Effects of Resistance Training on 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.

Non invasive techniques for direct muscle quality assessment after exercise intervention in older adults: a systematic review

BACKGROUND

The aging process induces neural and morphological changes in the human musculoskeletal system, leading to a decline in muscle mass, strength and quality. These alterations, coupled with shifts in muscle metabolism, underscore the essential role of physical exercise in maintaining and improving muscle quality in older adults. Muscle quality's morphological domain encompasses direct assessments of muscle microscopic and macroscopic aspects of muscle architecture and composition. Various tools exist to estimate muscle quality, each with specific technical requirements. However, due to the heterogeneity in both the studied population and study methodologies, there is a gap in the establishment of reference standards to determine which are the non-invasive and direct tools to assess muscle quality after exercise interventions. Therefore, the purpose of this review is to obtain an overview of the non-invasive tools used to measure muscle quality directly after exercise interventions in healthy older adults, as well as to assess the effects of exercise on muscle quality.

MAIN TEXT

To address the imperative of understanding and optimizing muscle quality in aging individuals, this review provides an overview of non-invasive tools employed to measure muscle quality directly after exercise interventions in healthy older adults, along with an assessment of the effects of exercise on muscle quality.

RESULTS

Thirty four studies were included. Several methods of direct muscle quality assessment were identified. Notably, 2 studies harnessed CT, 20 utilized US, 9 employed MRI, 2 opted for TMG, 2 adopted myotonometry, and 1 incorporated BIA, with several studies employing multiple tests. Exploring interventions, 26 studies focus on resistance exercise, 4 on aerobic training, and 5 on concurrent training.

CONCLUSIONS

There is significant diversity in the methods of direct assessment of muscle quality, mainly using ultrasound and magnetic resonance imaging; and a consistent positive trend in exercise interventions, indicating their efficacy in improving or preserving muscle quality. However, the lack of standardized assessment criteria poses a challenge given the diversity within the studied population and variations in methodologies.. These data emphasize the need to standardize assessment criteria and underscore the potential benefits of exercise interventions aimed at optimizing muscle quality.

Effect of blood flow restriction training on health promotion in middle-aged and elderly women: a systematic review and meta-analysis

Background: Physical activities play an important role in alleviating the aging problem and improving the physical fitness of middle-aged and elderly people. Blood flow restriction (BFR) training, also known as pressure training, has been widely used to improve athletes' performance and rehabilitation, which is a relatively novel exercise method for improving the physical fitness of middle-aged and elderly people. The purpose of this study is to conduct a systematic review and meta-analysis of domestic and foreign randomized controlled trial studies on BFR training for middle-aged and elderly women, further explore the impact of BFR training on health status. Methods: Meta-analysis was performed according to PRISMA standards, and charts were drawn using Review Manager 5.4 and Stata 17 software. In this study, the keywords such as "pressure training", "blood restriction training", "elderly women", "KAATSU", "blood flow restriction training" were used on CNKI, China Science and Technology Journal Database, PubMed, Embase, Web of Science, Cochrane Library, EBSCO, Scopus, and randomized controlled trials were searched in all languages. The search was performed from the establishment of database to 2 January 2024. The results of the combined effect were represented by standard mean differences. Results: Among the 681 literature retrieved, six eligible English articles were included in this meta-analysis. The overall effect test of the combined effect was performed on 10 groups of data, and the results were SMD = -0.18 (95%CI: -0.91 to 0.56; p > 0.05), the maximum dynamic force of 1RM SMD = 0.97 (95%CI: 0.35 to 1.58; p < 0.05), leg compression force SMD = -0.10 (95%CI: -0.78 to 0.57; p > 0.05), heart rate SMD = 0.33 (95%CI: -2.50 to 3.17; p > 0.05), systolic blood pressure (SBP) SMD = -1.44 (95%CI: -2.17 to -0.70; p < 0.05), diastolic blood pressure (DBP) SMD = -0.69 (95%CI: 2.54 to 1.15; p > 0.05). Conclusion: BFR training had a significant effect on the increase of the maximum dynamic force of 1RM and decrease of blood pressure in middle-aged and elderly women, but there was no significant difference found in heart rate and leg compression force. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42024491642.

Association between wearable device usage and engagement of strength activity among people with and without disabilities

There is a lack of literature examining the engagement in strength activities of people with disabilities (PWD) using and not using wearable devices. The objectives of the current study were to determine the prevalence of strength activity engagement among wearable device users with disabilities, and to compare strength activity engagement between wearable device users and non-users with and without disabilities. Wearable device users and non-users with and without disabilities from eight states of the CDC's 2017 Behavioral Risk Factor Surveillance were included in the analysis. Linear regression was used to examine the association between wearable device use and disability status and the interaction term for frequency of strength activity per week, while logistic regression was used to determine the association between the two variables and the interaction term for strength activity engagement and meeting strength activity guidelines. 7055 wearable device users and non-users with and without disabilities were included in the analysis. No interaction effects were found between wearable device use and disability status. In unadjusted logistic regressions, wearable device users were more likely to engage in strength activity (OR = 1.16, 95% CI [1.16, 2.20]) and meet strength activity guidelines (OR = 1.50, 95% CI [1.07, 2.09]), whereas PWDs were less likely to engage in strength activity (OR = 0.57, 95% CI [0.44, 0.75]) and meet strength activity guidelines (OR = 0.72, 95% CI [0.53, 0.98]). The use of wearable devices could lead to engagement in strength activity. However, further research is needed to determine its effectiveness in PWD.

E-PROOF: E-intervention for protein intake and resistance training to optimize function: A study protocol

BACKGROUND

Accounting for more than 60% of cancer survivors, older (≥65 years) cancer survivors have a 2- to 5-fold risk of physical function impairment, compared to cancer-free peers. One strategy to improve physical function is dietary and resistance training interventions, which improve muscle strength and mass by stimulating muscle protein synthesis. The E-PROOF (E-intervention for Protein Intake and Resistance Training to Optimize Function) study will examine the feasibility, acceptability, and preliminary efficacy of a 12-week randomized controlled trial of an online, tailored nutritional and resistance training education and counseling intervention to improve physical function and associated health outcomes (muscle strength, health-related quality of life (HRQoL), self-efficacy, and weight management).

METHODS

In this study, 70 older cancer survivors will be randomized to one of two groups: experimental (receiving remote behavioral counseling and evidence-based education and resources), and control (general survivorship education). We will examine the intervention effects on physical function, muscle strength, HRQoL, self-efficacy, weight, and waist circumference during a 12-week period between the experimental and control groups. Three months following the end of the intervention, we will conduct a follow-up assessment to measure physical function, muscle strength, and HRQoL.

SIGNIFICANCE AND IMPACT

This study is the first synchronous, online protein-focused diet and resistance training intervention among older cancer survivors. This novel study advances science by promoting independent health behaviors among older cancer survivors to improve health outcomes, and provide foundational knowledge to further address this growing problem on a wider scale through online platforms.

Comparison of Participation in Strength Activity Among People With and Without Disabilities: 2013-2017 Behavioral Risk Factor Surveillance System

BACKGROUND

The current physical activity guidelines recommend engagement in strength activities at least 2 days per week. Currently, there is a lack of literature examining strength activities among people with disabilities. The purpose of this study is to estimate and compare the prevalence of engagement in strength activities and adherence to strength activity guidelines among adults with and without disabilities in the United States.

METHODS

A total of 1,005,644 adults (18-80 y old) with and without disabilities from the 2013 to 2017 Behavioral Risk Factor Surveillance System were included in this secondary data analysis. Descriptive analyses were performed to describe the prevalence of strength activity behaviors of adults with and without disabilities. Logistic and Poisson regression models were performed to evaluate the relative contribution of disability status on strength activity behaviors.

RESULTS

A higher proportion of participants without disabilities (46.42%, 95% CI, 46.18-46.65) reported engaging in strength activities compared with participants with disabilities (30.68%, 95% CI, 30.29-31.08; P < .01). Participants with disabilities were less likely to engage in strength activities (odds ratio = 0.51, 95% CI, 0.50-0.52; adjusted odds ratio = 0.75, 95% CI, 0.73-0.77) and meet strength activity guidelines (odds ratio = 0.56, 95% CI, 0.54-0.57; adjusted odds ratio = 0.75, 95% CI, 0.73-0.77) than participants without disabilities.

CONCLUSION

Experiencing a disability is associated with lower engagement in strength activities; thus, it is important to identify effective and efficient approaches to promoting strength activities among people with disabilities.

Multifactorial Exercise Intervention Decreases Falls Risk in High-risk and Low-risk Older Adults

BACKGROUND

Each year, 1 in 4 people over the age of 65 years of age will experience a fall. It is important to identify and address modifiable risk factors that are associated with falls in adults at high and low risk for falls.

HYPOTHESIS

Falls risk improves in both high-risk and low-risk participants with the implementation of Stay Active and Independent for Life (SAIL).

