Evidence for Increased Bone Formation Following a Brief Endurance-Type Training Intervention in Adolescent Males

Authors

  • Alon Eliakim,

    Corresponding author
    1. Department of Research, Connecticut Children's Medical Center, University of Connecticut, Hartford, Connecticut, U.S.A.
    • Division of Research, Connecticut Children's Medical Center, 282 Washington Street, Hartford, CT 06106 U.S.A.
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  • Lawrence G. Raisz,

    1. Division of Endocrinology, University of Connecticut Health Center, Farmington, Connecticut, U.S.A.
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  • Jo Anne Brasel,

    1. Division of Pediatric Endocrinology, Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, California, U.S.A.
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  • Dan M. Cooper

    1. Department of Research, Connecticut Children's Medical Center, University of Connecticut, Hartford, Connecticut, U.S.A.
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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.

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