[Aging and physical activity data on which to base recommendations for exercise in older adults]

Effects of Power Training on Functional Capacity Related to Fall Risk in Older Adults: A Systematic Review and Meta-analysis

OBJECTIVE

Functional capacity is 1 of the main risk factors for falls among older adults. The aim of this systematic review and meta-analysis was to determine the effect of power training on functional capacity test (FCT) related to fall risk in older adults.

DATA SOURCES

Systematic searches were conducted in 4 databases, including PubMed, Web of Science, Scopus, and SPORTDiscus, from inception to November 2021.

STUDY SELECTION

Randomized controlled trials (RCTs) assessing the effect of power training on functional capacity compared with another type of training program or control group in older adults with the ability to exercise independently.

DATA EXTRACTION

Two independent researchers evaluated eligibility and used the PEDro scale to assess risk of bias. The information extracted was related to article identification (authors, country and year of publication), participant characteristics (sample, sex, and age), strength training protocols (exercises/intensity/weeks), and the outcome of the FCT used related to fall risk. The Cochran Q statistic and I2 statistics was used to assess heterogeneity. Random-effects model were conducted to pool the effect sizes expressed as mean differences (MD).

DATA SYNTHESIS

Twelve studies (478 subjects) were selected for systematic review. A meta-analysis comprised 6 studies (217 subjects) where the outcome measure was the 30-second Sit to Stand (30s-STS) test, and another comprised 4 studies (142 subjects) where the outcome measure was the timed Up and Go (TUG) test. There was an improvement in performance in favor of the experimental group in both the TUG subgroup (MD -0.31 s; 95% CI -0.63, 0.00 s; P=.05), and the 30s-STS subgroup (MD 1.71 reps; 95% CI -0.26, 3.67 reps; P=.09).

CONCLUSIONS

In conclusion, power training increases functional capacity related to fall risk further than other types of exercise in older adults.

Conceptualization of frailty in rehabilitation interventions with adults: a scoping review

Purpose: We aimed to synthesize the literature that considered frailty in the evaluation of rehabilitation interventions for adults (aged ≥18) by answering: (1) how is frailty defined in rehabilitation intervention research?; (2) how is frailty operationalized in rehabilitation intervention research?; (3) what are the characteristics of rehabilitation interventions for frail adults and what frailty related outcomes are assessed?Materials and methods: A scoping review was conducted. Data were analyzed using descriptive statistics and qualitative content analysis.Results: 53 articles met the inclusion criteria. Most studies were conducted in Europe and involved randomized control trials. The included studies reported on rehabilitation interventions that only included individuals aged 50 or older. Thirteen studies used Fried's definition of frailty, but most (n = 27) did not use any definition. Many studies did not differentiate between the conceptualization (e.g., definition) and operationalization (e.g., use of inclusion/exclusion criteria, outcome measures) of frailty. Most interventions focused on exercise. Instrumental activities of daily living reported most frequently as outcomes (n = 11).Conclusions: There is an absence of consistent definitions of frailty in rehabilitation interventions and current definitions tend to focus on physical functioning. The authors suggest rehabilitation researchers consider an expanded definition of frailty informed by the International Classification of Functioning, Disability and Health framework.IMPLICATIONS FOR REHABILITATIONRehabilitation professionals should use an expanded definition of frailty, informed by the International Classification of Functioning, Disability and Health framework, should include physical, mental, personal, environmental, and social factors to decrease, delay, or prevent frailty in adults.Rehabilitation professionals should consider a broader operationalization of frailty that is not dependent on age and physical functioning.Rehabilitation professionals that consider a broader conceptualization of frailty should tailor interventions to the specific needs of frail adults.

Effects of the exercise mobile app and distance supervision on the functional performance of the older adults. Protocol of a clinical, randomized, controlled trial

Objective: To check the effects of the exercise mobile app with face-to-face and distance supervision on the functional performance, postural balance, and lower limb strength of older adults. Methods: This is a protocol of a controlled, randomized, and blind clinical trial in which we will recruit older adults of both genders, who will be randomized into two types of training: a control group (exercises using a mobile app with face-to-face monitoring by the therapist) and an experimental group (exercises with a mobile app without face-to-face monitoring by the therapist). The training will be carried out with the free app "Exercício para idosos", which should be installed on the participants' smartphones. The participants should do the proposed exercises three times a week for eight consecutive weeks. The evaluations will be conducted in person pre-training and after the 12th and 24th sessions. Functional performance, postural balance, and lower limb strength will be assessed. The data in each evaluation will be compared as well as the difference between the groups. It is believed that physical exercise apps for older people will benefit both groups by improving functional capacity, postural balance, and lower limbs of older adults.

