.
abstract: OBJECTIVE
  The purpose of this review is to evaluate the current state-of-the-science for interventions to increase bone mass gains in children and adolescents using weight-bearing physical activity or calcium supplementation.
  
  
  METHODS
  Studies were located using computerized and manual searches of the empirical literature. Inclusion criteria were: (a) intervention study targeting weight-bearing physical activity or calcium intake; (b) inclusion of a control group; (c) subject age range under 18 years; and (d) outcome measured bone mineral density or bone mineral content.
  
  
  RESULTS
  Weight-bearing physical activity and calcium supplement intervention studies both consistently show positive effects on bone mass gains in children and adolescents. The most consistent findings for both weight-bearing physical activity and calcium were for lumbar spine and total body bone sites. Only weight-bearing physical activity interventions had significant effects on the femoral neck sites. Low power may have contributed to the lack of statistically significant findings in several studies and also prevented proper evaluation of potential interactions between pubertal status and interventions on bone mass gains.
  
  
  CONCLUSIONS
  Increases in weight-bearing physical activity or calcium intake have positive effects on bone mass gains in children and adolescents. Further research is needed to evaluate: (a) the long-term durability of these effects; (b) specific dose-response associations; (c) interactions between weight-bearing physical activity and calcium intake; and (d) interactions between pubertal development and weight-bearing physical activity or calcium intake on bone mass outcomes.
authors.affiliation: Division of Epidemiology, School of Public Health, University of Minnesota, 1300 South Second Street, Suite 300, Minneapolis, 55454-1015, USA. french@epi.umn.edu
authors.forename: S A
authors.initials: SA
authors.lastname: French
authors.forename: J A
authors.initials: JA
authors.lastname: Fulkerson
authors.forename: M
authors.initials: M
authors.lastname: Story
mesh_terms: D000293:Adolescent; D015519:Bone Density / Q000502:physiology*; D001846:Bone Development / Q000502:physiology*; D017610:Calcium Compounds / Q000008:administration & dosage*; D002648:Child; D002675:Child, Preschool; D002986:Clinical Trials as Topic; D019587:Dietary Supplements; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D012016:Reference Values; D012680:Sensitivity and Specificity; D016474:Weight-Bearing
chemical_list: D017610:Calcium Compounds