PURPOSE: Bone mineral density (BMD) is used as an indirect indicator of risk of osteoporosis and bone fracture. Both swimming and running have been found to have a positive effect on bone mineral density. A comparison of the effects of swimming and running on bone mineral density in humans has not yet been performed. The purpose of this study was to compare the effects of running and swimming on bone mineral density in young individuals versus mature individuals and to compare intrinsic variables of body weight, height, gender, years swimming or running, distance ran or swam per week, and hours of physical activity per week.
METHODS: This was a quantitative, correlational study that sought to determine whether statistically significant differences in bone mineral density exist between swimmers and runners across the lifespan. Heel bone mineral density of each participant was assessed using the GE Achilles Ultrasonometer.
SUMMARY of RESULTS: This study included 54 total participants with 12 runners under age 30, 18 runners over age 30, 11 swimmers under age 30, and 13 swimmers over age 30. No statistically significant difference in bone mineral density existed between swimmers and runners in the young adult or mature adult groups (P = 0.618). Athlete weight was the only factor that had statistically significant differences in bone mineral density. The results do not indicate that the mode of activity (swimming/running) correlates with significantly different findings in BMD.
CONCLUSION: No correlation between mode of activity and bone mineral density can be established at this time. The degree of causality cannot be determined due to the study’s correlational nature. The results demonstrate that swimming and running have similar effects on bone density. Athlete weight had statistically significant differences in bone mineral density. This indicates that the overall body weight plays a larger role in the formation/maintenance of bone mineral density than activity selection did in this study.