Maria A. Fiatarone Singh

Exercise and Physical Activity for Older Adults

The purpose of this Position Stand is to provide an overview of issues critical to understanding the importance of exercise and physical activity in older adult populations. The Position Stand is divided into three sections: Section 1 briefly reviews the structural and functional changes that characterize normal human aging, Section 2 considers the extent to which exercise and physical activity can influence the aging process, and Section 3 summarizes the benefits of both long-term exercise and physical activity and shorter-duration exercise programs on health and functional capacity. Although no amount of physical activity can stop the biological aging process, there is evidence that regular exercise can minimize the physiological effects of an otherwise sedentary lifestyle and increase active life expectancy by limiting the development and progression of chronic disease and disabling conditions. There is also emerging evidence for significant psychological and cognitive benefits accruing from regular exercise participation by older adults. Ideally, exercise prescription for older adults should include aerobic exercise, muscle strengthening exercises, and flexibility exercises. The evidence reviewed in this Position Stand is generally consistent with prior American College of Sports Medicine statements on the types and amounts of physical activity recommended for older adults as well as the recently published 2008 Physical Activity Guidelines for Americans. All older adults should engage in regular physical activity and avoid an inactive lifestyle.

High-velocity resistance training increases skeletal muscle peak power in older women.

OBJECTIVES: Peak power declines more precipitously than strength with advancing age and is a reliable measure of impairment and a strong predictor of functional performance. We tested the hypothesis that a high‐velocity resistance‐training program (HI) would increase muscle power more than a traditional low‐velocity resistance‐training program (LO).

Insulin-like growth factor I in skeletal muscle after weight-lifting exercise in frail elders

To assess muscle remodeling and functional adaptation to exercise and diet interventions, 26 men and women aged 72-98 yr underwent a vastus lateralis biopsy before and after placebo control condition, and progressive resistance training, multinutrient supplementation, or both. Type II atrophy, Z band, and myofibril damage were present at baseline. Combined weight lifting and nutritional supplementation increased strength by 257 ± 62% ( P = 0.0001) and type II fiber area by 10.1 ± 9.0% ( P = 0.033), with a similar trend for type I fiber area (+12.8 ± 22.2%). Exercise was associated with a 2.5-fold increase in neonatal myosin staining ( P = 0.0009) and an increase of 491 ± 137% ( P < 0.0001) in IGF-I staining. Ultrastructural damage increased by 141 ± 59% after exercise training ( P = 0.034). Strength increases were largest in those with the greatest increases in myosin, IGF-I, damage, and caloric intake during the trial. Age-related sarcopenia appears largely confined to type II muscle fibers. Frail elders respond robustly to resistance training with musculoskeletal remodeling, and significant increases in muscle area are possible with resistance training in combination with adequate energy intakes.

Efficacy of progressive resistance training on balance performance in older adults : a systematic review of randomized controlled trials.

The serious health, social and economic consequences of falls are well documented. Lower extremity muscle weakness and power as well as balance impairment are major independent intrinsic contributors to falls and amenable to intervention. Progressive resistance training (PRT) is widely accepted as an appropriate modality for treating sarcopenia and has been reported to improve balance. However, other studies affirm no significant effect of PRT on balance. To date, there is no clear, definitive statement or synthesis of studies that has examined the effect of PRT on balance. Therefore, our objective was to systematically review the literature to probe the merit of PRT as a single intervention on balance performance in older adults. We conducted a comprehensive search of major electronic databases to October 2006, with citation searches and bibliographic searches of journal articles and literature/systematic reviews. Two independent reviewers screened for eligibility and assessed the quality of the studies using the Physiotherapy Evidence Database scale for validity assessment. Randomized controlled trials of PRT only, with any balance outcome in participants with a mean age of ≥60 years (individual minimum age >50 years) were included. Trials that contained more than one intervention, providing the PRT and control groups matched the inclusion criteria, were also included. Because of the heterogeneity of interventions and balance outcomes, a meta-analysis was not performed. However, corrected effect sizes with confidence intervals were determined for each study outcome. Twenty-nine studies were compatible with the inclusion/exclusion criteria and were eligible for review. Participants (n = 2174) included healthy, community-dwelling, mobility-limited, frail cohorts and those with chronic comorbidities. Balance outcomes conducted were extensive and were broadly categorized by the authors as: static, dynamic, functional and computerized dynamic posturography. Some studies used more than one balance outcome. The number of balance tests in all totalled 68. Fourteen studies (15 tests representing 22% of all balance tests) reported improvements, significantly greater than controls, in balance performance following PRT. Improvements were not linked to a particular type of balance performance. The inconsistent effect of PRT on balance may be explained by heterogeneity of cohort and balance tests, variability in methodology of the balance test and sample size, inadequate dose of PRT and/or compliance to training, or lack of statistical power. Standardization of balance testing methodology and better reporting of procedures may ensure greater comparability of results in future studies. It is also possible that PRT alone is not a robust intervention for balance control. This is the first systematic synthesis of the literature to examine the effectiveness of PRT alone on balance performance in older adults. The limited evidence presented in currently published data has not consistently shown that the use of PRT in isolation improves balance in this population. However, further research should explore optimal resistance training regimens that: focus on the muscles most pertinent to balance control, best target neuromuscular adaptations that protect against postural challenges and elucidate mechanism(s) by which PRT may affect balance control.

