Exercise frequency and bone mineral density development in exercising postmenopausal osteopenic women. Is there a critical dose of exercise for affecting bone? Results of the Erlangen Fitness and Osteoporosis Prevention Study

Developing an exercise intervention to minimise hip bone mineral density loss following traumatic lower limb amputation: a Delphi study

OBJECTIVE

To elicit expert opinion and gain consensus on specific exercise intervention parameters to minimise hip bone mineral density (BMD) loss following traumatic lower limb amputation.

METHODS

In three Delphi rounds, statements were presented to a panel of 13 experts from six countries. Experts were identified through publications or clinical expertise. Round 1 involved participants rating their agreement with 22 exercise prescription statements regarding BMD loss post amputation using a 5-point Likert scale. Agreement was deemed as 3-4 on the scale (agree/strongly agree). Statements of <50% agreement were excluded. Round 2 repeated remaining statements alongside round 1 feedback. Round 3 allowed reflection on round 2 responses considering group findings and the chance to change or maintain the resp onse. Round 3 statements reaching ≥70% agreement were defined as consensus.

RESULTS

All 13 experts completed rounds 1, 2 and 3 (100% completion). Round 1 excluded 12 statements and added 1 statement (11 statements for rounds 2-3). Round 3 reached consensus on nine statements to guide future exercise interventions. Experts agreed that exercise interventions should be performed at least 2 days per week for a minimum of 6 months, including at least three different resistance exercises at an intensity of 8-12 repetitions. Interventions should include weight-bearing and multiplanar exercises, involve high-impact activities and be supervised initially.

CONCLUSION

This expert Delphi process achieved consensus on nine items related to exercise prescription to minimise hip BMD loss following traumatic lower limb amputation. These recommendations should be tested in future interventional trials.

The effects of high velocity resistance training on bone mineral density in older adults: A systematic review

OBJECTIVE

To determine the effects of high velocity resistance training (HVRT) on bone mineral density (BMD) in older adults.

METHODS

A systematic review was conducted using five databases. Records were screened by two independent reviewers.

INCLUSION CRITERIA

adults ≥50 years old, HVRT defined as rapid concentric and slow eccentric phase against an external load, control group and/or other intervention group, BMD measured using dual X-ray absorptiometry, and ≥6 months.

RESULTS

25 studies met the inclusion criteria. 12 were original intervention studies (8 RCTs) with n = 1203 people. 13 papers were follow up studies of these original interventions. Heterogeneity of studies meant no meta-analysis was performed. Moderate evidence suggests a small statistically significant effect of HVRT on BMD in older adults at the lumbar spine, total hip, and femoral neck ranging from 0.9 % to 5.4 %. BMD measurements significantly decreased post-intervention in follow-up studies where the interventions had ceased. Dose-response of HVRT was shown to positively impact BMD when ≥2 sessions per week are completed.

CONCLUSIONS

HVRT plays a role in increasing BMD of the lumbar spine, femoral neck, and total hip. Doses of higher intensity exercise performed ≥2 sessions per week will yield the most skeletal benefits, and if exercise is stopped for >6 months, benefits achieved may be lost.

Patient preferences for lifestyle behaviours in osteoporotic fracture prevention: a cross-European discrete choice experiment

Using a discrete choice experiment, we aimed to assess patients' preferences with regard to adopting lifestyle behaviours to prevent osteoporotic fractures. Overall, the 1042 patients recruited from seven European countries were favourable to some lifestyle behaviours (i.e., engaging in moderate physical activity, taking calcium and vitamin D supplements, reducing their alcohol consumption and ensuring a normal body weight).

INTRODUCTION

Alongside medical therapy, healthy lifestyle habits are recommended for preventing osteoporotic fractures. In this study, we aimed to assess patients' preferences with regard to adopting lifestyle changes to prevent osteoporotic fractures.

METHODS

A discrete choice experiment was conducted in seven European countries. Patients with or at risk of osteoporosis were asked to indicate to what extent they would be motivated to adhere to 16 lifestyle packages that differed in various levels of 6 attributes. The attributes and levels proposed were physical activity (levels: not included, moderate or high), calcium and vitamin D status (levels: not included, taking supplements, improving nutrition and assuring a minimal exposure to sunlight daily), smoking (levels: not included, quit smoking), alcohol (levels: not included, moderate consumption), weight reduction (levels: not included, ensure a healthy body weight) and fall prevention (levels: not included, receiving general advice or following a 1-day fall prevention program). A conditional logit model was used to estimate a patient's relative preferences for the various attributes across all participants and per country.

