Leg-Raise Exercise Is Effective for Maintaining Bone Mineral Content and Density in the Lumbar Spine of Young Women

Background: Exercises performed at home and not requiring a change of clothes or special equipment are easy to start and can be continued long-term. To prevent COVID-19 infection, people worldwide have refrained from leaving their homes unnecessarily since the beginning of 2020. Fewer opportunities for outdoor exercise and less time spent in the sunlight can have serious negative effects on the bones. Objectives: Theaimof this studywasto clarify the effect of low-repetition leg-raise trainingonthe dual-energy X-ray absorptiometry measured bone mineral content (BMC) and density (BMD) of the lumbar spine. Methods: Eighteen healthy female university students performed leg-raise training at home, ten repetitions per day, three days per week, for six months. BMC and BMD (g/cm^2) of the right proximal femur and lumbar spine (L2–L4, anteroposterior view) were measured with dual-energy X-ray absorptiometry. Results: This low-repetition, low-frequency leg-raise training significantly increased lumbar spine BMC and BMD in these young women. However, there was no significant effect of exercise on the BMC or BMD at any proximal femur site. Conclusions: Home-based body weight leg-raise training may have effective mechanical stress to maintain or increase BMC and BMD of the lumbar spine.