Exercise Training in Patients Receiving Maintenance Hemodialysis: A Systematic Review of Clinical Trials

Background: Exercise is not routinely advocated in patients with end-stage renal disease (ESRD) receiving maintenance hemodialysis (HD), compared to best practice in other chronically diseased cohorts. Lack of widespread awareness of the exercise in HD literature may be contributing to these shortcomings of clinical practice. Therefore, our objectives are: (1) to systematically review trials of exercise training involving adult HD patients; (2) to provide empirical evidence that exercise can elicit health-related adaptations in this cohort, and (3) to provide recommendations for future investigations. Method: A systematic review of the literature using computerized databases was performed. Results: According to the 29 trials reviewed, HD patients can safely derive a myriad of health-related adaptations from engaging in appropriately structured exercise regimens involving aerobic and/or resistance training. However, methodological limitations within this body of literature may be partially responsible for minimal advocacy for exercise in this cohort. Conclusions: Robustly designed RCTs with thorough, standardized reporting are required if clinical practice and quality of life of this cohort is to be enhanced through the integration of exercise training and mainstream medical practice. Future trials should demonstrate the clinical importance, and long-term feasibility and applicability of exercise training for this vulnerable patient population.

Higher dietary variety is associated with better nutritional status in frail elderly people

OBJECTIVE A narrow range of food choices may lead to dietary inadequacies, a particular concern in elderly people. We hypothesized that consumption of a more diverse diet would predict better nutritional status in frail elderly persons. SUBJECTS Subjects included 98 frail nursing home residents (36 men, 62 women), mean age 87.1+/-5.5 (72 to 98) years. METHODS 3-day dietary variety scores ranging from 23 to 48 and fruit and vegetable variety scores ranging from 5 to 20 were calculated from weighed 3-day food records as the number of different food or fruit and vegetable choices consumed. A higher score indicates a more varied diet. Nutritional status was assessed by weight, height, body mass index (BMI), skinfold thickness, circumference measures, calculated mean arm muscle area, total body water, computerized tomography of the thigh, and total body potassium, as well as nutritional analysis, biochemical measures, and subject medical history. STATISTICAL METHODS Univariate regression analyses were performed to investigate the relationship between clinical and nutrition variables. Multiple linear regressions were used to develop models relating dietary variety scores to possible etiologic factors as well as indicators of nutritional status. Models were controlled for age, BMI, and energy intake when appropriate. RESULTS Mean dietary variety score was 35.2+/-4.5, and mean fruit and vegetable variety score was 11.3+/-3.0. Higher dietary variety score was associated with higher energy intake (beta = 20.5, P < .001) and both high dietary variety score and fruit and vegetable variety score were positively associated with intake for many nutrients (P < or = .05). High dietary variety score was related to high fruit and vegetable variety score and total intake of fruits and vegetables. In men, higher dietary variety score and fruit and vegetable variety score were associated with higher high-density lipoprotein (beta = 1.02), lower very-low-density lipoprotein (beta = -3.58) and triglycerol (beta = -3.51), and higher blood folate (beta = 4.72) concentrations in women (P < or = .05). In women, high dietary variety score was associated with higher BMI (beta = 0.34, P < .001) and higher total body potassium (beta = 1.30, P = .02); high fruit and vegetable variety score was associated with higher BMI (beta = 0.41), mid-arm circumference (beta = 0.34), and mid-arm muscle area (beta = 2.94) (P < or = .03). Dietary variety score was higher (mean 37.6+/-5.38 vs 34.6+/-4.14) in those who received assistance with feeding (beta = 2 .67, P = .01). History of cancer (beta = -2.04) and gastrointenstinal cancer (beta = -3.54) were associated with low dietary variety score (P < or = .05). CONCLUSIONS The results of this study suggest that a highly varied diet in elderly nursing home residents is associated with better nutritional status as assessed by nutrient intake, biochemical measures, and body composition measures. Dietary variety score is a straightforward tool for screening and identifying people at nutritional risk, as well as a mechanism for monitoring response to nutritional, medical, and environmental interventions. Preventive measures to improve dietary variety, as measured by the dietary variety score, should be evaluated and introduced before nutrition and health complications arise.

