Comparison of bone mineral density between male masters runners and cyclists

Abstract

For maintenance of bone mass during adulthood, it is commonly recommended to participate in relatively high level weight-bearing exercise. Weight-bearing exercise includes aerobic activities such as jogging or activities that produce high ground reaction forces such as jumping. Cycling is a popular form of aerobic exercise for older adults due to the reduced impact on the weight-bearing joints. However, due to the unloaded nature of cycling, some data suggest that bone mineral density at clinically important sites is reduced in cyclists. PURPOSE: To compare areal bone mineral density (aBMD) of the lumbar spine and non-dominant proximal femur between male masters runners and male masters cyclists. METHODS: Eight male masters runners (mean ± SD, age: 58.9 ± 4.4 yrs, height: 175.3 ± 6.9 cm, weight: 75.1 ± 14.3 kg) and eight male masters cyclists (mean ± SD, age: 63.8 ± 5.9 yrs, height: 176.8 ± 5.8 cm, weight: 76.8 ± 8.3 kg) underwent a dual energy x-ray absorptiometry (DXA) scan for assessment of aBMD of the non-dominant proximal femur (total hip and femoral neck) and lumbar spine (L1-L4) as well as percent body fat (%BF), and bone free lean body mass (BFLM). Data were analyzed using Independent Samples t-tests with an alpha level of 0.05. RESULTS: There were no significant differences in age, height, or weight between groups. Compared to masters cyclists, masters runners did not show any significant differences in %BF (16.8 ± 3.6 vs. 16.0 ± 3.3%, p=0.679), BFLM(59.1 ± 9.1 vs. 61.2 ± 7.6, p=0.618), lumbar spine aBMD (1.041 ± 0.130 vs. 0.991 ± 0.062, p=0.346), total hip aBMD (0.989 ± 0.152 vs. 0.917 ± 0.079, p=0.257), or femoral neck aBMD (0.816 ± 0.111 vs. 0.730 ± 0.074, p=0.090). CONCLUSION: Our preliminary findings suggest that male masters cyclists and runners do not differ in aBMD. However, our current findings are likely influenced by the small sample size which will be addressed in the near future.