How the Right Training Impacts Bones

The information provided below, collected in 2025, provides a glimpse into the research that has been conducted on exercise and bone health. ​
  • Research consistently shows that High-intensity Resistance and Impact Training (HiRIT) improves bone mineral density (BMD) and physical function in postmenopausal women and men with osteopenia or osteoporosis, with High-intensity Resistance Training (HiRT) especially beneficial for vertebral BMD and High-intensity Impact Training (HIT) especially beneficial for femoral neck BMD.
  • Numerous studies show that flexion exercises increase the risk of vertebral fractures.
  • Research shows that falls are the overwhelming cause of hip fractures and that the strongest predictors of falls are big toe, ankle and calf weakness.
  • To gauge intensity, HiRT is typically equivalent to 80-85% of an individual's 1 repetition maximum (1RM).
  • Long-term data show that benefits are sustained with continued exercise.
  • While a 1% improvement in BMD on your DXA scan may not be statistically significant, the same 1% BMD improvement in Randomized Controlled Trials (RCTs) is statistically and clinically significant. The 1-3% improvement in BMD shown in the LIFTMOR, FrOST and BEST Trials (see below) prove that exercise improves BMD safely, naturally, and with additional muscle, balance, and posture benefits. Despite sounding small, every 1% improvement in BMD at the hip/spine equates to a 8–12% lower fracture risk (meta-analyses, e.g., Marshall 1996; Cummings 2002). ​

Research on Exercise for Bone Health

Key:

BMD = Bone Mineral Density
​HiRT = High-intensity Resistance Training
HIT = High Impact training
​HiRIT = High-intensity Resistance and Impact Training
RCT = Randomized Controlled Trial
​1RM = One Repetition Maximum

2023 Position Statement

Bae S, Lee S, et al. Position Statement: Exercise Guidelines for Osteoporosis Management and Fall Prevention in Osteoporosis Patients. J Bone Metab. 2023 May 31;30(2):149–165. https://pmc.ncbi.nlm.nih.gov/articles/PMC10345999/
  • 50 RCTs reported that even with osteoporosis and osteopenia, resistance and impact training consistently maximized bone strength, improved body strength and balance, and eventually reduced fall incidences. Conclusion: A multi-component exercise mainly comprised of resistance and impact exercise seems to be an effective strategy to reduce the risk factors of osteoporosis and osteopenia. The integration of exercise guidelines and individualized exercise plans has significant potential to reduce the morbidity and mortality of osteoporosis.

2023 HIT Review

Manaye S, Cheran K, et al. The Role of High-intensity and High-impact Exercises in Improving Bone Health in Postmenopausal Women: A Systematic Review. Cureus. 2023 Feb 5;15(2):e34644. https://pubmed.ncbi.nlm.nih.gov/36895528/​
  • Systematic review of 12 studies found high-impact exercises improved hip/spine BMD in postmenopausal women, with low injury risk under supervision, recommending them as non-pharmacological options for fragility fracture sites.

2022 Exercise Frequency

Zitzmann AL, Shojaa M, et al. The effect of different training frequency on bone mineral density in older adults. A comparative systematic review and meta-analysis. Bone. 2022 Jan:154:116230. https://pubmed.ncbi.nlm.nih.gov/34624560/; https://www.sciencedirect.com/science/article/abs/pii/S8756328221003963
  • ​This systematic review and meta-analysis showed that a higher training frequency (≥2 sessions/week) significantly improves bone mineral density (BMD) in the lumbar spine in older adults compared to a lower frequency (<2 sessions/week), while a similar superior effect was not found for the hip. High-frequency training showed a 2.6% increase in lumbar spine BMD, while low-frequency training maintained it (0.0% change). Longer exercise durations and specific types of exercise further enhanced the positive effect on lumbar spine BMD. 

2021 HiRT Meta-analysis

Zhao R, Zhao M, et al. Impact of high-load resistance training on bone mineral density in osteoporosis and osteopenia: a meta-analysis. J Bone Miner Metab. 2021 Sep;39(5):787-803. https://pubmed.ncbi.nlm.nih.gov/33851269/​
  • Meta-analysis of 15 RCTs (n=638) found HiRT significantly increased lumbar spine BMD and femoral neck BMD in patients with osteoporosis/osteopenia, though heterogeneity and bias suggest need for more low-risk studies.

