High-resistance versus variable-resistance training in older adults

One-week quercetin intervention modifies motor unit recruitment patterns before and during resistance exercise in older adults: A randomized controlled trial

We investigated the effects of one-week quercetin ingestion on motor unit (MU) behavior and muscle contractile properties before, during, and after a single session of resistance exercise in older adults. Twenty-four older adults were divided into two groups: those receiving quercetin glycosides (QUE) or placebo (PLA), and they performed a single session of resistance exercise. MU behavior before and during resistance exercise and electrically elicited contraction before and after resistance exercise were measured (Day 1), and the same measurements were conducted again after 7 days of placebo or quercetin glycoside ingestion (Day 8). The MU recruitment threshold (RT) was decreased (p < 0.001, 25.6 ± 10.1 to 23.6 ± 9.5 %MVC) and the exerted force normalized by the MU firing rate (FR) was increased (p = 0.003, 1.13 ± 0.24 to 1.18 ± 0.22 %MVC/pps) from Days 1 to 8, respectively, in QUE but not PLA (p = 0.263, 22.6 ± 11.9 to 21.9 ± 11.6 %MVC; p = 0.713, 1.09 ± 0.20 to 1.10 ± 0.19 %MVC/pps, respectively). On Day 1, a significant correlation between MURT and%change in MUFR from the first to last contractions during the resistance exercise was observed in both groups (QUE: p = 0.009, rs = 0.308; PLA: p < 0.001, rs = 0.403). On Day 8 %change in MUFR was negatively correlated with MURT in QUE (p = 0.044, rs = -0.251), but there was no significant correlation in PLA (p = 0.844). There was no difference in electrically elicited contraction before and after the resistance exercise between QUE and PLA (p < 0.05). These results suggest that one-week quercetin ingestion in older adults lowered MURT and led to greater fatigue in MU with higher RT than with lower RT during resistance training.

Resistance training and inter-interindividual response differences on cardiorespiratory fitness in older adults: An ancillary meta-analysis of randomized controlled trials

Examine true inter-individual response differences (IIRD) as a result of resistance training on cardiorespiratory fitness in older adults. Data from a recent meta-analysis of 22 randomized controlled trials representing 552 men and women (292 resistance training, 260 control) ≥ 60 years of age were included. The primary outcome was cardiorespiratory fitness (VO2max) in ml.kg-1.min-1. Using the inverse variance heterogeneity (IVhet) model, statistically significant treatment effect (resistance training minus control) increases in VO2max in ml.kg-1.min-1 were found (mean, 1.8, 95% CI, 0.4 to 3.3 ml.kg-1.min-1, p = 0.01; Q = 82.8, p < 0.001; I2 = 74.6%, 95% CI, 61.6 to 83.3%; τ 2 =1.1). The 95% prediction interval (PI) was -0.8 to 4.5 ml.kg-1.min-1. However, no statistically significant IIRD was observed (mean, 0.6, 95% CI, -1.1 to 1.4 ml.kg-1.min-1; τ 2 =1.5). The 95% PI was -1.8 to 2.0 ml.kg-1.min-1. In conclusion, while progressive resistance training may increase VO2max in ml.kg-1.min-1, a lack of true resistance-training-associated IIRD exist.

Resistance Training and Weight Loss in Older Adults: A Scoping Review

Resistance training (RT) is one of the most effective interventions available to older adults wishing to slow the progressive loss of muscle size and strength known to occur with age. Less is known about the ability of RT to resist the onset of an equally problematic condition related to increased age: obesity. The objective of this scoping review was to characterize current research associated with RT and weight loss in older adults, including protocols, feasibility, and gaps in current knowledge. We searched six databases using variations of the terms "resistance training," "weight loss," and "older adults" for experimental or quasi-experimental studies published in the year 2009 or later. Studies were included if they featured at least one treatment group with a mean age of > 65 years that engaged in an RT-only exercise protocol with no aerobic or high-intensity interval component. Of the 6102 references identified by the initial database search, 24 were retained for analysis. Older women and older adults with obesity or sarcopenic obesity were the most studied groups (n = 13), followed by healthy community-dwelling older adults (n = 11) and studies involving older adults and some aspect of either dietary control or pharmaceutical intervention (n = 8). Significant between-study heterogeneity was observed in the RT characteristics researchers thought optimal for improving body composition measures in older adults. Changes in body composition, rather than total body mass, were found to be the essential variables to consider when evaluating the effectiveness of an RT intervention aimed at reducing chronic disease in older adults. Weight loss alone appears to be an incomplete and problematic outcome measure for older adults, with changes in body composition (ratio of fat mass to lean mass) being the more appropriate variable to emphasize in this population. However, it is important to note that only one study, showing questionably reproducible findings, found a significant lean body mass gain. The lack of abundant high-quality evidence demonstrating combined RT and a healthy diet can lead to significant fat loss and lean body mass gain, coupled with high attrition rates observed in many of the studies reviewed, highlight the need for further rigorous research.

The role of resistance exercise training for improving cardiorespiratory fitness in healthy older adults: a systematic review and meta-analysis

BACKGROUND

Declines in cardiorespiratory fitness (CRF) and muscle mass are both associated with advancing age and each of these declines is associated with worse health outcomes. Resistance exercise training (RET) has previously been shown to improve muscle mass and function in the older population. If RET is also able to improve CRF, as it has been shown to do in younger populations, it has the potential to improve multiple health outcomes in the expanding older population.

METHODS

This systematic review aimed to identify the role of RET for improving CRF in healthy older adults. A search across CINAHL, MEDLINE, EMBASE and EMCARE databases was conducted with meta-analysis performed on eligible papers to identify improvements in established CRF parameters (VO2 peak, aerobic threshold (AT), 6-minute walking distance test (6MWT) following RET intervention. Main eligibility criteria included older adults (aged over 60), healthy cohorts (disease-specific cohorts were excluded) and RET intervention.

RESULTS

Thirty-seven eligible studies were identified. Meta-analysis revealed a significant improvement in VO2 peak (MD 1.89 ml/kg/min; 95% confidence interval (CI) 1.21-2.57 ml/kg/min), AT (MD 1.27 ml/kg/min; 95% CI 0.44-2.09 ml/kg/min) and 6MWT (MD 30.89; 95% CI 26.7-35.08) in RET interventions less than 24 weeks. There was no difference in VO2 peak or 6MWT in interventions longer than 24 weeks.

DISCUSSION

This systematic review adds to a growing body of evidence supporting the implementation of RET in the older population for improving whole-body health, particularly in time-limited timeframes.

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.

The curvilinear relationship between servant leadership and work-family conflict: the moderating role of age in Chinese female workers

Purpose

Building on social exchange theory and selection, optimization and compensation theory, this study aims to examine a moderated curvilinear relationship between servant leadership (SL) and work-family conflict (WFC).

