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Effects of repetitive loading on the growth‐induced changes in bone mass and cortical bone geometry: A 12‐month study in pre/peri‐ and postmenarcheal tennis players
Author(s) -
Ducher Gaele,
Bass Shona L,
Saxon Leanne,
Daly Robin M
Publication year - 2011
Publication title -
journal of bone and mineral research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.882
H-Index - 241
eISSN - 1523-4681
pISSN - 0884-0431
DOI - 10.1002/jbmr.323
Subject(s) - peri , medicine , medullary cavity , bone mass , cortical bone , skeleton (computer programming) , menarche , bone mineral content , endocrinology , urology , bone density , anatomy , osteoporosis
Pre‐ and early puberty may be the most opportune time to strengthen the female skeleton, but there are few longitudinal data to support this claim. Competitive female premenarcheal (pre/peri, n = 13) and postmenarcheal (post, n = 32) tennis players aged 10 to 17 years were followed over 12 months. The osteogenic response to loading was studied by comparing the playing and nonplaying humeri for dual‐energy X‐ray absorptiometry (DXA) bone mineral content (BMC) and magnetic resonance imaging (MRI) total bone area (ToA), medullary area (MedA), cortical area (CoA), and muscle area (MCSA) at the humerus. Over 12 months, growth‐induced gains (nonplaying arm) in BMC, ToA, and CoA were greater in pre/peri (10% to 19%, p < .001) than in post (3% to 5%, p < .05 to .001) players. At baseline, BMC, ToA, CoA, and MCSA were 8% to 18% greater in the playing versus nonplaying arms in pre/peri and post players (all p < .001); MedA was smaller in the playing versus nonplaying arms in post only players ( p < .05). When comparing the annual gains in the playing arm relative to changes in the nonplaying arm, the increases in ToA and CoA were greater in pre/peri than post players (all p < .05). The smaller the side‐to‐side differences in BMC and CoA at baseline, the larger the exercise benefits at 12 months ( r = −0.39 to −0.48, p < .01). The exercise‐induced change in MCSA was predictive of the exercise benefits in BMC in pre/peri players only ( p < .05). In conclusion, both pre/peri‐ and postmenarcheal tennis players showed significant exercise‐induced skeletal benefits within a year, with greater benefits in cortical bone geometry in pre/perimenarcheal girls. © 2011 American Society for Bone and Mineral Research.