Association between physical activity & sedentary time on frailty status in males and females living with diabetes mellitus: A cross-sectional analysis

BACKGROUND

Physical activity (PA) is a cornerstone for the prevention and the treatment of diabetes mellitus (DM) and frailty. However, no consensus exists on which intensities and types of PA are associated with frailty status among individuals living with DM. To investigate the association between different intensities and types of PA on frailty status in males and females living with DM.

METHODS

A cross-sectional analysis of the 2003-2006 cycles from the National Health and Nutrition Examination Survey (NHANES) was performed in 711 participants living with DM. Frailty status was measured using the 43-item deficit model and DM was self-reported. Weekly PA levels were measured by accelerometer, while resistance training (RT) was measured via questionnaire. Linear and logistic regressions were performed to investigate the associations between different intensities and types of PA and frailty status.

RESULTS

Total time spent performing light PA was associated with a better frailty status in males (ß - 0.041 ± 0.012; p < 0.001) and females (ß - 0.070 ± 0.010; p < 0.0001), while total moderate-to-vigorous PA (MVPA) was associated with a better frailty status in females only (ß-0.235 ± 0.061; p < 0.05). However, once fully adjusted, the different intensities and types of PA were associated more with frailty status for female. When investigating whether different intensities and types of PA were associated with being considered frail, total time spent at MVPA and light PA were associated with higher odds along with total sedentary time for female (all p < 0.01).

CONCLUSION

Each minute engaged in PA was associated with a better frailty status in males and females living with DM, although RT does not appear associated with a better frailty status in adults with DM. Replacing sedentary time with PA is important, especially for females living with DM to have a better frailty status. These results are important as they provide insights into the prevention and the management of frailty in individuals living with DM.

Physical Activity and Exergames Among Older Adults: A Scoping Review

Recently, exergames have been widely applied as exercise platforms among older adults. However, studies on the influence of exergames on older adults' physical activity remain scarce. The review article highlights the potential benefit of exergames as a physical activity tool for older adults. The literature search followed the PRISMA guidelines on databases PubMed (Public/Publisher MEDLINE), CINAHL (Cumulative Index to Nursing and Allied Health Literature), Cochrane, and Scopus. The literature included studies that evaluated the influence of exergames on older adults' physical activity. Articles were excluded if the mixed intervention was used, emphasizing specific limbs, improving specific tasks, or not mentioning intervention. The review article identified 25 studies that reported on 855 older adults 55 years of age and older. In addition, the common exergaming technology platforms examined were Microsoft Kinect™, Nintendo^® Wii™, cybercycling, and interactive video dance games. Meanwhile, 11 studies used a pretest/post-test design and randomized controlled trial design in 14 studies. The review found that exergames significantly impacted the older adults' physical activity level as participants experienced improved balance and cognitive function, and enjoyed playing exergame, thus prolonging their game engagement. Although research on exergames is still new, current evidence showed a significant potential benefit of exergames as a physical activity tool for older adults. To overcome the limitation on various parameters that showed different effects and outcomes of exergames, the study recommends implementing randomized controlled trials with long-term observation using a mixed-method approach. Moreover, a multidisciplinary method involving exercise and neuromotor control experts could determine potential mechanisms of action that benefited from the exercises.

High-velocity resistance training as a tool to improve functional performance and muscle power in older adults

The aging process results in several physiological impairments that, in turn, may predispose older individuals to a series of restrictions on their functional capacity. These impairments are important to understand so that suitable conditions for healthier aging can be pursued. In this review, we first summarize the effects of aging on the neuromuscular system, as well as on the relation between the main age-associated physiological impairments and functional performance with an emphasis on muscle power output. We then proceed to discuss the effects of resistance training, specifically high-velocity resistance training (HVRT), on the aforementioned neuromuscular impairments, and on functional performance in healthy and mobility-limited older adults. Collectively, available evidence suggests that HVRT seems to be a safe and effective intervention for improving muscle power, functional performance, and mobility of older individuals. It also seems that mobility-limited older adults may improve power and functional performance to a greater extent than their healthy counterparts after HVRT, which is in line with the principle of diminishing returns. Considering that only a very limited number of investigations directly compared the effects of HVRT in more than one of the aforementioned groups, studies comparing the adaptations to HVRT of middle-aged adults and older adults with distinct functional capacities would be valuable to determine whether there are differences in neuromuscular adaptations, functional performance, and functional reserve among these groups.