2019 HIT

Montgomery G, Abt G, et al. The mechanical loading and muscle activation of four common exercises used in osteoporosis prevention for early postmenopausal women. J Electromyogr Kinesiol. 2019 Feb:44:124-131. https://pubmed.ncbi.nlm.nih.gov/30611015/
  • A randomized study of 14 postmenopausal women examined mechanical loading and muscle activation of 4 common osteoporosis prevention exercises in early postmenopausal women: countermovement jumps, box drops, heel drops, and stomping. The researchers ranked the 4 exercises on a wide range of criteria including how well each exercise maintained the bone health of the postmenopausal women. Countermovement jumps, box drops, and heel drops exceeded stomping in maintaining postmenopausal bone health.

2020 FrOST Trial (HiRT)

Kemmler W, Shojaa M, et al. Effects of High-Intensity Resistance Training on Osteopenia and Sarcopenia Parameters in Older Men with Osteosarcopenia-One-Year Results of the Randomized Controlled Franconian Osteopenia and Sarcopenia Trial (FrOST). J Bone Miner Res. 2020 Sep;35(9):1634-1644. https://pubmed.ncbi.nlm.nih.gov/32270891/
  • In 43 older men with osteosarcopenia, 1 year of twice-weekly HiRT plus nutrition (both intervention and control groups were adequately supplemented with whey protein, vitamin D, and calcium) increased lumbar spine BMD by 2.1% and preserved femoral neck BMD, with 95% attendance and no injuries, demonstrating feasibility for combined interventions.​

2020 LIFTMOR-M Trial (HiRIT)

Harding AT, Weeks BK, et al. Effects of supervised high-intensity resistance and impact training or machine-based isometric training on regional bone geometry and strength in middle-aged and older men with low bone mass: The LIFTMOR-M semi-randomised controlled trial. Bone. 2020 Jul:136:115362. https://pubmed.ncbi.nlm.nih.gov/32289518/
  • ​RCT of 93 men (55–80 yrs) with low BMD; 8 months, 2×/week supervised HiRIT (deadlifts, squats, overhead presses at >80–85% 1RM + impact drop landings) vs. low-intensity isometrics. HiRIT improved hip cortical thickness, bone strength (FEA), and preserved femoral neck BMD; there was no improvement in the isometrics control group. No fractures/injuries; 93% compliance.​

2018 LIFTMOR Trial (HiRIT)

Watson SL, Weeks BK, et al. High-Intensity Resistance and Impact Training Improves Bone Mineral Density and Physical Function in Postmenopausal Women With Osteopenia and Osteoporosis: The LIFTMOR Randomized Controlled Trial. J Bone Miner Res. 2018 Feb;33(2):211-220. https://pubmed.ncbi.nlm.nih.gov/28975661/
  • The LIFTMOR (Lifting Intervention For Training Muscle and Osteoporosis Rehabilitation) Trial was a randomized trial of 101 postmenopausal women with osteopenia/osteoporosis, led by Belinda Beck and colleagues at Griffith University. The trial demonstrated that supervised high-intensity resistance training combined with impact loading is safe and effective for improving BMD in postmenopausal women and older men with low bone mass.
  • Intervention (LIFTMOR Protocol): 2 days/week, supervised and progressive for 8 months. Strength training included 5 sets of 5 reps at >80-85% 1RM of squats, deadlifts, and overhead presses. Impact loading consisted of jumping chin-ups with drop landings.
  • Results: The protocol increased lumbar spine BMD by 2.9% and femoral neck BMD by 0.3%, outperforming low-intensity controls, with 92% compliance and no serious adverse events. Also improved strength, balance, and height; no fractures.

