Functional benefit of power training for older adults

Correlation between Power Elbow Flexion and Physical Performance Test: A Potential Predictor for Assessing Physical Performance in Older Adults

BACKGROUND

With the increasing number of older adults and their declining motor and cognitive function, it is crucial to find alternative methods for assessing physical functionality. The Short Physical Performance Battery (SPPB), the Time Up and Go (TUG) test, the 4 Meter Walk Test and the Barthel Index (BI) have been used to evaluate mobility and fragility and predict falls. But some of these functional test tasks could be difficult to perform for frail older adults or bedridden patients that cannot ambulate. This study aimed to evaluate the relationship between these functional tests and the power elbow flexion (PEF test).

MATERIAL AND METHODS

A correlation study was designed with 41 older adults over 65 years of age. The upper limb muscle power was measured using a linear encoder (VITRUBE VBT) with the flexion of the elbow.

RESULTS

Strong correlations were found between the PEF test and the 4mWT (rho = 0.715, p = 0.001) and TUG (rho= -0.768, p = 0.001), indicating that the greater the upper limb muscle power is, the greater physical performance will be. Moderate correlations were also found between the PEF and Barthel Index (rho = 0.495, p = 0.001) and SPPB (rho = 0.650, p < 0.001).

CONCLUSIONS

There is a strong correlation between PEF and the functional tests, proving that older adults that have greater upper limb muscle power have better physical performance. Upper limb muscle power and PEF could be an interesting tool for the assessment of physical performance in bedridden older adults.

High-velocity power training has similar effects to traditional resistance training for functional performance in older adults: a systematic review

QUESTIONS

What is the effect of high-velocity power training (HVPT) compared with traditional resistance training (TRT) on functional performance in older adults? What is the quality of intervention reporting for the relevant literature?

DESIGN

Systematic review and meta-analysis of randomised controlled trials.

PARTICIPANTS

Older adults (aged > 60 years), regardless of health status, baseline functional capacity or residential status.

INTERVENTIONS

High-velocity power training with the intent to perform the concentric phase as quickly as possible compared with traditional moderate-velocity resistance training performed with a concentric phase of ≥ 2 seconds.

OUTCOME MEASURES

Short Physical Performance Battery (SPPB), Timed Up and Go test (TUG), five times sit-to-stand test (5-STS), 30-second sit-to-stand test (30-STS), gait speed tests, static or dynamic balance tests, stair climb tests and walking tests for distance. The quality of intervention reporting was assessed with the Consensus on Exercise Reporting Template (CERT) score.

RESULTS

Nineteen trials with 1,055 participants were included in the meta-analysis. Compared with TRT, HVPT had a weak-to-moderate effect on change from baseline scores for the SPPB (SMD 0.27, 95% CI 0.02 to 0.53; low-quality evidence) and TUG (SMD 0.35, 95% CI 0.06 to 0.63; low-quality evidence). The effect of HVPT relative to TRT for other outcomes remained very uncertain. The average CERT score across all trials was 53%, with two trials rated high quality and four rated moderate quality.

CONCLUSION

HVPT had similar effects to TRT for functional performance in older adults, but there is considerable uncertainty in most estimates. HVPT had better effects on the SPPB and TUG, but it is unclear whether the benefit is large enough to be clinically worthwhile.

Effects of 8 weeks of resistance training in combination with a high protein diet on body composition, muscular performance, and markers of liver and kidney function in untrained older ex-military men

Background

The effects of a high protein diet in combination with chronic resistance training (RT) on skeletal muscle adaptation responses in untrained older ex-military men is unknown. Therefore, we compared the effects of 8 weeks of RT in combination with either a high (1.6 g/kg/d) or low protein diet (0.8 g/kg/d) on body composition [skeletal muscle mass (SMM) and body fat percentage (BFP)], muscular strength, power, and endurance (upper and lower body), markers of liver [alanine transaminase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transferase (GGT)] and kidney (creatinine and urea) function, and lipid profile low-density lipoprotein (LDL), high-density lipoprotein (HDL), and cholesterol levels in a cohort of healthy, untrained older ex-military males.

Methods

Forty healthy untrained older ex-military males (age: 61 ± 2 yr, body mass index: 23.2 ± 1.3 kg.m^-2) performed 8 weeks (three sessions·w^-1) of RT with either 1.6 g/kg/d (RHP; n = 20) or 0.8 g/kg/d of protein (RLP; n = 20). Body composition (assessed by Inbody 720), muscular strength (1-RM for chest and leg press), power (Wingate test), endurance (75% 1-RM for chest and leg press), and markers of liver and kidney function (biochemical kits) were assessed pre and post-intervention.

Results

SMM and muscular strength (upper and lower body) increased post-intervention in both groups and were significantly greater in RHP compared to RLP, while muscular power increased to the same extent in both groups (p < 0.05) with no between-group differences (p > 0.05). In contrast, there were no post-intervention changes in muscular endurance, HDL, and BFP remained in either group (p > 0.05). ALT and creatinine significantly increased in RHP compared to RLP while GGT, AST, and urea only increased in the RLP group (p < 0.05). LDL and cholesterol significantly decreased in both groups (p < 0.05).

Conclusion

A daily intake of 1.6 g/kg/d protein was superior to 0.8 g/kg/d (current recommended daily intake) for promoting greater improvements in SMM and muscle strength and thus may be a more suitable level of intake for promoting such adaptive responses. Notwithstanding observed between-group differences in ALT and creatinine and the fact that levels remained within normal ranges, it is feasible to conclude that this daily protein intake is efficacious and well tolerated by healthy, untrained older ex-military males.

Reliability of Gallon-Jug Shelf-Transfer Power Equations in Older Women

ABSTRACT

Ly, A, Strand, KL, Courtney, KJ, Barry, SS, Liscano, JA, Trebotich, TL, Martin-Diala, C, Martin, E, and Signorile, JF. Reliability of gallon-jug shelf-transfer test power equations in older women. J Strength Cond Res XX(X): 000-000, 2022-This study examined the test-retest reliability of the gallon-jug shelf-transfer (GJST) test as a measure of upper-body functional power in older women. Although the validity of the predictive equations for power during the GJST test has been established, for the test to be viable in either a laboratory or clinical environment, between-day and within-day reliability must be established. Thirty-four independently living older women (mean ± SD: 75.0 ± 6.4 years) performed 2 sets of 3 repetitions of the GJST test on 2 days separated by at least 48 hours. Using the established predictive equations, the values for peak power and average power were then computed. Statistical analyses to assess reliability included intraclass correlation coefficient, coefficient of variation (CV), SEM, minimal detectable change (MDC), and Cronbach's α values. Furthermore, Bland-Altman plots evaluated the agreement between the tests. Intraclass correlation coefficient (>0.91, p < 0 001), CV (<8.1%), SEM (<5.94 W), MDC (<14 W), and Cronbach's α (>0.95) indicated excellent reliability. The lines of equality for all Bland-Altman plots fell within the 95% confidence interval of the mean difference, implying that there were no significant differences between tests. Furthermore, bias values were small (<11.15 W), and the limits of agreement (LOA) were within an acceptable range. Based on our statistical analyses, the GJST test is a highly reliable assessment for determining object transfer power for healthy older women.

Effective Throughput Analysis of Different Task Execution Strategies for Mid-Air Fitts' Tasks in Virtual Reality

Fitts' law and throughput based on effective measures are two mathematical models frequently used to analyze human motor performance in a standardized pointing task, e.g., to compare the performance of input and output devices. Even though pointing has been deeply studied in 2D, it is not well understood how different task execution strategies affect throughput in pointing in 3D virtual environments. In this work, we examine the effective throughput measure, claimed to be invariant to task execution strategies, in Virtual Reality (VR) systems with three such strategies, "as fast, as precise, and as fast and as precise as possible" for ray casting and virtual hand interaction, by re-analyzing data from a 3D pointing ISO 9241-411 study. Results show that effective throughput is not invariant for different task execution strategies in VR, which also matches a more recent 2D result. Normalized speed vs. accuracy curves also did not fit the data. We thus suggest that practitioners, developers, and researchers who use MacKenzie's effective throughput formulation should consider our findings when analyzing 3D user pointing performance in VR systems.