Older Adults' Perceptions toward Walking: A Qualitative Study Using a Social-Ecological Model

Objectives: In this study, we aimed to investigate older adults’ perceptions of their walking experiences, using the social-ecological model as a guiding framework and to propose future walking intervention content. Methods: Thirty-eight participants (19 women; 47% from private elderly centers; mean age = 72.8 (SD = 7.4 years) took part in semi-structured interviews. Qualitative data analysis software QSR-NVivo was used for thematic coding. Results: Thematic deductive analysis revealed pertinent themes at the individual level (health benefits and barriers, fall risk, perseverance, and walking as a suitable activity for older adults), social environment level (social support and social interaction), physical environment level (density, land-use mix, and connectivity; perceived safety, pedestrian facilities (benches, quality of walking paths and sidewalks, and aesthetics), other pedestrian behaviors, and weather, and policy level (lack of walking programs in the community, and supportive culture for an active lifestyle). Discussion: Our findings provide insights for the planning of future multilevel walking intervention programs for older adults in Hong Kong. It is suggested that future walking intervention should include professionals (e.g., physiotherapist or coach) in a group setting, practical walking recommendations such as proper walking posture, and additional fun activities for older adults.

Home-Based Physical Activity in Patients With Breast Cancer: During and/or After Chemotherapy? Impact on Cardiorespiratory Fitness. A 3-Arm Randomized Controlled Trial (APAC)

Objectives:

Physical activity (PA) programs are recommended for breast cancer care. However, their modalities remain to be discussed. This study determined the best time to begin a personalized or adapted program based on cardiopulmonary exercise test function. This randomized controlled trial evaluated the effect of home-based adapted PA (APA) performed during or after treatment on cardiorespiratory fitness (CRF) at 12 months.

Method:

The primary endpoint was the peak oxygen consumption (VO_2peak) at 12 months (group A vs C and B vs C). Secondary endpoints included the 6-minute walking test, assessment of muscle strength, fatigue, quality of life, anxiety, and depression, and a questionnaire on PA levels. All tests were evaluated at baseline and at 6 and 12 months. A total of 94 patients with breast cancer were randomized to 3 different groups: group A, performing 6 months of APA during adjuvant care; group B, 6 months of APA after adjuvant care; and group C, 12 months of APA during and after specific care. The program combined 1 resistance session and 2 aerobic sessions per week. Analysis of variance was used for repeated measures, Student’s t-test or the Mann–Whitney U-test for continuous variables, and χ² test for binary or categorical variables.

Results:

The study assessed 81 participants at 6 months and 73 at 12 months. The majority of patients completed more than 85% of the exercise sessions. The baseline for VO_2peak and secondary outcomes did not differ among the groups. VO_2peak increased during the exercise period and decreased during the chemotherapy period without APA, but at 12 months no significant difference was observed. The same variation was observed in the 6-minute walking test, with significance at 6 months between A+C versus B (P = .04), but no difference among the groups at 12 months. In the 3 groups, no decreases in other studied parameters were noted, except at 6 months in group B without APA.

Conclusion:

Home-based APA in breast cancer patients has a positive effect on CRF and physical functions, with no differences based on the timing of this program based on specific cancer treatment.

Trial Registration:

ClinicalTrials.gouv.fr (NCT01795612). Registered 20 February 2013.

Effects of slow- v. fast-digested protein supplementation combined with mixed power training on muscle function and functional capacities in older men