RESULTS

In total, 1042 patients completed the questionnaire. Overall, patients were favourable to lifestyle behaviours for preventing osteoporotic fractures. However, among the lifestyle behaviours proposed, patients were consensually not prone to engage in a high level of physical activity. In addition, in Ireland, Belgium, the Netherlands and Switzerland, patients were also not inclined to participate in a 1-day fall prevention program and Belgian, Swiss and Dutch patients were not prone to adhere to a well-balanced nutritional program. Nevertheless, we observed globally that patients felt positively about reducing their alcohol consumption, engaging in moderate physical activity, taking calcium and vitamin D supplements and ensuring a normal body weight, all measures aimed at preventing fractures.

CONCLUSIONS

In a patient-centred approach, fracture prevention should take these considerations and preferences into account.

Strong, steady and straight: UK consensus statement on physical activity and exercise for osteoporosis

Exercise and physical activity can improve bone strength and the risk of falls, which may offer benefits in the prevention and management of osteoporosis. However, uncertainty about the types of exercise that are safe and effective instigates lack of confidence in people with osteoporosis and health professionals. Existing guidelines leave some questions unresolved. This consensus statement aimed to determine the physical activity and exercise needed to optimise bone strength, reduce fall and fracture risk, improve posture and manage vertebral fracture symptoms, while minimising potential risks in people with osteoporosis. The scope of this statement was developed following stakeholder consultation. Meta-analyses were reviewed and where evidence was lacking, individual studies or expert opinion were used to develop recommendations. A multidisciplinary expert group reviewed evidence to make recommendations, by consensus when evidence was not available. Key recommendations are that people with osteoporosis should undertake (1) resistance and impact exercise to maximise bone strength; (2) activities to improve strength and balance to reduce falls; (3) spinal extension exercise to improve posture and potentially reduce risk of falls and vertebral fractures. For safety, we recommend avoiding postures involving a high degree of spinal flexion during exercise or daily life. People with vertebral fracture or multiple low trauma fractures should usually exercise only up to an impact equivalent to brisk walking. Those at risk of falls should start with targeted strength and balance training. Vertebral fracture symptoms may benefit from exercise to reduce pain, improve mobility and quality of life, ideally with specialist advice to encourage return to normal activities. Everyone with osteoporosis may benefit from guidance on adapting postures and movements. There is little evidence that physical activity is associated with significant harm, and the benefits, in general, outweigh the risks.

The effect of different training frequency on bone mineral density in older adults. A comparative systematic review and meta-analysis

Exercise frequency is a key aspect of exercise protocols. In this systematic review and meta-analysis, we determined the effect of training frequency on (areal) bone mineral density (BMD) at lumbar spine (LS) and hip. Reviewing seven electronic databases up to April 2021, we conducted a systematic review of the literature according to the PRISMA statement. Inclusion criteria were (a) controlled exercise trials (b) with at least two study arms that compared low versus high exercise frequency, (c) an intervention ≥6 months and (d) BMD assessments at lumbar spine (LS) or hip. The analysis was conducted as a mixed-effect meta-analysis and used "type of exercise" and "study duration" as moderators in subgroup analyses. Standardized mean differences (SMD) for LS- and hip-BMD changes were defined as outcome measures. Seven studies with 17 exercise groups were included in the analysis. We observed significantly higher effects of high (≥2 sessions/week) vs. low net training frequency (1-<2 sessions/week) exercise on LS- (SMD 0.55, 95%-CI: 0.20-0.90) but not hip-BMD (0.19, -0.06 to 0.45). Study duration was found to be a significant moderator for the effect of training frequency at LS- but not hip-BMD. In parallel, the type of exercise moderately influences the effect of training frequency on LS- but not on hip-BMD. We observed a superior effect of higher net training frequency on BMD. Longer exercise exposition increases this effect. Considering e.g. holidays, indisposition or other temporary absence, exercise programs on osteoporosis should provide at least 3 sessions/week/year to allow a net training frequency of more than two sessions/week. STUDY REGISTRATION: PROSPERO (CRD42021246804).