STUDY DESIGN

Cohort study.

LEVEL OF EVIDENCE

Level 3.

METHODS

Seventy-eight older adults (age, 70.9 ± 5.1 years) were included in this study and categorized into high risk and low risk for falling based on the falls risk score from the Physiological Profile Assessment. High risk was defined as having a preintervention falls risk score >1, whereas low risk was defined as having a preintervention falls risk score <1. Both groups had the same 10-week intervention. A multivariate analysis of covariance was used to compare differences pre- and postintervention, using preintervention falls risk score as covariate.

RESULTS

Results showed that regardless of preintervention falls risk, participants showed significant improvements in right and left knee extensor strength and sit-to-stand after participation in the 10-week SAIL program. Also, noteworthy is that 15 participants who were considered at high risk for falling preintervention were considered low risk for falling postintervention.

CONCLUSION

The positive outcomes noted on modifiable risk factors suggest SAIL can be beneficial for decreasing falls risk in older adults, regardless of risk of falling, using a multifactorial exercise intervention. Our results also showed that it was possible for participants not only to improve falls risk but to improve to such a degree that they change from high risk to low risk of falling.

CLINICAL RELEVANCE

Our results demonstrated that SAIL was effective in improving overall fall risk after a 10-week intervention. Targeted community-based interventions for the aging population can bring physical health benefits that can decrease falls risk.

A meta-analysis on the impact of resistance training on phase angle in middle-aged and older individuals

PURPOSE

To determine the impact of resistance training (RT) on phase angle (PhA) in middle-aged and older individuals via meta-analysis, explore effects in subgroups, and identify optimal RT protocol.

MATERIALS AND METHODS

We searched five databases using predefined criteria, assessed literature quality per Cochrane 5.1 Handbook, and used Revman 5.3 for effect size aggregation, bias assessment, sensitivity analysis, and subgroup analysis.

RESULTS

RT improved PhA in middle-aged and older individuals (d = 0.34, 95 % CI: 0.27-0.40, P < 0.05). Effective subgroups included Suspension (d = 0.62, 95 % CI: 0.33-0.90, P < 0.05), free-weights and machine (d = 0.36, 95 % CI: 0.28-0.45, P < 0.05), equipment training (d = 0.24, 95 % CI: 0.13-0.36, P < 0.05), and moderate-intensity RT (d = 0.34, 95 % CI: 0.27-0.42, P < 0.05). RT was conducted 2-3 times/week (d = 0.20, 95 % CI: 0.01-0.38, P < 0.05) or (d = 0.38, 95 % CI: 0.30-0.47, P < 0.05). PhA improved after 8 weeks (d = 0.37, 95 % CI: 0.23-0.51, P < 0.05), 12 weeks (d = 0.35, 95 % CI: 0.26-0.44, P < 0.05), and ≥ 24 weeks (d = 0.26, 95 % CI: 0.11-0.41, P < 0.05) of RT in aged and older individuals. Low- and high-intensity RT, elastic band training, and weekly exercises did not significantly improve PhA.

CONCLUSIONS

RT enhances PhA in middle-aged and older adults. For optimal results, we recommend 2-3 weekly sessions of free weights and machine training lasting at least 8 weeks.

The Effectiveness of Water- versus Land-Based Exercise on Specific Measures of Physical Fitness in Healthy Older Adults: An Integrative Review

As the population ages, maintaining an active lifestyle becomes increasingly vital to promote overall health and well-being in older individuals. Water- and land-based exercises have emerged as popular options, each offering a distinct set of benefits tailored to the unique needs of this population group. An electronic database search, including PubMed, Scopus, MEDLINE, and Web of Science, was conducted until 15 September 2023, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, to investigate the effects of water-based compared to land-based exercise on selected fitness parameters in older healthy individuals. The eligibility criteria included studies with at least two groups of participants aged 60 and older, with physical fitness outcome measures. A total of ten studies met the inclusion criteria and were analyzed. While both exercise modalities may offer significant benefits, this review's findings emphasized the absence of conclusive evidence and consensus for recommending a single exercise category applicable to aquatic or land environments and providing more definite guidance to improve health-related physical fitness parameters in healthy older individuals. Finally, combining both training approaches may lead to a comprehensive array of health benefits for this age group population by also considering individual's needs, preferences, and fitness goals.

Mechanisms of mechanical overload-induced skeletal muscle hypertrophy: current understanding and future directions

Mechanisms underlying mechanical overload-induced skeletal muscle hypertrophy have been extensively researched since the landmark report by Morpurgo (1897) of "work-induced hypertrophy" in dogs that were treadmill trained. Much of the preclinical rodent and human resistance training research to date supports that involved mechanisms include enhanced mammalian/mechanistic target of rapamycin complex 1 (mTORC1) signaling, an expansion in translational capacity through ribosome biogenesis, increased satellite cell abundance and myonuclear accretion, and postexercise elevations in muscle protein synthesis rates. However, several lines of past and emerging evidence suggest that additional mechanisms that feed into or are independent of these processes are also involved. This review first provides a historical account of how mechanistic research into skeletal muscle hypertrophy has progressed. A comprehensive list of mechanisms associated with skeletal muscle hypertrophy is then outlined, and areas of disagreement involving these mechanisms are presented. Finally, future research directions involving many of the discussed mechanisms are proposed.

ADAPTations to low load blood flow restriction exercise versus conventional heavier load resistance exercise in UK military personnel with persistent knee pain: protocol for the ADAPT study, a multi-centre randomized controlled trial

BACKGROUND

Muscle atrophy, muscle weakness and localised pain are commonly reported following musculoskeletal injury (MSKI). To mitigate this risk and prepare individuals to return to sport or physically demanding occupations, resistance training (RT) is considered a vital component of rehabilitation. However, to elicit adaptations in muscle strength, exercise guidelines recommend lifting loads ≥ 70% of an individual's one repetition maximum (1-RM). Unfortunately, individuals with persistent knee pain are often unable to tolerate such high loads and this may negatively impact the duration and extent of their recovery. Low load blood flow restriction (LL-BFR) is an alternative RT technique that has demonstrated improvements in muscle strength, hypertrophy, and pain in the absence of high mechanical loading. However, the effectiveness of high-frequency LL-BFR in a residential rehabilitation environment remains unclear. This study will compare the efficacy of high frequency LL-BFR to 'conventional' heavier load resistance training (HL-RT) on measures of physical function and pain in adults with persistent knee pain.

METHODS

This is a multicentre randomised controlled trial (RCT) of 150 UK service personnel (aged 18-55) admitted for a 3-week residential rehabilitation course with persistent knee pain. Participants will be randomised to receive: a) LL-BFR delivered twice daily at 20% 1-RM or b) HL-RT three-times per week at 70% 1-RM. Outcomes will be recorded at baseline (T1), course discharge (T2) and at three-months following course (T3). The primary outcome will be the lower extremity functional scale (LEFS) at T2. Secondary outcomes will include patient reported perceptions of pain, physical and occupational function and objective measures of muscle strength and neuromuscular performance. Additional biomechanical and physiological mechanisms underpinning both RT interventions will also be investigated as part of a nested mechanistic study.

DISCUSSION

LL-BFR is a rehabilitation modality that has the potential to induce positive clinical adaptations in the absence of high mechanical loads and therefore could be considered a treatment option for patients suffering significant functional deficits who are unable to tolerate heavy load RT. Consequently, results from this study will have a direct clinical application to healthcare service providers and patients involved in the rehabilitation of physically active adults suffering MSKI.

TRIAL REGISTRATION

ClinicalTrials.org reference number, NCT05719922.

Recovery from Resistance Exercise in Older Adults: A Systematic Scoping Review

BACKGROUND

Resistance exercise is recommended for maintaining muscle mass and strength in older adults. However, little is known about exercise-induced muscle damage and recovery from resistance exercise in older adults. This may have implications for exercise prescription. This scoping review aimed to identify and provide a broad overview of the available literature, examine how this research has been conducted, and identify current knowledge gaps relating to exercise-induced muscle damage and recovery from resistance exercise in older adults.

METHODS

Studies were included if they included older adults aged 65 years and over, and reported any markers of exercise-induced muscle damage after performing a bout of resistance exercise. The following electronic databases were searched using a combination of MeSH terms and free text: MEDLINE, Scopus, Embase, SPORTDiscus and Web of Science. Additionally, reference lists of identified articles were screened for eligible studies. Data were extracted from eligible studies using a standardised form. Studies were collated and are reported by emergent theme or outcomes.

RESULTS

A total of 10,976 possible articles were identified and 27 original research articles were included. Findings are reported by theme; sex differences in recovery from resistance exercise, symptoms of exercise-induced muscle damage, and biological markers of muscle damage.

CONCLUSIONS

Despite the volume of available data, there is considerable variability in study protocols and inconsistency in findings reported. Across all measures of exercise-induced muscle damage, data in women are lacking when compared to males, and rectifying this discrepancy should be a focus of future studies. Current available data make it challenging to provide clear recommendations to those prescribing resistance exercise for older people.