Strength-Cognitive Training: A Systemic Review in Adults and Older Adults, and Guidelines to Promote "Strength Exergaming" Innovations

Background

Despite functional and cognitive benefits, few adults and older adults do strength training twice per week with sufficient intensity. Exercise-based active video games (exergaming) may amplify the cognitive benefits of exercise and increase adherence and motivation toward training. However, the benefits of a well-defined and monitored dose of strength training, executed simultaneously or sequentially with a cognitive element, has received little attention. In this study we have two aims: First, to systematically gather the available evidence; second, to suggest possible ways to promote strength exergaming innovations.

Methods

We systematically reviewed randomized controlled trials using simultaneous or sequent combined strength and cognitive training or strength exergaming to improve cognitive or functional outcomes in adults and older adults.

Results

After screening 1,785 studies (Google Scholar, ACM Digital Library, IEEE Xplore Library, PsycARTICLES, Scopus, Cochrane Library and PubMed) we found three eligible studies. Of the two studies using sequent strength and cognitive training, one showed improved functionality, but the other showed negative effects on cognition. The third study using simultaneous intervention, reported a positive influence on both cognition and function, when compared with either strength training alone or a control group. Moderate level of evidence was showed on GRADE analysis.

Conclusion

The existing little evidence suggests that strength and cognitive training improves cognition and function in adults and older adults. The following suggestions may help to promote further innovation: (1) ensure minimal dosage of strength training (30-60 min, 2 × /week), (2) use machine-based strength training devices to control volume and intensity (to prevent cognitive components from interfering with strength training), (3) include power training by using cognitive tasks requiring rapid reactions, and (4) add cognitive memory tasks (to extend the cognitive benefits of strength training per se), and (5) include motivational exergame elements to increase adherence.

Effects of an App-Based Physical Exercise Program on Selected Parameters of Physical Fitness of Females in Retirement: A Randomized Controlled Trial

Modern technologies enable new options in the delivery of physical exercise programs. Specially designed app-based programs can be used to help older people in particular to integrate physical exercise into their daily lives. This study examines the influence of an app-based physical exercise program on selected parameters of physical fitness, such as muscular strength, balance, and flexibility. The women (n = 110) were on average 65.3 (± 1.5) years old and, compared to age-specific norm values, healthy. The 14-week intervention consisted of an app-based, unsupervised physical exercise program, in which the exercise frequency and duration of sessions were self-selected. The physical exercise program consisted of simple, functional exercises such as arm circles, squats, lateral raises. The participants were provided with an elastic resistance band and an exercise ball allowing them to increase exercise intensity if needed. Participants were randomly assigned to intervention group (IG) and control group (CG). 71% of the IG used the physical exercise program at least 1.2 times per week, whereas 25% of the IG showed usage rates above four times per week. Significant effects were found in the domains of muscular strength and flexibility. While IG could maintain their performance in isometric muscular strength tests and increased their flexibility, CG faced a decrease in those parameters. Thus, this app-based physical exercise program had positively influenced muscular strength and flexibility in women over 60 years of age.

Periodized Resistance Training With and Without Functional Training Improves Functional Capacity, Balance, and Strength in Parkinson's Disease

ABSTRACT

Strand, KL, Cherup, NP, Totillo, MC, Castillo, DC, Gabor, NJ, and Signorile, JF. Periodized resistance training with and without functional training improves functional capacity, balance, and strength in Parkinson's disease. J Strength Cond Res 35(6): 1611-1619, 2021-Periodized progressive resistance training (PRT) is a common method used to improve strength in persons with Parkinson's disease (PD). Many researchers advocate the addition of functional training to optimize translation to activities of daily living; however, machine-based PRT, using both force and velocity training components, may elicit similar benefits. Thirty-five persons with PD (Hoehn and Yahr I-III) were randomized into a strength, power, and hypertrophy (SPH; n = 17) or strength, power, and functional (SP + Func; n = 18) group, training 3 times weekly for 12 weeks. Both groups performed machine-based strength and power training on days 1 and 2 each week, respectively; whereas, on day 3, SPH group performed machine-based hypertrophy training and SP + Func group performed functional training. Functional performance was tested using the timed up and go, 30-second sit-to-stand (30-s STS), gallon-jug shelf-transfer, and seated medicine ball throw (SMBT) tests. Balance (Mini-BESTest), strength, motor symptoms (UPDRS-III), quality of life, and freezing of gait (FOG) were also assessed. Repeated measures analysis of variance revealed a main effect for time (p ≤ 0.05) with significant improvements for the sample in the 30-s STS (p = 0.002), SMBT (p = 0.003), Mini-BESTest (p < 0.001), upper-body strength (p = 0.002) and lower-body strength (p < 0.001). A significant group × time interaction was seen for FOG, with SP + Func alone showing improvement (p = 0.04). Furthermore, the SPH group produced a clinically important difference for the UPDRS-III (mean difference = 4.39, p = 0.18). We conclude that both exercise strategies can be equally effective at improving functional capacity, balance, and muscular strength in individuals with PD. In addition, FOG and motor symptoms may be targeted through SP + Func and SPH, respectively. The results provide options for individualized exercise prescriptions.

Effectiveness of a Community-Based Muscle Strengthening Exercise Program to Increase Muscle Strength Among Pre-frail Older Persons in Malaysia: A Pilot Study

Deterioration in muscle mass and muscle strength is common among the frail older persons, cause functional dependence and decrease in the quality of life. Therefore, the identification of cost-effective interventions to prevent or ameliorate frailty is crucially needed. The aim of this study is to determine the effectiveness of a Community-based Muscle Strengthening Exercise (COME) program to increase muscle strength among pre-frail older persons. This study was a quasi-experimental study. A total of 32 older persons aged 60 years and older with pre-frail symptoms were recruited from the community center. The COME was developed based on the Growing Stronger program and the Otago Home Exercise Program. COME was designed to strengthen all of the major muscle groups in the upper and lower extremities. The exercise program was conducted for 12 weeks and divided into 3 parts; (1) to strengthen the body slowly and gently, using only body weight, (2) to introduce dumbbells and ankle weights to increase strength and (3) to add various new ways to boost strength even more. Functional tests were measured before and after the intervention. The results revealed non-significant p-value for pre- and post-intervention comparison for all study outcomes. Observing the values of mean difference, the study intervention was shown to have slightly improved the time up and go (Mean difference = -0.25), and sit-to-stand duration (Mean difference = -0.41) as well as the handgrip strength (Mean difference = 0.68) among the participants. On the assessment of Cohen ES, all three improvements exhibited small effect sizes. Sit-to-stand duration was shown to have most benefited from the intervention with highest ES among the outcome variables (ES = 0.20). COME intervention program among pre-frail older persons showed favorable trend toward improvement of upper and lower extremities muscle strength. This study should be further tested in randomized control trial to confirm its effectiveness.

