Dancing for bone health: a 3-year longitudinal study of bone mineral accrual across puberty in female non-elite dancers and controls
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Weight-bearing exercise during growth enhances peak bone mass. However, the window of opportunity for optimizing positive effects of exercise on peak bone mass remains to be fully defined. Ballet dancing provides a model of mechanical loading patterns required to site-specifically modulate bone.
We assessed the effects of ballet dancing on bone mineral accrual in female non-elite dancers and normally active controls for 3 years across puberty. We recruited 82 ballet dancers and 61 controls age 8–11 years at baseline. Participants were measured over 3 consecutive years; however, the overlap in ages allowed analysis of the groups across 8–14 years of age. We annually assessed bone mineral content (BMC) at the total body (TB), including upper and lower limb regions, and biannually assessed BMC at the proximal femur and lumbar spine (LS) using dual x-ray absorptiometry (DXA). We derived TB lean mass and fat mass from DXA TB scans. Anthropometry, exercise levels, and calcium intake were also measured biannually. Maturational age was determined by age at peak height velocity (PHV). A multilevel regression model was used to determine the independent effects of body size, body composition, maturation, exercise levels, and calcium intake at each measurement occasion.
When adjusted for growth and maturation, dancers had significantly greater BMC at the TB, lower limbs, femoral neck (FN), and LS than controls. Excepting the FN region, these differences became apparent at 1 year post-PHV, or the peripubertal years, and by 2 years post-PHV the differences represented a cumulative advantage in dancers of 0.6–1.3% (p<0.05) greater BMC than controls. At the FN, dancers had 4% (p<0.05) greater BMC than controls in prepuberty and maintained this advantage throughout the pubertal years.
Results from this novel population provide evidence for modest site-specific and maturity-specific effects of mechanical loading on bone.
KeywordsBone mineral accrual Exercise Girls Growth Longitudinal
This project was funded by grants from the National Health and Medical Research Council (project grant number 980662), the University of Melbourne, the H&L Hecht Trust, the Medical Advances Without Animals Trust, Australia and New Zealand Charitable Trusts, and the Estate of Daniel Scott. We are most grateful to the dance schools and primary schools for recruitment assistance, and we thank the girls who participated in the study and their parents. Our thanks also go to Sue Kantor, Bahtiyar Kaymacki, and Lee Bell for their assistance with data collection.
- 9.Ross W, Marfell-Jones M (1991) Kinanthropometry. In: MacDougall J, Wenger H, Green H (eds) Physiological testing of the high-performance athlete. Human Kinetic Books, Champaign Illinois pp 223–308Google Scholar
- 15.Young D, Hopper J, Nowson C, Green R, Sherwin A, Kaymakci B, Smid M, Guest C, Larkins R, Wark J (1995) Determinants of bone mass in 10-to 26-year-old females: A twin study. J Bone Miner Res 4:558–567Google Scholar
- 18.Schofield WN (1985) Predicting basal metabolic rate, new standards and review of previous work. Human Nutrition Clin Nutr 39C(Suppl 1):5–41Google Scholar
- 20.Baxter-Jones AD, Mirwald R (2004) Multilevel modeling. In: Hauspie R, Cameron N, Molinari L (eds) Methods in human growth research. Cambridge University Press, Cambridge, UK pp 306–330Google Scholar
- 21.Goldstein H, Rasbash J, Plewis I, Draper D, Browne W, Yang M, Woodhouse G, Healy MJR (1998) A user’s guide to MLwiN. Multilevel Models Project, Institute of Education, University of London, LondonGoogle Scholar
- 23.Courteix D, Jaffrè C, Obert P, Benhamou L (2001) Bone mass and somatic development in young female gymnasts: a longitudinal study. Pediatr Exerc Sci 13:422–434Google Scholar
- 26.McKay HA, Petit MA, Schutz RW, Prior JC, Barr SI, Khan KM (2000) Augmented trochanteric bone mineral density after modified physical education classes: a randomized school-based exercise intervention study in prepubescent and early pubescent children. J Pediatr 136:156–162CrossRefPubMedGoogle Scholar
- 31.Juul A, Dalgaard P, Blum WF, Bang P, Hall K, Michaelsen KF, Muller J, Skakkebaek NE (1995) Serum levels of insulin-like growth factor (IGF)-binding protein-3 (IGFBP-3) in healthy infants, children, and adolescents: the relation to IGF-I, IGF-II, IGFBP-1, IGFBP-2, age, sex, body mass index, and pubertal maturation. J Clin Endocrinol Metab 80:2534–2542CrossRefPubMedGoogle Scholar
- 36.Malina RM, Bouchard C, Bar-Or O (2004) Growth, maturation, and physical activity. Human Kinetics, Champaign IllGoogle Scholar
- 44.Goldstein H (1995) Multilevel statistical models. E. Arnold, LondonGoogle Scholar
- 48.Nevitt MC, Ross PD, Palermo L, Musliner T, Genant HK, Thompson DE (1999) Association of prevalent vertebral fractures, bone density, and alendronate treatment with incident vertebral fractures: effect of number and spinal location of fractures. The Fracture Intervention Trial Research Group. Bone 25:613–619CrossRefPubMedGoogle Scholar
- 49.Kontulainen S, Kannus P, Haapasalo H, Sievanen H, Pasanen M, Heinonen A, Oja P, Vuori I (2001) Good maintenance of exercise-induced bone gain with decreased training of female tennis and squash players: a prospective 5-year follow-up study of young and old starters and controls. J Bone Miner Res 16:195–201PubMedCrossRefGoogle Scholar