The exercise that builds strong bones and better balance | Dr Lora Giangregorio

What It Covers

Dr. Lora Giangregorio, Tier 1 Research Chair in Bone Health and Exercise Science at the University of Waterloo, breaks down the evidence on osteoporosis, fragility fractures, and exercise prescription. She covers DEXA interpretation, fracture risk tools like FRAX, balance training, resistance training, and widespread misinformation around weighted vests and commercial bone-loading programs.

Key Questions Answered

• •Fracture risk beyond bone density: DEXA-derived bone mineral density is only one component of fracture risk. The FRAX algorithm combines BMD with independent risk factors — age, oral glucocorticoid use, rheumatoid arthritis, diabetes, smoking, and alcohol intake above three units daily — to calculate a 10-year fracture probability. Two people with identical femoral neck BMD can carry meaningfully different fracture risk based on these additional variables, which is why clinical decisions now rely on FRAX probability rather than T-score alone.
• •Balance training is the highest-certainty intervention: Evidence from roughly 80 to 90 randomised controlled trials — rated high certainty — confirms that balance and functional training reduces falls. No other exercise category carries this level of evidence for fracture prevention. Effective programs target four balance domains: anticipatory control, dynamic stability, functional stability limits, and reactive control. Training should occur at least three times per week, using exercises challenging enough to require full concentration, tailored to the individual's current ability level.
• •Muscle loss independently predicts fracture risk: Data from a Manitoba cohort study showed that losing muscle mass is an independent fracture risk factor even after controlling for bone density and all other known risk factors. Critically, this held true in people already taking osteoporosis medication — those losing muscle remained at higher fracture risk than those who were not. Maintaining muscle through resistance training therefore reduces fracture risk through pathways entirely separate from bone mineral density changes.
• •Resistance plus impact training for bone density: In people with low bone mass, the best available evidence points to combining resistance training and impact exercise for bone density outcomes. Impact is classified on a continuum — walking is low, hopping is moderate, jumping from a box is high — based on ground reaction forces. Resistance training stimulates bone via muscle pull on attachment sites. Progression should begin at low impact and advance gradually, allowing tendons and muscles to adapt before introducing higher-force movements.
• •Progressive overload and specificity determine outcomes: Bone and muscle adaptations are specific to the forces applied. Femoral neck BMD is particularly difficult to change because no major muscles attach there, making impact loading more relevant than muscle pull for that site. Progressive overload — consistently increasing challenge so the body must adapt — is essential; performing the same 15-repetition set for two years produces no further adaptation. Difficulty level, not absolute load, is the operative variable, meaning slowing tempo or using single-leg variations can substitute for adding weight.
• •Weighted vests and OsteoStrong lack sufficient evidence: Systematic review of weighted vest research shows mixed or null results, including a randomised trial by Dr. Beavers in which weighted vest walking failed to prevent bone loss during caloric restriction. OsteoStrong, an isometric-style commercial franchise, has no high-quality randomised controlled trial demonstrating efficacy independent of medication. A 2025 Greek study published in the Journal of Clinical Endocrinology and Metabolism showed bone density gains only in the medication group, not in OsteoStrong alone, yet generated widespread positive media coverage.
• •Menopause accelerates bone loss; HRT reduces fracture risk: Estrogen suppresses osteoclast activity and number. During the three-to-five years surrounding menopause, women can experience accelerated bone loss as the body adjusts to lower estrogen levels, with the magnitude varying considerably between individuals. Hormone replacement therapy is associated with reduced fracture risk and can attenuate this loss, but suitability is individual — contraindications include personal history of certain cancers. Early or surgical menopause extends the duration of low-estrogen bone loss, compounding age-related decline over a longer period.