Comparing the Effects of Swimming Among Male and Female Elite Athletes on Bone Mineral Density Acquisition

Background: Despite the many therapeutic benefits of swimming, there is still conflicting evidence about its benefits for bone health and osteoporosis prevention, especially in elite swimmers according to their sex. It is known that sex differences can affect the acquisition of minerals by the bone. Objectives: The aims of this study were to compare the bone mineral density (BMD) of swimmers with that of non-athletes (NA) and compare the corresponding values in male (MS) and female swimmers (FS). Methods: This cross-sectional study was performed on young athletes (18 - 24 years old) of the Iranian national swimming team, who were training for at least 11 hours per week and NA. To this end, 56 swimmers (14 males, 14 females) and NA (14 males, 14 females) were enrolled in 4 groups. The DEXA device was used to assess BMD (g/cm2) and T-scores of the proximal femur and lumbar spine. Results: All the swimmers had significantly higher BMD of the femur neck, trochanter, Ward’s triangle, and lumbar spine than NA (males/females) (P < 0.05). Also, the BMD of FS (except in trochanter and Ward’s triangle) was significantly higher than MS (P < 0.05). Finally, T-scores of FS in lumbar spine and femur neck areas were significantly higher than MS and NA (P < 0.05). Conclusions: Unexpectedly, BMD relatively improved by performing competitive swimming. Meanwhile, FS, especially in the femur neck, seemed more adaptable to swimming-related loads and BMD acquisition in comparison to MS. Further studies are needed to determine the definitive response to bone acquisition by sex, given the limitations of the present study.