Functional autonomy and sarcopenia markers in women over 55 years of age

Introduction: Some parameters used to diagnose sarcopenia and functional autonomy disorders can lead to interpretation and classification errors. Objective: To analyze sarcopenia markers and their relationship with the strength and gait of physically active older women aged between 55 and 76 years. Materials and Methods: Analytical observational study conducted in 178 physically active Colombian women who were distributed in two age groups (group 1: 55-66 years, n=98, and group 2: 67-76 years, n=80). A multiple linear regression model was used to establish possible correlations between strength and gait indicators (dependent variables) and body composition (independent variables). Results: Fat mass and appendicular mass (appendicular lean/height2(kg/m2)) explained power variance in the lower limbs in group 1 (G1) (SJ: p=0.001, R2=0.56; CMJ: p=0.001, R2=0.51; CMJAS: R2=0.60, p=0.001). Similar results were observed in group 2 (G2) (SJ: R2=0.32, DW1=2.14; CMJ: R2=0.51, DW2=2.38; CMJAS: R2=0.41, DW3=2.56). Furthermore, fat mass explained variance in gait pattern in G1 and G2 differently (G1: p=-0.006; R2=20%; G2: p=-0.001; R2=29%). Conclusion: Recording fat and appendicular mass allow studying negative changes in lower limb strength and their effect on gait pattern, as well as identifying the type of sarcopenia and functional autonomy disorders in physically active Colombian women aged 55 to 76 years.

Effects of a power training program in the functional capacity, on body balance and lower limb muscle strength of elderly with type 2 diabetes mellitus

BACKGROUND

The effects of interventions with muscle power training on balance and functionality in individuals with type 2 diabetes mellitus (T2DM) are still poorly investigated. We evaluated the efficacy of a twelve-week power training program in the functional capacity, balance and lower limb muscle power and strength of elderly with T2DM.

METHODS

Twenty-one subjects (14 women and seven men) were allocated into two groups. One of the groups (PTG) performed a power training program twice a week (N.=11; age 70.5±7.8 years old), and the other was an active control group (CG) that performed a weekly stretching session (N.=10; age 66±3.2 years old). Outcomes of interest were assessed at baseline and after 12 weeks, these included functional capacity, balance, muscle strength and power.

RESULTS

The PTG participants improved their dynamic balance (P=0.027) and decrease in the time to perform the gait speed test (P<0.001), evaluated by the short physical performance battery (SPPB). Also showed a statically significant change muscle power (P=0.034) and maximal dynamic knee extension strength (P=0.023), with increments of 24% and 34%, respectively, in comparison to the CG. Both groups showed significant changes in the performance of the five-times-sit-to-stand test (P<0.001) and the SPPB score (P=0.001).

CONCLUSIONS

The power training program was able to promote improvements in some functional parameters as on the body balance and functional capacity and muscle strength of the elderly with T2DM. The training method was effective and safe, with no adverse effects during sessions.

High-Speed Bodyweight Resistance Training Improves Functional Performance Through Maximal Velocity in Older Females

The authors compared the effects of bodyweight resistance training at moderate- or high-speed conditions on muscle power, velocity of movement, and functional performance in older females. In a randomized, single-blinded noncontrolled trial, participants completed 12 weeks (three sessions/week) of bodyweight resistance training at high (n = 14; age = 70.6 ± 4.3 years) or moderate (n = 12; age = 72.8 ± 4.2 years) speeds. Data were analyzed with an analysis of variance (Group × Time) with α level set at <.05. After the intervention, timed up and go test performance (p < .05) and the rising from a chair test mean (22.4%) and maximal velocity (28.5%), mean (24.4%) and maximal power (27.7%), normalized mean (25.1%), and normalized maximal power (28.5%) increased in the high-speed group (p < .05). However, the moderate-speed group achieved no improvements (Δ6.7-14.4%; p > .2). The authors conclude that high-speed bodyweight resistance training is an effective and economically practical strategy to improve the functional capacity of older women relevant to daily life activities.

Optimal Approach to Load Progressions during Strength Training in Older Adults

Progressive resistance training (RT) is one of the most effective interventions for reducing age-related deficits in muscle mass and functional capacity.

PURPOSE

To compare four approaches to load progressions in RT for older adults to determine if an optimal method exists.

METHODS

Eighty-two healthy community-dwelling older adults (71.8 ± 6.2 yr) performed 11 wk of structured RT (2.5 d·wk) in treatment groups differing only by the method used to increase training loads. These included percent one repetition maximum (%1RM): standardized loads based on a percentage of the one repetition maximum (1RM); rating of perceived exertion (RPE): loads increased when perceived difficulty falls below 8/10 on the OMNI-Resistance Exercise Scale perceived exertion scale; repetition maximum (RM): loads increased when a target number of repetitions can be completed with a given load; repetitions in reserve (RiR): identical to RM except subjects must always maintain ≥1 "repetition in reserve," thus avoiding the possibility of training to temporary muscular failure.

RESULTS

Multiple analyses of covariance indicated no significant between-group differences on any strength (chest press 1RM; leg press 1RM) or functional performance outcome (usual walking speed, maximum walking speed, 8-ft timed up-and-go, gallon jug transfer test, 30 s sit-to-stand). The RPE group found the exercise to be significantly more tolerable and enjoyable than subjects in the RiR, RM, and %1RM groups.

CONCLUSION

Given the RM, RPE, %1RM, and RiR methods appear equally effective at improving muscular strength and functional performance in an older population, we conclude that the RPE method is optimal because it is likely to be perceived as the most tolerable and enjoyable, which are two important factors determining older adults' continued participation in RT.

Effects of Home- and Center-Based Exercise Programs on the Strength, Function, and Gait of Prefrail Older Women: A Randomized Control Trial

The aims of this study were to compare the effects of a multicomponent exercise program provided at a center (CB) versus done part at home and part at a center (H+CB) on frailty status, strength, physical function, and gait of prefrail older women. Twenty-five women were randomly allocated into the CB (n = 14; 69 ± 6 years) and the H+CB (n = 11; 69 ± 7 years) groups. Both groups completed an exercise program including strengthening, balance, and gait exercises. The program was 12 weeks long, done three times per week, for 60 min per session. Frailty, knee and hip muscle strength, spatiotemporal parameters of the usual and maximum speed dual-task gait, and physical function were assessed at baseline and after program completion. The exercise program reversed the prefrail status of most participants independently of the mode of delivery. Strength increased in both groups, but the CB group had more pronounced improvements in gait and physical function. H+CB exercise programs are good options for prefrail older women.

Resistance Training for Older Adults: Position Statement From the National Strength and Conditioning Association

Fragala, MS, Cadore, EL, Dorgo, S, Izquierdo, M, Kraemer, WJ, Peterson, MD, and Ryan, ED. Resistance training for older adults: position statement from the national strength and conditioning association. J Strength Cond Res 33(8): 2019-2052, 2019-Aging, even in the absence of chronic disease, is associated with a variety of biological changes that can contribute to decreases in skeletal muscle mass, strength, and function. Such losses decrease physiologic resilience and increase vulnerability to catastrophic events. As such, strategies for both prevention and treatment are necessary for the health and well-being of older adults. The purpose of this Position Statement is to provide an overview of the current and relevant literature and provide evidence-based recommendations for resistance training for older adults. As presented in this Position Statement, current research has demonstrated that countering muscle disuse through resistance training is a powerful intervention to combat the loss of muscle strength and muscle mass, physiological vulnerability, and their debilitating consequences on physical functioning, mobility, independence, chronic disease management, psychological well-being, quality of life, and healthy life expectancy. This Position Statement provides evidence to support recommendations for successful resistance training in older adults related to 4 parts: (a) program design variables, (b) physiological adaptations, (c) functional benefits, and (d) considerations for frailty, sarcopenia, and other chronic conditions. The goal of this Position Statement is to a) help foster a more unified and holistic approach to resistance training for older adults, b) promote the health and functional benefits of resistance training for older adults, and c) prevent or minimize fears and other barriers to implementation of resistance training programs for older adults.