The effects of exercise training on body composition in postmenopausal women: a systematic review and meta-analysis

Introduction

We conducted a systematic review and meta-analysis to investigate the effect of exercise training on body composition outcomes in postmenopausal women.

Methods

PubMed, Web of Science, CINAHL, and Medline were searched to identify the randomized controlled trials which evaluated effect of exercise training versus control in postmenopausal women. Standardized mean differences (SMD), weighted mean differences (WMD) and 95% confidence intervals (95% CIs) were calculated using random effects model.

Results

One hundred and one studies involving 5,697 postmenopausal women were included in the meta-analysis. Results indicated that exercise training effectively increased muscle mass/ volume, muscle and fiber cross-sectional area and fat-free mass, and decreased fat mass, body fat percentage, waist circumference and visceral fat. Furthermore, subgroup analyses results revealed that aerobic and combined training had greater beneficial effects on fat mass outcomes, whereas resistance and combined training had greater beneficial effects on muscle mass outcomes.

Discussion

Overall, our results revealed that exercise training is effective for improving body composition in postmenopausal women. To be specific, aerobic training is effective on fat loss, whereas resistance training is effective on muscle gain. However, combination of aerobic and resistance trainings may be considered a viable strategy to improve body composition in postmenopausal women.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42021283425.

Use of symptom-guided physical activity and exercise rehabilitation for COVID-19 and other postviral conditions

There are many similarities in symptoms between postviral conditions, including clinical features such as fatigue, reduced daily activity and postexertional symptom exacerbation. Unfavourable responses to exercise have influenced the wider debate on how to reintegrate physical activity (PA) and exercise while simultaneously managing symptoms during recovery from post-COVID-19 syndrome (or Long COVID). This has resulted in inconsistent advice from the scientific and clinical rehabilitation community on how and when to resume PA and exercise following COVID-19 illness. This article provides commentary on the following topics: (1) controversies surrounding graded exercise therapy as a treatment modality for post-COVID-19 rehabilitation; (2) evidence supporting PA promotion, resistance exercise and cardiorespiratory fitness for population health, and the consequences of physical inactivity in patients with complex rehabilitation needs; (3) population-based challenges for UK Defence Rehabilitation practitioners for the management of postviral conditions; and (4) 'symptom guided PA and exercise rehabilitation' as an appropriate treatment option for managing individuals with multifaceted medical needs.

Effects of a 14-week community health program of exercise and learning/education in older adults: A single-arm pre-post comparison study

This study was initiated in 2022 in Miyaki Town, Saga Prefecture, Japan, to determine the impact of an intervention that combined brain and physical function training and health education in older residents. Miyaki has a population of approximately 26,000, 35% of whom are considered to be aging. A 14-week program consisting of strength training, brain function training, and health lectures was conducted with 34 older residents of the community. Body composition, motor function, brain function, and various blood tests were evaluated before and after the intervention. Brain function was assessed using the Trail Making Test-A. Physical function was assessed by Open-Close Stepping, Functional Reach Test, Open-Leg Standing Time, and Two-Step Test. The intervention group showed significant improvements in brain function (p< 0.0001), physical function (p = 0.0037), body composition (p = 0.0053), and LDL-C (p = 0.017). This study provides substantial evidence that community-based combined programs can be beneficial for older adults.

Attentional Focus Strategies to Improve Motor Performance in Older Adults: A Systematic Review

Previous literature shows the beneficial effects of an external focus of attention on various sports skills in young adults. The objective of this systematic review is to evaluate the effects of external and internal focus of attention on motor performance in healthy older adults. The literature search was conducted in five electronic databases (PsycINFO, PubMed, SPORTDiscus, Scopus, and Web of Science). Eighteen studies that met the inclusion criteria were evaluated. Most of the motor tasks targeting older adults were related to postural control and gait. Over 60% of the included studies reported that the effect of an external focus was superior to that of an internal focus on motor performance in older adults. An external focus generally results in better motor performance than an internal focus among healthy older adults. However, the advantage of an external focus on locomotion may not be as significant as those illustrated in previous attentional focus studies. A challenging cognitive task may allow more automatic motor control than an external focus. Practitioners might provide clear instruction cues guiding performers to divert their attention away from their body and towards the movement effect for better performance, particularly in balancing tasks.

Effect of resistance training on local muscle endurance in middle-aged and older adults: A systematic review with meta-analysis and meta-regression

BACKGROUND

Local muscle endurance (LME) is a significant indicator of muscle health and function in middle-aged and older adults. However, resistance training (RT) practices which optimise performance in this population are currently unclear. This study examined: 1) the effect of RT on LME; and 2) the impact of acute resistance exercise program variables on LME in middle-aged and older adults.

METHODS

Five electronic databases were searched using terms related to RT, LME, and older adults. Random effects (Hedges' g) meta-analyses were undertaken to estimate the effect of RT on upper and lower body LME assessed via maximal repetitions during an isotonic test. The impact of resistance exercise program variables on LME effects was explored using meta-regression analyses.

RESULTS

Fifteen studies met the inclusion criteria for this review. Upon sensitivity analysis, one study was removed. Large effects favoured RT for LME of the upper body (g = 1.10, p < 0.001) and lower body (g = 1.18, p < 0.001). Large effects on LME from RT were found irrespective of training intensity or other resistance exercise program variables. Moderate heterogeneity and publication bias were found in most analyses.

DISCUSSION

RT is an effective means for improving LME in middle-aged and older adults. Optimal training characteristics have not been defined by this review, as improvement in LME was unrelated to RT volume or loading intensity. Caution is warranted when interpreting the findings due to heterogeneity and bias present in existing literature. Additional studies are needed with direct comparisons of various training techniques.

Association between Fat-Free Mass Loss after Diet and Exercise Interventions and Weight Regain in Women with Overweight

PURPOSE

This study aimed to determine if percent fat-free mass loss (% FFML) after diet alone, diet plus aerobic, or diet plus resistance exercise is a predictor of weight regain in women with overweight.

METHODS

One hundred and forty-one premenopausal women with overweight (body mass index, 28 ± 1 kg·m -2 ; age, 35 ± 6 yr) enrolled in a weight loss program to achieve a body mass index <25 kg·m -2 (diet alone, diet plus resistance, or diet plus aerobic exercise) and were followed for 1 yr. Body weight and composition (with dual-energy x-ray absorptiometry) were measured at baseline, after weight loss, and at 1 yr.

RESULTS

Participants lost 12.1 ± 2.6 kg of body weight, 11.3 ± 2.5 kg of fat mass, and 0.5 ± 1.6 kg of fat-free mass during the weight loss intervention, followed by weight regain at 1 yr (6.0 ± 4.4 kg, 51.3% ± 37.8%; P < 0.001 for all). % FFML was -3.6 ± 12.4, and a greater % FFML was associated with more weight regain ( r = -0.216, P = 0.01, n = 141), even after adjusting for the intervention group ( β = -0.07; 95% confidence interval, -0.13 to -0.01; P = 0.017).

CONCLUSIONS

% FFML is a significant predictor of weight regain in premenopausal women with overweight. These results support strategies for conserving fat-free mass during weight loss, such as resistance training. Future research should try to identify the mechanisms, at the level of both appetite and energy expenditure, responsible for this association.

Gradual Strength Training Improves Sleep Quality, Physical Function and Pain in Women with Fibromyalgia

BACKGROUND

Fibromyalgia (FM) is characterized by chronic and generalized musculoskeletal pain. There is currently no cure for FM, but alternative treatments are available. Among them, gradual strength training programs (ST) which on daily activities are a valid option to improve some of the pronounced symptoms of FM that affect quality of life, such as fatigue, pain, sleep quality, and physical function. However, there is a need for more information on optimal training programs to improve anxiety and fatigue symptoms.

AIM

To analyze the effects of a 24-week gradual and progressive ST on sleep quality, fatigue, pain domains, physical function, and anxiety-state.

METHODS

41 women with FM participated in the 24 weeks of intervention based on gradual and progressive ST. Two, 60 min, training sessions per week were con-ducted. Participants were evaluated before the ST program (week 0), in week 12 and at the end of the ST program (week 24). The Revised Fibromyalgia Impact Questionnaire was used to assess sleep quality and fatigue scales. Anxiety-state was evaluated with the State Anxiety Inventory, and pain domains by means of the Brief Pain Inventory. Senior Fitness Test was used for physical function measurements. One-way analysis of variance (ANOVA) was applied to assess the mean differences between phases, and Spearman's correlations were used to assess the associations between physical and psychological symptoms, and physical function.

RESULTS

The results demonstrated that 24 weeks of ST improves physical function, sleep quality and pain domains (p ≤ 0.05). Higher anxiety and pain interference scores were related to worsening physical function.