Ageing leads to a progressive loss of muscle function (MF) and quality (MQ: muscle strength (MS)/lean muscle mass (LM)). Power training and protein (PROT) supplementation have been proposed as efficient interventions to improve MF and MQ. Discrepancies between results appear to be mainly related to the type and/or dose of proteins used. The present study aimed at determining whether or not mixed power training (MPT) combined with fast-digested PROT (F-PROT) leads to greater improvements in MF and MQ in elderly men than MPT combined with slow-digested PROT (S-PROT) or MPT alone. Sixty elderly men (age 69 (sd 7) years; BMI 18-30 kg/m2) were randomised into three groups: (1) placebo + MPT (PLA; n 19); (2) F-PROT + MPT (n 21) and (3) S-PROT + MPT (n 20) completed the intervention. LM, handgrip and knee extensor MS and MQ, functional capacity, serum metabolic markers, skeletal muscle characteristics, dietary intake and total energy expenditure were measured. The interventions consisted in 12 weeks of MPT (3 times/week; 1 h/session) combined with a supplement (30 g:10 g per meal) of F-PROT (whey) or S-PROT (casein) or a placebo. No difference was observed among groups for age, BMI, number of steps and dietary intake pre- and post-intervention. All groups improved significantly their LM, lower limb MS/MQ, functional capacity, muscle characteristics and serum parameters following the MPT. Importantly, no difference between groups was observed following the MPT. Altogether, adding 30 g PROT/d to MPT, regardless of the type, does not provide additional benefits to MPT alone in older men ingesting an adequate (i.e. above RDA) amount of protein per d.

Objectively Measured Sitting and Standing in Workers: Cross-Sectional Relationship with Autonomic Cardiac Modulation

Excessive sitting and standing are proposed risk factors for cardiovascular diseases (CVDs), possibly due to autonomic imbalance. This study examines the association of objectively measured sitting and standing with nocturnal autonomic cardiac modulation. The cross-sectional study examined 490 blue-collar workers in three Danish occupational sectors. Sitting and standing during work and leisure were assessed during 1⁻5 days using accelerometers. Heart rate (HR) and heart rate variability (HRV) were obtained during nocturnal sleep as markers of resting autonomic modulation. The associations of sitting and standing still (h/day) with HR and HRV were assessed with linear regression models, adjusted for age, gender, body mass index, smoking, and physical activity. More sitting time during leisure was associated with elevated HR (p = 0.02), and showed a trend towards reduced HRV. More standing time at work was associated with lower HR (p = 0.02), and with increased parasympathetic indices of HRV (root mean squared successive differences of R-R intervals p = 0.05; high-frequency power p = 0.07). These findings, while cross-sectional and restricted to blue-collar workers, suggest that sitting at leisure is detrimental to autonomic cardiac modulation, but standing at work is beneficial. However, the small effect size is likely insufficient to mitigate the previously shown detrimental effects of prolonged standing on CVD.

Psychometric Properties of the Modified Social Environment Questionnaire in Chinese Older Adults

This study evaluated the psychometric properties of a Chinese version of the 24-item Social Environment Questionnaire (SEQ-C). Confirmatory factor analysis was used to examine the factor validity and measurement invariance (Purpose 1) of the SEQ-C in 453 older adults in Hong Kong. Convergent validity (Purpose 2) and test-retest reliability (Purpose 3) were also measured. The results of the confirmatory factor analysis and measurement invariance supported the four-factor structure (representing companionship, encouragement, neighborhood social cohesion, and role models) of the SEQ-C, in a 15-item model that closely fitted the data. The SEQ-C was also found to have acceptable to satisfactory internal consistency, test-retest reliability, composite reliability, and moderate convergent validity in correlating perceived social support. This study showed that the SEQ-C is a suitable means of measuring the social environments of older adults in Hong Kong.

The Association of Vitamin D Levels and the Frailty Phenotype Among Non-geriatric Dialysis Patients: A Cross-sectional Study

OBJECTIVES

The aim of this study was to investigate the frequency of frailty and the association of vitamin D levels and the frailty phenotype among non-geriatric dialysis patients.

METHOD

Seventy-four stable, chronic hemodialysis patients from the hemodialysis unit of the hospital were enrolled in the study. The patients' medical histories and laboratory findings were obtained from the medical records of the dialysis unit. Serum parathyroid hormone and 25-hydroxy vitamin D levels were determined using chemiluminometric immunoassays. Frailty was defined by Fried et al. as a phenotype; shrinking, weakness, self-reported exhaustion, decreased activity and slowed walking speed were evaluated.

RESULTS

Forty-one (55%) of the patients were males. The patients were divided into 3 groups according to frailty scores: 39 (53%) patients were frail, 6 (8%) patients were intermediately frail, and 28 (39%) patients were normal. Significant differences were found for 25-hydroxy vitamin D and hemoglobin levels among the groups; however, no differences were observed in body mass index, comorbidities, sex, marital status, education, disease and dialysis durations, or parathyroid hormone, creatinine, serum calcium, phosphorus, and potassium levels.