Models of care for osteoporosis: A systematic scoping review of efficacy and implementation characteristics

BACKGROUND

Osteoporosis affects over half of adults over 50 years worldwide. With an ageing population, osteoporosis, fractures and their associated costs are increasing. Unfortunately, despite effective therapies, many with osteoporosis remain undiagnosed and untreated. Models of care (MoC) to improve outcomes include fracture liaison services, screening, education, and exercise programs, however efficacy for these is mixed. The aim of this study is to summarise MoC in osteoporosis and describe implementation characteristics and evidence for improving outcomes.

METHODS

This systematic scoping review identified articles via Ovid Medline and Embase, published in English between 01/01/2009 and 15/06/2021, describing MoC for adults aged ≥18 years with, or at risk of, osteoporosis and / or health professionals caring for this group. All included at least one of clinical, consumer or clinician outcomes, with fractures and bone mineral density (BMD) change the primary clinical outcomes. Exclusion criteria were studies assessing pharmaceuticals or procedures without other interventions, or insufficient operational details. All study designs were included, with no comparator necessary. Title and abstract were reviewed by two reviewers. Full text review and data extraction was performed by these reviewers for 20% of article and, thereafter by a single author. As the review was predominantly descriptive, no comparator statistics were used.

FINDINGS

314 articles were identified describing 289 MoC with fracture liaison services (n=89) and education programs (n=86) predominating. The population had prior fragility fracture in 77 studies, the median (IQR) patient number was 210 (87, 667) and the median (IQR) follow-up duration for outcome assessment was 12 (6, 12·5) months. Fracture reduction was reported by 65 studies, with 16 (37%) graded as high quality, and 19 / 47 studies with a comparator group found a reduction in fractures. BMD change was reported by 73 studies, with 41 finding improved BMD. Implementation characteristics including reach, fidelity and loss to follow-up were under-reported, and consumer and clinician perspectives rare.

INTERPRETATION

This comprehensive review of MoC for osteoporosis demonstrated inconsistent evidence for improving outcomes despite similar types of models. Future studies should include implementation outcomes, consumer and clinician perspectives, and fracture or BMD outcomes with sufficient duration of follow-up. Authors should consider pragmatic trial designs and co-design with clinicians and consumers.

Effects of exercise frequency and training volume on bone changes following a multi-component exercise intervention in middle aged and older men: Secondary analysis of an 18-month randomized controlled trial

Progressive resistance training (PRT) combined with weight-bearing impact exercise are recommended to optimize bone health, but the optimal frequency and dose of training remains uncertain. This study, which is a secondary analysis of an 18-month intervention in men aged 50-79 years, examined the association between exercise frequency and the volume of training with changes in DXA and QCT-derived femoral neck (FN) and lumbar spine (LS) bone outcomes, respectively. Men were allocated to either thrice-weekly PRT plus impact exercise training (n = 87) or a non-exercising (n = 85) group. Average weekly exercise frequency (ExFreq) and training volume per session [PRT volume (weight lifted, kg), number of weight-bearing impacts (jumps completed) and total training volume] over the 18-months were calculated from the participants' exercise cards. Regression analysis showed that average weekly ExFreq and training volume per session were positively associated with the 18-month changes in FN BMD and LS trabecular volumetric BMD. Men completing on average 1 to <2 and ≥2 sessions/week had a 1.6 to 2.2% greater net gain in FN BMD relative to non-exercising men, while those completing ≥2 sessions/week had 3.9 to 5.2% net gain in LS trabecular vBMD compared to non-exercising men and those completing <1 session/week. Further analysis showed that the average number of impact loads per session, but not the average PRT weight-lifted, was positively associated with changes in BMD. Every 10 impact loads per session over 18 months was associated with a 0.3% and 1.3% increase in FN BMD and LS trabecular vBMD, respectively. In conclusion, this study indicates that exercise frequency and training volume were predictors of the changes in hip and spine BMD following a multi-component exercise program, and that the number of impact loads rather than PRT weight lifted per session was more important for eliciting positive skeletal responses in middle-aged and older men.