CONCLUSIONS

Gradual ST significantly improves sleep quality, pain, and physical function, but not anxiety and fatigue.

Use It or Lose It? A Meta-Analysis on the Effects of Resistance Training Cessation (Detraining) on Muscle Size in Older Adults

This review aimed to explore the effect of resistance training cessation (detraining) on muscle size in older adults. Five databases were searched to find eligible studies. Their methodological quality was assessed using the PEDro checklist. The data were pooled in a random-effects meta-analysis. Six studies, with eight groups, were included in the review. Resistance training interventions lasted from 9 to 24 weeks. The detraining duration was from 12 to 52 weeks. Studies were classified as being of fair or good methodological quality. Compared to the baseline data, muscle size significantly increased following the resistance training intervention (Cohen's d: 0.99; 95% confidence interval: 0.63, 1.36). Compared to the post-resistance training data, there was a significant decrease in muscle size following training cessation (Cohen's d: -0.83; 95% confidence interval: -1.30, -0.36). In subgroup analyses, there was no significant decrease in muscle size following 12-24 weeks of training cessation (Cohen's d: -0.60; 95% confidence interval: -1.21, 0.01). There was a significant decrease in muscle size following 31-52 weeks of training cessation (Cohen's d: -1.11; 95% confidence interval: -1.75, -0.47). In summary, resistance training increases muscle size in older adults. In contrast, training cessation is associated with a decrease in muscle size. However, the loss of muscle size might be related to detraining duration, with greater muscle loss occurring during longer duration detraining periods. Future studies are required to establish the time course of muscle size changes during detraining in older adults.

Understanding heterogeneity of responses to, and optimizing clinical efficacy of, exercise training in older adults: NIH NIA Workshop summary

Exercise is a cornerstone of preventive medicine and a promising strategy to intervene on the biology of aging. Variation in the response to exercise is a widely accepted concept that dates back to the 1980s with classic genetic studies identifying sequence variations as modifiers of the VO₂max response to training. Since that time, the literature of exercise response variance has been populated with retrospective analyses of existing datasets that are limited by a lack of statistical power from technical error of the measurements and small sample sizes, as well as diffuse outcomes, very few of which have included older adults. Prospective studies that are appropriately designed to interrogate exercise response variation in key outcomes identified a priori and inclusive of individuals over the age of 70 are long overdue. Understanding the underlying intrinsic (e.g., genetics and epigenetics) and extrinsic (e.g., medication use, diet, chronic disease) factors that determine robust versus poor responses to various exercise factors will be used to improve exercise prescription to target the pillars of aging and optimize the clinical efficacy of exercise training in older adults. This review summarizes the proceedings of the NIA-sponsored workshop entitled, "Understanding Heterogeneity of Responses to, and Optimizing Clinical Efficacy of, Exercise Training in Older Adults" and highlights the importance and current state of exercise response variation research, particularly in older adults, prevailing challenges, and future directions.

Exercise-Induced Muscle Damage and Protein Intake: A Bibliometric and Visual Analysis

Numerous studies have covered exercise-induced muscle damage (EIMD) topics, ranging from nutritional strategies to recovery methods, but few attempts have adequately explored and analyzed large volumes of scientific output. The purpose of this study was to assess the scientific output and research activity regarding EIMD and protein intake by conducting a bibliometric and visual analysis. Relevant publications from 1975-2022 were retrieved from the Web of Science Core Collection database. Quantitative and qualitative variables were collected, including the number of publications and citations, H-indexes, journals of citation reports, co-authorship, co-citation, and the co-occurrence of keywords. There were 351 total publications, with the number of annual publications steadily increasing. The United States has the highest total number of publications (26.21% of total publications, centrality 0.44). Institutional cooperation is mostly geographically limited, with few transnational cooperation links. EIMD and protein intake research is concentrated in high-quality journals in the disciplines of Sport Science, Physiology, Nutrition, and Biochemistry & Molecular Biology. The top ten journals in the number of publications are mostly high-quality printed journals, and the top ten journals in centrality have an average impact factor of 13.845. The findings of the co-citation clusters and major keyword co-occurrence reveal that the most discussed research topics are "exercise mode", "nutritional strategies", "beneficial outcomes", and "proposed mechanisms". Finally, we identified the following research frontiers and research directions: developing a comprehensive understanding of new exercise or training models, nutritional strategies, and recovery techniques to alleviate EIMD symptoms and accelerate recovery; applying the concept of hormesis in EIMD to induce muscle hypertrophy; and investigating the underlying mechanisms of muscle fiber and membrane damage.

Comparison of Participation in Strength Activity Between Wearable Device Users and Nonusers: 2017 Behavioral Risk Factors Surveillance System

BACKGROUND

There are many benefits associated with engaging in strength physical activity. Many studies did not examine the engagement of strength activity among wearable device users. This study aimed to examine the association between wearable device usage and engagement of strength activity in free-living settings using nationally representative data.

METHODS

A total of 8250 adult wearable device users and nonusers from 8 states of the 2017 Behavioral Risk Factors Surveillance System were included in analysis. Multiple regression models were performed to determine the association between the dependent variables of strength activities and the independent variable of wearable devices.

RESULTS

Wearable device users were 1.26 (95% confidence interval, 1.01-1.81) times the odds of nonusers in engaging in strength activity. Users also had higher odds of meeting both the strength and aerobic physical activity guidelines than nonusers (odds ratio = 1.49; 95% confidence interval, 1.07-2.06; adjusted odds ratio = 1.43; 95% confidence interval, 1.02-2.00). No associations were found between wearable device utilization and frequency of strength activity per week.

CONCLUSION

Wearable device users were more likely to engage in strength activity than nonusers. However, additional studies are needed to determine the effectiveness of wearable devices in promoting strength activity.

Improvement of lower-extremity stability by rotational leg press training

BACKGROUNDS

Previous reports revealed that balance and stability are essential for human physical activity. The present study aimed to evaluate the comparative outcome of a novel beginning movement load training (BMLT) versus conventional leg press training in terms of improvement of lower-extremity stability.

RESEARCH QUESTION

Does the leg press training improve the stability of lower extremities?

METHODS

Twenty adult, asymptomatic and active amateur basketball players were enrolled in this study and randomized in equal numbers into a BMLT group (study group) and a conventional leg press training group (control group).

RESULTS

The results after eight-week course of training showed that conventional leg press training had an opposite effect on dynamic stability in the left leg (p = 0.015) and backward movement of the right leg (p = 0.038). The athletes in the study group revealed superior dynamic stability maintenance in both legs backwards (p = 0.001), the left leg (p = 0.013), the right leg backwards (p = 0.022) and overall stability (p = 0.002).

SIGNIFICANCE

The study group showed better postural stability in terms of the medial/lateral index (p = 0.017), and the athletes in the control group exhibited a significant inability to maintain postural stability in the medial/lateral aspect after the training (p = 0.016). Rotational BMLT lower-extremity press training yielded superior enhancement of dynamic stability and maintenance of center of gravity and postural stability.

A Randomized Trial of the Effects of Dietary n3-PUFAs on Skeletal Muscle Function and Acute Exercise Response in Healthy Older Adults

Skeletal muscle is critical for maintaining mobility, independence, and metabolic health in older adults. However, a common feature of aging is the progressive loss of skeletal muscle mass and function, which is often accompanied by mitochondrial impairments, oxidative stress, and insulin resistance. Exercise improves muscle strength, mitochondrial health, and cardiorespiratory fitness, but older adults often exhibit attenuated anabolic responses to acute exercise. Chronic inflammation associated with aging may contribute to this "anabolic resistance" and therapeutic interventions that target inflammation may improve exercise responsiveness. To this end, we conducted a randomized controlled trial to determine the effect of 6 months of dietary omega-3 polyunsaturated fatty acids (n3-PUFA) supplementation on skeletal muscle function (mass, strength), mitochondrial physiology (respiration, ATP production, ROS generation), and acute exercise responsiveness at the level of the muscle (fractional synthesis rate) and the whole-body (amino acid kinetics) in healthy older adults. When compared with a corn oil placebo (n = 33; 71.5 ± 4.8 years), older adults treated with 4 g/day n3-PUFA (n = 30; 71.4 ± 4.5 years) exhibited modest but significant increases in muscle strength (3.1 ± 14.7% increase in placebo vs. 7.5 ± 14.1% increase in n3-PUFA; p = 0.039). These improvements in muscle strength with n3-PUFA supplementation occurred in the absence of any effects on mitochondrial function and a minor attenuation of the acute response to exercise compared to placebo. Together, these data suggest modest benefits of dietary n3-PUFAs to muscle function in healthy older adults. Future studies may elucidate whether n3-PUFA supplementation improves the exercise response in elderly individuals with co-morbidities, such as chronic inflammatory disease or sarcopenia.

