Effects of Vibration Resistance Training on Bone Mineral Density of Postmenopausal Females

Abstract

PURPOSE: To determine the effects of vibration resistance training on bone mineral density (BMD) of postmenopausal females, and to compare the results of different resistance trainings. METHOD: Forty eight postmenopausal females (66.1±0.9 yrs) were randomized into two groups. One group participated in a conventional resistance training (CRT), and another completed a vibration resistance training (VCT) on lower limbs 40 min one day, 3 days a week for 24 weeks. BMD at spine, femur neck and greater trochanter were determined before and after trainings. Data were compared and analyzed using 2-way repeated measures ANOVA. RESULTS: There was no obvious before-after change in BMD at spine (1.06±0.04 vs. 1.07±0.05 g/cm2; p > 0.05, ES=1.92, but a positive change at femur neck (0.82±0.05 vs.0.86±0.04 g/cm2; p<0.05, ES=26.50) and greater trochanter (0.73±0.03vs. 0.78±0.03 g/cm2; p<0.05, ES=17.52) of postmenopausal females in CRT group. BMD at spine (1.07±0.05 vs. 1.10±0.03 g/cm2, p<0.05, ES=7.91), femur neck (0.83±0.04 vs. 0.93±0.03g/cm2, p<0.05, ES=19.26) and greater trochanter (0.73±0.04 vs. 0.80±0.06 g/cm2, p<0.05, ES=4.88) were elevated significantly in VRT group after training. BMD at each part was increased greater in CRT group than those in VRT group. CONCLUSIONS: While CRT on lower limbs was more effective in improving BMD of the femur region in postmenopausal females, VRT showed a more significant improvement at both spine and femur regions. Therefore, VRT may be a more effective intervention for promoting core strength and balance ability, as a result for reducing fall frequency of postmenopausal females. The effectiveness of a combined CRT and VRT should be examined.