Why Your Bones Need Attention Right Now
If you're in your mid-40s to mid-50s and experiencing irregular periods, mood changes, or other signs of perimenopause, your bones are changing too. And not in ways you can feel.
Women lose up to 10% of their bone mass during menopause and the decade following. Half of all women over 50 will sustain a fragility fracture—a break that occurs from low-impact trauma like a fall from standing height or less.
The time to act is during the menopausal transition, not after osteoporosis has already developed. Yet most clinical trials testing interventions for bone health have excluded women within 5 years of menopause.
That's about to change.
The STOP-EM Study: Testing Prevention During the Window That Matters
Researchers at the University of Calgary are conducting a 9-month feasibility trial called STOP-EM (Strength Training for Osteoporosis Prevention during Early Menopause). The study will test whether high-intensity resistance and impact training (HiRIT) is feasible—meaning women can and will stick with it—during the menopausal transition.
The study will enroll 40 women aged 45-60 who are either perimenopausal (irregular cycles, variable cycle length) or within 5 years of their final menstrual period. Participants will be randomized to either a 9-month supervised exercise intervention or a waitlist control group.
What HiRIT Actually Involves
HiRIT isn't your typical "light weights, high reps" approach that's often recommended to women. It's heavy, progressive resistance training combined with impact exercises.
The intervention consists of five phases:
Foundation phase (1 month): Postural and joint integrity exercises, movement patterning to establish proper form and reduce injury risk.
Building phase (2 months): Introduction of loaded movements using dumbbells, kettlebells, and barbells. Intensity increases by 5% per week for 6 weeks, followed by a deload week and maximal testing week.
Three strength phases (6 months total): The core of the program. Each 8-week cycle includes two sessions per week with exercises performed at 80-85% of one-repetition maximum or an 8-9 rating on the rated perceived exertion scale.
Typical exercises include:
Deadlifts or rack pulls
Barbell or dumbbell chest press
Back squats to box
Dumbbell rows
Barbell or dumbbell shoulder press
Assisted pull-ups
Each session finishes with drop landings from a box (progressive height), balance exercises, and core work.
Why This Differs from Previous HiRIT Studies
Previous HiRIT trials in late postmenopausal women (well past menopause) showed safety, feasibility, and efficacy for improving bone mass via DXA scans. But perimenopausal and early postmenopausal women face different constraints—employment demands, caregiving responsibilities, and the physical symptoms of the menopausal transition itself.
The STOP-EM study includes a longer foundation phase to ensure all participants have adequate joint mobility and proper movement patterns before adding heavy loads. Sessions are one hour instead of 30 minutes to allow for adequate warm-up. And the exercise selection ensures all muscle groups are targeted, not just those directly related to bone loading.
Why Standard Bone Scans Don't Tell the Full Story
Most studies of exercise and bone health use DXA (dual X-ray absorptiometry) scans, which measure areal bone mineral density—a two-dimensional measurement used as a surrogate for bone strength.
DXA has limitations. Exercise typically shows only marginal improvements in bone density by DXA (about 0.85% change at the lumbar spine), yet meta-analyses demonstrate more than a 60% relative reduction in fracture risk from exercise.
That discrepancy tells us that exercise improves bone health in ways DXA can't detect.
The STOP-EM study uses HR-pQCT (high-resolution peripheral quantitative CT), a three-dimensional imaging device with resolution as fine as 61 micrometers—about the width of a human hair. HR-pQCT can assess:
Cortical bone (the dense outer shell)
Trabecular bone (the spongy inner structure)
Volumetric bone mineral density
Bone microarchitecture (the detailed structure)
Estimated bone strength via finite element analysis
This level of detail is particularly relevant for assessing the efficacy of exercise interventions, which appear to improve bone structure and strength beyond what DXA can detect.
What About Muscle?
Bone loss isn't the only concern during menopause. Women also experience accelerated loss of muscle mass and strength during the menopausal transition, driven by declining estrogen production, reduced physical activity, and insufficient protein intake.
The STOP-EM study will measure:
Lean body mass via DXA
Maximal isometric voluntary contractions of the knee extensors
Hand grip strength
Muscle power via countermovement jump on a force plate
Physical function via the four-square-step test (dynamic balance) and 6-minute walk test (aerobic fitness)
This comprehensive approach recognizes that bone and muscle health are interconnected and that both decline during menopause.
Primary Outcomes: Is It Feasible?
The primary purpose of this study isn't to prove that HiRIT works—it's to determine whether perimenopausal and early postmenopausal women can commit to and complete a 9-month, twice-weekly supervised training program.
The study will be considered feasible if:
More than 50% of interested and eligible participants enroll
Participants attend more than 60% of exercise sessions (approximately 1.2 sessions per week over 9 months)
At least 65% of participants complete the final study visit
These benchmarks are based on previous exercise interventions and account for the possibility that women during the menopausal transition may face more time constraints than late postmenopausal women.
If the study meets these feasibility criteria, the research team will proceed with a larger, longer trial to evaluate the efficacy of HiRIT for preventing bone and muscle loss during the menopausal transition.
Secondary Outcomes: Preliminary Data on Effectiveness
Although the study is powered for feasibility outcomes, researchers will collect exploratory data on bone, muscle, physical function, and quality of life to inform the design of a future efficacy trial.
Secondary outcomes include:
Bone microarchitecture and estimated bone strength (via HR-pQCT)
Bone mineral density at the hip, spine, and total body (via DXA)
Biomarkers of bone turnover (c-terminal telopeptide, procollagen 1 intact N-terminal propeptide)
Reproductive hormones (estradiol, follicle-stimulating hormone)
Muscle mass, strength, and power
Physical function (balance, aerobic fitness)
Physical activity levels (via accelerometer)
Menopausal symptoms and quality of life
Researchers will compare changes between the exercise intervention group and waitlist control group, adjusting for baseline values and stratifying by hormone replacement therapy use and menopausal status (perimenopausal vs. early postmenopausal).
What This Means for You
If you're in the menopausal transition and wondering what you should be doing for your bone health, this study provides a roadmap—even before the results are published.
The evidence from late postmenopausal women is clear: high-intensity resistance training works. Systematic reviews show that high-intensity exercise is more effective for bone than low or moderate-intensity exercise. Recent trials demonstrate safety, feasibility, and efficacy.
The STOP-EM study is testing whether women during the menopausal transition—when bone loss is most rapid—can participate in and benefit from this type of training.
You don't need to wait for the results to start strength training. But you should work with a qualified professional who understands progressive overload, proper movement patterns, and how to modify exercises based on your individual needs and constraints.
The Bigger Picture: Prevention Over Treatment
The dominant approach to osteoporosis is reactive: wait until bone density is low enough to diagnose osteoporosis or osteopenia, then prescribe pharmacotherapy.
But osteoporosis medications come with side effects, costs, and the reality that they're treating a condition that's already developed. Some women will need medication regardless of lifestyle interventions. But many could benefit from proactive prevention during the years when bone loss is most rapid.
The STOP-EM study represents a shift toward prevention. If HiRIT proves feasible and effective in perimenopausal and early postmenopausal women, it could provide an evidence-based intervention during the window that matters most.
The study is expected to complete enrollment by December 2025, with results likely published in 2026.
Source: Alexander, C.J., Kaluta, L., Whitman, P.W., Billington, E.O., Burt, L.A., & Gabel, L. (2025). Strength training for osteoporosis prevention during early menopause (STOP-EM): a pilot study protocol for a single centre randomised waitlisted control trial in Canada. BMJ Open, 15, e093711. https://doi.org/10.1136/bmjopen-2024-093711