2018 HIT RCT

Gómez-Cabello A, Ara I, et al. Effect of 2 years of endurance and high-impact training on preventing osteoporosis in postmenopausal women: randomized clinical trial. Menopause. 2018 Mar;25(3):301-306. https://pubmed.ncbi.nlm.nih.gov/29040219/
  • RCT of 36 postmenopausal women showed 2 years of high-impact training plus calcium and vitamin D supplementation prevented femoral neck BMD loss (vs. walking controls), with no lumbar spine differences, supporting targeted exercises for prevention.​

2017 SHEAF (Extension & Back Strength)

Katzman WB, Vittinghoff E, et al. Targeted spine strengthening exercise and posture training program to reduce hyperkyphosis in older adults: results from the study of hyperkyphosis, exercise, and function (SHEAF) randomized controlled trial. Osteoporos Int. 2017 Oct;28(10):2831-2841. https://pubmed.ncbi.nlm.nih.gov/28689306/
  • RCT of 99 older adults (women and men) with osteoporosis and hyperkyphosis examined a 6-month program of spinal extension exercises, including modified yoga poses (e.g., cobra, bridge) and resistance-based back strengthening. Participants showed a 4.4% improvement in kyphosis angle and a 2.8% increase in lumbar spine BMD. The study found no new vertebral fractures in the extension group, unlike the control group performing flexion-based yoga (6% fracture incidence).

2015 EFOPS Trial follow-up

Kemmler W, Bebenek M, et al. Exercise and fractures in postmenopausal women. Final results of the controlled Erlangen Fitness and Osteoporosis Prevention Study (EFOPS). Osteoporos Int. 2015 Oct;26(10):2491-9. https://pubmed.ncbi.nlm.nih.gov/25963237/
  • In 1998 initially, 137 early-postmenopausal, osteopenic women were included in the Erlangen Fitness and Osteoporosis Prevention Study (EFOPS) trial. EFOPS found that a 3-year low-volume, high-intensity exercise program for early postmenopausal women maintained BMD at the spine and hip. ​The exercise group also experienced reduced spinal pain frequency and intensity. See "2006 EFOPS Trial" below for more information. 
  • In 2014, 105 subjects were included in the 16-year follow-up analysis. The final results of EFOPS showed that a long-term, multipurpose exercise program significantly reduced the risk and rate of low-trauma fractures in postmenopausal women compared to a control group. While both groups experienced a decrease in bone mineral density (BMD), the loss was significantly more pronounced in the control group. The study concluded that complex, multipurpose exercise programs are highly effective for fracture prevention in older adults. ​​
  • See "2006 EFOPS Trial".

2015 Unilateral hopping (HIT)

Allison SJ, Poole KE, et al. ​The Influence of High-Impact Exercise on Cortical and Trabecular Bone Mineral Content and 3D Distribution Across the Proximal Femur in Older Men: A Randomized Controlled Unilateral Intervention. J Bone Miner Res. 2015 Sep;30(9):1709-16. https://pubmed.ncbi.nlm.nih.gov/25753495/
  • Follow-up to 2013 study showed that unilateral hopping increased cortical and trabecular BMC at the femoral neck and that localized adaptations reduced fragility.​

2013 Unilateral hopping (HIT)

Allison SJ, Folland JP, et al. High impact exercise increased femoral neck bone mineral density in older men: a randomised unilateral intervention. Bone. 2013 Apr;53(2):321-8. https://pubmed.ncbi.nlm.nih.gov/23291565/
  • 12 months of 50 daily hops on one leg in 50 men ~70 years old increased femoral neck BMD +2-5% in the exercised leg vs. control leg; feasible and effective.​ The hops were multidirectional hops, 50 per leg, with progressing intensity. The site-specific BMD gains at the hip were similar to side-to-side differences seen in tennis players, where the dominant arm/leg has higher BMD due to unilateral loading.