Evidence of bilinearity in the relationship between rate of neuromuscular excitation and rate of force development

The purpose was to examine the relationship between the rate of neural excitation (rate of rise in the electromyogram, EMG) and the rate of isometric force development (RFD) to determine whether surface EMG measures can detect nonlinearity that is expected due to underlying motor unit discharge behavior and the summation of progressively larger motor unit potentials throughout recruitment. Due to interest in obtaining a change point, a bilinear model was hypothesized to provide the best fit of the EMG-RFD relationship compared to a linear model, exponential model and log-transformed data. 21 young adult participants performed isometric dorsiflexion contractions to 40% of their maximal voluntary contraction (MVC) force. Contractions were performed in RFD conditions ranging from slow (20 %MVC/s) to fast (peak volitional rate). The Akaike Information Criterion supported nonlinear best fit models in 16 of the 21 participants with the greatest overall support for the bilinear model (n = 13). The bilinear models indicated a mean change point at 204%MVC/s. The present data do not identify the specific motor unit control mechanisms at play and the influence of amplitude cancellation on the electromyogram must be carefully considered.

Effect of a 12-week mixed power training on physical function in dynapenic-obese older men: does severity of dynapenia matter?

INTRODUCTION

Mobility disability affects nearly 15% of people aged 65 or over worldwide. Excess weight or obesity (OB), along with an accentuated loss of muscle strength (dynapenia), is recognized to be one of the most common risk factors for mobility impairment among the elderly.

OBJECTIVE

To investigate the effect of a 12-week mixed power training (MPT high-velocity resistance training mixed with functional exercises) on physical function in obese older men exhibiting different severities of dynapenia.

METHODS

Community-dwelling older men (69 ± 6 years) were assigned to the study if they were considered obese (OB, fat mass ≥ 25% body weight, BW) and to one of the two groups according to severity of dynapenia [(handgrip strength-HS)/BW]: type 1(OB-DY1) or type 2(OB-DY2), < 1 or 2SD from a young reference group. Participants followed a 12-week MPT, three times/week, 75 min/session. Main outcomes included the performance on the 4-m and 6-min walking tests, Timed Up and Go, stair and balance tests.

RESULTS AND DISCUSSION

At baseline, OB-DY1 performed better than OB-DY2 in all functional tests (p < 0.05). Following the intervention, medium-to-large training effect size (ES) were observed for fat (ES = 0.21) and lean (ES = 0.32, p < 0.001) masses, functional performance (ES 0.11-0.54, p < 0.05), HS (ES = 0.10, p < 0.05) and lower limb muscle strength (ES = 0.67, p < 0.001) and power (ES = 0.60, p < 0.05). Training-by-group interaction showed that OB-DY1 lost more FM (ES = 0.11, p = 0.03) and OB-DY2 improved more HS (ES = 0.19, p = 0.006) than their counterparts.

CONCLUSIONS

Seniors with obesity and severe dynapenia have poorer physical function than those in the early stage of dynapenia. Both seem to benefit from a high-velocity resistance training mixed with functional exercises, although by slightly different pathways.

A Simple Target Interception Task as Test for Activities of Daily Life Performance in Older Adults

Previous research showed that a simple target interception task reveals differences between younger adults (YA) and older adults (OA) on a large screen under laboratory conditions. Participants intercept downward moving objects while a horizontally moving background creates an illusion of the object moving in the opposite direction of the background. OA are more influenced by this illusory motion than YA. OA seem to be less able to ignore irrelevant sensory information than YA. Since sensory integration relates to the ability to perform Activities of Daily Living (ADL), this interception task can potentially signal ADL issues. Here we investigated whether the results of the target interception task could be replicated using a more portable setup, i.e., a tablet instead of a large touch screen. For YA from the same, homogeneous population, the main effects were replicated although the task was more difficult in the tablet set-up. After establishing the tablet's validity, we analyzed the response patterns of OA that were less fit than the OA in previous research. We identified three different illusion patterns: a (large) illusion effect (indicating over integration), a reverse illusion effect, and no illusion effect. These different patterns are much more nuanced than previously reported for fit OA who only show over integration. We propose that the patterns are caused by differences in the samples of OA (OA in the current sample were older and had lower ADL scores), possibly modulated by increased task difficulty in the tablet setup. We discuss the effects of illusory background motion as a function of ADL scores using a transitional model. The first pattern commences when sensory integration capability starts to decrease, leading to a pattern of over-integration (illusion effect). The second pattern commences when compensatory mechanisms are not sufficient to counteract the effect of the background motion, leading to direction errors in the same direction as the background motion (reverse illusion). The third pattern commences when the task requirements are too high, leading OA to implement a probabilistic strategy by tapping toward the center of the screen.

Low Volume, Home-Based Weighted Step Exercise Training Can Improve Lower Limb Muscle Power and Functional Ability in Community-Dwelling Older Women

Stepping exercise can be used as a scalable form of high intensity exercise to enhance important aspects of physical fitness in older populations. The addition of supplementary weights increases the resistive element of stepping, with the potential for training improvements in muscular strength, power, and functional abilities alongside other fitness outcomes. The aim of this study was to evaluate the effects of a low-volume, home-based weighted step exercise programme on muscular strength, power, and functional ability in previously inactive community-dwelling older women. Eleven participants, aged between 65⁻74 years, independently completed a six-week individualised and progressive step exercise training programme wearing a weighted vest. Knee extensor strength, lower limb power output, and physical function using a battery of functional tests were measured at baseline, following a 6-week control period, and again following the 6-week training programme. Following training, lower limb power output improved by 10⁻11% (p < 0.05) and was accompanied by a corresponding 9% (p < 0.01) improvement in stair climb time and 10% (p < 0.01) improvement in normalised stair climbing power, highlighting the beneficial effects of weighted stepping for transferable improvements in functional fitness. The magnitude of observed training improvements suggest that weighted step training has the potential to prolong independence and prevent age-related health conditions such as sarcopenia.

Comparison of neural excitation measures from the surface electromyogram during rate-dependent muscle contractions

Peak power and peak rate of isometric force development (RFD) predict performance and functional mobility. Surface electromyography (EMG) is used to quantify the amplitude and rate of neuromuscular excitation. To inform the selection of EMG measures in research on rate-dependent muscle contractions, this methodological study compared amplitude-, area- and rate-based measures based on their correlations with RFD. Considering populations in whom a quiet EMG baseline is challenging, we included measures that do not require the determination of EMG onset. Twenty-one young adults performed isometric dorsiflexion contractions to 40% of their maximal force at increasing RFD. EMG was recorded from tibialis anterior. Relationships between EMG measures and RFD were quantified with Spearman's rho. RMS amplitude of the initial 75 ms of EMG had the strongest correlation with peak RFD (ρ = 0.80) among measures computed from EMG onset. Peak rate of EMG rise (RER) had the strongest relationship with peak RFD (ρ = 0.69) among measures that did not require determination of EMG onset. The strength of the relationship between RER and RFD and the strong correlation between RER and RMS75 during rapid contractions (ρ = 0.86) supports the use of RER in experiments where neural excitation might not be initiated from a quiet baseline.

Effects of linear periodization versus daily undulating periodization on neuromuscular performance and activities of daily living in an elderly population

BACKGROUND

Periodization is a systematic training calendar designed to provide variations in performance targeting, while maximizing results and reducing the potential for overtraining. When provided across multiple weeks, termed a mesocycle, it may also incorporate active recovery periods using specified drills designed to translate neuromuscular gains into targeted functional abilities. There are a number of models that can be used when applying periodization to resistance training (RT). Among the most common are the linear (LP) and daily fixed non-linear (NLP) models. It is currently unknown whether an optimal periodization strategy exists that will maximize benefits for older adults; therefore, we compared the impact of these two periodization models on neuromuscular and functional measures in a group of older persons living independently in the community.