Design/methodology/approach

Participants were 329 female workers recruited from a Chinese small business in the service Industry. A three-step hierarchical regression was conducted to examine the relationships among the variables and the incremental contribution of SL and age and the squared term of SL.

Findings

Study results confirmed a curvilinear relationship between SL and WFC and the moderating effect of age. When younger female employees perceived a moderate range of SL from their supervisors, they reported higher WFC compared to the low or high level of perceived SL. On the contrary, senior female employees reported a lower level of WFC when they perceived a moderate level of SL than when they perceived very low or high levels.

Originality/value

SL research has experienced a period of exponential growth in the past decade. This study advanced the field of leadership by arguing that SL perceived by female employees is curvilinearly related to WFC and the curvilinear relationship is moderated by age.

Effects of High-Speed Versus Traditional Resistance Training in Older Adults

BACKGROUND

The losses of strength, agility, balance, and functionality caused by aging are harmful to the elderly population. Resistance training (RT) may be an efficient tool to mitigate such neuromuscular decline and different RT methods can be used. Therefore, it is important to investigate the different responses to different training methods.

HYPOTHESIS

Eight weeks of traditional resistance training (TRT) are expected to promote similar results to high-speed training (HST) in physical functional performance (PFP) and quality of life in the elderly.

STUDY DESIGN

A clinical trial.

LEVEL OF EVIDENCE

Level 3.

METHODS

Participants (n = 24) with a mean age of 67.8 ± 6.3 years completed 8 weeks of RT. They were allocated into HST (n = 12) and TRT (n = 12). TRT involved training with 10 to 12 repetitions at controlled velocity until momentary muscle failure, while HST involved performing 6 to 8 repetitions at 40% to 60% of 1 repetition maximum (1RM) at maximum velocity. Pre- and posttraining, the participants were tested for (1) maximum strength in the 45° leg press and chest press; (2) PFP in the 30-second chair stand, timed-up-and-go (TUG), and medicine ball throw test; and (3) quality of life.

RESULTS

Both groups improved muscle strength in the 45° leg press, with greater increases for TRT (HST: +21% vs TRT: +49%, P = 0.019). There was no change in chest press strength for HST (-0.6%) (P = 0.61), but there was a significant increase for the TRT group (+21%, P = 0.001). There was a similar improvement (P < 0.05) for both groups in TUG (HST: 7%; TRT: 10%), chair stand (HST: 18%; TRT: 21%), and medicine ball throwing performance (HST: 9%; TRT: 9%), with no difference between groups (P = 0.08-0.94). Emotional aspect significantly increased by 20% (P = 0.04) in HST and 50% (P = 0.04) in TRT.

CONCLUSION

Both TRT and HST are able to promote improvements in functional performance in the elderly with greater in strength gains for TRT. Therefore, exercise professionals could choose based on individual characteristics and preferences.

CLINICAL RELEVANCE

The findings provide important insights into how health care professionals can prescribe HST and TRT, considering efficiency, safety, and individual aspects.

Periodization: Variation in the Definition and Discrepancies in Study Design

Over the past several decades, periodization has been widely accepted as the gold standard of training theory. Within the literature, there are numerous definitions for periodization, which makes it difficult to study. When examining the proposed definitions and related studies on periodization, problems arise in the following domains: (1) periodization has been proposed to serve as the macro-management of the training process concerning the annual plan, yet research on long-term effects is scarce; (2) periodization and programming are being used interchangeably in research; and (3) training is not periodized alongside other stressors such as sport (i.e., only resistance training is being performed without the inclusion of sport). Overall, the state of the literature suggests that the inability to define periodization makes the statement of its superiority difficult to experimentally test. This paper discusses the proposed definitions of periodization and the study designs which have been employed to examine the concept.

Ratings of Perceived Exertion During Walking Predicts Endurance Independent of Physiological Effort in Older Women

Hunter, GR, Neumeier, WH, Chandler-Laney, PC, Carter, SJ, Borges, JH, Hornbuckle, LM, Plaisance, EP, and Fisher, G. Ratings of perceived exertion during walking predicts endurance independent of physiological effort in older women. J Strength Cond Res 34(5): 1340-1344, 2020-This study aimed to determine whether ratings of perceived exertion (RPE) and physiological effort at different exercise intensities relate to exercise endurance. Ninety-eight sedentary women (older than 60 years) completed 3 submaximal locomotion tasks: (a) stair climbing, (b) flat walking at 2 mph, and (c) grade walking at 2 mph. Maximal treadmill endurance was measured at least 3 days before the submaximal tests. Oxygen uptake was measured during all tests, and RPE were collected for the submaximal tasks. Ratings of perceived exertion during moderate-intensity exercise (walking on the flat at 43% V[Combining Dot Above]O2max, partial R = -0.35, p < 0.01), but not higher intensity exercise (grade walk at 59% V[Combining Dot Above]O2max, p = 0.49, and stair climbing at 67% V[Combining Dot Above]O2max, p = 0.17), were related to endurance even after adjusting for aerobic capacity and physiological effort (composite of maximal heart rate, ventilation, and respiratory exchange ratio). However, physiological effort was significantly related to endurance for the higher intensity exercise (both grade walk and stair climbing partial R >-0.24, p < 0.02). Similar to previous findings that subjective ratings of fatigue at rest were related to RPE during low/moderate-intensity exercise, but not higher intensity exercise, these data further support Ekkekakis's dual-mode hypothesis that cognitive factors influence RPE during low/moderate-intensity exercise. A practical application is that the coach and personal trainer should know that physiological effort seems to play a greater role in influencing endurance than RPE as intensity of exercise increases.

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.

Effects of linear versus nonperiodized resistance training on isometric force and skeletal muscle mass adaptations in sarcopenic older adults

The aim of this study was to compare the effects of linear periodization (LP) versus nonperiodized (NP) resistance training on upper-body isometric force and skeletal muscle mass (SMM) in sarcopenic older adults. Twenty sarcopenic older adults were randomly assigned into the LP and NP groups and performed 16 weeks of resistance training. The SMM was measured by octopolar bioelectrical impedance. The isometric force for handgrip and trunk were assessed by dynamometer. Evaluations were performed at baseline, after 4, 8, 12, and 16 weeks of resistance training. For total weight lifted, there was a main effect for time (F=126.986, P<0.001), statistically significant difference between condition (F=13.867, P=0.001) and interaction (F=8.778, P<0.001), whereby total weight lifted was greater for NP after 4 months of training. Isometric force for handgrip and trunk increased across time (P<0.001) but no significant differences between groups or interaction were observed (P>0.05). The SMM increased across time (P<0.05), however no significant difference between groups or interaction were observed (P>0.05). There were strong and significant correlations between handgrip maximum force and SMM (LP: rho=0.79, P=0.004 vs. NP: rho=−0.43, P=0.244) and handgrip mean force and SMM (LP: rho=0.68, P=0.021 vs. NP: rho=−0.37, P=0.332) only for the LP group. In conclusion, LP and NP resistance training induced similar benefits on upper-body isometric force and SMM in sarcopenic older adults. However, LP presented lower total weight lifted, suggesting that it is possible to obtain similar gains in isometric force and SMM with less total work.