Progressive Exercise for Anabolism in Kidney Disease (PEAK): A Randomized, Controlled Trial of Resistance Training during Hemodialysis

Skeletal muscle wasting is common and insidious in patients who receive maintenance hemodialysis treatment for the management of ESRD. The objective of this study was to determine whether 12 wk of high-intensity, progressive resistance training (PRT) administered during routine hemodialysis treatment could improve skeletal muscle quantity and quality versus usual care. Forty-nine patients (62.6 +/- 14.2 yr; 0.3 to 16.7 yr on dialysis) were recruited from the outpatient hemodialysis unit of the St. George Public Hospital (Sydney, Australia). Patients were randomized to PRT + usual care (n = 24) or usual care control only (n = 25). The PRT group performed two sets of 10 exercises at a high intensity (15 to 17/20 on the Borg Scale) using free weights, three times per week for 12 wk during routine hemodialysis treatment. Primary outcomes included thigh muscle quantity (cross-sectional area [CSA]) and quality (intramuscular lipid content via attenuation) evaluated by computed tomography scan. Secondary outcomes included muscle strength, exercise capacity, body circumference measures, proinflammatory cytokine C-reactive protein, and quality of life. There was no statistically significant difference in muscle CSA change between groups. However, there were statistically significant improvements in muscle attenuation, muscle strength, mid-thigh and mid-arm circumference, body weight, and C-reactive protein in the PRT group relative to the nonexercising control group. These findings suggest that patients with ESRD can improve skeletal muscle quality and derive other health-related adaptations solely by engaging in a 12-wk high-intensity PRT regimen during routine hemodialysis treatment sessions. Longer training durations or more sensitive analysis techniques may be required to document alterations in muscle CSA.

Strength Training for Treatment of Osteoarthritis of the Knee: A Systematic Review

OBJECTIVE To assess the effectiveness of isolated resistance training on arthritis symptoms, physical performance, and psychological function in people with knee osteoarthritis. METHODS A comprehensive systematic database search for randomized controlled trials was performed. Two reviewers independently assessed studies for potential inclusion. Study quality indicators, arthritis symptoms, muscle strength, functional performance, and psychological outcomes were extracted. The relative effect sizes (ES) were calculated with 95% confidence intervals. RESULTS Eighteen studies enrolling 2,832 subjects were reviewed; the mean cohort age range was 55-74 years. In general, the quality of the reviewed literature was moderately robust; on average, 8 out of 12 quality criteria were accounted for in the reviewed literature. Self-reported measures of pain, physical function, and performance, along with muscle strength (mean 17.4%), maximal gait speed and chair stand time, and balance improved significantly following resistance training in 56-100% of studies where they were measured. Limitations included lack of data available for ES calculations and lack of adverse event and compliance reporting, particularly with regard to the actual training intensity versus the prescribed training intensity. CONCLUSION Resistance training improved muscle strength and self-reported measures of pain and physical function in over 50-75% of this cohort; 50-100% of the studies reported a significant improvement in all but 1 performance-based physical function measure (walk time). The effects of resistance training on health-related quality of life and depression are yet to be confirmed. More research needs to be conducted to establish dose-response relationships and the effect of resistance training on long-term disability, disease pathology, and progression.

