By Ghazaleh Barghgir, MD, and Nancy Selfridge, MD

Dr. Barghgir is a Clinical Skills Facilitator, Clinical Foundations Department, Ross University School of Medicine, Barbados, West Indies.

Dr. Selfridge is Professor, Clinical Foundations Department, Ross University School of Medicine, Barbados, West Indies.

Dr. Barghgir and Dr. Selfridge report no financial relationships relevant to this field of study.

SUMMARY POINTS

• Exercise can significantly decrease the risk of falls and injurious falls in older adults.

• Moderate or intense exercise, two to three times per week, averaging 50 minutes per session, is recommended to reduce the risk of falls and injuries caused by falls.

• Exercise will not significantly diminish the risk of mortality, hospitalization, multiple falls, or fractures in older adults.

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SYNOPSIS: The authors of this meta-analysis of 46 multinational randomized, controlled trials exploring the association between long-term exercise training and risk of serious outcomes in adults older than 60 years of age noted a statistically significant reduction in risk for some fall-related outcomes depending on the frequency and intensity of exercise training.

SOURCE: de Souto Barreto P, Rolland Y, Vellas B, et al. Association of long-term exercise training with risk of falls, fractures, hospitalizations, and mortality in older adults: A systematic review and meta-analysis. JAMA Intern Med 2019;179:394-405.

The health benefits of regular physical exercise for adults include reduced all-cause mortality, prevention of chronic disease, and optimized management of, and improved outcomes for, chronic disease. Optimizing body weight/composition, maintaining or increasing muscle mass and strength, and improving mood, sleep, and neurocognitive function are additional benefits. The strength of evidence is substantial enough that multiple federal agencies support state and local programs to promote physical activity and exercise for all ages.¹

Falls are a significant cause of morbidity and mortality in the elderly, leading to fractures, hospitalizations, decreased functional status, and reduction in quality of life.² The Centers for Disease Control and Prevention reported that 28.7% of adults 65 years of age or older experienced falls in 2014, contributing to a total of 29 million falls for that year. Furthermore, there were 33,000 fall-related deaths documented in 2015.³ The risk of falls in the elderly is multifactorial; weakness, frailty, balance problems, cognitive decline and impairment, medication side effects, nutrition, and multiple environmental factors increase risk.² It is no surprise that multifactorial interventions, including exercise programs, are associated with fall-related benefits.^2,4,5 Simultaneously, safety concerns about exercise programs for the elderly have arisen from the results of the Lifestyle Interventions and Independence for Elders (LIFE) study, the largest and the longest study trial to date in sedentary older adults. The study showed increased hospitalizations and mortality in exercising elders compared with controls, although the results did not reach statistical significance.⁶

This systematic review was performed to fill an evidence gap concerning benefits and risks of long-term exercise for older adults. Data from multiple randomized, controlled trials (RCTs) were pooled and analyzed to determine the effect of long-term exercise interventions of one year or more in duration on both the risk and consequences of falls in adults 60 years of age or older. The data was used to determine the optimum type, intensity, frequency, and duration of exercise associated with the greatest reductions in risk of falls and fall-related adverse events. To address concerns raised by the LIFE study, they explored the risks of serious outcomes associated with exercise interventions, including hospitalizations and mortality.

For this preplanned meta-analysis, the authors performed an electronic database search, identifying 46 published studies (n = 22,709 participants) that met the following eligibility criteria:

• The study had to be an RCT with an exercise intervention length of one year or more (or more than 12 months or more than 48 weeks).
• The study compared the effects of at least one exercise intervention against a control comparator group that received no intervention, attention, or another active intervention.
• Participants were 60 years of age or older at baseline, or the mean participant age was 60 years or older.

Studies investigating co-interventions were eligible if the only difference between intervention and comparator groups was the exercise intervention. Exercise interventions could include home- or group-based programs, but unsupervised exercise interventions were included only if a personalized exercise plan was provided to the participant.

Six binary outcomes were measured:

• Mortality
• Hospitalization (inpatient, 24 hours or more in duration)
• Participants who fell at least once
• Participants who fell at least twice (multiple falls)
• Participants who suffered an injurious fall (e.g., sustained head trauma, a wound, or required medical care or hospitalization for the injury)
• Fractures

The mean participant age was 73.1 years, 66.3% of participants were women, and most trials involved community dwellers. Sixteen of the studies involved patients with specific clinical conditions or diseases. RCTs included both parallel (35) and cluster (11) designs. Multicomponent exercise (aerobic plus strength plus balance training) was the most common exercise intervention (29 studies). Aerobic exercise alone was studied in eight trials, and strength training alone was studied in five trials. The mean intervention length for the studies was 17 months.