The Health Benefits of Egg Protein

Once the general public accepts that dietary cholesterol is not a concern for cardiovascular disease risk, foods that have been labeled as high-cholesterol sources, including eggs, may be appreciated for their various other dietary components. One of the nutrients in eggs that deserves further discussion is egg protein. Egg protein has been recognized to be highly digestible and an excellent source of essential amino acids, with the highest attainable protein digestibility-corrected amino acid score. Egg protein has been shown to decrease malnutrition in underdeveloped countries, possibly increase height in children, and protect against kwashiorkor. Egg protein has been demonstrated to be important to skeletal muscle health and protective against sarcopenia. Egg protein also can decrease appetite, resulting in a reduction in the caloric intake from the next meal and weight reduction. Other protective effects of egg protein addressed in this review include protection against infection as well as hypotensive and anti-cancer effects.

Randomised Controlled Trial of Fish Oil Supplementation on Responsiveness to Resistance Exercise Training in Sarcopenic Older Women

This study aims to investigate the effects of fish oil supplementation on the muscle adaptive response to resistance exercise training, physical performance and serum levels of inflammatory cytokines in sarcopenic older women. A randomised, double-blind, placebo-controlled trial is performed with thirty-four sarcopenic women (2010 European Consensus of Sarcopenia), aged ≥ 65 years. The participants are allocated into the following two groups: Exercise and Fish Oil (EFO) and Exercise and Placebo (EP). Both groups undertook a resistance exercise programme over 14 weeks. All participants are instructed to ingest 4 g/day of food supplements; the EP group received sunflower oil capsules, and the EFO group, fish oil capsules. The cross-sectional area (CSA) of the quadriceps muscle is calculated using magnetic resonance imaging (MRI). The strength of the lower limbs is measured using isokinetic dynamometry. Both groups show improvements in CSA and strength after the intervention. Changes in EFO are significantly greater compared with EP for muscle strength (peak torque, 19.46 Nm and 5.74 Nm, respectively, p < 0.001). CSA increased after the intervention in both groups (EFO; 6.11% and EP; 2.91%), although there is no significant difference between the groups (p = 0.23). There are no significant intra-group, inter-group or time differences in any of the cytokines measured. The use of fish oil supplementation potentiates the neuromuscular response to the anabolic stimulus from training, increasing muscle strength and physical performance in sarcopenic older women.

Metabolic adaptation after combined resistance and aerobic exercise training in older women

OBJECTIVE

This study investigated whether combined aerobic and resistance training in older women leads to metabolic adaptation.

METHODS

A total of 80 women (64 White individuals; BMI: 30.0 [4.4] kg/m² ; age: 64.8 [3.5] years) followed 32 weeks of aerobic and resistance training. Body weight/composition (dual-energy X-ray absorptiometry) and resting metabolic rate (RMR; indirect calorimetry) were measured at baseline, week 16, and week 32. Metabolic adaptation was defined as significantly lower measured versus predicted RMR. A regression model to predict metabolic adaptation was developed that included race, age, baseline fat-free mass, RMR and respiratory quotient, and changes in net submaximal oxygen consumption after different tasks.

RESULTS

There was significant metabolic adaptation at week 16 (-59 [136] kcal/d, p = 0.002), following a 640-kcal/wk energy loss (-0.7 [2.6] kg of weight loss). In 53 women with complete data, metabolic adaptation was seen both at week 16 (-64 [129] kcal/d, p = 0.001) and at week 32 (-94 [127] kcal/d, p < 0.001). Metabolic adaptation at week 16 was predicted by race, age, baseline fat-free mass, RMR and respiratory quotient, and change in net oxygen consumption of walking (R² adjusted = 0.90, p < 0.001). Similar results were seen at week 32.

CONCLUSIONS

In older women with overweight and obesity, a minimal energy deficit induced by aerobic and resistance exercise is associated with metabolic adaptation at the level of RMR.

Effectiveness of a Hybrid Exercise Program on the Physical Abilities of Frail Elderly and Explainable Artificial-Intelligence-Based Clinical Assistance

Background: Due to the low physical fitness of the frail elderly, current exercise program strategies have a limited impact. Eight-form Tai Chi has a low intensity, but high effectiveness in the elderly. Inspired by it, we designed an exercise program that incorporates eight-form Tai Chi, strength, and endurance exercises, to improve physical fitness and reverse frailty in the elderly. Additionally, for the ease of use in clinical practice, machine learning simulations were used to predict the frailty status after the intervention. Methods: For 24 weeks, 150 frail elderly people completed the experiment, which comprised the eight-form Tai Chi group (TC), the strength and endurance training group (SE), and a comprehensive intervention combining both TC and SE (TCSE). The comparison of the demographic variables used one-way ANOVA for continuous data and the chi-squared test for categorical data. Two-way repeated measures analysis of variance (ANOVA) was performed to determine significant main effects and interaction effects. Eleven machine learning models were used to predict the frailty status of the elderly following the intervention. Results: Two-way repeated measures ANOVA results before the intervention, group effects of ten-meter maximum walking speed (10 m MWS), grip strength (GS), timed up and go test (TUGT), and the six-minute walk test (6 min WT) were not significant. There was a significant interaction effect of group × time in ten-meter maximum walking speed, grip strength, and the six-minute walk test. Post hoc tests showed that after 24 weeks of intervention, subjects in the TCSE group showed the greatest significant improvements in ten-meter maximum walking speed (p < 0.05) and the six-minute walk test (p < 0.05) compared to the TC group and SE group. The improvement in grip strength in the TCSE group (4.29 kg) was slightly less than that in the SE group (5.16 kg). There was neither a significant main effect nor a significant interaction effect for TUGT in subjects. The stacking model outperformed other algorithms. Accuracy and the F1-score were 67.8% and 71.3%, respectively. Conclusion: A hybrid exercise program consisting of eight-form Tai Chi and strength and endurance exercises can more effectively improve physical fitness and reduce frailty among the elderly. It is possible to predict whether an elderly person will reverse frailty following an exercise program based on the stacking model.

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.

Effect of Aerobic, Resistance, and Combined Exercise Training on Depressive Symptoms, Quality of Life, and Muscle Strength in Healthy Older Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Aerobic training, resistance training, or combined training are interventions that can be modified to suit the needs of aged people.

OBJECTIVE

This meta-analysis aimed to investigate the impact of exercise training on depression symptoms, quality of life, and muscle strength in healthy people aged 60 or more.

DATA SOURCES

Searches were conducted in PubMed, Web of Science, Medline, Google Scholar, and Scopus databases from inception to February 2022.

RESULTS

Eighteen studies, totaling 1354 participants, were included in the meta-analysis. Overall, exercise training significantly declined depressive symptoms (standard mean difference (SMD): -.52, 95% confidence interval (CI): -.76 to -.28; p < .001). Moreover, there was a significant reduction in bodily pain (p < .05) and body mass (p < .01), and a significant increase in mental health (p < .001), physical functioning (p < .01), and general health (p < .001) subscales of quality of life as well as upper- (p < .001) and lower-limb strength (p < .001). Subgroup analysis revealed that depression decreased significantly when aerobic training (p = .000) and resistance training (p = .003) were applied, and for studies including both genders (p = .000) or men subjects (p = .002). Moreover, subgroup analysis demonstrated that depression reduced following both medium- (p = .006) and long-term (p = .002) interventions.

CONCLUSION

These findings demonstrate that exercise interventions may produce improvements in depressive symptoms, some components of quality of life, muscle strength, and body mass. Additional research is required to define the optimal dose of exercise training interventions.

THE EFFECT OF PROGRESSIVE RESISTANCE TRAINING ON FUNCTIONALITY AND HANDGRIP STRENGTH IN THE OLDER INDIVIDUALS OF A COMMUNITY: A QUASI-EXPERIMENTAL STUDY

BACKGROUND

Muscle weakness is associated with negative outcomes, in addition to being related to the pathogenesis of frailty and functional disability in the older individuals. Muscle strength and functionality are considered biomarkers of aging. Progressive resistance training (PRT) is a type of training that has been the subject of studies as it presents itself as a therapeutic option to fight the reduction of muscle strength and functionality in older individuals. However, few studies have assessed the clinically-relevant gains in the levels of muscle strength and functionality of older individuals after PRT, in addition to the need of testing new PRT approaches, including individualization and periodization in training programs. Therefore, this article aims to assess the effect of a individual and periodized PRT protocol on handgrip strength and functionality in older individuals. Thus, the study sample included 69 older individuals, divided into two groups: case (n = 41) and control (n = 28). The case group participated in a progressive resistance training protocol for 12 weeks, with two weekly sessions. When compared to the control group, which received only health education, the individuals in the case group had a greater magnitude of improvement in all variables related to the assessed functionality (Timed up and go test, gait speed, and handgrip strength), proving the applicability of the assessed protocol to improve strength and functionality in the older individuals people of a community.