CONCLUSIONS

Weakness and slowness are serious outcomes of both vitamin D deficiency and frailty, and vitamin D deficiency has been associated with increased risks of decreased physical activity, falls, fractures and death in postmenopausal women and older men. Although studies on frailty have focused on older adults, growing evidence indicates that the frailty phenotype is becoming a factor associated with poor health outcomes in non-geriatric populations with chronic disease.

Increased Physical Activity and Fitness above the 50(th) Percentile Avoid the Threat of Older Adults Becoming Institutionalized: A Cross-sectional Pilot Study

The objective of this study was to analyze the impact of physical fitness and physical activity on the threat of older adults without cognitive impairment becoming institutionalized. This cross-sectional study involved 195 non-institutionalized (80.1 ± 4.4 years) and 186 institutionalized (83.8 ± 5.2years) participants. Cognitive impairment was assessed using Mini-Mental State Examination, measures of physical fitness were determined by the Senior Fitness Test, and physical activity was assessed using the International Physical Activity Questionnaire. Multivariate binary logistic analysis selected four main determinants of institutionalization in both genders: The likelihood of becoming institutionalized increased by +18.6% for each additional year of age, whereas it decreased by -24.8% by each fewer kg/m(2) in body mass index (BMI), by -0.9% for each additional meter performed in the aerobic endurance test, and by -2.0% for each additional 100 metabolic equivalent of task (MET)-min/week of physical activity expenditure (p < 0.05). Values ≤50(th) percentile (age ≥81 years, BMI ≥26.7 kg/m(2), aerobic endurance ≤367.6 meters, and physical activity ≤693 MET-min/week) were computed using receiver operating characteristics analysis as cutoffs discriminating institutionalized from non-institutionalized older adults. The performance of physical activity, allied to an improvement in physical fitness (mainly BMI and aerobic endurance), may avoid the threat of institutionalization of older adults without cognitive impairment only if they are above the 50(th) percentile. The following parameters are highly recommended: Expending ≥693 MET-min/week on physical activity, having a BMI ≤26.7 kg/m(2), and being able to walk ≥367.6 meters in the aerobic endurance test, especially above the age of 80 years. The discovery of this trigger justifies the development of physical activity programs targeting the pointed cutoffs in old and very old adults.

The role of high-intensity physical exercise in the prevention of disability among community-dwelling older people

Background

Moderate to vigorous physical activity (MVPA) is considered important to prevent disability among community-dwelling older people. To develop MVPA programs aimed at reducing or preventing disability more insight is needed in the contributions of exercise duration and intensity and the interplay between the two.

Methods

Longitudinal data of 276 Dutch community-dwelling persons aged 65 years and older participating in the Elderly And their Neighbourhood (ELANE) study were used. MVPA exercise (yes/no), duration (hours per two weeks), intensity (Metabolic Equivalent of Task; METs), and energy expenditure (MET-hours per two weeks), and disability in instrumental activities of daily living (range 0–8) were measured twice within 9 months to account for fluctuations over time. Associations between the four exercise measures and disability were tested with longitudinal tobit regression analyses.

Results

MVPA exercise was associated with fewer disabilities. While exercise duration was not associated with disability, whereas an increase of one MET in exercise intensity was associated with 0.14 fewer disabilities (95 % CI: -0.26 to -0.02). For exercise energy expenditure, an increase of one MET-hour exercise per two weeks was associated with 0.03 fewer disabilities (95 % CI: -0.05 to -0.01).

Conclusions

Higher-intensity exercise may help to prevent disability among community-dwelling older people. Further investigation is needed to explore the preventive effects in more detail.

Muscle activity during daily life in the older people

BACKGROUND

Daily muscle activity is important for functional independence. This study examined muscle activity patterns during normal daily life and simulated daily tasks and compared muscle activity and energy consumption during active and passive transport tasks in older adults.

METHODS

Nine volunteers (70 ± 6 years) were measured for quadriceps and hamstring muscle activity (EMG) during normal daily life, treadmill walking, and during passive and active transport tasks. EMG was normalized to that recorded during maximal voluntary contraction (MVC). Oxygen uptake (VO2) was measured during treadmill and transport tasks.

RESULTS

During daily life the mean EMG amplitude was 5.9 ± 2.4 % of EMGMVC, activity time was 187 ± 43 min and the longest continuous inactivity periods were 20.9 ± 10.0 min. During stair ascend the peak EMG activity was 120 % of EMGMVC and the peak VO2 values were only about 70 % of VO2max. One kilometer walk consumed 3.5 times more energy than passive transport by bus, and using stairs consumed 11.7 times more energy than using an elevator.