2011 Falls and foot/calf strength

Spink MJ, Fotoohabadi MR, et al. Foot and ankle strength, range of motion, posture, and deformity are associated with balance and functional ability in older adults. Arch Phys Med Rehabil. 2011 Jan;92(1):68-75. https://pubmed.ncbi.nlm.nih.gov/21187207/
  • Cross-sectional study of 305 community-dwelling older adults (aged 65–93) found that reduced ankle plantar flexor (calf) strength and hallux (big toe) plantar flexion strength were two of the strongest independent predictors of poorer balance and functional performance. Of 88 tested correlations between foot/ankle characteristics and balance/function tests, 76% were significant; calf strength and ankle inversion/eversion range of motion together explained up to 25% of the variance in dynamic balance and mobility tasks. The authors concluded that weak calf and ankle muscles substantially impair the ability to maintain stability during movement, directly contributing to fall risk in older adults.
  • ​See "1999 Falls and hip fracture" and "2009 Falls and toe strength" for more related information.

2009 Extension to Halt Progression of Kyphosis

Ball JM, Cagle P, et al. Spinal extension exercises prevent natural progression of kyphosis. Osteoporos Int. 2009 Mar;20(3):481-9. https://pubmed.ncbi.nlm.nih.gov/18661090/
  • Extension exercises halted kyphosis progression in women aged 50–59. The progression of kyphosis was greater in women who did not perform extension exercises compared to those who performed extension exercises three times per week for 1 year. The difference in change in the cervical curve and the thoracic curve between the two groups was highly significant.

2009 Falls and toe strength

Mickle KJ, Munro BJ, et al. ISB Clinical Biomechanics Award 2009: toe weakness and deformity increase the risk of falls in older people. Clin Biomech (Bristol). 2009 Dec;24(10):787-91. https://pubmed.ncbi.nlm.nih.gov/19751956/
  • A prospective study assessed the feet of 312 men and women aged 60-90 years for the presence of lesser toe deformities and hallux valgus (bunion on big toe) and were followed prospectively to determine their fall incidence over 12 months. Non-falling seniors had 20% more toe strength than the seniors who fell. Compared to non-fallers, fallers displayed significantly less strength of the hallux (big toe) and lesser toes, and were more likely to have hallux valgus (bunion of big toe) and lesser toe deformity. Interestingly, there was no difference in quadriceps or ankle strength between the fallers and the non-fallers, confirming that toe weakness, not generalized weakness, is responsible for the falls.
  • See "1999 Falls and hip fracture" and "2011 Falls and foot/calf strength" for more related information.​​

2007 HiRT RCT

Maddalozzo GF, Widrick JJ, et al. The effects of hormone replacement therapy and resistance training on spine bone mineral density in early postmenopausal women. Bone. 2007 May;40(5):1244-51. https://pubmed.ncbi.nlm.nih.gov/17291843/
  • RCT of 141 early postmenopausal women; self-selected HRT users/non-HRT users (HRT/NHRT), then randomized to RT (resistance training) or no RT (no resistance training). 1 year, 2x/week site-specific RT (focus on squats/deadlifts + other spine-loading exercises). RT alone preserved lumbar spine BMD (+0.43% NHRT+RT vs. −1.8% controls); HRT+RT +0.70%; no additive benefit beyond RT alone for spine BMD in this population.​ This was part of the influential BEST Trial.

2006 EFOPS Trial

Engelke K, Kemmler W, et al. Exercise maintains bone density at spine and hip EFOPS: a 3-year longitudinal study in early postmenopausal women. Osteoporos Int. 2006 Jan;17(1):133-42. https://pubmed.ncbi.nlm.nih.gov/16096715/
  • In 1998 initially, 137 early-postmenopausal, osteopenic women were included in the Erlangen Fitness and Osteoporosis Prevention Study (EFOPS) trial. Subjects of the exercise group conducted two supervised group and two home exercise sessions/week. The program consisted of a comprehensive, multipurpose routine that included components for endurance, strength, power, and coordination. The control group was requested to maintain their physical activity.
  • EFOPS found that a 3-year low-volume, high-intensity exercise program for early postmenopausal women maintained BMD at the spine and hip. The control group experienced significant bone loss, particularly at the spine. Compared to the control group, the exercise group showed significantly less bone loss at the spine and hip, and the exercise group also experienced reduced spinal pain frequency and intensity.
  • See "2015 EFOPS Trial follow-up".