Data from RCTs with attrition rates greater than 40% and those with exercise compliance rates of less than 30% did not enter into the primary analysis, but were added in sensitivity analyses. Trials with no data available for a specific outcome were not included in analyses of data for that outcome. Exploratory meta-regressions were performed to determine which aspects of the exercise intervention associated most strongly with the effect size of the outcomes. Exercise variables included frequency (two to three times per week vs. fewer than twice per week); volume (fewer than 120 minutes per week, 120-180 minutes per week, and more than 180 minutes per week); intensity (vigorous vs. moderate); and type (aerobic, strength, other type, and multicomponent). Effective exercise volume was determined separately, calculated as a product of weekly exercise volume and adherence. Multicomponent interventions that included balance training were further compared to all other exercise types combined.

Data on the primary outcomes were obtained from baseline until the end of the intervention period. Heterogeneity, using the I² statistic, was considered substantial for I² values greater than 50%. Subgroup analyses were performed to explore substantial heterogeneity, including stratifying analyses of separate study populations categorized as clinically specific, disease-specific, and
non-clinically specific. Sensitivity analyses were performed to help ensure the robustness of overall meta-analysis results.

Results are summarized in Table 1. There was no statistical difference in mortality between participants in exercise groups or control groups except for sensitivity analyses restricted to clinically specific and disease-specific populations, which showed a reduced risk of mortality in exercisers (relative risk, 0.70; 95% confidence interval, 0.49-1.00; P = 0.05). Exercise did not affect the risk of being hospitalized; despite heterogeneity of studies (I² = 59.2%), subgroup and sensitivity analyses were consistent with these findings. At least one fall was experienced by 43.1% and 48.2% of individuals in the exercise and control groups, respectively. Exercisers demonstrated a significantly reduced risk (12%) for becoming a faller, and a similar, but not statistically significant, relative risk of experiencing multiple falls. Interestingly, meta-regressions for exercise frequency and effective exercise frequency more than three times weekly were associated with an increased risk of becoming a faller. Exercisers had a significantly reduced risk (26%) of experiencing injurious falls. A reduced risk of fractures also was noted in exercisers, although the results did not reach statistical significance.

Commentary

This analysis of pooled RCT data is the first to look at the effects of long-term exercise on specific outcomes, including falls, in adults older than 60 years of age. It also is the first attempt to look at the effect of exercise on the risk of experiencing multiple falls in this age group, although the paucity of data in the selected studies relevant to this specific outcome likely limits interpretation of results. Overall results corroborate existing evidence that exercise of any duration has positive effects on fall-related outcomes. Exercising two to three times weekly appears to be the optimum exercise frequency, below which, risk reduction for fall outcomes is not apparent. A surprising finding was that exercising more than three times weekly appeared to be associated with an increased risk of falls, suggesting an optimum exercise volume for older adults, above which, risks may begin to accumulate.

The significant heterogeneity noted in the fall analyses suggest that these particular results need to be interpreted with care. Inclusion in this review of the studies that focused on clinical conditions and disease-specific populations may make it irrational to generalize advice concerning exercise volume upper limits to healthy patients with no clinical disease.

Fortunately, no increased risk of mortality, hospitalization, falls, or injurious results of falls were noted in this data analysis, helping allay concerns about exercise safety raised by the LIFE study. Meta-regression analyses also showed that vigorous-intensity exercise is as safe as moderate-intensity exercise.

The limitations of this review include risks of bias inherent in the original studies — blinding of subjects, allocation concealment, and blinding of outcome assessment. Some studies did not report exercise adherence, which would affect analyses of exercise volume. The average heterogeneity of studies and of analysis results was substantial, requiring caution in generalizing findings to all
populations.

Nonetheless, this review supports exercise recommendations comprised of moderate-intensity multicomponent training, including balance exercises (two to three sessions weekly, 30 to 60 minutes per session) for older adults for protection against falls and adverse outcomes. Patients can be reassured that research supports this exercise prescription as safe and effective.

REFERENCES

1. U.S. Department of Health and Human Services. Physical Activity Guidelines for Americans. 2nd ed. Washington, DC;2018.
2. Jin J. Prevention of falls in older adults. JAMA 2018;319:1734.
3. Centers for Disease Control and Prevention, National Centers for Injury Prevention and Control. Web-based injury statistics query and reporting system (WISQARS). Updated March 30, 2020. https://www.cdc.gov/injury/wisqars/index.html
4. Guirguis-Blake JM, Michael YL, Perdue LA, et al. Interventions to prevent falls in older adults: Updated evidence report and systematic review for the U.S. Preventive Services Task Force. JAMA 2018;319:1705-1716.
5. Shier V, Trieu E, Ganz DA. Implementing exercise programs to prevent falls: Systematic descriptive review. Inj Epidemiol 2016;3:16.
6. Pahor M, Guralnik JM, Ambrosius WT, et al. Effect of structured physical activity on prevention of major mobility disability in older adults: The LIFE study randomized clinical trial. JAMA 2014;311:2387-2396.