An 8-month high-intensity resistance and impact training program (HiRIT, Onero) led to greater gains in lumbar spine bone mineral density (BMD) and leg/back strength than a low-intensity Pilates-based program (Buff Bones).
These findings are from the Medication and Exercise for Osteoporosis (MEDEX-OP) trial, which included 115 postmenopausal women with low bone mass. Patients were randomly assigned to attend either the HiRIT or Pilates-based exercise program. The participants attended supervised 45-min sessions twice weekly.
HiRIT was better than the low-intensity Pilates-based exercise program for enhancing bone mass, muscle strength, functional performance, and stature, the researchers report. The low-intensity program did improve function, but to a lesser extent
Of the 115 participants, most (86) were not taking osteoporosis medicine. For the 29 women who were receiving it, the medication appeared to enhance the effect of exercise.
Melanie Fischbacher, PhD candidate, Griffith University, Gold Coast, Australia, presented these findings in an oral session at the American Society of Bone and Mineral Research (ASBMR 2021) Annual Meeting; the study was also published in the Journal of Bone and Mineral Research.
The study’s senior author, Belinda R. Beck, PhD, director, the Bone Clinic, Brisbane, Australia, developed the Onero HiRIT program and has licensed it to others in Australia.
“It is a very effective program and we have shown it can be undertaken safely, but it must be supervised because of the heavy weights and high-risk clientele,” Beck stressed to Medscape Medical News in an e-mail.
“This is not a program you should just hand to a patient and tell them to do in a gym,” she said.
“Both forms of exercise in our study were beneficial for functional outcomes but Onero improved back extensor strength, mobility and stature considerably more than Buff Bones,” Fischbacher told Medscape in an e-mail.
Nevertheless, “the contribution of functional capacity to risk of falling and fracture cannot be overstated, and bone medications do not address function,” she noted.
“More trials combining bone medication and bone-targeted exercise are needed,” the researchers conclude.
Compliance Stands Out, Study Supports High-Intensity Exercise
Kristen M. Beavers, PhD, MPH, RD, who was not involved with this research, told Medscape that participant compliance in the study really stands out.
“Compliance to an 8-month, 2 day/week high-intensity resistance training program among older women with low bone mass was quite good in this study (>80%), with very few adverse events reported,” said Beavers, of the Department of Health and Exercise Science, Wake Forest University, Winston Salem, North Carolina.
“A lot of individuals wouldn’t even consider recommending this type/intensity of exercise to this population, because they are worried it is too risky and/or the uptake will be low,” she said.
Although the benefit in BMD and strength wasn’t seen universally across all bone/muscle outcomes assessed, the findings do reinforce the idea that high-intensity exercise is more efficacious for bone health than low-intensity exercise, she noted.
“The possible additive effect of high-intensity exercise when combined with medication is worth confirming in larger, adequately designed/powered studies,” according to Beavers.
“The general consensus in the field is that higher-intensity exercise is more osteogenic than low-intensity exercise, but improving muscle mass, quality, and function (including balance) are also important to reduce the risk of falls, which is a major contributor to incident fracture,” she noted.
Exercise, even low-intensity exercise, reduces the risk for falls, as shown in a recent meta-analysis, she added. This is something antiresorptive medications don’t do, she said.
Building on the LIFTMOR and LIFTMOR-M Trials
Previously, the Australian group showed that HiRIT is efficacious and safe for bone formation in individuals with low to very low bone mass ― in postmenopausal women in the LIFTMOR study, and in men in the LIFTMOR-M study.
The current study compared two exercise programs.
The researchers randomly assigned 86 women who were not taking antiresorptive medication to the high-intensity (42) or low-intensity (44) exercise program.
They also assigned 29 women who were receiving antiresorptive medication to the high-intensity (15) or low-intensity (14) exercise program.
In the high-intensity exercise plus medication subgroup, the women were taking denosumab (12), risedronate (2) or alendronate (1). In the low-intensity exercise plus medication subgroup, the women were taking denosumab (9), risedronate (1), alendronate (3), or zoledronic acid (1).
The mean age of the women was 64 to 68 years. The mean lumbar spine T score was -1.5 to -2.3, and the mean femoral neck T score was -1.7 to -2.0 (determined by dual-energy x-ray absorptiometry) .
The HiRIT training program consisted of three free-weight resistance training exercises (deadlift, back squat, overhead press), one high-impact exercise (jump drop), and two balance exercises. The exercises varied each session.
The low-intensity training consisted of bone-specific Pilates-based exercises performed on the mat; standing weight-bearing exercise with 1-kg dumbbells; and impact exercises, such as heel drops and stomping.
At 8 months, compared to women in the low-intensity exercise program, those in the HiRIT program demonstrated greater improvement in lumbar spine BMD (1.9% vs 0.1%) and stature (0.2 cm vs 0.0 cm), muscle strength, and functional performance.
Functional performance improved with both exercise programs, but the HiRIT program led to greater leg and back muscle strength and better results in the five times sit-to-stand test (P < .05).
HiRIT plus bone medication improved BMD at the femoral neck and total hip, whereas HiRIT alone did not. Low-intensity exercise plus bone medication improved BMD at the lumbar spine and total hip, whereas low-intensity exercise alone did not.
The retention rate was 90%. The rate of exercise compliance was 83% in the high-intensity group and 82% in the low-intensity group.
Thirty falls were reported by 24 participants (21%). One fracture occurred in each exercise group. Three adverse events occurred in the low-intensity group, and four occurred in the high-intensity group.
Beck owns the Bone Clinic and sells licenses to the Onero program. The other researchers have disclosed no relevant financial relationshps.