2006 HiRT Meta-analysis

​Martyn-St James M, et al. High-intensity resistance training and postmenopausal bone loss: a meta-analysis. Osteoporos Int. 2006;17(8):1225-40. https://pubmed.ncbi.nlm.nih.gov/16823548/
  • Meta-analysis of 14 RCTs showed HiRT increased lumbar spine BMD by 0.006 g/cm² in postmenopausal women, with homogeneous effects, though femoral neck results were heterogeneous; supports HiRT as a strategy for bone preservation.​

2005 HIT RCT

Torvinen S, Kannus P, et al. ​Effects of high-impact exercise on bone mineral density: a randomized controlled trial in premenopausal women. Osteoporos Int. 2005 Feb;16(2):191-7. https://pubmed.ncbi.nlm.nih.gov/15221206/
  • RCT of 120 premenopausal women found 12 months of high-impact training increased lumbar spine BMD by 2.1% and femoral neck by 1.3%, generalizable for osteoporosis prevention as a safe, low-cost intervention.

2005 SPEED Program

Sinaki M, Brey RH, et al. Significant reduction in risk of falls and back pain in osteoporotic-kyphotic women through a Spinal Proprioception Extension Exercise Dynamic (SPEED) program. Mayo Clin Proc. 2005 Jul;80(7):849-55. https://pubmed.ncbi.nlm.nih.gov/16007888/
  • 4-week extension-focused SPEED program improved balance, gait, and back strength and reduced fall risk.
  • At baseline, there were significant differences between the osteoporotic-kyphotic group and the control group in balance, gait, and strength. After a 4-week intervention, comparison of the kyphotic group's baseline and follow-up results showed a significant change in balance and several gait parameters. Mean back extensor strength also improved significantly and back pain decreased significantly.

2002  Extension vs Flexion follow-up

Sinaki M, Itoi E, et al. Stronger back muscles reduce the incidence of vertebral fractures: a prospective 10-year follow-up of postmenopausal women. Bone. 2002 Jun;30(6):836-41. https://pubmed.ncbi.nlm.nih.gov/12052450/
  • This RCT observed 50 participants 10 years after they had completed the 1984 Sinaki et al 2 year RCT and showed that extensor strengthening reduces fracture risk over time.​​
  • The difference between the two groups was still statistically significant at 10 year follow-up. The difference in BMD, which was not significant between the two groups at baseline and 2 year follow-up, was significant at 10 year follow-up.
  • The extension group showed a 16% reduction in vertebral fracture incidence and a 3% improvement in thoracic spine BMD compared to controls. The relative risk for compression fracture was 2.7 times greater in the Control group than in the Extension group. Extension exercises strengthened paraspinal muscles, reducing kyphotic posture and anterior vertebral stress. ​
  • Note: Sinaki conducted many studies involving flexion vs extension and vertebral fracture incidence, including a small case study conducted in 2013 that showed flexion-based yoga poses caused vertebral compression fractures even in osteopenia (Sinaki M. Yoga spinal flexion positions and vertebral compression fracture in osteopenia or osteoporosis of spine: case series. Pain Pract. 2013 Jan;13(1):68-75. https://pubmed.ncbi.nlm.nih.gov/22448849/)​
  • See "1984 Flexion vs Extension" for original study.

1999 Falls and hip fractures

Parkkari J, Kannus P, et al. Majority of hip fractures occur as a result of a fall and impact on the greater trochanter of the femur: a prospective controlled hip fracture study with 206 consecutive patients. Calcif Tissue Int. 1999 Sep;65(3):183-7. https://pubmed.ncbi.nlm.nih.gov/10441647/
  • A prospective controlled study of 206 consecutive patients with fresh hip fracture. In 98% of the hip fracture patients, the fracture was a result of a fall. The majority of the patients (76%) reported that they had fallen directly to the side.  The main clinical takeaway is that preventing falls is the most effective way to prevent hip fractures in this population.
  • Note: Since there is a reported mortality rate of 20-24% in the first year after a hip fracture (2024 Epidemiology of Osteoporosis and Fragility Fractures by the International Osteoporosis Foundation), preventing falls becomes critical. See "2009 Falls and toe strength" and "2011 Falls and foot/ankle strength" above to understand the link between toe and ankle strength and falls.
  • ​See "2009 Falls and toe strength" and "2011 Falls and foot/calf strength" for more related information.