Periodized Resistance Training for Enhancing Skeletal Muscle Hypertrophy and Strength: A Mini-Review

Prescribing the proper resistance training (RT) program is critical to optimize skeletal muscle hypertrophy and strength. Periodization is a strategy that entails planned manipulations of training variables to maximize fitness adaptations while minimizing the risk of overtraining. Multiple meta-analyses have shown periodized RT to be superior to non-periodized RT for enhancing muscular strength. These findings are consistent irrespective of training status or training volume. Both the linear model and the undulating model are effective for enhancing strength, although a greater benefit might be achieved through the undulating model. Despite the suggested superiority of periodized RT for strength development, some authors suggest that this might be a consequence of the study designs employed rather than the nature of periodized training. In addition, several limitations exist in the periodization literature, making it difficult to accurately assess the efficacy of periodized RT. With regard to enhancing skeletal muscle hypertrophy, both the undulating model and the linear model appear equally effective; however, this conclusion can only be generalized to untrained populations. When comparing periodized RT to non-periodized RT programs, the research is unclear on whether periodized RT is necessary to maximize skeletal muscle hypertrophy.

Repeated sit-to-stand exercise enhances muscle strength and reduces lower body muscular demands in physically frail elders

PURPOSE

To examine the effect of a conditioning program consisting of repeated sit-to-stand exercise on knee extensor strength and muscular activities during body mass-based squat movement in physically frail elders.

METHODS

Fourteen men and women aged 75 to 88 years who used the long-term care insurance system participated in the 12-week training program (48 reps/session, 3 sessions/week). Isometric knee extension torque (KET) during a maximum voluntary contraction (MVC) and electromyogram (EMG) activities of the rectus femoris and vastus lateralis muscles during the MVC and a body mass-based squat task were determined at baseline, and following 4 and 12 weeks training. KET was expressed relative to body mass (KET/BM) and EMG activities during the squat task were normalized to that during a MVC and averaged (QF %EMGmax).

RESULTS

KET/BM increased from 1.07 ± 0.28 Nm/kg at baseline to 1.26 ± 0.26 Nm/kg at week 4 and 1.31 ± 0.28 Nm/kg at week 12 (P < 0.001), and QF %EMGmax decreased from 67.2 ± 17.2% to 49.3% at week 4 (P < 0.001) and 43.5 ± 7.7% at week 12 (P = 0.016). At each of the three measurement time points KET/BM was inversely correlated with QF %EMGmax (r = -0.78 to -0.86, P ≤ 0.001).

CONCLUSION

For physically frail elders, a short-term conditioning program consisting of repeated sit-to-stand exercise is effective in increasing knee extensor strength and reducing the muscular effort required for lowering and raising the body.

Effect of low-intensity versus high-intensity resistance training on the functioning of the institutionalized frail elderly

Frailty has emerged as an important risk factor for disability. Age-related declines in physical and physiological function lead to increased risk of loss of independence and poor quality of life. Recent evidence has shown the effectiveness of physical exercise programmes in preventing or reversing frailty. The aim of this study was to evaluate changes in the functioning of frail elderly individuals after undergoing resistance training for 3 days a week for 8 weeks. The effectiveness of exercise training was investigated in 48 frail elderly individuals who were randomly assigned to the following intervention groups: high-intensity (HI; n=16; age: 69-96 years) or low-intensity (LI; n=16; age: 77-93 years) strength training groups or a control group (n=16; age: 76-93 years) with no specific exercise programme. Participants were assessed for muscle strength, physical function, activities of daily living, depression and quality of life. The HI group had significantly better results (P<0.05) on the Short Physical Performance Test than the LI group; however, the LI group did show a significant improvement in those scores, whereas the scores of the control group worsened. Results for the other evaluations were similarly favourable in both exercise groups (P>0.05). The study showed that LI exercise was as effective as HI exercise for most parameters tested. Exercise training is useful for the prevention or treatment of frailty, as it improves functioning by contributing positively to muscle strength, gait, balance and quality of life.

Racial Differences in Relative Skeletal Muscle Mass Loss During Diet-Induced Weight Loss in Women

OBJECTIVE

It is unclear whether there are race-specific differences in the maintenance of skeletal muscle during energy restriction. Changes in relative skeletal muscle index (RSMI; limb lean tissue divided by height squared) were compared following (1) diet alone, (2) diet + aerobic training, or (3) diet + resistance training.

METHODS

Overweight, sedentary African American (AA; n = 72) and European American (EA; n = 68) women were provided an 800-kcal/d diet to reduce BMI < 25 kg/m² . Regional fat-free mass was measured with dual-energy x-ray absorptiometry. Steady-state VO₂ and heart rate responses during walking were measured.

RESULTS

AA women had greater RSMI and preserved RSMI during diet alone, while RSMI was significantly reduced among EA women (EA women -3.6% vs. AA women + 1.1%; P < 0.05). Diet + resistance training subjects retained RSMI (EA women + 0.2% vs. AA women + 1.4%; P = 50.05), whereas diet + aerobic training subjects decreased RSMI (EA women -1.4% vs. AA women -1.5%; P < 0.05). Maintenance of RSMI was related to delta walking ease and economy.

CONCLUSIONS

Compared with AA women, EA women are less muscular and lose more muscle during weight loss without resistance training. During diet-induced weight loss, resistance training preserves skeletal muscle, especially among premenopausal EA women. Maintenance of muscle during weight loss associates with better ease and economy of walking.

Effects of elastic band exercise on lean mass and physical capacity in older women with sarcopenic obesity: A randomized controlled trial

Sarcopenia is associated with loss of muscle mass as well as an increased risk of physical disability in elderly people. This study was aimed to investigate the effect of elastic band resistance training (ERT) on muscle mass and physical function in older women with sarcopenic obesity. A randomized controlled trial with an intention-to-treat analysis was conducted. A total of 56 women (mean ± SD age 67.3 ± 5.1 years) were randomly assigned to the experimental group receiving 12 weeks of ERT and to the control group receiving no exercise intervention. Lean mass (measured using a dual-energy X-ray absorptiometer), physical capacity (assessed using the global physical capacity score), and a 36-item short form questionnaire were conducted at the baseline examination (T₀), as well as the 3-month (T₁) and 9-month followups (T₂). At T₁ and T₂, the between-group difference was measured in total skeletal mass relative to T₀, with mean differences of 0.70 kg (95% CI 0.12-1.28; P < 0.05) and 0.72 kg (95% CI 0.21-1.23; P < 0.01), respectively. Similar results were found in muscle quality, physical capacity, and physical function outcomes. The ERT exerted a significant beneficial effect on muscle mass, muscle quality, and physical function in older women with sarcopenic obesity.