Muscle-Specific Cellular and Molecular Adaptations to Late-Life Voluntary Concurrent Exercise

Murine exercise models can provide information on factors that influence muscle adaptability with aging, but few translatable solutions exist. Progressive weighted wheel running (PoWeR) is a simple, voluntary, low-cost, high-volume endurance/resistance exercise approach for training young mice. In the current investigation, aged mice (22-mo-old) underwent a modified version of PoWeR for 8 wk. Muscle functional, cellular, biochemical, transcriptional, and myonuclear DNA methylation analyses provide an encompassing picture of how muscle from aged mice responds to high-volume combined training. Mice run 6-8 km/d, and relative to sedentary mice, PoWeR increases plantarflexor muscle strength. The oxidative soleus of aged mice responds to PoWeR similarly to young mice in every parameter measured in previous work; this includes muscle mass, glycolytic-to-oxidative fiber type transitioning, fiber size, satellite cell frequency, and myonuclear number. The oxidative/glycolytic plantaris adapts according to fiber type, but with modest overall changes in muscle mass. Capillarity increases markedly with PoWeR in both muscles, which may be permissive for adaptability in advanced age. Comparison to published PoWeR RNA-sequencing data in young mice identified conserved regulators of adaptability across age and muscles; this includes Aldh1l1 which associates with muscle vasculature. Agrn and Samd1 gene expression is upregulated after PoWeR simultaneous with a hypomethylated promoter CpG in myonuclear DNA, which could have implications for innervation and capillarization. A promoter CpG in Rbm10 is hypomethylated by late-life exercise in myonuclei, consistent with findings in muscle tissue. PoWeR and the data herein are a resource for uncovering cellular and molecular regulators of muscle adaptation with aging.

The effect of medium-term recovery status after COVID-19 illness on cardiopulmonary exercise capacity in a physically active adult population

A failure to fully recover following coronavirus disease 2019 (COVID-19) may have a profound impact on high-functioning populations ranging from frontline emergency services to professional or amateur/recreational athletes. The aim of the study is to describe the medium-term cardiopulmonary exercise profiles of individuals with “persistent symptoms” and individuals who feel “recovered” after hospitalization or mild-moderate community infection following COVID-19 to an age, sex, and job-role matched control group. A total of 113 participants underwent cardiopulmonary functional tests at a mean of 159 ± 7 days (∼5 mo) following acute illness; 27 hospitalized with persistent symptoms (hospitalized-symptomatic), 8 hospitalized and now recovered (hospitalized-recovered); 34 community managed with persistent symptoms (community-symptomatic); 18 community managed and now recovered (community-recovered); and 26 controls. Hospitalized groups had the least favorable body composition (body mass, body mass index, and waist circumference) compared with controls. Hospitalized-symptomatic and community-symptomatic individuals had a lower oxygen uptake (V̇o₂) at peak exercise (hospitalized-symptomatic, 29.9 ± 5.0 mL/kg/min; community-symptomatic, 34.4 ± 7.2 mL/kg/min; vs. control 43.9 ± 3.1 mL/kg/min, both P < 0.001). Hospitalized-symptomatic individuals had a steeper V̇e/V̇co₂ slope (lower ventilatory efficiency) (30.5 ± 5.3 vs. 25.5 ± 2.6, P = 0.003) versus. controls. Hospitalized-recovered had a significantly lower oxygen uptake at peak (32.6 ± 6.6 mL/kg/min vs. 43.9 ± 13.1 mL/kg/min, P = 0.015) compared with controls. No significant differences were reported between community-recovered individuals and controls in any cardiopulmonary parameter. In conclusion, medium-term findings suggest that community-recovered individuals did not differ in cardiopulmonary fitness from physically active healthy controls. This suggests their readiness to return to higher levels of physical activity. However, the hospitalized-recovered group and both groups with persistent symptoms had enduring functional limitations, warranting further monitoring, rehabilitation, and recovery.

NEW & NOTEWORTHY At 5 mo postinfection, community-treated individuals who feel recovered have comparable cardiopulmonary exercise profiles to the physically trained and active controls, suggesting a readiness to return to higher intensity/volumes of exercise. However, both symptomatic groups and the hospital-recovered group have persistent functional limitations when compared with active controls, supporting the requirement for ongoing monitoring, rehabilitation, and recovery.

Skeletal muscle properties show collagen organization and immune cell content are associated with resistance exercise response heterogeneity in older persons

In older individuals, hypertrophy from progressive resistance training (PRT) is compromised in approximately one- third of participants in exercise trials. The objective of this study was to establish novel relationships between baseline muscle features and/or their PRT-induced change in vastus lateralis muscle biopsies with hypertrophy outcomes. Multiple linear regression analyses adjusted for sex were performed on phenotypic data from older adults (n=48, 70.8±4.5 years) completing 14 weeks of PRT. Results show that baseline muscle size associates with growth regardless of hypertrophy outcome measure (fiber cross-sectional area (fCSA), β=-0.76, Adj. p<0.01; thigh muscle area by CT, β=-0.75, Adj. p<0.01; DXA thigh lean mass, β=-0.47, Adj. p<0.05). Furthermore, loosely packed collagen organization (β=-0.44, Adj. p<0.05) and abundance of CD11b+/CD206- immune cells (β=-0.36, Adj. p=0.10) were negatively associated with whole muscle hypertrophy, with a significant sex interaction on the latter. Additionally, a composite hypertrophy score generated using all three measures reinforces significant fiber level findings that changes in myonuclei (β=0.67, Adj. p<0.01), changes in immune cells (β=0.48, Adj. p<0.05; both CD11b+/CD206+ and CD11b+/CD206- cells), and capillary density (β=0.56, Adj. p<0.01) are significantly associated with growth. Exploratory single cell RNA-sequencing of CD11b+ cells in muscle in response to resistance exercise showed that macrophages have a mixed phenotype. Collagen associations with macrophages may be an important aspect in muscle response heterogeneity. Detailed histological phenotyping of muscle combined with multiple measures of growth response to resistance training in older persons identify potential new mechanisms underlying response heterogeneity and possible sex differences.

Development of Duchenne Video Assessment scorecards to evaluate ease of movement among those with Duchenne muscular dystrophy

Background

Patients with Duchenne muscular dystrophy (DMD) adopt compensatory movement patterns as muscles weaken. The Duchenne Video Assessment (DVA) measures patient ease of movement through identification of compensatory movement patterns. The DVA directs caregivers to video record patients performing specific movement tasks at home using a secure mobile application, and DVA-certified physical therapists (PTs) score the videos using scorecards with prespecified compensatory movement criteria. The goal of this study was to develop and refine the DVA scorecards.

Methods

To develop the initial scorecards, 4 PTs collaboratively created compensatory movement lists for each task, and researchers structured the lists into scorecards. A 2-round modified Delphi process was used to gather expert opinion on the understandability, comprehensiveness, and clinical meaningfulness of the compensatory movements on the scorecards. Eight PTs who had evaluated ≥50 patients with DMD and participated in ≥10 DMD clinical trials were recruited for the panel. In Round 1, panelists evaluated compensatory movement criteria understandability via questionnaire and tested the scorecards. In Round 2, panelists participated in an in-person meeting to discuss areas of disagreement from Round 1 and reach consensus (≥75% agreement) on all revisions to the scorecards.

Results

During the Round 1 revisions to the scorecards, there were 67 changes (44%) to the wording of 153 original compensatory movement criteria and 3 criteria were removed. During the Round 2 revisions to the scorecards, there were 47 changes (31%) to the wording of 150 compensatory movement criteria, 20 criteria were added, and 30 criteria were removed. The panel reached 100% agreement on all changes made to scorecards during Round 2.

Conclusion

PTs with extensive experience evaluating patients with DMD confirmed that the compensatory movement criteria included in the DVA scorecards were understandable, comprehensive, and clinically meaningful.

Traditional and Undulating Periodization on Body Composition, Strength Levels and Physical Fitness in Older Adults

Introduction: Undulating training has been investigated in sedentary and trained adults, but less is known about the influence of undulating training in older adults. Purpose: This study aimed to evaluate body composition, strength levels, and physical fitness in response to traditional or undulating training in older adults. Methods: A controlled, double-arm trial was conducted in eighteen older adults (10 males, 8 females; 64 ± 2.1 years; 165.12 ± 7.5 cm; 72.5 ± 11.4 kg; 26.5 ± 3.2 k·gm⁻²) who were randomly assigned to traditional (n = 9, TT) or undulating training (n = 9, UT) for eight weeks. Dual X-ray absorptiometry was used to measure fat-free mass (FFM), fat mass (FM), and bone mineral density (BMD). Strength levels were evaluated by the handgrip strength and the one-repetition maximum in vertical chest press, rowing machine, squat, monopodal horizontal leg press, and leg extension. In addition, functional capacity was assessed using the Senior Fitness Test (SFT). Statistical analysis included mean/median comparisons to establish the difference after the intervention (paired Student’s t-test or Wilcoxon test), and effect size calculations based on estimates. Results: After correction for fat-free adipose tissue, a significant increase in FFM was observed in both groups, while no significant changes were found in FM and BMD. Upper- and lower-limbs strength showed significant increases in both groups, although clinical significance varied among exercises. Favorable results were seen on the cardiorespiratory fitness and strength components of the SFT in both groups. Conclusions: The 8-week UT and TT protocols are valid options for improving FFM and increasing strength and functional capacity in women and men over 60 years of age.

