We investigated the effects of different weight-bearing and non weight-bearing physical activities on bone mineral density (BMD) and appendicular muscle mass (AMM) in male competitors. Sixty-five male (aged 18-25 yrs) volunteered. The sample included flatwater kayakers (Kflat; ? = 18), slalom kayakers (?slalom; ? = 14), and runners (R; ? = 18) who competed at national and international level. Fifteen age-matched non athletic individuals served as controls (C). All competitors exercised regularly at least 8 yrs for an average of 10 mo per year, 6 d·wk-1 for a minimum of 3 h·d-1. Segmental, total BMD and AMM were assessed with a dual-energy x-ray absorptiometry (DEXA). DEXA analysis also includes bone mineral content (BMC) and fat and lean masses. Total BMD was significantly higher (p < 0.01) in flatwater kayakers (mean ± SD: 1.30 ± 0.18 g·cm-2), slalom kayakers (1.34 ± 0.18 g·cm-2) and runners (1.49 ± 0.19 g·cm-2) than the C group (1.08 ± 0.16 g·cm-2) while runners revealed the highest. Runners had significantly higher regional BMD of the legs (1.62 ± 0.12 g·cm-2) compared with the three groups (p < 0.05). AMM was significantly higher (p < 0.01) in all three athletic groups (Kflat: 33.9 ± 3.8 kg; ?slalom: 30.2 ± 3.6 kg; R: 31.1 ± 2.9 kg) compared with C (26.1 ± 3.8kg). Body fat percentage (% weight) was significantly lower (p < 0.05) in all competitors (?slalom: 13.7 ± 6.0; Kflat: 10.1 ± 3.9 and R: 9.6 ± 3.4) than the C group (17.5 ± 7.1). Individuals engaged in competitive weight-bearing activities (runners) and also non weight-bearing activities (flatwater and slalom kayakers), have significantly higher total BMD and AMM than controls. These results suggest that competing at a high level either in weight or non weight-bearing activities may be an important factor in achieving a high peak bone mass and reducing osteoporosis risk in elite male competitors.
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