SWIMMING AND BONE MINERAL DENSITY: A SPORT WITHOUT OSTEOGENIC STIMULATION?

Introduction: The osteogenic effects generated by different sports are the subject of a growing number of research projects. Regular physical activity is one of the main recommendations for the stimulation of bone mineral density (BMD). However, evidence has shown that not all physical activities promote similar effects. In this context, the osteogenic effects of swimming need to be clarified. Objective:To verify and compare total and regional BMD levels between male and female swimming athletes and university non-athletes. METHODS:The sample, composed of 60 participants of both sexes, was divided into two groups: 30 swimming athletes (GA): 15 men (22.2 +/- 3.92 years; 73.61 +/- 16.55 kg; 1.76 +/- 0.08 m) and 15 women (21.91 +/- 2.21 years; 53.15 +/- 8.36 kg; 1.64 +/- 0.06 m) and a control group (CG): 30 university non-athletes: 15 men (20.73 +/- 1.27 years; 74.4 +/- 5.54 kg, 1.74 +/- 0.04 m) and 15 women (19.93 +/- 2.05 years; 59.72 +/- 1.33 kg; 1.63 +/- 0.004 m). BMD (total, arms, legs, pelvis and spine) was measured using dual energy X-ray absorptiometry (DXA). The results were compared with one-way ANOVA using Scheffe's post hoc test, when necessary. Results: When compared with the women, the men of both groups presented superior results for all BMD values analyzed. In addition, GA had higher BMD of arms and spine when compared to the CG, both for males (p = 0.016 and p = 0.001, respectively) and females (p = 0.0001 and p = 0.011, respectively). Conclusions: The results of this study demonstrate that young male adults, athletes and non-athletes, present higher levels of BMD than their peers of the opposite sex. In addition, the results suggest that when undertaken for competitive purposes and with a weekly training volume of 12 hours or more, swimming may be beneficial for the bone development of young athletes when compared to non-athlete controls.