Effectiveness of Pilates and Yoga to improve bone density in adult women: A systematic review and meta-analysis

BACKGROUND

The ageing population brings about the appearance of age-related health disorders, such as osteoporosis or osteopenia. These disorders are associated with fragility fractures. The impact is greater among postmenopausal women due to an acceleration of bone mineral density (BMD) loss.

OBJECTIVE

To estimate the effectiveness of Pilates or Yoga on BMD in adult women.

METHODS

Five electronics databases were searched up to April 2021. Randomized controlled trials (RCTs), non-RCTs and pre-post studies were included. The main outcome was BMD. Risk of bias was evaluated using the Cochrane risk of bias tool. A random effects model was used to pool data from primary studies. Subgroup analyses based on the type of exercise were conducted.

RESULTS

Eleven studies including 591 participants aged between 45 and 78 years were included. The mean length of the interventions ranged from 12 to 32 weeks, and two studies were performed for a period of at least one year. The pooled effect size for the effect of the intervention (Pilates/Yoga) vs the control group was 0.07 (95% Confidence interval [CI]: -0.05 to 0.19; I2 = 0.0%), and 0.10 (95% CI: 0.01 to 0.18; I2 = 18.4%) for the secondary analysis of the pre-post intervention.

CONCLUSIONS

Despite of the non-significant results, the BMD maintenance in the postmenopausal population, when BMD detrimental is expected, could be understood as a positive result added to the beneficial impact of Pilates-Yoga in multiple fracture risk factors, including but not limited to, strength and balance.

Different Methods of Physical Training Applied to Women Breast Cancer Survivors: A Systematic Review

Objective: The objective of this systematic review was to identify the effects of different training methods in women who have survived breast cancer (WSBC). Data Sources: Studies were identified by searching SportDiscus, Web of Science, PubMed, Scopus, Scielo, and Bireme. Study Selection: The inclusion criteria were articles that addressed only breast cancer in women, were randomized clinical trials, and interventions involving physical training with Consort ≥80. Data Extraction: The PICO and CONSORT strategies were used for the selection of articles and quality assessment of randomized clinical trials, respectively. Two independent reviewers searched for articles among the databases. Disagreements were discussed, and in the case of an impasse, a third reviewer was consulted. Data Synthesis: Evidence that demonstrated the beneficial effects of physical exercise programs carried out by WSBC. Moderate or high-intensity exercise sessions have been shown to benefit women survivors of breast cancer. Among the modalities, the resistance exercise showed effects from 55% of one-repetition maximum (1 RM), exclusively or associated with other training regimes, such as aerobic (from 48% of heart rate), high-intensity interval training (HIIT), or impact. The main benefits include increased muscle strength, promoted by the practice of resistance exercise in combination with other types of exercises or alone; decreased fatigue; improved quality of life; improved psychosocial effects, and increased leisure time. Conclusions: Physical training performed at a moderate or high intensity (aerobic or anaerobic) can reduce fatigue, improve quality of life, improve sleep quality, and increase bone mineral density in women survivors of breast cancer.

Changes in Menopausal Risk Factors in Early Postmenopausal Osteopenic Women After 13 Months of High-Intensity Exercise: The Randomized Controlled ACTLIFE-RCT

The menopausal transition is a critical period in women's lives. Exercise might be the most promising non-pharmaceutic intervention to address the large variety of risk factors related to the pronounced estradiol decline during peri- and early-postmenopause. The aim of this study was to determine the effect of an 18-month multipurpose exercise program on risk factors and symptoms related to the menopausal transition. Fifty-four women 1-5 years postmenopause with osteopenia or osteoporosis were randomly assigned 1) to a high impact weight-bearing/high-intensity/velocity resistance training group (EG: n=27) exercising three times a week or 2) to an attendance control group (CG: n=27) that performed low-intensity exercise once a week. Both groups were supplemented with cholecalciferol and calcium. The primary study endpoint was bone mineral density (BMD) at lumbar spine (LS) and total hip, secondary outcomes were lean body mass (LBM), total and abdominal body percentage, metabolic syndrome Z-Score (MetS-Z), menopausal symptoms and muscle strength and power. Due to COVID-19, the study was stopped after 13 months. We observed significant effects for BMD-LS (EG: 0.002±.018 versus CG: -.009±0.018 mg/cm2, p=0.027) but not for BMD total hip (EG: -0.01±.016 versus CG: -.009±0.020 mg/cm2, p=0.129). LBM improved significantly in the EG and decreased in the CG (0.39±1.08 vs -0.37±1.34 kg, p=0.026). Total and abdominal body fat improved significantly in the EG and was maintained in the CG (-1.44±1.49 vs -0.02±1.55 kg, p=0.002 and -1.50±2.33 vs 0.08±2.07 kg, p=0.011). Significant effects in favor of the EG were also determined for menopausal symptoms (p=0.029), hip/leg extension strength (p<0.001) and power (p<0.001). However, changes of the MetS-Z did not differ significantly (p=0.149) between EG and CG. In summary, with minor exceptions, we demonstrated the effectiveness of a multipurpose exercise protocol dedicated to early-postmenopausal women on various risk factors and complaints related to the menopausal transition.