METHODS

Thirty-six older adults, 58-80 years of age, were randomly assigned to either a LP (n = 16; 69.3 ± 4.6 y) or NLP (n = 14; 68.9 ± 6.7 y) group. The LP group performed 12 weeks of training comprised of separate 4-week strength and power training cycles, each followed by a 2-week recovery period incorporating translational exercises. The NLP group performed the strength, power, and translational training on three separate days during the week. Neuromuscular testing included seated chest press and leg press strength and power tests, while physical function testing included the gallon jug shelf test, laundry transfer test, floor stand-up, chair-to-stand test, and 8 foot timed up-and-go.

RESULTS

3 (time) × 2 (sex) × 2 (group) repeated measures ANOVA revealed both periodization strategies were equally effective at inducing neuromuscular and functional improvements and that men generally produced more strength and power than women.

CONCLUSIONS

Both LP and NLP can be used to improve strength, power, and functional performance in healthy untrained older adults when strength, power and functional training cycles are involved. Therefore, personal preference and variety should be considered when deciding which approach to use, provided high-speed power and translational recovery components are included.

Effects of 12-month home-based physiotherapy on duration of living at home and functional capacity among older persons with signs of frailty or with a recent hip fracture - protocol of a randomized controlled trial (HIPFRA study)

Background

Health concerns, such as frailty and osteoporotic fractures decrease functional capacity and increase use of health and social care services in the aging population. The ability to continue living at home is dependent on functional capacity, which can be enhanced by rehabilitation.

We study the effects of a 12-month home-based physiotherapy program with 12-month follow-up on duration of living at home, functional capacity, and the use of social and health care services among older persons with signs of frailty, or with a recently operated hip fracture.

Methods

This is a non-blinded, parallel group, randomized controlled trial performed in South Karelia Social and Health Care District, Finland (population 131,000). Three hundred community-dwelling older persons with signs of frailty (age ≥ 65) and 300 persons with a recent hip fracture (age ≥ 60) will be recruited. Frailty is screened by FRAIL questionnaire and verified by modified Fried’s frailty criteria. Both patient groups will be randomized separately to a physiotherapy and a usual care arm. Individualized, structured and progressive physiotherapy will be carried out for 60 min, twice a week for 12 months at the participant’s home. The primary outcome at 24 months is duration of living at home. Our hypothesis is that persons assigned to the physiotherapy arm will live at home for six months longer than those in the usual care arm. Secondary outcomes are functional capacity, frailty status, health-related quality-of-life, falls, use and costs of social and health care services, and mortality. Assessments, among others Short Physical Performance Battery, Functional Independence Measure, Mini Nutritional Assessment, and Mini-Mental State Examination will be performed at the participant’s home at baseline, 3, 6, and 12 months. Register data on the use and costs of social and health care services, and mortality will be monitored for 24 months.

Discussion

Our trial will provide new knowledge on the potential of intensive, long-term home-based physiotherapy among older persons at risk for disabilities, to enhance functional capacity and thereby to postpone the need for institutional care, and diminish the use of social and health care services.

Trial registration

ClinicalTrials.gov Identifier: NCT02305433, Registered Nov 28, 2014.

Exercise to improve functional outcomes in persons with osteoporosis: a systematic review and meta-analysis

Osteoporosis affects many aspects of daily life. The aim of this systematic review was to assess the effects of exercise interventions on functional outcomes in persons with osteoporosis, in comparison with controls.

METHODS

Four databases were searched and yielded 1587 citations. Two reviewers independently determined study eligibility, rated risk of bias, appraised methodological quality of studies, and resolved discordance by consensus.

RESULTS

A total of 28 studies examining 2113 participants met inclusion criteria; 25 studies were suitable for meta-analyses. Four categories of exercise were identified using the ProFaNE taxonomy. After removing studies with high risk of bias and sorting them into intervention sub-types, we were able to sufficiently reduce the heterogeneity. The standardized mean difference (SMD) favored multicomponent exercise for mobility (- 0.56, 95% CI [- 0.81, - 0.32], p = 0.06, I² = 51%); balance (0.50, 95% CI [0.27, 0.74], p = 0.28, I² = 21%); and self-reported measures of functioning (- 0.69, 95% CI [- 1.04, - 0.34], p = 0.02, I² = 61%). Trials were judged at low or unclear risk of selection bias, indicating inadequate reporting and at high risk of performance bias due to lack of participant blinding. The mean methodological quality rating of the studies was 63.5% indicating moderate quality.

CONCLUSIONS

A multicomponent exercise program of high-speed training combined with simulated functional tasks is promising to enhance functional outcomes. Due to substantial clinical heterogeneity of the target groups and specific demands of exercise modes, it is unclear which exercise program is optimal.

Explosive movement in the older men: analysis and comparative study of vertical jump

BACKGROUND

Loss of power has been demonstrated to have severe functional consequences to perform physical daily living tasks in old age.

PURPOSE

This study aimed to assess how moment and velocity were affected for each joint of the lower limbs during squat jumping for older men in comparison with young adults.

METHODS

Twenty-one healthy older men (74.5 ± 4.6 years) and 22 young men (21.8 ± 2.8 years) performed maximal squat jumps. Inverse dynamics procedure was used to compute the net joint power, moment and velocity produced at the hip, knee and ankle joints.

RESULTS AND DISCUSSION

Vertical jump height of the elderly was 64 % lower than the young adults. The maximal power of the body mass center (P _max^bmc ) was 57 % lower in the older population. For the instant at P _max^bmc , the vertical ground reaction force and the vertical velocity of the body mass center were 26 % and 35 % less in the older adults than in the young adults, respectively (p < 0.05; ES = -1.64 for vertical ground reaction force; p < 0.05; ES = -1.10). A lower value of the hip (-60 %), knee (-72 %) and ankle (-68 %) joint powers was observed in older adults. This was explained by both lower values of joint moments (-64, -57 and -61 % for the hip, knee and ankle, respectively) and angular velocities (-59, -49 and -52 % for the hip, knee and ankle, respectively).

CONCLUSION

This study showed a lower joint power when performing vertical jump. This smaller power resulted from both a lower moment and angular velocity produced at each joint.

Effects of Resistance Training on Lower-Extremity Muscle Power in Middle-Aged and Older Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Resistance training (RT) has been investigated as a potential intervention strategy for improving muscle function, but the effects on lower-extremity muscle power in middle-aged and older adults have not been systematically reviewed.

OBJECTIVE

The aim of this meta-analysis is to provide a quantitative estimate of the effect of RT on lower-extremity muscle power in middle-aged and older adults and to examine independent moderators of this relationship.

METHODS

Randomized controlled trials that examined the effects of RT on either leg press (LP) or knee extension (KE) muscle power in adults aged ≥50 years were included. Data were aggregated with meta-analytic techniques, and multi-level modeling was used to adjust for nesting effects. A total of 52 effects from 12 randomized controlled trials were analyzed with a random-effects model to estimate the effect of RT on lower-extremity muscle power. A multiple-regression analysis was conducted to examine independent moderators of the mean effect.

RESULTS

The adjusted aggregated results from all studies indicate that RT has a small-to-moderate effect on lower-extremity muscle power (Hedges' d = 0.34, 95% confidence interval [CI] 0.25-0.43), which translated to 54.90 watts (95 % CI 40.37-69.43). Meta-regression analyses indicated that high-velocity RT was superior to traditional RT (Δ = 0.62 vs. 0.20, respectively) for increasing lower-extremity muscle power. In addition, training volume significantly moderated the effect of RT on muscle power.

CONCLUSION

The findings from this meta-analysis indicate that RT is an efficacious intervention strategy for improving LP and KE muscle power in adults aged ≥50 years. Training mode and volume independently moderate the effect of RT on lower-extremity muscle power, and should be considered when prescribing RT exercise for middle-aged and older adults.