Effects of Exercise on Adiponectin: A Systematic Review

Secreted from white adipose tissue, circulating concentrations of adiponectin are reduced in the presence of metabolic and cardiovascular disease such as obesity and type 2 diabetes. The aim of this systematic review is to assess the body of evidence critically for the effects of exercise on adiponectin levels. Literature searches using the Medline, CINAHL, Cochrane Controlled Trials registry, EMBASE, and SportDiscus databases were conducted from 1966 to September 2006 using keywords pertaining to “adiponectin” and “exercise.” Thirty‐three trials met the inclusion criteria. Study designs consisted of 5 cross‐sectional studies, 7 trials of acute exercise, 11 uncontrolled trials, 2 non‐randomized controlled trials, and 8 randomized controlled trials (RCTs). Exercise of varying prescription has been shown to increase serum adiponectin in 38% of RCTs, demonstrating small‐to‐moderate effect sizes (ESs). One study reported a dose–response effect of resistance training intensity and the augmentation of adiponectin. Inconsistent support in the literature exists for increasing adiponectin levels after short‐term exposure to robust aerobic or resistance training of moderate‐to‐high intensities. Particular attention should be directed toward high‐risk cohorts, in whom augmentation of the anti‐inflammatory cytokine adiponectin may assume critical importance.

Integration of balance and strength training into daily life activity to reduce rate of falls in older people (the LiFE study): randomised parallel trial

Objectives To determine whether a lifestyle integrated approach to balance and strength training is effective in reducing the rate of falls in older, high risk people living at home. Design Three arm, randomised parallel trial; assessments at baseline and after six and 12 months. Randomisation done by computer generated random blocks, stratified by sex and fall history and concealed by an independent secure website. Setting Residents in metropolitan Sydney, Australia. Participants Participants aged 70 years or older who had two or more falls or one injurious fall in past 12 months, recruited from Veteran’s Affairs databases and general practice databases. Exclusion criteria were moderate to severe cognitive problems, inability to ambulate independently, neurological conditions that severely influenced gait and mobility, resident in a nursing home or hostel, or any unstable or terminal illness that would affect ability to do exercises. Interventions Three home based interventions: Lifestyle integrated Functional Exercise (LiFE) approach (n=107; taught principles of balance and strength training and integrated selected activities into everyday routines), structured programme (n=105; exercises for balance and lower limb strength, done three times a week), sham control programme (n=105; gentle exercise). LiFE and structured groups received five sessions with two booster visits and two phone calls; controls received three home visits and six phone calls. Assessments made at baseline and after six and 12 months. Main outcome measures Primary measure: rate of falls over 12 months, collected by self report. Secondary measures: static and dynamic balance; ankle, knee and hip strength; balance self efficacy; daily living activities; participation; habitual physical activity; quality of life; energy expenditure; body mass index; and fat free mass. Results After 12 months’ follow-up, we recorded 172, 193, and 224 falls in the LiFE, structured exercise, and control groups, respectively. The overall incidence of falls in the LiFE programme was 1.66 per person years, compared with 1.90 in the structured programme and 2.28 in the control group. We saw a significant reduction of 31% in the rate of falls for the LiFE programme compared with controls (incidence rate ratio 0.69 (95% confidence interval 0.48 to 0.99)); the corresponding difference between the structured group and controls was non-significant (0.81 (0.56 to 1.17)). Static balance on an eight level hierarchy scale, ankle strength, function, and participation were significantly better in the LiFE group than in controls. LiFE and structured groups had a significant and moderate improvement in dynamic balance, compared with controls. Conclusions The LiFE programme provides an alternative to traditional exercise to consider for fall prevention. Functional based exercise should be a focus for interventions to protect older, high risk people from falling and to improve and maintain functional capacity. Trial registration Australia and New Zealand Clinical Trials Registry 12606000025538.