Evidence on physical activity and osteoporosis prevention for people aged 65+ years: a systematic review to inform the WHO guidelines on physical activity and sedentary behaviour

BACKGROUND

Various physical activity interventions for prevention and treatment of osteoporosis have been designed and evaluated, but the effect of such interventions on the prevention of osteoporosis in older people is unclear. The aim of this review was to investigate the association between physical activity and osteoporosis prevention in people aged 65 years and above.

METHODS

A systematic review was conducted and searches for individual studies were conducted in PubMed (January 2010 to March 2020) and for systematic reviews were conducted in PubMed, Embase, CINAHL and SPORTDiscus (January 2008 to July 2020). Records were screened according to the following eligibility criteria: i) population: adults aged 65 years and older; ii) exposure: greater volume, duration, frequency, or intensity of physical activity; iii) comparison: no physical activity or lesser volume, duration, frequency, or intensity of physical activity; iv) outcome: osteoporosis related measures (e.g., bone mineral density). The methodological quality of included studies was assessed and meta-analysis summarised study effects. The GRADE approach was used to rate certainty of evidence.

RESULTS

We included a total of 59 studies, including 12 observational studies and 47 trials. Within the included trials, 40 compared physical activity with no intervention controls, 11 compared two physical activity programs, and six investigated different doses of physical activity. Included studies suggest that physical activity interventions probably improve bone health among older adults and thus prevent osteoporosis (standardised effect size 0.15, 95% CI 0.05 to 0.25, 20 trials, moderate-certainty evidence, main or most relevant outcome selected for each of the included studies). Physical activity interventions probably improve lumbar spine bone mineral density (standardised effect size 0.17, 95% CI 0.04 to 0.30, 11 trials, moderate-certainty evidence) and may improve hip (femoral neck) bone mineral density (standardised effect size 0.09, 95% CI - 0.03 to 0.21, 14 trials, low-certainty evidence). Higher doses of physical activity and programs involving multiple exercise types or resistance exercise appear to be most effective. Typical programs for which significant intervention impacts were detected in trials were undertaken for 60+ mins, 2-3 times/week for 7+ months. Observational studies suggested a positive association between long-term total and planned physical activity on bone health.

CONCLUSIONS

Physical activity probably plays a role in the prevention of osteoporosis. The level of evidence is higher for effects of physical activity on lumbar spine bone mineral density than for hip. Higher dose programs and those involving multiple exercises and resistance exercises appear to be more effective.

Effects of dynamic resistance exercise on bone mineral density in postmenopausal women: a systematic review and meta-analysis with special emphasis on exercise parameters