Effects of aquatic exercise on muscle strength and functional performance of individuals with osteoarthritis: a systematic review

Water-based exercises are recommended for people with osteoarthritis (OA), due to the beneficial effects on physical function, quality of life and symptom reduction. However, the effects on muscle strength are still controversial. The aim of this review was to assess and compare the effects of aquatic exercise programs on muscle strength and physical function in people with OA. A systematic search was performed at Pubmed, Scopus and Web of Science databases. Clinical trials with interventions involving aquatic exercises for individuals with OA were included. The methodological quality of the studies was evaluated using the PEDro scale. 296 studies were found and twelve were selected: six studies comparing water-based exercises with land-based exercise, and six comparing water-based exercise groups with the control group. Exercise programs included muscle strengthening, aerobic, balance, flexibility and stretching exercises. Duration of the program, weekly frequency, intensity and progression varied between studies. Beneficial effects of aquatic exercise were found on physical function. However, only two of five studies that assessed muscle strength observed positive effect of aquatic exercise. Although it is difficult to compare studies and establish guidelines for the standardized protocol formulation, it was observed that water-based exercises can be effective on improving physical function and increasing muscle strength, since they are well-structured, with exercise intensity and overload controlled.

Handgrip strength, quadriceps muscle power, and optimal shortening velocity roles in maintaining functional abilities in older adults living in a long-term care home: a 1-year follow-up study

Purpose

To assess the relative role of handgrip strength (HGS), quadriceps muscle power (P_max), and optimal shortening velocity (υ_opt) in maintaining functional abilities (FAs) in older adults living in a long-term care home over a 1-year follow-up.

Subjects and methods

Forty-one inactive older institutionalized adults aged 69.8±9.0 years participated in this study. HGS, P_max, υ_opt, cognitive function using the Mini-Mental State Examination, depressive symptoms using the Geriatric Depression Scale, nutritional status using the Mini Nutritional Assessment (MNA), and physical activity (PA) using the Seven-Day Physical Activity Recall Questionnaire were assessed at baseline and at 1-year follow-up. FAs were assessed with activities of daily living (ADL), instrumental ADL, and Timed Up & Go test.

Results

Both at baseline and at follow-up, FAs were related to age, HGS, P_max/kg, υ_opt, MNA, and PA. These associations were generally similar in both sexes. As revealed in multiple regression analysis, υ_opt was the strongest predictor of FA, followed by P_max/kg, PA, and MNA. FA deteriorated after 1 year as measured by ADL and Timed Up & Go test. P_max and υ_opt, but not HGS, also decreased significantly after 1 year. Nevertheless, 1-year changes in FAs were not related to changes in HGS, P_max, υ_opt, or PA.

Conclusion

The 1-year period of physical inactivity among older institutionalized adults was found to have a negative effect on their FAs, P_max, and υ_opt. The present study demonstrates that P_max and, especially, υ_opt correlated with FAs of older adults more than HGS, both at baseline and at follow-up. Despite this, 1-year natural fluctuations of PA, P_max, and υ_opt are not significant enough to influence FAs in inactive institutionalized older adults.

Threshold of chair stand power necessary to perform activities of daily living independently in community-dwelling older women

PURPOSE

To determine (1) the reproducibility of measurements of chair stand mean power (CSMP), (2) the relationships of CSMP with age, height, body mass, and body mass index, and (3) to identify the threshold of CSMP below which performing activities of daily living (ADL) is limited in older women.

METHODS

Eighty-seven older women (70-88 years) were divided into an independent group (n = 48) who needed no assistance and a dependent group (n = 39) who needed assistance to perform ADL. The CSMP expressed in watts (velocity × load) for each repetition was assessed by a device that measures mean velocity.

RESULTS

The intraclass correlation coefficient for CSMP suggested a high level of reproducibility (intra-class correlation coefficient = 0.88-0.92, P < .05). Relationships existed between CSMP and age (r = -0.37; P < .001), CSMP and height (r = 0.31; P < .001), CSMP and body mass (r = 0.43; P < .001), and CSMP and body mass index (r = 0.30; P < .001). A receiver operator characteristic curve analysis revealed the optimal threshold criteria; a CSMP of 214 watts resulted in the highest combination of sensitivity (82.1%) and specificity (81.2%).

CONCLUSION

The threshold of CSMP below which assistance is required to perform ADL in community-dwelling older women was identified.

Effect of traditional resistance and power training using rated perceived exertion for enhancement of muscle strength, power, and functional performance

The present study compared the effects of 12 weeks of traditional resistance training and power training using rated perceived exertion (RPE) to determine training intensity on improvements in strength, muscle power, and ability to perform functional task in older women. Thirty healthy elderly women (60-75 years) were randomly assigned to traditional resistance training group (TRT; n = 15) or power training group (PT; n = 15). Participants trained twice a week for 12 weeks using six exercises. The training protocol was designed to ascertain that participants exercised at an RPE of 13-18 (on a 6-20 scale). Maximal dynamic strength, muscle power, and functional performance of lower limb muscles were assessed. Maximal dynamic strength muscle strength leg press (≈58 %) and knee extension (≈20 %) increased significantly (p < 0.001) and similarly in both groups after training. Muscle power also increased with training (≈27 %; p < 0.05), with no difference between groups. Both groups also improved their functional performance after training period (≈13 %; p < 0.001), with no difference between groups. The present study showed that TRT and PT using RPE scale to control intensity were significantly and similarly effective in improving maximal strength, muscle power, and functional performance of lower limbs in elderly women.

Strength and Power Training Effects on Lower Limb Force, Functional Capacity, and Static and Dynamic Balance in Older Female Adults

It has been proposed that muscle power is more effective to prevent falls than muscle force production capacity, as rapid reactions are required to allow the postural control. This study aimed to compare the effects of strength and power training on lower limb force, functional capacity, and static and dynamic balance in older female adults. Thirty-seven volunteered healthy women had been allocated into the strength-training group (n = 14; 69 ± 7.3 years, 155 ± 5.6 cm, 72 ± 9.7 kg), the power-training group (n = 12; 67 ± 7.4 years, 153 ± 5.5 cm, 67.2 ± 7 kg), and control group (n = 11; 65 ± 3.1 years, 154 ± 5.6 cm, 70.9 ± 3 kg). After 12 weeks of training, the strength-training and power-training groups increased significantly maximum dynamic strength (29% and 27%), isometric strength (26% and 37%), and step total time (13% and 14%, dynamic balance), respectively. However, only the power-training group increased the rate of torque development (55%) and the functional capacity in 30-second chair stand (22%) and in time up and go tests (-10%). Empirically, power training may reduce the risk of injuries due to lower loads compared to strength training, and consequently, the physical effort demand during the training session is lower. Therefore, power training should be recommended as attractive training stimuli to improve lower limb force, functional capacity, and postural control of older female adults.

Sex difference in age-related changes in knee extensor strength and power production during a 10-times-repeated sit-to-stand task in Japanese elderly

Background

For middle-aged and elderly women, age-related decline in an index representing power production during STS task (STS-PI), calculated by using an equation reported previously, has been shown to be greater than that in the force generation capability of lower extremity. Whether this is specific to women remains unclear. This study examined how the age-related changes in knee extensor strength and power production during STS differ between Japanese men and women aged 65 years or older.

Methods

The time taken for a 10-times-repeated STS test (STS time) and force developed during maximal voluntary isometric knee extension (KE-F) were determined in Japanese younger-old (262 men and 285 women) aged 65–74 years and older-old (96 men and 89 women) aged 75–90 years. STS-PI was calculated using the following equation: STS-PI = (body height − 0.4) × body mass × 10/STS time.

