E-Poster Presentation 30th Australian and New Zealand Bone and Mineral Society Annual Scientific Meeting 2020

The effect of exercise intensity on postmenopausal BMD: a meta-analysis (#104)

Melanie Kistler-Fischbacher 1 2 , Benjamin K Weeks 1 2 , Belinda R Beck 1 2 3
  1. Menzies Health Institute Queensland , Griffith University, Gold Coast, Queensland, Australia
  2. School of Allied Health Sciences, Griffith University, Gold Coast, Queensland, Australia
  3. The Bone Clinic, Brisbane, Queensland, Australia

Background: Exercise trials often report unremarkable effects on bone. While a strong positive relationship exists between load magnitude and bone response in animal research, human trials rarely test high intensity exercise. Meta-analysing according to exercise intensity was required to fully elucidate exercise effects.

Objectives: To determine the effects of intensity on exercise effect on aBMD in postmenopausal women.

Methods: Electronic databases and reference lists were searched for RCTs reporting the effect of exercise on DXA-derived lumbar spine, femoral neck or total hip aBMD in healthy postmenopausal women. Interventions were classified and pooled as low, moderate or high intensity. Mean differences (MD) were calculated using random effects models and risk of bias analyses were undertaken.

Results: Fifty-three trials, testing 63 interventions (19 low, 40 moderate, 4 high intensity) were included. At the lumbar spine, high intensity exercise yielded greater BMD effects (MD = 0.031 g/cm2 95% CI [0.012, 0.049], p=0.002) than moderate (MD = 0.012 g/cm2 95% CI [0.008, 0.017], p<0.001) and low intensity (MD = 0.010 g/cm2 95% CI [0.005, 0.015], p<0.001). Low and moderate intensity exercise was equally effective at the femoral neck (low: 0.011 g/cm2 95% CI [0.006, 0.016], p<0.001, moderate: 0.011 g/cm2 95% CI [0.007, 0.015], p<0.001), but no effect of high intensity exercise was observed. Moderate intensity exercise increased total hip aBMD (0.008 g/cm2 95% CI [0.004, 0.012], p<0.001), but low intensity did not. There were insufficient data to meta-analyse high intensity exercise effects at the total hip.

Conclusion: High intensity exercise is a more effective stimulus for lumbar spine aBMD than low or moderate intensity. While data from high intensity interventions are limited, this meta-analysis demonstrates the same positive relationship between load magnitude and bone response in humans as observed from animal research. Findings have implications for optimal exercise prescription for osteoporosis in postmenopausal women.