This systematic review and meta-analysis set out to determine the effect of dynamic resistance exercise (DRT) on areal bone mineral density (aBMD) in postmenopausal women and derive evidence-based recommendations for optimized training protocols. A systematic review of the literature according to the PRISMA statement included (a) controlled trials, (b) of isolated DRT with at least one exercise and one control group, (c) with intervention durations ≥ 6 months, (d) aBMD assessments at lumbar spine or proximal femur, (e) in cohorts of postmenopausal women. We searched eight electronic databases up to March 2019 without language restrictions. The meta-analysis was performed using a random-effects model. Standardized mean differences (SMD) for BMD changes at lumbar spine (LS), femoral neck (FN), and total hip (TH) were defined as outcome measures. Moderators of the exercise effects, i.e., "intervention length," "type of DRT," "training frequency," "exercise intensity," and "exercise volume," were addressed by sub-group analyses. The study was registered in the international prospective register of systematic reviews (PROSPERO) under ID: CRD42018095097. Seventeen articles with 20 exercise and 18 control groups were eligible. SMD average is 0.54 (95% CI 0.22-0.87) for LS-BMD, 0.22 (0.07-0.38) for FN-BMD, and 0.48 (0.22-0.75) for TH-BMD changes (all p ≤ 0.015). While sub-group analysis for FN-BMD revealed no differences within categories of moderators, lower training frequency (< 2 sessions/week) resulted in significantly higher BMD changes at LS and TH compared to higher training frequency (≥ 2 sessions/week). Additionally, free weight training was significantly superior to DRT devices for improving TH-BMD. This work provided further evidence for significant, albeit only low-moderate, effects of DRT on LS-, FN-, and TH-BMD. Unfortunately, sub-analysis results did not allow meaningful exercise recommendations to be derived. This systematic review and meta-analysis observed a significant low-moderate effect of dynamic resistance exercise on bone mineral density changes in postmenopausal women. However, sub-group analyses focusing on exercise characteristics found no results that enable the derivation of meaningful exercise recommendations in the area of exercise and osteoporosis prevention or therapy.

Effect of Exercise Training on Bone Mineral Density in Post-menopausal Women: A Systematic Review and Meta-Analysis of Intervention Studies

Osteoporosis is a major health problem in post-menopausal women (PMW). Exercise training is considered a cost-effective strategy to prevent osteoporosis in middle aged-older people. The purpose of this study is to summarize the effect of exercise on BMD among PMW. A comprehensive search of electronic databases was conducted through PubMed, Scopus, Web of Science, Cochrane, Science Direct, Eric, ProQuest, and Primo. BMD changes (standardized mean differences: SMD) of the lumbar spine (LS) femoral neck (FN) and/or total hip were considered as outcome measures. After subgroup categorization, statistical methods were used to combine data and compare subgroups. Seventy-five studies were included. The pooled number of participants was 5,300 (intervention group: n = 2,901, control group: n = 2,399). The pooled estimate of random effect analysis was SMD = 0.37, 95%-CI: 0.25–0.50, SMD = 0.33, 95%-CI: 0.23–0.43, and SMD = 0.40, 95%-CI: 0.28–0.51 for LS, FN, and total Hip-BMD, respectively. In the present meta-analysis, there was a significant (p < 0.001), but rather low effect (SMD = 0.33–0.40) of exercise on BMD at LS and proximal femur. A large variation among the single study findings was observed, with highly effective studies but also studies that trigger significant negative results. These findings can be largely attributed to differences among the exercise protocols of the studies. Findings suggest that the true effect of exercise on BMD is diluted by a considerable amount of studies with inadequate exercise protocols.

Effects of a 12-Month Supervised, Community-Based, Multimodal Exercise Program Followed by a 6-Month Research-to-Practice Transition on Bone Mineral Density, Trabecular Microarchitecture, and Physical Function in Older Adults: A Randomized Controlled Trial

Multicomponent exercise programs are recommended to reduce fracture risk; however, their effectiveness in real-world community settings remain uncertain. This 18-month randomized controlled trial investigated the effects of a 12-month, community-based, supervised multicomponent exercise program followed by a 6-month "research-to-practice" transition on areal bone mineral density (BMD), trabecular bone microarchitecture, functional performance, and falls in older adults at increased fracture risk. One-hundred and sixty-two adults aged ≥60 years with osteopenia or at increased falls risk were randomized to the Osteo-cise: Strong Bones for Life multicomponent exercise program (n = 81) or a control group (n = 81). Exercise consisted of progressive resistance, weight-bearing impact, and balance training (3-days/week) performed at community leisure centers. Overall 148 (91%) participants completed the trial, and mean exercise adherence was 59% after 12 months and 45% during the final 6 months. After 12 months, there were significant net beneficial effects of exercise on lumbar spine and femoral neck BMD (1.0% to 1.1%, p < 0.05), muscle strength (10% to 13%, p < 0.05), and physical function (timed stair climb 5%; four-square step test 6%; sit-to-stand 16%, p ranging <0.05 to <0.001), which persisted after the 6-month transition. There were no significant effects of the 18-month intervention on distal femur or proximal tibia trabecular bone microarchitecture or falls incidence, but per protocol analysis (≥66% exercise adherence) revealed there was a significant net benefit of exercise (mean [95% confidence interval] 2.8% [0.2, 5,4]) on proximal tibia trabecular bone volume fraction (Osteo-cise 1.5% [-1.2, 4.2]; controls -1.3% [-2.6, 0.1]) after 18 months due to changes in trabecular number (Osteo-cise 1.7% [-0.9, 4.3]; controls -1.1% [-2.4, 0.2]) but not trabecular thickness (Osteo-cise - 0.2% [-0.5, 0.2]; controls -0.2% [-0.4, 0.0]). In conclusion, this study supports the effectiveness of the Osteo-cise: Strong Bones for Life program as a real-world, pragmatic, evidence-based community exercise program to improve multiple musculoskeletal health outcomes in older adults at increased fracture risk. © 2019 American Society for Bone and Mineral Research.

