The effect of intense gymnastic training on bone mineral density was investigated in 16 elite prepubertal (9.82 ± 0.89 years) (mean ± SD) gymnasts (GYM) and 16 normoactive (9.87 ± 0.75 years) controls (CON). Pubertal status was determined according to the criteria of Tanner. Additionally the mother of each subject was recruited, and was included in all measurements as an estimate of hereditability. GYM were in elite pre-competitive or competitive programs for at least two years, and trained on average 18 hr per week. Areal bone mineral density (BMD) and body composition (%BF) was measured for the whole body, and BMD for the left hip and lumbar spine (L1-L4) by dual energy x-ray absorptiometry (DXA), and volumetric BMD for the distal
radius by peripheral QCT (pQCT). There were no significant differences between groups for age, pubertal status or body mass; however GYM were significantly shorter (129.3 ± 5.7 vs. 136.7 ± 4.4 cm; P<0.01) and leaner (15.12 + 1.95 vs. 19.58 + 4.29 %BF) than CON. In an attempt to account for inter-group height differences, areal DXA measurements were converted to apparent bone mineral density (BMAD). GYM had significantly (P<0.05) greater femoral neck (0.698 ± 0.058 vs. 0.648 + 0.064 g.cm⁻²) and trochanteric (0.616 ± 0.060 vs. 0.530 + 0.084 g.cm⁻²) BMD. Additionally GYM had significantly greater whole body (0.101 ± 0.009 vs 0.094 ± 0.007 g.cm⁻³) BMAD than CON. GYM also had significantly greater total 367.75 ± 51.61 vs 307.37 ± 27.59 mg.cm⁻³), trabecular (207.93 ± 45.35 vs 163.76 ± 31.41 mg.cm⁻³) and cortical (496.94
± 67.51 vs 429.80 ± 33.78 mg.cm⁻³) volumetric BMD than CON at the distal radius. There were no significant differences between mothers of GYM or CON for any of the variables studied. Significant daughter mother correlations existed only for lumbar spine BMD (r=0.55). These results suggest that participation in elite gymnastics prior to puberty elicits favourable whole body adaptations in bone mineral density, and also that striking regional differences are observed at the wrist, a site subjected to repetitive high impact loading during training. / Thesis / Master of Science (MSc)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/22720 |
| Date | 11 1900 |
| Creators | Dyson, Kerry |
| Contributors | Blimkie, C. J., Human Biodynamics |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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