Effect of office-based brief high-impact exercise on bone mineral density in healthy premenopausal women: the Sendai Bone Health Concept Study

Abstract

Although there is ample evidence supporting the effectiveness of physical activity in the prevention and treatment of osteoporosis, there are no previous studies to examine the effect of office-based brief high-impact exercise (HIE) on bone mineral density (BMD) in healthy premenopausal women. This study evaluated the effects of office-based HIE on BMD in healthy premenopausal Japanese women. Ninety-one healthy premenopausal women were randomized to receive stretching exercise (SE) or HIE (stretching, along with up to 5 × 10 vertical and versatile jumps) for 12 months. The BMD of the lumbar spine and proximal femur was measured using dual-energy X-ray absorptiometry. Several cardiovascular risk factors and leg strength also were assessed. An accelerometer-based recorder was used to measure daily impact loading in four 1-week samples. The progression of the HIE program was ensured by the accelerometer. Thirty-three women (71.7%) in the SE group and 34 (75.6%) in the HIE group completed the study. There was a significant difference in the change in the femoral neck BMD between the groups in favor of the HIE group [0.6% (95% CI: -0.4, 1.7) vs. -1.0% (95% CI: -2.2, 0.2)]. Adiponectin, LDL, HDL, and the leg strength of participants in both the groups improved during the intervention. These finding suggested that office-based brief HIE can be recommended for premenopausal women for preventing bone mineral loss.

A meta-analysis of brief high-impact exercises for enhancing bone health in premenopausal women

“…The exercise intervention in three studies [18,19,24] comprised of brief bouts of highimpact jumping exercises 6 days in a week. Similar interventions were carried out by two other studies [21,26] on alternate days (three sessions per week). Bailey and Brooke-Wavell [20] had three intervention groups who completed the same hopping exercise on 2, 4 or 7 days per week.…”

“…Premenopausal status was based on self-completed lifestyle and menstrual history questions. The sample size varied from 42 [21] to 91 participants [26]. Only three studies [20,24,26] reported a power calculation and estimated achievement of at least 80% power to detect between 2% and 3% differences in BMD of premenopausal women in response to the brief high-impact exercise intervention at the 0.05 alpha level.…”

“…The sample size varied from 42 [21] to 91 participants [26]. Only three studies [20,24,26] reported a power calculation and estimated achievement of at least 80% power to detect between 2% and 3% differences in BMD of premenopausal women in response to the brief high-impact exercise intervention at the 0.05 alpha level. While there were generally mild variances in the number of participants allocated to each group (intervention versus control) across the studies at baseline, in one trial [19], there were five more subjects in the intervention group due to a higher anticipated dropout rate in the exercise group.…”

“…In two of the studies [20,21], the control group participants were requested to maintain their usual diet and lifestyle, while Bassey et al [19] gave no information on any form of intervention to control participants. The participants in the control groups of the other three studies [18,24,26] performed mild stretching (sham) exercises which followed a similar regime with their respective experimental group in terms of duration, frequency and time commitment. The exercise intervention in three studies [18,19,24] comprised of brief bouts of highimpact jumping exercises 6 days in a week.…”

“…Strong [24] also had 2 intervention groups, 1 of whom performed 10 high-impact jumps and the other who performed 20 jumps. The number of high-impact jumps completed as part of the intervention varied across the studies, but they were commonly completed in five sets of ten high-impact jumps or hops, which were interspersed with rest intervals [18][19][20]26]. Kato et al [21] employed only one set of ten vertical jumps each interspersed with 8-12 s of rest, while Strong [24] employed either one or two sets of ten high-impact jumps.…”