CONCLUSIONS

In daily life, older adults use only a small fraction of muscle's maximal capacity and have long continuous inactivity periods. Negotiating stairs produce significant load to neuromuscular, but not to cardiovascular system, thus providing an effective strength training stimulus.

Intramuscular phosphagen status and the relationship to muscle performance across the age spectrum

PURPOSE

To examine age-related differences in intramuscular concentrations of adenosine triphosphate (ATP), free creatine (FCr), phosphocreatine (PCr) and total creatine (TCr) and if these differences were related to muscle performance.

METHODS

Forty-two healthy, non-sedentary, males between 20 and 76 years provided muscle samples to determine [ATP], [FCr], [PCr], and [TCr]. Maximal strength and endurance were assessed and correlated with intramuscular variables.

RESULTS

Intramuscular [ATP] decreased by 13.5% (p = 0.013) in the older cohort (18.0 ± 0.6 mmol/kg dry wt) vs. the young cohort (20.8 ± 0.9 mmol/kg dry wt) and was significantly correlated to age (r = -0.38, p = 0.008). No other differences were observed between age groups for intramuscular [PCr], [FCr], [TCr], or [PCr]:[TCr] (p > 0.05). The older cohort consumed significantly less (p < 0.05) dietary protein when compared to the young cohort. Bivariate correlations were found for intramuscular [ATP] and lower body 1RM (r = 0.24, p = 0.066), leg press volume and free creatine (r = 0.325, p = 0.036) and leg press repetitions and free creatine (r = 0.373, p = 0.015). Partial correlations controlling for age eliminated the relationship between [ATP] and 1RM while intramuscular free creatine and leg press repetitions remained significant (p < 0.05) and leg press volume approached significance (p = 0.095).

CONCLUSION

These results expand upon previous observations indicative of age-related reductions in intramuscular [ATP] and dietary protein intake. The lack of change in other intramuscular PCr system markers are suggestive of dysfunctions at the mitochondrial level while the impact of neuromuscular changes, lean mass cross-sectional area and differences in physical activity are also important.

Evidence-based risk assessment and recommendations for physical activity clearance: Consensus Document 2011

The Physical Activity Readiness Questionnaire (PAR-Q) and the Physical Activity Readiness Medical Evaluation (PARmed-X) are internationally known preparticipation screening tools developed on the basis of expert opinion. The primary purposes of this consensus document were to seek evidence-based support for the PAR-Q and PARmed-X forms, to identify whether further revisions of these instruments are warranted, to determine how people responding positively to questions on the PAR-Q can be safely cleared without medical referral, and to develop exercise clearance procedures appropriate for various clinical conditions across the human lifespan. Seven systematic reviews were conducted, examining physical-activity-related risks and effective risk-stratification procedures for various prevalent chronic conditions. An additional systematic review assessed the risks associated with exercise testing and training of the general population. Two gap areas were identified and evaluated systematically: the role of the qualified exercise professional and the requisite core competencies required by those working with various chronic conditions; and the risks associated with physical activity during pregnancy. The risks associated with being physically inactive are markedly higher than transient risks during and following an acute bout of exercise in both asymptomatic and symptomatic populations across the lifespan. Further refinements of the PAR-Q and the PARmed-X (including online versions of the forms) are required to address the unique limitations imposed by various chronic health conditions, and to allow the inclusion of individuals across their entire lifespan. A probing decision-tree process is proposed to assist in risk stratification and to reduce barriers to physical activity. Qualified exercise professionals will play an essential role in this revised physical activity clearance process.

Age- and sex-related differences for electromyography gaps during daily activity and a discrete task

Temporal patterns of quiescent electromyography termed 'gaps' were investigated in young and old men and women for a discrete task and daily activity. Gaps in women (1.3±3.2) and old adults (1.5±3.4) were fewer compared with men (4.7±6.7) and young adults (4.6±6.9) for the discrete task (p<0.001). Gap duration was shorter for women (0.1±0.2s) and old adults (0.1±0.3s) compared with men (0.2±0.3s) and young adults (0.2±0.2s) (p<0.01). For daily activity, gap number was similar with age, but gap duration and percentage of total time occupied by gaps were less in old compared with young adults (50%), and in women compared with men (43%) (p<0.001). Results suggest gap activity is sensitive to type and duration of activity and that old adults and women demonstrate less quiescent electromyography than young adults and men.