Effects of Traditional and Pyramidal Resistance Training Systems on Muscular Strength, Muscle Mass, and Hormonal Responses in Older Women: A Randomized Crossover Trial

Ribeiro, AS, Schoenfeld, BJ, Fleck, SJ, Pina, FLC, Nascimento, MA, and Cyrino, ES. Effects of traditional and pyramidal resistance training systems on muscular strength, muscle mass, and hormonal responses in older women: a randomized crossover trial. J Strength Cond Res 31(7): 1888-1896, 2017-The purpose of this study was to investigate the effect of resistance training (RT) performed in a pyramid (PR) versus a traditional (TD) system on muscular strength, muscle mass, and hormonal responses in older women. Twenty-five older women (67.6 ± 5.1 years, 65.9 ± 11.1 kg, 154.7 ± 5.8 cm, and 27.5 ± 4.5 kg·m) performed both a TD and PR system RT program in a balanced crossover design. The TD program consisted of 3 sets of 8-12 repetition maximum (RM) with a constant load for the 3 sets, whereas the PR system consisted of 3 sets of 12/10/8-RM with incrementally higher loads for each set. Training was performed in 2 phases of 8 weeks each, with a 12-week washout between the 8-week phases. One repetition maximum (1RM) tests were used as measures of muscular strength. Dual X-ray absorptiometry was used to estimate skeletal muscle mass. Testosterone and IGF-1 concentrations were determined preintervention and postintervention after 12 hours fasting. Significant (p ≤ 0.05) increases were observed in both groups for muscular strength in the 1RM chest press (TD = 12.4% and effect size [ES] = 0.86 vs. PR = 11.5% and ES = 0.74), knee extension (TD = 12.5% and ES = 0.61 vs. PR = 11.8% and ES = 0.62), preacher curl (TD = 10.9% and ES = 0.63 vs. PR = 8.6% and ES = 0.54), and for skeletal muscle mass (TD = 3.6% and ES = 0.32 vs. PR = 2.4% and ES = 0.24) with no differences between groups. There were no significant (p > 0.05) main effects for IGF-1 and testosterone. The results suggest that the PR and TD systems performed are similarly effective for promoting positive adaptations in muscular strength and hypertrophy in older women.

Low-Load High-Velocity Resistance Exercises Improve Strength and Functional Capacity in Diabetic Patients

This study investigated the effects of low-load high-velocity resistance exercises on neuromuscular and functional outcomes in patients with Type 2 diabetes (T2D) during the early-phase of resistance training. Thirty participants with T2D performed 18 training sessions (6 weeks - 3x week) in one of two groups: low-load high-velocity exercises (LLHV, n=15, 62.1±10.5 years) or recreational activities (RA, n=15 56.7 ± 19.4 years). LLHV performed resistance exercises with 3x 8reps as fast as possible with 50-60% 1RM. RA performed light activities. Strength, power, and functional tests were assessed. There was significant increasing in the knee extension peak-torque at 60°/s (7.6%) and 180°/s (12.2%), rate of force development in the LLHV group (P<0.05), whereas there were no changes in the RA group. Significant increases in functional test were observed in the LLHV group (P<0.01) with no changes in the RA group. In conclusion, the LLHV induced marked improvements in neuromuscular parameters, as well as in the functional capacity of participants with T2D.

The Effect of Different Intensity Modalities of Resistance Training on Beat-to-Beat Blood Pressure in Cardiac Patients

Background

Resistance training has been introduced in cardiac rehabilitation to give more benefit than traditional training. Haemodynamic evaluation of cardiac patients to resistance training has generally consisted of continuous HR monitoring and discontinuous blood pressure measurements.

Design and Methods

Blood pressure (BP) and heart rate (HR) responses to resistance training were evaluated using continuous monitoring (Finapres) during low (four sets of 17 repetitions at 40% of the one-repetition maximum strength [1-RM]) and high intensity resistance training (four sets of 10 repetitions at 70% of 1-RM) on a leg extension machine in 14 patients who participated in a rehabilitation programme. Work volume was identical in the low- and high-level resistance training.

Results

The HR and systolic blood pressure (SBP) during low intensity resistance training were always larger than during high intensity (P<0.001). Peak SBP increased from set 1 to set 3 and 4 during both low and high intensity resistance training (P<0.05). Peak HR was larger in set 4 (95 ± 11 bpm) than in set 1 only during low intensity resistance training (91 ± 12 bpm) (P<0.05). One-minute recovery periods did not allow a return to baseline HR and SBP during both low and high intensity modalities.

Conclusions

The SBP and HR responses to resistance training are related to the duration of exercise. Sets with ≥ 10 repetitions of high intensity should be preferred to longer sets with low intensity. Pauses between exercise sets should exceed 1 min. Blood pressure should be measured during the last repetitions of the exercise set. Eur J Cardiovasc Prev Rehabil 12:12-17 © 2005 The European Society of Cardiology

The efficacy of periodised resistance training on neuromuscular adaptation in older adults

PURPOSE

This study compared the effect of periodised versus non-periodised (NP) resistance training on neuromuscular adaptions in older adults.

METHODS

Forty-one apparently healthy untrained older adults (female = 21, male = 20; 70.9 ± 5.1 years; 166.3 ± 8.2 cm; 72.9 ± 13.4 kg) were recruited and randomly stratified to an NP, block periodised (BP), or daily undulating periodised (DUP) training group. Outcome measures were assessed at baseline and following a 22-week resistance training intervention (3 day week^-1), including: muscle cross-sectional area (CSA), vertical jump performance, isometric and isokinetic peak torque, isometric rate of force development (RFD), and muscle activation. Thirty-three participants satisfied all study requirements and were included in analyses (female = 17, male = 16; 71.3 ± 5.4 years; 166.3 ± 8.5 cm; 72.5 ± 13.7 kg).

RESULTS

Block periodisation, DUP, and NP resistance training induced statistically significant improvements in muscle CSA, vertical jump peak velocity, peak power and jump height, and peak isometric and isokinetic torque of the knee extensors at 60 and 180° s^-1, with no between-group differences. Muscle activity and absolute RFD measures were statistically unchanged following resistance training across the entire cohort.

CONCLUSIONS

Periodised resistance training, specifically BP and DUP, and NP resistance training are equally effective for promoting increases in muscular hypertrophy, strength, and power among untrained older adults. Consequently, periodisation strategies are not essential for optimising neuromuscular adaptations during the initial stages of resistance training in the aging population.