Effect of Cardiac Rehabilitation on Glomerular Filtration Rate Using Serum Cystatin C Concentration in Patients With Cardiovascular Disease and Renal Dysfunction

PURPOSE

Among patients with chronic kidney disease (CKD), little is known about whether the effect of cardiac rehabilitation (CR) on renal function differs across baseline estimated glomerular filtration rate using the serum concentration of cystatin C (eGFRcys). The aim of this study was to evaluate the effect of CR on renal function in patients with CKD.

METHODS

We performed a retrospective cohort study of patients with CKD (15 ≤ eGFRcys < 60 mL/min/1.73 m2) who participated in our CR program for cardiovascular disease. First, the patients were divided into three groups according to the baseline severity of the eGFRcys: G3a, G3b, and G4 groups. We compared the eGFRcys before and after the CR in each group. Second, to determine the association of baseline eGFRcys with the effect of CR, we fitted a linear regression model using the percent change in the eGFRcys (%ΔeGFRcys) as an outcome.

RESULTS

Of the 203 patients, 122 were in G3a, 60 were in G3b, and 21 were in G4 groups. The mean improvement of eGFRcys in each group was 1.3, 3.1, and 4.8 mL/min/1.73 m2, respectively. The %ΔeGFRcys was larger among patients with lower baseline eGFRcys (0.47% greater improvement of %ΔeGFRcys/one lower baseline eGFRcys; 95% CI, 0.23-0.72%). This association remained significant after adjustment for potential confounders (0.63% greater improvement of %ΔeGFRcys/one lower baseline eGFRcys; 95% CI, 0.35-0.91%).

CONCLUSIONS

The effect of CR on renal function was greater in patients with worse renal dysfunction measured by eGFRcys. A CR program could be useful for patients with severe renal dysfunction and it might have a beneficial effect on their renal function.

Recovery from resistance exercise in older adults: a protocol for a scoping review

Introduction

Resistance exercise has been shown to improve muscle health in older adults and is recommended as a front-line treatment for many health conditions, including sarcopenia and frailty. However, despite considerable research detailing the potential benefits of resistance exercise programmes, little is known about how older adults recover from individual exercise sessions. This scoping review will examine the current evidence surrounding the acute post-exercise effects of resistance exercise and the exercise recovery process in older adults to inform future research and exercise prescription guidelines for older adults.

Methods and analysis

The methodological framework of Arksey and O’Malley (2005) will be applied for this scoping review. A systematic search of five online databases and the hand-searching of reference lists of identified articles will be used to identify relevant papers. Studies that aim to measure exercise-induced muscle damage or exercise recovery following a resistance exercise session in participants aged 65 years and over will be included. Qualitative and quantitative data from relevant studies will be presented in a tabular format. Results will be summarised in narrative format. Key findings will be discussed concerning resistance exercise prescription in older adults.

Dissemination

This review will be used to direct further research surrounding the exercise recovery process from resistance exercise in older adults and will also aid in designing specific exercise prescription guidelines for an older population. Findings will be relevant to researchers, clinicians, health workers and policy-makers and disseminated through publications and presentations.

The Effects of Exercise on Aging-Induced Exaggerated Cytokine Responses: An Interdisciplinary Discussion

Aging is generally known to be associated with dynamic biological changes, physiological dysfunction, and environmental and psychological decline. Several studies have suggested that aging is associated with increased inflammatory cytokines, causing several diseases. However, the effect of exercise on aging has been less delineated, and the relationships between cytokine activation, aging, and exercise also need further study. Here, we discuss some ideas about the effect of exercise on aging-induced exaggerated cytokine responses and discuss the possible roles of the aging-induced exaggerated cytokine response following exercise. Evidence from these findings suggests that exercise is a beneficially applicable model to use in studies on the mechanisms underlying the age-associated gradated cytokine response, and these results may provide guidelines for health professionals with diverse backgrounds.

Long-term, induced expression of Hand2 in peripheral sympathetic neurons ameliorates sarcopenia in geriatric mice

BACKGROUND

The discovery of adrenoceptors, which mediate the effects of the sympathetic nervous system neurotransmitter norepinephrine on specific tissues, sparked the development of sympathomimetics that have profound influence on skeletal muscle mass. However, chronic administration has serious side effects that preclude their use for muscle-wasting conditions such as sarcopenia, the age-dependent decline in muscle mass, force, and power. Devising interventions that can adjust neurotransmitter release to changing physiological demands will require understanding how the sympathetic nervous system affects muscle motor innervation and muscle mass, which will prevent sarcopenia-associated impaired mobility, falls, institutionalization, co-morbidity, and premature death. Here, we tested the hypothesis that prolonged heart and neural crest derivative 2 (Hand2) expression in peripheral sympathetic neurons (SNs) ameliorates sympathetic muscle denervation, motor denervation, and sarcopenia in geriatric mice.

METHODS

We delivered either a viral vector encoding the transcription factor Hand2 or an empty vector (EV) driven to SNs by the PRSx8 promoter by injecting the saphenous vein in 16-month-old C57BL/6 mice that were sacrificed 10-11 months later. Studies relied on sympathetic and muscle immunohistochemistry analysed by confocal microscopy, nerve and muscle protein expression assessed by immunoblots, nerve-evoked and muscle-evoked maximal muscle contraction force, extensor digitorum longus (EDL) muscle RNA sequencing, SN real-time PCR, and tests of physical performance using an inverted-cling grip test and in an open-arena setting.

RESULTS

Examining the mice 10-11 months later, we found that inducing Hand2 expression in peripheral SNs preserved (i) the number of neurons (EV: 0.32 ± 0.03/μm² , n = 6; Hand2: 0.92 ± 0.08/μm² , n = 7; P < 0.0001) and size (EV: 279 ± 18 μm² , n = 6; Hand2: 396 ± 18 μm² , n = 7; P < 0.0001); (ii) lumbricalis muscle sympathetic innervation (EV: 1.4 ± 1.5 μm/μm² , n = 5; Hand2: 12 ± 1.8 μm/μm² , n = 5; P < 0.001); (iii) tibialis anterior, gastrocnemius, EDL, and soleus muscles weight and whole-body strength (EV: 48 ± 6.4 s, n = 6; Hand2: 102 ± 6.8 s, n = 6; P < 0.001); (iv) EDL type IIb, IIx, and II/IIx and soleus type I, IIa, IIx, IIa/IIx, and IIb/IIx myofibre cross-sectional area; (v) nerve-evoked (EV: 16 ± 2.7 mN; Hand2: 30 ± 4.4 mN; P < 0.001) and muscle-evoked (EV: 24 ± 3.8 mN, n = 5; Hand2: 38 ± 3.0 mN, n = 8; P < 0.001) muscle force by 150 Hz-3 s pulses; and (vi) motor innervation assessed by measuring presynaptic/postsynaptic neuromuscular junction area overlay.

CONCLUSIONS

Preserving Hand2 expression in SNs from middle-aged to very old mice attenuates decreases in muscle mass and force by (i) maintaining skeletal muscle sympathetic and motor innervation, (ii) improving membrane and total acetylcholine receptor stability and nerve-evoked and muscle-evoked muscle contraction, (iii) preventing the elevation of inflammation and myofibrillar protein degradation markers, and (iv) increasing muscle autophagy.

Daily Leucine Intake Is Positively Associated with Lower Limb Skeletal Muscle Mass and Strength in the Elderly

Higher daily protein intake, with an emphasis on leucine content, is thought to mitigate age-related anabolic resistance, potentially counteracting age-related morphological and functional declines. The present study investigated potential associations between total daily leucine intake and dependent variables, including quadriceps muscle cross-sectional area (CSA) and maximum dynamic muscle strength (1-RM) in a cohort of healthy free-living older individuals of both sexes (n = 67; 34/33 men/women). Participants performed three 24 h dietary recalls and underwent a magnetic resonance imaging exam followed by 1-RM tests. Our results demonstrate moderate associations between total daily leucine and both quadriceps CSA (r = 0.42; p = 0.004) and 1-RM (r = 0.45; p = 0.001). Furthermore, our exploratory biphasic linear regression analyses, adjusted for sex, age, and protein intake relative to body weight, revealed a plateau for daily leucine intake and muscle mass and muscle strength (~7.6–8.0 g·day⁻¹) in older adults. In conclusion, we demonstrated that total daily leucine intake is associated with muscle mass and strength in healthy older individuals and this association remains after controlling for multiple factors, including overall protein intake. Furthermore, our breakpoint analysis revealed non-linearities and a potential threshold for habitual leucine intake, which may help guide future research on the effects of chronic leucine intake in age-related muscle loss.