The effectiveness of exercise interventions for the management of frailty: a systematic review

This systematic review examines the effectiveness of current exercise interventions for the management of frailty. Eight electronic databases were searched for randomized controlled trials that identified their participants as “frail” either in the title, abstract, and/or text and included exercise as an independent component of the intervention. Three of the 47 included studies utilized a validated definition of frailty to categorize participants. Emerging evidence suggests that exercise has a positive impact on some physical determinants and on all functional ability outcomes reported in this systematic review. Exercise programs that optimize the health of frail older adults seem to be different from those recommended for healthy older adults. There was a paucity of evidence to characterize the most beneficial exercise program for this population. However, multicomponent training interventions, of long duration (≥5 months), performed three times per week, for 30–45 minutes per session, generally had superior outcomes than other exercise programs. In conclusion, structured exercise training seems to have a positive impact on frail older adults and may be used for the management of frailty.

Sisters in motion: a randomized controlled trial of a faith-based physical activity intervention

OBJECTIVES

To evaluate a faith-based intervention (Sisters in Motion) intended to increase walking in older, sedentary African-American women.

DESIGN

Randomized controlled trial using within-church randomization.

SETTING

Three Los Angeles churches.

PARTICIPANTS

Sixty-two African-American women aged 60 and older who reported being active less than 30 minutes three times per week and walked less than 35,000 steps per week as measured using a baseline pedometer reading.

INTERVENTION

Intervention participants received a multicomponent curriculum including scripture readings, prayer, goal-setting, a community resource guide, and walking competitions. Intervention and control participants both participated in physical activity sessions.

MEASUREMENTS

The primary outcome was change in weekly steps walked as measured using the pedometer. Secondary outcomes included change in systolic blood pressure (SBP). Outcomes were assessed at baseline and 6 months after the intervention.

RESULTS

Eighty-five percent of participants attended at least six of eight sessions. Intervention participants averaged 12,727 steps per week at baseline, compared with 13,089 steps in controls. Mean baseline SBP was 156 mmHg for intervention participants and 147 mmHg for controls (P=.10). At 6 months, intervention participants had increased their weekly steps by 9,883 on average, compared with an increase of 2,426 for controls (P=.02); SBP decreased on average by 12.5 mmHg in intervention participants and only 1.5 mmHg in controls (P=.007).

CONCLUSION

The Sisters in Motion intervention led to an increase in walking and a decrease in SBP at 6 months. This is the first randomized controlled trial of a faith-based physical activity program to increase physical activity in older African-American women and represents an attractive approach to stimulate lifestyle change in this population.

Muscle fatigue characteristics in paralyzed muscle after spinal cord injury

STUDY DESIGN

The study design used is cross-sectional.

OBJECTIVES

The aim of this study is to examine muscle contractile and excitability characteristics during fatigue of the tibialis anterior in six individuals with chronic spinal cord injury (SCI) and matched able-bodied (AB) controls.

SETTING

McMaster University, Hamilton, ON, Canada.

METHODS

Muscle compound action potential (M-wave) characteristics, muscle twitch properties, and summated force were examined during a 2 min fatigue protocol of intermittent bursts at 30 Hz (4 s tetanus, 2 s rest) or maximal voluntary contraction (MVC). Evoked twitch responses were followed during a recovery period.

RESULTS

M-wave amplitude was smaller in SCI (2.5 ± 1.6 mV in SCI, 5.7 ± 3.2 mV in AB) at baseline, but there was no change in M-wave amplitude or area during fatigue in either group. There was an increase in M-wave duration toward the end of recovery in the SCI group. Peak torque (PT) was not different between groups at baseline (3.8 ± 1.8 Nm in SCI, 3.7 ± 0.6 Nm in AB); PT potentiated significantly during fatigue in the AB, but not SCI group. There was significantly greater fatigue of both PT (43% decline) and summated force (57% decline) in the SCI group compared with the AB group (13% increase and 22% decline for PT and MVC, respectively).

CONCLUSION

The dorsiflexor muscles in people with SCI are significantly more fatiguable than those in AB controls, but decreases in muscle excitability do not seem to be an important contributor to the increased fatiguability. The mechanisms behind the increased fatigue must lie distal to the muscle membrane.