Resistance Training is Associated with Improved Mood in Healthy Older Adults

This study examined the effects of 24 wk. of resistance training on mood in healthy but sedentary older adults. 28 participants performed resistance training 3 times per week for 24 weeks. No significant differences were found in mood scores between high and variable resistance groups, and there were no significant interactions between resistance and sex or intervention, or among all three factors. For pooled data, significant improvement was found on measures of Confusion, Tension, Anger, and Total Mood Scores, although not for scores for Fatigue, Vigor, and Depression. Sex differences were found on some subscales, but no significant interactions between sex and resistance training. These findings support the effectiveness of resistance training in improving mood in healthy older adults, although further study is needed to control for effect size, as well as cohort, social, and attentional effects.

Exercise Training and Energy Expenditure following Weight Loss

PURPOSE

This study aims to determine the effects of aerobic or resistance training on activity-related energy expenditure (AEE; kcal·d(-1)) and physical activity index (activity-related time equivalent (ARTE)) following weight loss. It was hypothesized that weight loss without exercise training would be accompanied by decreases in AEE, ARTE, and nontraining physical activity energy expenditure (nonexercise activity thermogenesis (NEAT)) and that exercise training would prevent decreases in free-living energy expenditure.

METHODS

One hundred forty premenopausal women had an average weight loss of 25 lb during a diet (800 kcal·d(-1)) of furnished food. One group aerobically trained 3 times per week (40 min·d(-1)), another group resistance-trained 3 times per week (10 exercises/2 sets × 10 repetitions), and the third group did not exercise. Dual-energy x-ray absorptiometry was used to measure body composition, indirect calorimetry was used to measure resting energy expenditure (REE) and walking energy expenditure, and doubly labeled water was used to measure total energy expenditure (TEE). AEE, ARTE, and nontraining physical activity energy expenditure (NEAT) were calculated.

RESULTS

TEE, REE, and NEAT all decreased following weight loss for the no-exercise group, but not for aerobic and resistance trainers. Only REE decreased in the two exercise groups. Resistance trainers increased ARTE. HR and oxygen uptake while walking on the flat and up a grade were consistently related to TEE, AEE, NEAT, and ARTE.

CONCLUSIONS

Exercise training prevents a decrease in energy expenditure, including free-living energy expenditure separate from exercise training, following weight loss. Resistance training increases physical activity, whereas economy/ease of walking is associated with increased TEE, AEE, NEAT, and ARTE.

Dose-Response Relationships of Resistance Training in Healthy Old Adults: A Systematic Review and Meta-Analysis

BACKGROUND

Resistance training (RT) is an intervention frequently used to improve muscle strength and morphology in old age. However, evidence-based, dose-response relationships regarding specific RT variables (e.g., training period, frequency, intensity, volume) are unclear in healthy old adults.

OBJECTIVES

The aims of this systematic review and meta-analysis were to determine the general effects of RT on measures of muscle strength and morphology and to provide dose-response relationships of RT variables through an analysis of randomized controlled trials (RCTs) that could improve muscle strength and morphology in healthy old adults.

DATA SOURCES

A computerized, systematic literature search was performed in the electronic databases PubMed, Web of Science, and The Cochrane Library from January 1984 up to June 2015 to identify all RCTs related to RT in healthy old adults.

STUDY ELIGIBILITY CRITERIA

The initial search identified 506 studies, with a final yield of 25 studies. Only RCTs that examined the effects of RT in adults with a mean age of 65 and older were included. The 25 studies quantified at least one measure of muscle strength or morphology and sufficiently described training variables (e.g., training period, frequency, volume, intensity).

STUDY APPRAISAL AND SYNTHESIS METHODS

We quantified the overall effects of RT on measures of muscle strength and morphology by computing weighted between-subject standardized mean differences (SMDbs) between intervention and control groups. We analyzed the data for the main outcomes of one-repetition maximum (1RM), maximum voluntary contraction under isometric conditions (MVC), and muscle morphology (i.e., cross-sectional area or volume or thickness of muscles) and assessed the methodological study quality by Physiotherapy Evidence Database (PEDro) scale. Heterogeneity between studies was assessed using I2 and χ2 statistics. A random effects meta-regression was calculated to explain the influence of key training variables on the effectiveness of RT in terms of muscle strength and morphology. For meta-regression, training variables were divided into the following subcategories: volume, intensity, and rest. In addition to meta-regression, dose-response relationships were calculated independently for single training variables (e.g., training frequency).

RESULTS

RT improved muscle strength substantially (mean SMDbs = 1.57; 25 studies), but had small effects on measures of muscle morphology (mean SMDbs = 0.42; nine studies). Specifically, RT produced large effects in both 1RM of upper (mean SMDbs = 1.61; 11 studies) and lower (mean SMDbs = 1.76; 19 studies) extremities and a medium effect in MVC of lower (mean SMDbs = 0.76; four studies) extremities. Results of the meta-regression revealed that the variables "training period" (p = 0.04) and "intensity" (p < 0.01) as well as "total time under tension" (p < 0.01) had significant effects on muscle strength, with the largest effect sizes for the longest training periods (mean SMDbs = 2.34; 50-53 weeks), intensities of 70-79% of the 1RM (mean SMDbs = 1.89), and total time under tension of 6.0 s (mean SMDbs = 3.61). A tendency towards significance was found for rest in between sets (p = 0.06), with 60 s showing the largest effect on muscle strength (mean SMDbs = 4.68; two studies). We also determined the independent effects of the remaining training variables on muscle strength. The following independently computed training variables are most effective in improving measures of muscle strength: a training frequency of two sessions per week (mean SMDbs = 2.13), a training volume of two to three sets per exercise (mean SMDbs = 2.99), seven to nine repetitions per set (mean SMDbs = 1.98), and a rest of 4.0 s between repetitions (SMDbs = 3.72). With regard to measures of muscle morphology, the small number of identified studies allowed us to calculate meta-regression for the subcategory training volume only. No single training volume variable significantly predicted RT effects on measures of muscle morphology. Additional training variables were independently computed to detect the largest effect for the single training variable. A training period of 50-53 weeks, a training frequency of three sessions per week, a training volume of two to three sets per exercise, seven to nine repetitions per set, a training intensity from 51 to 69% of the 1RM, a total time under tension of 6.0 s, a rest of 120 s between sets, and a rest of 2.5 s between repetitions turned out to be most effective.

LIMITATIONS

The current results must be interpreted with caution because of the poor overall methodological study quality (mean PEDro score 4.6 points) and the considerable large heterogeneity (I2) = 80%, χ2 = 163.1, df = 32, p < 0.01) for muscle strength. In terms of muscle morphology, our search identified nine studies only, which is why we consider our findings preliminary. While we were able to determine a dose-response relationship based on specific individual training variables with respect to muscle strength and morphology, it was not possible to ascertain any potential interactions between these variables. We recognize the limitation that the results may not represent one general dose-response relationship.