Results

KE-F and STS-PI were significantly greater in the younger-old than in the older-old group (p < 0.0001) and in men than in women (p < 0.0001). STS-PI and KE-F, expressed as the percentages of the mean value of the corresponding variable for the younger-old group (%STS-PI and %KE-F, respectively), were negatively correlated to chronological age in both men (r = −0.386 and r = −0.269, respectively, p < 0.0001) and women (r = −0.504 and r = −0.294, respectively, p < 0.0001). Regression slopes in the relationship between age and %KE-F were not significantly different between men (−1.521) and women (−1.618). However, regression slope in the relationship between age and %STS-PI was significantly steeper in women (−3.108) than in men (−2.170) (p < 0.05). In OOG, %KE-F had no significant effect of sex, but %STS-PI was significantly lower in women than in men (p < 0.001).

Conclusions

In Japanese men and women aged 65 years or over, age-related loss in power production during STS is steeper in women than in men, with greater magnitude than that in knee extensor strength. This suggests a higher priority of improving power generation capability during whole-body movement such as STS in older women than in older men.

Sarcopenic obesity and complex interventions with nutrition and exercise in community-dwelling older persons--a narrative review

One of the many threats to independent life is the age-related loss of muscle mass and muscle function commonly referred to as sarcopenia. Another important health risk in old age leading to functional decline is obesity. Obesity prevalence in older persons is increasing, and like sarcopenia, severe obesity has been consistently associated with several negative health outcomes, disabilities, falls, and mobility limitations. Both sarcopenia and obesity pose a health risk for older persons per se, but in combination, they synergistically increase the risk for negative health outcomes and an earlier onset of disability. This combination of sarcopenia and obesity is commonly referred to as sarcopenic obesity. The present narrative review reports the current knowledge on the effects of complex interventions containing nutrition and exercise interventions in community-dwelling older persons with sarcopenic obesity. To date, several complex interventions with different outcomes have been conducted and have shown promise in counteracting either sarcopenia or obesity, but only a few studies have addressed the complex syndrome of sarcopenic obesity. Strong evidence exists on exercise interventions in sarcopenia, especially on strength training, and for obese older persons, strength exercise in combination with a dietary weight loss intervention demonstrated positive effects on muscle function and body fat. The differences in study protocols and target populations make it impossible at the moment to extract data for a meta-analysis or give state-of-the-art recommendations based on reliable evidence. A conclusion that can be drawn from this narrative review is that more exercise programs containing strength and aerobic exercise in combination with dietary interventions including a supervised weight loss program and/or protein supplements should be conducted in order to investigate possible positive effects on sarcopenic obesity.

Velocity during Strength and Power Training of the Ankle Plantar and Dorsiflexor Muscles in Older Patients Attending Day Hospital Rehabilitation

Power training has been proposed as a more effective type of resistance training for older adults for functional performance. It is not yet known whether older adults respond appropriately to instructions for power versus strength training. The purpose of this study was to determine the velocity during strength and power training, with elastic resistance bands, in older adults attending a geriatric rehabilitation day program. It was hypothesized that power training would be faster than strength training, but that there would be large interindividual differences. Nine older patients (70 to 86 years) performed power and strength training of the ankle dorsiflexor and plantar flexor muscles using elastic resistance bands. Training sessions were filmed to assess the velocity of training. Power training occurred at faster velocities as compared to strength training (P < 0.01) for both muscle groups. However, a wide variation was observed between participants in the training velocities. Older adults attending geriatric rehabilitation do have the potential to develop faster contractions during power training as compared to strength training. Nevertheless, the actual velocities achieved differed between individuals. This could explain some of the mixed findings of studies on power training. Hence, researchers should monitor velocity when comparing different types of resistance training.

Acute effect of whole-body vibration at optimal frequency on muscle power output of the lower limbs in older women

OBJECTIVE

The aim of this study was to identify the frequency of whole-body vibration (WBV) that elicits the greatest improvement in lower limb power output after an acute exposure in older women, with the hypothesis that an individualized optimal vibration frequency (OVF) would be more effective than a fixed vibration frequency.

DESIGN

Maximal power output was measured during a double leg press on an isoinertial dynamometer in nine women with a mean (SD) age of 71 (3) yrs, 1 and 5 mins after WBV on a platform at three different frequencies, in a random order: 20 Hz, 50 Hz, and OVF, determined for each subject by identifying the frequency corresponding to the maximal electromyographic muscle response.

RESULTS

The mean (SD) OVF was 33 (2.5) Hz. The 25.9% increase in maximal power output after 1 min of WBV at OVF was significantly higher (P < 0.05) than the 14.3% increase after 1 min of WBV at 20 Hz. Similarly, the 32.1% increase in maximal power output after 5 mins of WBV at OVF was significantly higher (P < 0.01) than the 16.1% and 16.3% increase after 5 mins of WBV at 20 Hz and 50 Hz, respectively.

CONCLUSIONS

Frequency of WBV should be prescribed in an individualized fashion, within the range of 30-35 Hz in this target population of older women.

A best practice fall prevention exercise program to improve balance, strength / power, and psychosocial health in older adults: study protocol for a randomized controlled trial

Background

With increasing age neuromuscular deficits (e.g., sarcopenia) may result in impaired physical performance and an increased risk for falls. Prominent intrinsic fall-risk factors are age-related decreases in balance and strength / power performance as well as cognitive decline. Additional studies are needed to develop specifically tailored exercise programs for older adults that can easily be implemented into clinical practice. Thus, the objective of the present trial is to assess the effects of a fall prevention program that was developed by an interdisciplinary expert panel on measures of balance, strength / power, body composition, cognition, psychosocial well-being, and falls self-efficacy in healthy older adults. Additionally, the time-related effects of detraining are tested.

Methods/Design

Healthy old people (n = 54) between the age of 65 to 80 years will participate in this trial. The testing protocol comprises tests for the assessment of static / dynamic steady-state balance (i.e., Sharpened Romberg Test, instrumented gait analysis), proactive balance (i.e., Functional Reach Test; Timed Up and Go Test), reactive balance (i.e., perturbation test during bipedal stance; Push and Release Test), strength (i.e., hand grip strength test; Chair Stand Test), and power (i.e., Stair Climb Power Test; countermovement jump). Further, body composition will be analysed using a bioelectrical impedance analysis system. In addition, questionnaires for the assessment of psychosocial (i.e., World Health Organisation Quality of Life Assessment-Bref), cognitive (i.e., Mini Mental State Examination), and fall risk determinants (i.e., Fall Efficacy Scale – International) will be included in the study protocol. Participants will be randomized into two intervention groups or the control / waiting group. After baseline measures, participants in the intervention groups will conduct a 12-week balance and strength / power exercise intervention 3 times per week, with each training session lasting 30 min. (actual training time). One intervention group will complete an extensive supervised training program, while the other intervention group will complete a short version ('3 times 3’) that is home-based and controlled by weekly phone calls. Post-tests will be conducted right after the intervention period. Additionally, detraining effects will be measured 12 weeks after program cessation. The control group / waiting group will not participate in any specific intervention during the experimental period, but will receive the extensive supervised program after the experimental period.

Discussion

It is expected that particularly the supervised combination of balance and strength / power training will improve performance in variables of balance, strength / power, body composition, cognitive function, psychosocial well-being, and falls self-efficacy of older adults. In addition, information regarding fall risk assessment, dose–response-relations, detraining effects, and supervision of training will be provided. Further, training-induced health-relevant changes, such as improved performance in activities of daily living, cognitive function, and quality of life, as well as a reduced risk for falls may help to lower costs in the health care system. Finally, practitioners, therapists, and instructors will be provided with a scientifically evaluated feasible, safe, and easy-to-administer exercise program for fall prevention.

