title: Evidence for increased bone formation following a brief endurance-type training intervention in adolescent males.
abstract: The effect of exercise training, particularly relatively brief periods, on bone turnover markers in adolescents has been poorly studied. Thirty-eight healthy males (16+/-0.7 years) participated in a 5-week summer school program in which 20 subjects were randomly assigned to a training group consisting of 2 h/day, 5 days/week of endurance exercise, and 18 subjects were assigned to a control group. Bone formation was assessed by measurements of circulating osteocalcin, bone-specific alkaline phosphatase (BSAP), and the C-terminal procollagen peptide (PICP). Bone resorption was assessed by urinary levels of free deoxypyridinoline cross-links (dPYR) and the C-(CTX) and N-terminal (NTX) telopeptide cross-links. Prior to training, there was a weak positive correlation between fitness and PICP (r = 0.27, p < 0.05), but no correlations were observed between fitness and either the other markers of bone formation or bone resorption. Training led to a significant increase in (1) osteocalcin (15+/-4%, p < 0.03), (2) BSAP (21+/-6%, p < 0.02), and (3) PICP (30+/-11%, p < 0.03) and to a significant decrease in NTX (-21 +/- 3%, p < 0.05). These bone turnover markers did not change in the control subjects (osteocalcin, 0+/-4%; BSAP, 2+/-4%; PICP, -4 +/- 6%; NTX, -6 +/- 4%). There was no change in urinary dPYR and CTX in either control or trained subjects. Fitness is only weakly, if at all, correlated with bone formation, but a relatively brief period of endurance training leads to a substantial increase in bone formation markers in adolescent males. School-based, short-term exercise training programs could play a role in enhancing bone formation in adolescents.
authors.affiliation: Department of Research, Connecticut Children's Medical Center, University of Connecticut, Hartford 06106, U.S.A.
authors.forename: A
authors.initials: A
authors.lastname: Eliakim
authors.forename: L G
authors.initials: LG
authors.lastname: Raisz
authors.forename: J A
authors.initials: JA
authors.lastname: Brasel
authors.forename: D M
authors.initials: DM
authors.lastname: Cooper
mesh_terms: D000293:Adolescent; D000469:Alkaline Phosphatase / Q000097:blood; D000596:Amino Acids / Q000652:urine; D015415:Biomarkers / Q000097:blood / Q000652:urine; D001846:Bone Development / Q000502:physiology*; D016723:Bone Remodeling / Q000502:physiology*; D001862:Bone Resorption / Q000097:blood / Q000503:physiopathology* / Q000652:urine; D003430:Cross-Sectional Studies; D006801:Humans; D008297:Male; D015675:Osteocalcin / Q000097:blood; D010446:Peptide Fragments / Q000097:blood / Q000652:urine; D010807:Physical Endurance; D011347:Procollagen / Q000097:blood / Q000652:urine; D011446:Prospective Studies
chemical_list: D000596:Amino Acids; D015415:Biomarkers; D010446:Peptide Fragments; D011347:Procollagen; C042813:procollagen type I carboxy terminal peptide; D015675:Osteocalcin; C036020:deoxypyridinoline; D000469:Alkaline Phosphatase