Effects of physical activity on bone mineral density in older adults: Korea National Health and Nutrition Examination Survey, 2008-2011

We compared the relationship between physical activity (PA) and bone mineral density (BMD) in men and women aged over 50 years. Only moderate-to-vigorous PA was positively associated with hip BMD in men. There was no association between PA and BMD at any site in women.

INTRODUCTION

Physical activity (PA) is widely recommended for osteoporosis. However, epidemiological data regarding the intensity or volume of PA required for bone health are lacking. We aimed to investigate and compare the relationship between PA and bone mineral density (BMD) in men and women.

METHODS

This population-based cross-sectional study used data from the 4th and 5th Korea National Health and Nutrition Examination Surveys and included 2767 men and 2753 women aged > 50 years. The intensity, frequency, and duration of PA were assessed using a questionnaire, and the participants were divided into the no activity, walking-only, moderate PA, and vigorous PA groups. BMD was measured at the lumbar spine (LS), femur neck (FN), and total hip (TH) using dual-energy X-ray absorptiometry.

RESULTS

Adjusted-BMDs of the hip were higher in men and women in the moderate and vigorous PA groups than those in men and women in the walking-only and no activity groups, while frequency and duration of PA were not associated with BMD at any site. The odds ratios for osteoporosis were the lowest at the FN and TH in men in the vigorous PA group (0.354, 95% confidence interval (CI) 0.139-0.901, P < 0.002, and 0.072, 95% CI 0.007-0.766, P < 0.003, respectively), while it was not significant in women.

CONCLUSION

Only moderate-to-vigorous PA was positively associated with the hip BMD in men. There was no association between PA and BMD at any site in women. It is necessary to assess the PA intensity for bone health based on the site and sex.

Effects of different intensities of strength and endurance training on some osteometabolic miRNAs, Runx2 and PPARγ in bone marrow of old male wistar rats

Bone tissue is known as a living dynamic and complex organ in response to physical activity and mechanical loading such as exercise training; thus, the purpose of this study was to determine the effect of different intensities of strength and endurance training on expression of some osteometabolic miRNAs and runt-related transcription factor 2 (Runx2) and peroxisome proliferator-activated receptor γ (PPARγ) in bone marrow of old male Wistar rats. To this end, a total number of 50 male Wistar rats (aged 23 months, 438.27 g) were obtained from Pasteur Institute of Iran. The rats were randomized into five groups (10 rats/per group) including moderate endurance training (MET), high-intensity endurance training (HET), moderate-intensity resistance training (MRT), high-intensity resistance training (HRT), and control (CON). The four training groups completed 8 weeks of a training program, 5 days a week, according to the study protocol. To evaluate miR-133a, miR-103a, miR-204, and other adipogenic and osteogenic genes such as RUNX2 and PPARγ via real-time PCR, total RNA including mRNA and miRNA was isolated from the bone marrow. The statistical analysis was then performed using two-way analysis of variance (ANOVA). No significant differences in miR-133a (p = 0.197), miR-103a (p = 0.302), miR-204 (p = 0.539), RUNX2 (p = 0.960), and PPARγ (P = 0.872) were observed between the intervention groups and the control one. Furthermore, there were no significant differences in bone force (p = 0.641), fracture energy (p = 0.982), stress (p = 0.753), module (p = 0.147), and elongation (p = 0.292) variables between the intervention groups and the control group. Investigating molecular and cellular changes in the bone after such exercises in longer time could provide clearer results about the beneficial or harmful effects of these types of exercises in healthy and passive elderly people.

