The effects of different exercise modes on the bone density in children

Introduction

This study investigated whether there were differences in quantitative ultrasound (QUS) assessment of the calcaneus between weight-bearing exercise, non-weight-bearing exercise and non-exercise children. During exercise, weight bearing plays an important role in improving the property of bone material. The effects of non-weight bearing exercise on bone, such as swimming, are still a controversial issue. In the present study, we designed three typical exercise modes, roller-skating, swimming and non-exercise to investigate their effects on the bone density of growing bone.

Methods

The subjects consist of 84 girls aged 10 to 11 years old, they were divided in three groups: roller skating group (n=32), swimming group (n=24) and non-exercise group. The girls in roller skating group have practiced roller skating for two years, they trained more than three times in one week. The girls in swimming group also took part in the swimming training three times in one week for two years running. Non-exercise group included 30 girls who took part in physical activities less in past two years. QUS assessment was performed using a QUS-2 scanner (Quidel Corp.) at the calcaneus. ANOVA was used to detect differences in BMD between groups.

Results

It was found that roller skating group has significant high BUA values than the swimming group and non-exercise group (p<0.01), there were no significant difference between swimming and non-exercise groups (p<0.1). Non-exercise group showed a significant low bone density.

Discussion/Conclusion

Mechanical loading of bone is crucial for the maintenance of normal bone architecture and may be transmitted to osteoblasts. Non-exercise and swimming exercise groups might provide less mechanical loading as roller skating exercise so that it usually shows a less effects on improvement of BMD or BMC. Exercise during growth is associated with increased peak bone mineral density. During the pre-pubertal period, physical activity positively influences bone size, geometry, mass and ultimately bone strength. The best exercise for bones is weight-bearing exercise such as walking, dancing, jogging, stair-climbing, racquet sports and roller-skating.

References

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