CONCLUSIONS

This systematic literature review and meta-analysis confirmed the effectiveness of RT on specific measures of upper and lower extremity muscle strength and muscle morphology in healthy old adults. In addition, we were able to extract dose-response relationships for key training variables (i.e., volume, intensity, rest), informing clinicians and practitioners to design effective RTs for muscle strength and morphology. Training period, intensity, time under tension, and rest in between sets play an important role in improving muscle strength and morphology and should be implemented in exercise training programs targeting healthy old adults. Still, further research is needed to reveal optimal dose-response relationships following RT in healthy as well as mobility limited and/or frail old adults.

Prediction of one-repetition maximum from submaximal ratings of perceived exertion in older adults pre- and post-training

BACKGROUND

Individual's one-repetition maximum (1-RM) is required to calculate and prescribe intensity for resistance training, while testing protocols enhance the risk of injuries and are time-consuming.

AIMS

The aim of the present study was to assess the accuracy of 1-RM prediction from ratings of perceived exertion (RPE) of resistance exercises performed at submaximal sets (intensity and volume) in older adult males before and after a 12-week rehabilitation program.

METHODS

18 untrained subjects (70.4 ± 4.5 years) first completed a 1-RM direct assessment with a horizontal leg press pre- and post-training. Thereafter, participants performed, in a random order, 2-repetition sets with loads unknown to them (corresponding to 20, 45 and 70 % of 1-RM). The RPE was recorded immediately after the sets. That RPE associated to its corresponding load was subjected to a linear regression analysis to extrapolate the maximal RPE score and its corresponding 1-RM.

RESULTS

RPE and relative intensities of sets appeared related pre- [r (2) = 0.59, standard error of estimate (SEE) = 13.3 %] and post-training (r (2) = 0.83, SEE = 8.1 %). Differences between measured and predicted 1-RM were reduced from the beginning to the end of training but standard deviations remained high (17.4 ± 11.8 vs. 4.2 ± 11.1 kg). Pre-training, 1-RM expressed relatively to body weight was negatively related with the errors of 1-RM predictions (r (2) = 0.39, p = 0.03).

CONCLUSIONS

In older subjects, RPE may be used to predict 1-RM; however, the predicted value deviates considerably from the measured one, necessitating cautious application. Importantly, this method allows to capture training-induced change in 1-RM, thus making possible assessing training's effectiveness and allowing its modification if necessary.

Influence of combined resistance training and healthy diet on muscle mass in healthy elderly women: a randomized controlled trial

The delivery of efficient nonpharmacological treatment to prevent the loss of muscle mass in older adults is a major challenge, and information on the combined effects of training and diet is particularly important. Here we aimed to evaluate the effects of 24 wk of resistance training combined with a healthy dietary approach (n-6/n-3 ratio < 2) in a population of healthy and physically active older women (65-70 years). The three-armed randomized controlled trial included a resistance training + healthy diet group (RT-HD), a resistance training group (RT), and controls (CON). All subjects included in the study were physically active and had low levels of serum inflammatory markers. In accordance with the dietary goals, the n-6/n-3 ratio dietary intake significantly decreased only in RT-HD by 42%. An increase in 1 repetition maximum in leg extension occurred in RT (+20.4%) and RT-HD (+20.8%), but not in CON. Interestingly, leg lean mass significantly increased only in RT-HD (+1.8%). While there were no changes in serum C-reactive protein and IL-6 levels, a significant decrease in serum level of the pro-inflammatory precursor arachidonic acid (-5.3 ± 9.4%) together with an increase in serum n-3 docosahexaenoic acid (+8.3%) occurred only in RT-HD. Altogether, this study demonstrates that the effects of resistance training on muscle mass in healthy older adults can be optimized by the adoption of a healthy diet.

Frequency of combined resistance and aerobic training in older women

The aim of this study was to determine the optimal frequency of combined aerobic and resistance training for improving muscular strength (MS), cardiovascular fitness (CF), and functional tasks (FTs) in women older than 60 years. Sixty-three women were randomly assigned to 1 of 3 exercise training groups. Group 1 performed 1 resistance exercise training (RET) and 1 aerobic exercise training (AET) session per week (AET/RET 1 × wk); group 2 performed 2 RET and 2 AET sessions per week (AET/RET 2 × wk); and group 3 performed 3 RET and 3 AET sessions per week (AET/RET 3 × wk). MS, CF, and FT measurements were made pretraining and 16 weeks posttraining. Repeated-measures analysis of variance indicated a significant time effect for changes in MS, CF, and FT, such that all improved after training. However, there were no significant training group or training group × time interactions. Sixteen weeks of combined AET/RET (1 × wk, 2 × wk, or 3 × wk) lead to significant improvements in MS, CF, exercise economy, and FT. However, there were no significant differences for MS, CF, or FT outcomes between groups.

Combined aerobic and strength training and energy expenditure in older women

PURPOSE

To examine the effects of three different frequencies of combined resistance and aerobic training on total energy expenditure (TEE) and activity-related energy expenditure (AEE) in a group of older adults.

METHODS

Seventy-two women, 60-74 yr old, were randomly assigned to one of three groups: 1 d · wk(-1) of aerobic training and 1 d · wk(-1) of resistance training (1 + 1), 2 d · wk(-1) of aerobic training and 2 d · wk(-1) resistance training (2 + 2), or 3 d · wk(-1) of aerobic training and 3 d · wk(-1) of resistance training (3 + 3). Body composition (dual-energy x-ray absorptiometry), feeling of fatigue, depression, and vigor (questionnaire), strength (one-repetition maximum), serum cytokines (enzyme-linked immunosorbent assay), maximal oxygen uptake (progressive treadmill test), resting energy expenditure, and TEE were measured before and after 16 wk of training. Aerobic training consisted of 40 min of aerobic exercise at 80% maximum heart rate, and resistance training consisted of two sets of 10 repetitions for 10 different exercises at 80% of one repetition maximum.

RESULTS

All groups increased fat-free mass, strength, and aerobic fitness and decreased fat mass. No changes were observed in cytokines or perceptions of fatigue/depression. No time-group interaction was found for any fitness/body composition variable. TEE and AEE increased with the 2 + 2 group but not with the other two groups. Nonexercise training AEE (nonexercise training activity-related thermogenesis) increased significantly in the 2 + 2 group (+200 kcal · d(-1)), group 1 + 1 showed a trend for an increase (+68 kcal · d(-1)), and group 3 + 3 decreased significantly (-150 kcal · d(-1)).

CONCLUSION

Results indicate that 3 + 3 training may inhibit nonexercise training activity-related thermogenesis by being too time consuming and does not induce superior training adaptations to 1 + 1 and 2 + 2 training.