Exercise for the prevention of osteoporosis in postmenopausal women: an evidence-based guide to the optimal prescription

BACKGROUND

Osteoporosis and related fragility fractures are a global public health problem in which pharmaceutical agents targeting bone mineral density (BMD) are the first line of treatment. However, pharmaceuticals have no effect on improving other key fracture risk factors, including low muscle strength, power and functional capacity, all of which are associated with an increased risk for falls and fracture, independent of BMD. Targeted exercise training is the only strategy that can simultaneously improve multiple skeletal and fall-related risk factors, but it must be appropriately prescribed and tailored to the desired outcome(s) and the specified target group.

OBJECTIVES

In this review, we provide an overview of the general principles of training and specific loading characteristics underlying current exercise guidelines for the prevention of osteoporosis, and an update on the latest scientific evidence with regard to the type and dose of exercise shown to positively influence bone mass, structure and strength and reduce fracture risk in postmenopausal women.

Exercise Early and Often: Effects of Physical Activity and Exercise on Women's Bone Health

In 2011 over 1.7 million people were hospitalized because of a fragility fracture, and direct costs associated with osteoporosis treatment exceeded 70 billion dollars in the United States. Failure to reach and maintain optimal peak bone mass during adulthood is a critical factor in determining fragility fracture risk later in life. Physical activity is a widely accessible, low cost, and highly modifiable contributor to bone health. Exercise is especially effective during adolescence, a time period when nearly 50% of peak adult bone mass is gained. Here, we review the evidence linking exercise and physical activity to bone health in women. Bone structure and quality will be discussed, especially in the context of clinical diagnosis of osteoporosis. We review the mechanisms governing bone metabolism in the context of physical activity and exercise. Questions such as, when during life is exercise most effective, and what specific types of exercises improve bone health, are addressed. Finally, we discuss some emerging areas of research on this topic, and summarize areas of need and opportunity.

Exercise Frequency and Fracture Risk in Older Adults-How Often Is Enough?

PURPOSE OF REVIEW

Due to older people's low sports participation rates, exercise frequency may be the most critical component for designing exercise protocols that address fracture risk. The aims of the present article were to review and summarize the independent effect of exercise frequency (ExFreq) on the main determinants of fracture prevention, i.e., bone strength, fall frequency, and fall impact in older adults.

RECENT FINDINGS

Evidence collected last year suggests that there is a critical dose of ExFreq that just affects bone (i.e., BMD). Corresponding data for fall-related fracture risk are still sparse and inconsistent, however. The minimum effective dose (MED) of ExFreq that just favorably affects BMD at the lumbar spine and femoral neck has been found to vary between 2.1 and 2.5 sessions/week. Although this MED cannot necessarily be generalized to other cohorts, we speculate that this "critical exercise frequency" might not significantly vary among adult cohorts.

Effects of strength training on osteogenic differentiation and bone strength in aging female Wistar rats

The effects of strength training (ST) on the mechanical bone strength and osteogenic differentiation of bone marrow mesenchymal stromal cells (BMSCs) from adult, aged and exercised aged rats were determined. The exercised aged animals displayed higher values of areal bone mineral density, compression test, alkaline phosphatase activity (ALP) and biological mineralization, while oil red O staining for adipocytes was lower. ST increased gene expression of runt-related transcription factor 2 (Runx2), osterix (Osx) as well as bone matrix protein expression, and reduced expression of peroxisome proliferator-activated receptor gamma (Pparγ). The production of pro-inflammatory cytokine tumor necrosis factor alpha (TNF-α) was lower in BMSCs of the aged exercised group. The ST practice was able to improve the bone mechanical properties in aged female rats, increasing the potential for osteogenic differentiation of BMSCs, reducing the adipogenic differentiation and pro-inflammatory cytokine level. In summary, the data achieved in this study showed that strength training triggers physiological responses that result in changes in the bone microenvironment and bring benefits to biomechanical parameters of bone tissue, which could reduce the risk of fractures during senescent.