Trial registration

ClinicalTrials.gov Identifier: NCT01906034

Executive functions, physical fitness and mobility in well-functioning older adults

The objective of this study was to examine the relationships between executive functions, physical fitness and mobility in well-functioning older adults. Forty-eight well functioning older adults (70.5±5.3years old; 20 men, 28 women) were included in this study. Two median splits were conducted based on each individual's performance for the 10MWT and TUG. Comparisons between groups of slower and faster individuals were made with regard to executive functions and physical fitness parameters. A correlational approach was used to assess the association between variables. Between groups comparisons revealed that faster individuals in mobility tests demonstrate better performances in measures of cognitive flexibility (0.68<g<0.90). After including covariates from the medical/social domain, significant correlations were established between faster mobility tests and better cognitive flexibility (TUG: r=0.565; 10MWT: r=0.324). Between groups comparisons also revealed that faster individuals in mobility tests presented higher physical fitness levels (aerobic: 0.49<g<0.77, strength: 0.34<g<1.31). Significant correlations were found between better physical fitness and better cognitive flexibility (strength: r=-0.380; VO2 peak: r=-0.325) even after including age, education, fat-free mass and gender as covariates. These results suggest that the TUG and the 10MWT could potentially help distinguish individuals with poor neuromuscular, aerobic and cognitive flexibility performances.

Influência do treinamento da potência muscular sobre a capacidade de execução de tarefas motoras em mulheres idosas

INTRODUÇÃO: A manutenção da capacidade de geração de potência muscular é fator preponderante para a independência física e funcional do idoso. OBJETIVO: Avaliar o efeito de um programa de treinamento contra resistência em velocidade (PTCRV) sobre a potência muscular e o desempenho em tarefas motoras em idosas. MÉTODOS: 58 voluntárias sedentárias e fisicamente independentes foram divididas em dois subgrupos: 31 pertencentes ao grupo intervenção (GI), 68,7±5,2 anos de idade e 27 ao grupo controle (GC) 67,7±3,8 anos de idade. O GI foi submetido a um programa de 24 sessões, três vezes semanais, de treinamento contra resistência em velocidade. Foram avaliadas a carga (CR), a potência (PT) e a velocidade (VL) no exercício extensão de joelhos (EJ) e no teste motor de levantar-se da cadeira (LC), utilizando o sistema computadorizado Tendo Weightlifting Analyzer (TWA). Foi avaliado também o tempo de execução das tarefas motoras: marcha em velocidade de conforto (MVC) e marcha em velocidade máxima (MVM). Para comparação das variáveis estudadas, aplicou-se o teste t, admitindo-se p=0,05. RESULTADOS: Foi observado no GI para o exercício EJ ganho significativo na capacidade de geração da potência (49,56±13,52w / 66,87±16,27w, p=0,0002). No teste LC, houve aumento significativo na capacidade de geração da potência (370,71±106,26w / 434,52±107,15w, p=0,02185) e da velocidade (0,61±0,14m/s / 0,72±0,14m/s, p=0,00274). Nos testes motores, MVC e MVM, houve redução significativa no tempo de execução (4,56±0,63s / 4,20±0,50s, p=0,01560) e (3,45±0,40s / 3,23±0,34s, p=0,02222), respectivamente. No GC não foi observada melhora significativa em nenhum dos testes aplicados. CONCLUSÃO: O PTCRV contribuiu para melhorar os níveis de potência muscular, além de melhorar o desempenho nas tarefas motoras no grupo estudado.

Traditional Versus Functional Strength Training: Effects on Muscle Strength and Power in the Elderly

The aim was to determine whether strength training with machines vs. functional strength training at 80% of one-repetition maximum improves muscle strength and power among the elderly. Sixty-three subjects (69.9 ± 4.1 yr) were randomized to a high-power strength group (HPSG), a functional strength group (FSG), or a nonrandomized control group (CG). Data were collected using a force platform and linear encoder. The training dose was 2 times/wk, 3 sets × 8 reps, for 11 wk. There were no differences in effect between HPSG and FSG concerning sit-to-stand power, box-lift power, and bench-press maximum force. Leg-press maximum force improved in HPSG (19.8%) and FSG (19.7%) compared with CG (4.3%;p= .026). Bench-press power improved in HPSG (25.1%) compared with FSG (0.5%,p= .02) and CG (2%,p= .04). Except for bench-press power there were no differences in the effect of the training interventions on functional power and maximal body strength.

Associations between isokinetic muscle strength, high-level functional performance, and physiological parameters in patients with chronic obstructive pulmonary disease

High-level activities are typically not performed by patients with chronic obstructive pulmonary disease (COPD), which results in reduced functional performance; however, the physiological parameters that contribute to this reduced performance are unknown. The aim of this study was to determine the relationships between high-level functional performance, leg muscle strength/power, aerobic power, and anaerobic power. Thirteen patients with COPD underwent an incremental maximal cardiopulmonary exercise test, quadriceps isokinetic dynamometry (isometric peak torque and rate of torque development; concentric isokinetic peak torque at 90°/sec, 180°/sec, and 270°/sec; and eccentric peak torque at 90°/sec), a steep ramp anaerobic test (SRAT) (increments of 25 watts every 10 seconds), and three functional measures (timed up and go [TUG], timed stair climb power [SCPT], and 30-second sit-to-stand test [STS]). TUG time correlated strongly (P < 0.05) with all muscle strength variables and with the SRAT. Isometric peak torque was the strongest determinant of TUG time (r = −0.92). SCPT and STS each correlated with all muscle strength variables except concentric at 270°/sec and with the SRAT. The SRAT was the strongest determinant of SCPT (r = 0.91), and eccentric peak torque at 90°/sec was most significantly associated with STS (r = 0.81). Performance on the SRAT (anaerobic power); slower-velocity concentric, eccentric, and isometric contractions; and rate of torque development are reflected in all functional tests, whereas cardiopulmonary exercise test performance (aerobic power) was not associated with any of the functional or muscle tests. High-level functional performance in patients with COPD is associated with physiological parameters that require high levels of muscle force and anaerobic work rates.

Efeito de diferentes intervalos de recuperação entre as séries sobre o desempenho muscular no exercício leg-press em idosas não treinadas

OBJETIVO: Verificar a influência de dois diferentes intervalos de recuperação (IR) entre as séries no exercício leg-press sobre o número e sustentabilidade das repetições e no volume total, em idosas não treinadas. MÉTODOS: Onze idosas (66,5 ± 5,0 anos; 59,2 ± 9,1kg; 146,4 ± 34,9cm) foram submetidas a duas sessões experimentais de exercícios com pesos com intensidade de 15 repetições máximas. Cada sessão experimental foi composta por três séries realizadas até a fadiga muscular utilizando IR de um (IR-1) ou três minutos (IR-3). As sessões experimentais foram separadas por, no mínimo, 48 horas. Todas as participantes realizaram ambos os protocolos e um delineamento cross-over balanceado foi utilizado para determinar a ordem das sessões experimentais. RESULTADOS: Para ambos os IR entre as séries, reduções significativas (P < 0,05) no número e na sustentabilidade das repetições foram observadas da primeira para a segunda e terceira séries e da segunda para a terceira séries. Diferenças significativas (P < 0,05) entre os IR foram observadas nas duas séries finais. O volume total da sessão realizada com IR-3 foi estatisticamente superior (20,4%; P < 0,05) quando comparada a sessão IR-1. CONCLUSÃO: O número e a sustentabilidade das repetições e o volume total de treino de idosas não treinadas são influenciados pelo IR empregado entre as séries. Maiores IR devem ser utilizados quando a finalidade for otimizar o volume de treino por meio da sustentabilidade das repetições. Em contrapartida, menores IR devem ser utilizados quando a meta for obter maiores níveis de fadiga muscular.