Optimal osteogenic mechanical loading requires the application of high-magnitude strains at high rates. High intensity resistance training (HiPRT) applies high strain, but is not traditionally recommended for individuals with osteoporosis owing to a perceived high risk of fracture. The purpose of the LIFTMOR trial was to determine the safety and efficacy of HiPRT to reduce parameters of fracture risk in postmenopausal women with low bone mass.
Postmenopausal women with low bone mass (T-score <-1.0, screened for conditions and medications that influence bone and physical function) were recruited and randomized to either 8 months of twice-weekly, 30-minute, supervised HiPRT (5 repetitions of >85% 1 repetition maximum) or a home-based, low intensity exercise program (CON). Pre and post intervention testing included whole body, lumbar spine and proximal femur BMD, muscle and fat mass (Medix DR, Medilink, France), and indices of functional performance (timed up-and-go, functional reach, 5 times sit-to-stand, back and leg strength). Compliance and adverse events were monitored. Intervention effects were tested using repeated measures ANCOVA (intention-to-treat), controlling age and initial values.
Eighty-four women (65±5 years, 161.6±6.0cm, 62.7±10.6kg) participated. HiPRT (n=41) improved lumbar spine BMD (+2.7±3.2% vs -1.2±2.5%, p<0.001), femoral neck BMD (+0.15±2.7% vs -1.9±3.1%, p=0.001), height (+0.2±0.6cm vs -0.2±0.5cm, p=0.002), and all functional measures (p<0.01), compared to CON (n=43). No between-group effect was observed for weight, lean or fat mass, however, within-group benefits were observed for fat (HiPRT, -1.4±1.8kg, p<0.001; CON, -1.5±1.9kg, p<0.001) and lean mass (HiPRT, +1.2±2.0kg, p<0.001; CON, +0.8±1.5kg, p=0.01). Compliance was high (HiPRT, 90±11%; CON 84±26%). There was only one adverse event (HiPRT: minor low back spasm, 2 training sessions missed).
Our novel, brief HiPRT programme enhances bone, muscle, and functional performance in postmenopausal women with low bone mass. Contrary to common opinion, HiPRT is a safe and efficacious therapy for this demographic.