Upper extremity muscle volumes and functional strength after resistance training in older adults

Aging leads to a decline in strength and an associated loss of independence. The authors examined changes in muscle volume, maximum isometric joint moment, functional strength, and 1-repetition maximum (1RM) after resistance training (RT) in the upper extremity of older adults. They evaluated isometric joint moment and muscle volume as predictors of functional strength. Sixteen healthy older adults (average age 75 ± 4.3 yr) were randomized to a 6-wk upper extremity RT program or control group. The RT group increased 1RM significantly (p < .01 for all exercises). Compared with controls, randomization to RT led to greater functional pulling strength (p = .003), isometric shoulder-adduction moment (p = .041), elbow-flexor volume (p = .017), and shoulder-adductor volume (p = .009). Shoulder-muscle volumes and isometric moments were good predictors of functional strength. The authors conclude that shoulder strength is an important factor for performing functional reaching and pulling tasks and a key target for upper extremity RT interventions.

Weight loss and exercise training effect on oxygen uptake and heart rate response to locomotion

Effects of resistance and aerobic training on the ease of physical activity during and after weight loss are unknown. The purpose of the study was to determine what effect weight loss combined with either aerobic or resistance training has on the ease of locomotion (net V[Combining Dot Above]O2 and heart rate). It is hypothesized that exercise training will result in an increased ease, lowers heart rate during locomotion. Seventy-three overweight premenopausal women were assigned to diet and aerobic training, diet and resistance training, or diet only. Subjects were evaluated while overweight, after diet-induced weight loss (average, 12.5 kg loss), and 1 year after weight loss (5.5 kg regain). Submaximal walking, grade walking, stair climbing, and bike oxygen uptake and heart rate were measured at all time points. Weight loss diet was 800 kcal per day. Exercisers trained 3 times per week during weight loss and 2 times per week during 1-year follow-up. Resistance training increased strength, and aerobic training increased maximum oxygen uptake. Net submaximal oxygen uptake was not affected by weight loss or exercise training. However, heart rate during walking, stair climbing, and bicycling was reduced after weight loss. No significant differences in reduction in heart rate were observed among the 3 treatment groups for locomotion after weight loss. However, during 1-year follow-up, exercise training resulted in maintenance of lower submaximal heart rate, whereas nonexercisers increased heart rate during locomotion. Results suggest that moderately intense exercise is helpful in improving the ease of movement after weight loss. Exercise training may be helpful in increasing the participation in free-living physical activity.

The reliability of the one maximum repetition in sedentary, active and strength-trained subjects

The aim of the study was to verify the reliability of one maximum repetition (1-RM) in three different groups, according levels of physical fitness. The sample was composed for thirty subjects (aged 18 to 34 years old) divided in three groups with ten subjects each: sedentary (SG), physical active (PAG) and strength-trained (STG). The subjects were submitted to two familiarization sessions and two sessions of maximum strength test (1-RM1 and 1-RM2) at the following exercises: bench press and 45º leg press. The comparison between 1-RM values was made by two-way ANOVA (test and group) and association between both by intraclass coefficient correlation (p ≤ 0.05). Data presented high correlation values between both tests (from 0.922 to 0.997; p < 0.001), however, significant differences (p < 0.05) was observed between 1-RM1 and 1-RM2 at bench press exercise in SG (56.40 ± 8.00 kg e 57.60 ± 7.89 kg, respectively), PAG (68,80 ± 9,26 kg e 69,40 ± 8,78 kg, respectively) and STG (87.20 ± 19.94 kg e 88.60 ± 19.86 kg, respectively), as well in the leg press in SG (222,5 ± 38,24 kg e 229,50 ± 38,55 kg, respectively), PAG (238.50 ± 26.25 kg e 244.00 ± 24.70, respectively) and STG (321.50 ± 46.19 kg e 336.40 ± 40.44 kg, respectively). It can be concluded that the subject’s level of physical fitness does not appear to be a critical behavior at 1-RM reliability.

Effects of hydraulic-resistance exercise on strength and power in untrained healthy older adults

The purpose of this study was to determine the efficacy of hydraulic-resistance exercise (HDRE) in improving strength and power in healthy older adults. Thirty-nine older adults (68.6 ± 4.9 years; 15 men, 24 women) were divided into a training group or control group (CON). Hydraulic-resistance exercise consisted of a 12-week supervised program, 50 min · d(-1), 3 d · wk(-1). Hydraulic-resistance exercise was used for 10 exercises: Chest press and pull, shoulder press and pull, low back flexion and extension squat, leg adduction/abduction, leg press, and elbow extension/flexion. The number of the sets and the hydraulic-resistance dial setting (D) were gradually increased in 3 stages during the 12-week program. Strength, rating of perceived exertion, and relative intensity during exercise increased significantly from stage to stage whereas repetition velocity decreased. Total work was higher in the second stage compared with the first but lower in the final stage because of reduced repetitions. Peak torque at D2 and D11 increased (p < 0.05) for knee extension (58 and 9%) and flexion (94 and 21%), chest press (35 and 12%) and pull (29 and 14%), shoulder press (14 and 18%) and pull (75 and 18%), and low back flexion (59 and 46%) and extension (84 and 34%). Peak power at D2 and D11 also increased (p < 0.05) for knee extension (140 and 26%) and flexion (96 and 36%), chest press (54 and 28%) and pull (62 and 23%), shoulder press (55 and 31%) and pull (159 and 30%), and low back flexion (177 and 127%) and extension (104 and 66%). There were no significant changes in the CON. Hydraulic-resistance exercise elicits significant improvements in strength and power in older adults. Therefore, HDRE is an effective form of resistance training that provides benefits using low and moderate intensity of training for older adults.

Combined effects of low-intensity blood flow restriction training and high-intensity resistance training on muscle strength and size

We investigated the combined effect of low-intensity blood flow restriction and high-intensity resistance training on muscle adaptation. Forty young men (aged 22-32 years) were randomly divided into four groups of ten subjects each: high-intensity resistance training (HI-RT, 75% of one repetition maximum [1-RM]), low-intensity resistance training with blood flow restriction (LI-BFR, 30% 1-RM), combined HI-RT and LI-BFR (CB-RT, twice-weekly LI-BFR and once-weekly HI-RT), and nontraining control (CON). Three training groups performed bench press exercises 3 days/week for 6 weeks. During LI-BFR training sessions, subjects wore pressure cuffs on both arms that were inflated to 100-160 mmHg. Increases in 1-RM were similar in the HI-RT (19.9%) and CB-RT (15.3%) groups and lower in the LI-BFR group (8.7%, p < 0.05). Maximal isometric elbow extension (MVC) increased in the HI-RT (11.3%) and CB-RT (6.6%) groups; there was no change in the LI-BFR group (-0.2%). The cross-sectional area (CSA) of the triceps brachii (TB) increased (p < 0.05) in the HI-RT (8.6%), CB-RT (7.2%), and LI-BFR (4.4%) groups. The change in relative isometric strength (MVC divided by TB CSA) was greater (p < 0.05) in the HI-RT group (3.3%) than in the LI-BFR (-3.5%) and CON (-0.1%) groups. Following training, relative dynamic strength (1-RM divided by TB CSA) was increased (p < 0.05) by 10.5% in the HI-RT group and 6.7% in the CB-RT group. None of the variables in the CON group changed. Our results show that low-intensity resistance training with BFR-induced functional muscle adaptations is improved by combining it with HI-RT.