1995-2001 BEST Trial (HiRIT)

The BEST Trial (Bone Estrogen Strength Training Project) was a landmark NIH-funded RCT (1995–2001, with extensions/follow-ups) led by Christine M. Snow, PhD (formerly at Oregon State University, later University of Arizona/collaborations). It is one of the earliest and most influential studies proving that structured strength + weight-bearing exercise (combined with adequate calcium) can maintain or increase BMD in early postmenopausal women — with or without hormone replacement therapy (HRT).
  • RCT of 320 healthy early postmenopausal women (average age ~55, 1–8 years post-menopause, calcium-replete ~1,000–1,500 mg/day).
  • Intervention (BEST Protocol): 3 days/week, supervised/progressive for 12 months. Strength training included squats, deadlifts, military press, lat pulldown, back extension (2–3 sets of 6–8 reps at 70–85% 1RM). Weight-bearing/aerobic consisted of jumping (tuck/squat/box jumps, progressing to 50–100 reps/session) + stair climbing/walking. No injuries from the protocol; excellent adherence (~80–90% compliance).
  • Results: Exercise alone: Prevented hip/spine loss or small gains (0–2%). Exercise + HRT: Similar or slightly better (no strong synergy). HRT alone: Slowed loss but inferior to exercise at some sites.​ Controls: Lost 2–3.6% spine BMD in year 1.
  • ​Sources: 
    • ​Milliken LA, Going SB, Houtkooper LB, et al. Effects of exercise training on bone remodeling, insulin-like growth factors, and bone mineral density in postmenopausal women with and without hormone replacement therapy (Core 1-year results). Calcif Tissue Int. 2003 Apr;72(4):478-84. https://pubmed.ncbi.nlm.nih.gov/12574871/
    • Maddalozzo GF, Widrick JJ, Cardinal BJ, et al. The effects of hormone replacement therapy and resistance training on spine bone mineral density in early postmenopausal women (Spine-focused sub-analysis). Bone. 2007 May;40(5):1244-51. https://pubmed.ncbi.nlm.nih.gov/17291843/​

1996 HIT RCT

Heinonen A, Kannus P, et al. Randomised controlled trial of effect of high-impact exercise on selected risk factors for osteoporotic fractures. Lancet. 1996 Nov 16;348(9038):1343-7. https://pubmed.ncbi.nlm.nih.gov/8918277/
  • In 98 premenopausal women, 18 months of 3x/week high-impact exercises increased femoral neck BMD by 1.6% (vs. 0.6% in controls) and improved balance/strength, suggesting reduced future fracture risk.​

1994 HiRT RCT

Kerr D, Morton A, et al. Effects of high-intensity strength training on multiple risk factors for osteoporotic fractures. A randomized controlled trial. JAMA. 1994 Dec 28;272(24):1909-14. https://pubmed.ncbi.nlm.nih.gov/7990242/
  • RCT of 65 postmenopausal women found 1 year of HiRT preserved lumbar spine BMD (vs. 2% loss in controls) and improved strength/balance, concluding it's effective for multiple fracture risk factors.​

1984 Flexion vs. Extension

Sinaki M, Mikkelsen BA. (1984). Postmenopausal spinal osteoporosis: flexion versus extension exercises. Arch Phys Med Rehabil. 1984 Oct;65(10):593-6. https://pubmed.ncbi.nlm.nih.gov/6487063/
  • This seminal study compared groups doing flexion exercises, extension exercises (e.g., prone back extensions, supine bridge), both, or none. Exercises were performed 3 times per week, with progressive resistance. Flexion group had 89% new vertebral fractures; extension group had 16% new vertebral fractures, the group performing both flexion and extension exercises had 53% new vertebral fractures and the group not exercising had 67% new vertebral fractures. Results led researchers to recommend avoiding flexion and prioritizing extension.
  • See "2002 Extension vs. Flexion Follow-up" for more related information.​​​

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