Effects of Training and Detraining on Physical Fitness, Physical Activity Patterns, Cardiovascular Variables, and HRQoL after 3 Health-Promotion Interventions in Institutionalized Elders

The purpose of this study is to assess the effects of different strategies of health on the levels of physical activity (PA), physical fitness (PF), cardiovascular disease (CVD) risk factors and quality of life (QoL) of the institutionalized elderly. Concurrently studies were made of the effect of detraining on these same variables. In this investigation we carried out a prospective longitudinal study with an experimental design, with 1 year plus 3 months of a detraining period. Methodology. (a) A questionnaire with socio-demographic characteristics and a QoL scale (MOS SF-36); (b) Functional Fitness Test to assess PF; (c) An MTI Actigraph to evaluate the PA; (d) Biochemical analysis of blood, blood pressure and bio-impedance. The Main Results Indicated That: (i) ST significantly improved strength and body flexibility and AT the aerobic endurance, agility/dynamic balance and lower strength and flexibility; (ii) Implications of detraining were more evident on the PA groups in the lower body flexibility, which is associated with agility/dynamic balance and lower strength in the AT group; (iii) Cardiovascular variables improved significantly especially blood pressure, cholesterol and glucose in the ST and HDL in the AT group; not having undergone significant changes with the detraining. The results of this thesis contribute positively to highlight the importance of PA in the promotion of health, prevention and reduction of CVD risk factors and the improvement of the PF and QoL.

Influence of resistance exercise on lean body mass in aging adults: a meta-analysis

PURPOSE

sarcopenia plays a principal role in the pathogenesis of frailty and functional impairment that occur with aging. There are few published accounts that examine the overall benefit of resistance exercise (RE) for lean body mass (LBM) while considering a continuum of dosage schemes and/or age ranges. Therefore, the purpose of this meta-analysis was to determine the effects of RE on LBM in older men and women while taking these factors into consideration.

METHODS

this study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations. Randomized controlled trials and randomized or nonrandomized studies among adults ≥ 50 yr were included. Heterogeneity between studies was assessed using the Cochran Q and the I statistics, and publication bias was evaluated through physical inspection of funnel plots as well as formal rank-correlation statistics. Mixed-effects meta-regression was incorporated to assess the relationship between RE dosage and changes in LBM.

RESULTS

data from 49 studies, representing a total of 1328 participants, were pooled using random-effect models. Results demonstrated a positive effect for LBM, and there was no evidence of publication bias. The Cochran Q statistic for heterogeneity was 497.8, which was significant (P < 0.01). Likewise, I was equal to 84%, representing rejection of the null hypothesis of homogeneity. The weighted pooled estimate of mean LBM change was 1.1 kg (95% confidence interval = 0.9-1.2 kg). Meta-regression revealed that higher-volume interventions were associated (β = 0.05, P < 0.01) with significantly greater increases in LBM, whereas older individuals experienced less increase (β = -0.03, P = 0.01).

CONCLUSIONS

RE is effective for eliciting gains in LBM among aging adults, particularly with higher-volume programs. Findings suggest that RE participation earlier in life may provide superior effectiveness.

Dose-response relationship of resistance training in older adults: a meta-analysis

PURPOSE

The purpose of this study was to determine the dose-response relationship of resistance training (RT) to improve strength and function in older adults.

METHODS

A systematic literature search was performed in relevant databases and study reference lists to identify randomized controlled trials. Randomized controlled trials comparing the effects of different doses of strength training in older people (65 yr and older) on strength and functional outcomes were eligible. Two independent reviewers decided on study inclusion, extracted data, and assessed methodological quality. Standardized mean difference (SMD) and 95% confidence intervals (CI) were calculated for relevant outcomes and pooled using a random-effects model.

RESULTS

Twenty-nine trials with a total of 1313 subjects (mean age = 65-81 yr) are summarized in this review. Trials comparing different training intensities show strong effects of progressive resistance training (PRT) on maximal strength in a dose-dependent manner, with high-intensity (HI) PRT being more effective compared with moderate (MI)- and low-intensity (LI) PRT (SMD [HI vs LI] = 0.88, 95% CI = 0.21-1.55; SMD [HI vs MI] = 0.62, 95% CI = 0.22-1.03). PRT was also successful for improving functional outcomes, but gains were independent of training intensity. Power training (PT) was more effective for improving muscle power (SMD [PT vs PRT] = 1.66, 95% CI = 0.08-3.24) and functional outcomes than PRT. There was only little information available on training volume and frequency.

DISCUSSION

Higher training intensities are superior to lower intensities for improving maximal strength but not necessarily for functional performance of older adults. PT has shown to be a particularly effective method for enhancing muscle power and functional performance. More research is necessary to identify the effect of different training volumes and frequencies and the dose-response relationship for very old and frail populations.

Enhancing the weight training experience: a comparison of limb kinematics and EMG activity on three machines

The aim of the study was to compare the kinematics and the timing and amount of electromyographic (EMG) activity during the lat-pull down exercise performed on machines that afforded one, two, or three degrees of freedom for the movement. Seven healthy men (age 29.4 +/- 5.6 years) participated in the study. The exercise was performed with a 30% 1-RM load. Three types of machines with varying degrees of freedom were used: Type 1, the conventional device that restricted the movement to a frontal plane; Type 2, the addition of forearm supination-pronation; Type 3, the addition of forearm supination-pronation and horizontal extension-flexion about the shoulder. All exercises involved a technique known as beginning movement load (BML) training in which light loads are lifted with a relaxation-lengthening-shortening sequence of muscle activation. The Type-3 machine showed: (1) the greatest vertical displacement of the wrist (p < 0.05); (2) the greatest abduction-adduction displacement about the shoulder (p < 0.01); (3) the least flexion-extension displacement about the elbow joint (p < 0.01); (4) a peak vertical velocity for the shoulder that preceded (p < 0.01) those for the elbow and then wrist during the pull-down phase; (5) a progressive proximal-to-distal sequence of EMG activation involving the serratus anterior, posterior deltoid, latissimus dorsi, and triceps brachii muscles; (6) a reversal of the roles for biceps and triceps brachii during the pull-down phase. These results suggest that BML exercises with greater degrees of freedom can enhance the association between training actions and functional activities.