Effectiveness of a community-delivered pneumatic machine resistance training programme (Gym Tonic) for older adults at neighbourhood senior centres - a randomized controlled trial

Background

Resistance training with pneumatic machines attenuates the age-associated loss in muscle strength and function in older adults. However, effectiveness of scaled-up pneumatic machine resistance training in the community is not known. We evaluated the effectiveness of a multi-site community-delivered 12-week pneumatic machine resistance programme (Gym Tonic (GT)) on muscle strength and physical function in older adults.

Methods

Three hundred eighteen community-dwelling older adults aged ≥65 years were randomized into 12-week (twice/week) coach-supervised-community-based-GT-programme(n = 168) and wait-list control groups(n = 150). After 12 weeks, the intervention group continued with GT-training and the control group received supervised-GT-programme for further 12 weeks (partial-crossover-design). Fried frailty score, lower-extremity muscle strength and physical function (i.e., fast and habitual gait-speed, balance, repeated-chair-sit-to-stand, short physical performance battery (SPPB)) were determined at baseline, 12 and 24 weeks. Analysis adopted a modified-intention-to-treat-approach.

Results

After 12 weeks, lower-extremity muscle strength improved by 11–26%(all p < 0.05) and fast gait-speed improved by 7%(p = 0.008) in GT-intervention group(n = 132) than controls(n = 118), regardless of frailty status. Other physical function performance did not differ between control and intervention groups after 12 weeks (all p > 0.05). Frailty score improved by 0.5 in the intervention but not control group(p = 0.004). Within the intervention group, lower-extremity muscle strength and physical function outcomes improved at 24 weeks compared with baseline (all p < 0.001). Within controls, lower-extremity muscle strength, SPPB, repeated-chair-sit-to-stand and fast gait-speed improved post-GT (24-week) compared to both pre-GT (12-week) and baseline. Programme adherence was high in intervention [0–12-weeks,90%(SD,13%); 12–24-weeks,89%(SD,17%)] and control [12–24-weeks,90%(SD,19%)] groups.

Conclusion

Community-delivered GT resistance training programme with pneumatic machines has high adherence, improves muscle strength and fast gait-speed, and can be effectively implemented at scale for older adults. Future studies could examine if including other multi-modal function-specific training to complement GT can achieve better physical/functional performance in power, balance and endurance tasks.

Trial registration

ClinicalTrials.gov, NCT04661618, Registered 10 December 2020 - Retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11556-021-00273-x.

Influence of Angiotensin Converting Enzyme I/D Polymorphism on Hemodynamic and Antioxidant Response to Long-Term Intradialytic Resistance Training in Patients With Chronic Kidney Disease: A Randomized Controlled Trial

ABSTRACT

Corrêa, HdL, Deus, LA, Neves, RVP, Reis, AL, de Freitas, GS, de Araújo, TB, da Silva Barbosa, JM, Prestes, J, Simões, HG, Amorim, CE, dos Santos, MAP, Haro, A, de Melo, GF, Gadelha, AB, Neto, LS, and Rosa, TdS. Influence of angiotensin converting enzyme I/D polymorphism on hemodynamic and antioxidant response to long-term intradialytic resistance training in patients with chronic kidney disease: a randomized controlled trial. J Strength Cond Res 35(10): 2902-2909, 2021-The aim of the study was to verify the influence of Angiotensin-converting enzyme (ACE) I/D genotype on blood pressure, muscle mass, and redox balance response to long-term resistance training (RT) in end-stage renal disease patients. Three hundred and twenty subjects were randomized into 4 groups: II + ID control (II + ID CTL, n = 80), II + ID RT (II + ID RT, n = 79), DD control (DD CTL n = 83), and DD RT (DD RT, n = 78). The RT lasted 24 weeks with a frequency of 3 times per week, on alternative days. Each section consisted of 3 sets of 8-12 repetitions in 11 exercises, with training loads at 6 point (somewhat hard) to 8 point (hard) based on OMNI-RES scale and was prescribed during dialysis (intradialytic). Statistical significance was accepted with p < 0.05. The most relevant benefits in blood pressure were found for DD homozygotes (p < 0.0001), whereas allele I carriers displayed a higher increase in muscle mass (p < 0.0001). Hemodialysis clinics that already use RT for their patients could include the genotyping of ACE to identify the predisposal of the patients to respond to RT and to counteract kidney disease-related comorbidities.

Sarcopenia: Etiology, Nutritional Approaches, and miRNAs

Sarcopenia, an age-related decline in skeletal muscle mass and function, dramatically affects the quality of life. Although there is a consensus that sarcopenia is a multifactorial syndrome, the etiology and underlying mechanisms are not yet delineated. Moreover, research about nutritional interventions to prevent the development of sarcopenia is mainly focused on the amount and quality of protein intake. The impact of several nutrition strategies that consider timing of food intake, anti-inflammatory nutrients, metabolic control, and the role of mitochondrial function on the progression of sarcopenia is not fully understood. This narrative review summarizes the metabolic background of this phenomenon and proposes an integral nutritional approach (including dietary supplements such as creatine monohydrate) to target potential molecular pathways that may affect reduce or ameliorate the adverse effects of sarcopenia. Lastly, miRNAs, in particular those produced by skeletal muscle (MyomiR), might represent a valid tool to evaluate sarcopenia progression as a potential rapid and early biomarker for diagnosis and characterization.

Association of body composition with functional capacity and cognitive function in older adults living in nursing homes

BACKGROUND

Older adults living in nursing homes have an increased risk of adverse outcomes. However, the role of body composition in vital health and quality of life parameters such as functional capacity and cognitive function is less studied in this group of older adults compared to community-dwelling counterparts.

OBJECTIVE

The aim of the present study was to examine the association of body composition with functional capacity and cognitive function in nursing home residents.

METHODS

Fifty-three older adults (82.8±7.3 years) were enrolled in this study and they underwent body composition evaluation, functional capacity and cognitive function measurements.

RESULTS

The results showed a high prevalence of obesity accompanied by functional capacity limitations and cognitive impairment in older adults living in nursing homes. Partial correlations, controlling for age, showed that body fat percentage was positively correlated with sit-to-stand-5 (r=0.310, p=0.025) and timed-up-and-go (r=0.331, p=0.017), and negatively correlated with handgrip strength test results (r=-0.431, p<0.001), whereas greater lean body mass was associated with better sit-to-stand-5 (r=-0.410, p=0.003), handgrip strength (r=0.624, p<0.001) and cognitive function performance (r=0.302, p=0.037).

CONCLUSIONS

These important associations reinforce the need to develop effective healthy lifestyle interventions targeting both lean mass and body fat to combat functional and cognitive decline in nursing home residents.

Follistatin-induced muscle hypertrophy in aged mice improves neuromuscular junction innervation and function

Sarcopenia, or age-related loss of muscle mass and strength, is an important contributor to loss of physical function in older adults. The pathogenesis of sarcopenia is likely multifactorial, but recently the role of neurological degeneration, such as motor unit loss, has received increased attention. Here, we investigated the longitudinal effects of muscle hypertrophy (via overexpression of human follistatin, a myostatin antagonist) on neuromuscular integrity in C57BL/6J mice between the ages of 24 and 27 months. Following follistatin overexpression (delivered via self-complementary adeno-associated virus subtype 9 injection), muscle weight and torque production were significantly improved. Follistatin treatment resulted in improvements of neuromuscular junction innervation and transmission but had no impact on age-related losses of motor units. These studies demonstrate that follistatin overexpression-induced muscle hypertrophy not only increased muscle weight and torque production but also countered age-related degeneration at the neuromuscular junction in mice.

Volume Reduction: Which Dose is Sufficient to Retain Resistance Training Adaptations in Older Women?

We compared the effects of different resistance training (RT) volume reduction strategies on muscular strength and lean soft-tissue (LST) in older women. Fifty-seven physically independent women (>60 years) performed a 20-week pre-conditioning phase of a standardized whole-body RT program (eight exercises, three sets, 8-12 repetitions, three sessions a week), and were then randomly assigned to one of the following conditions: reduced volume for a single set (RV1, n=20) or two sets (RV2, n=19), or maintained volume of three sets (MV, n=18) for 8 weeks (specific training phase). Muscular strength in the chest press, leg extension, and preacher curl exercises was determined by one-repetition maximum tests. A dual-energy X-ray absorptiometry device was used to estimate LST. An increase in muscular strength (16.3-32.1%) and LST (3.2-7.9%) was observed after the pre-conditioning phase. There was an increase in chest press for all groups (9.4-16.7%) after the specific training phase. In contrast, only MV increased significantly in the leg extension (4.4%). No between-group differences were revealed for LST in the specific training phase. Our results suggest that reduced RT volume from three to one set per exercise for 8 weeks seems sufficient to retain neuromuscular adaptations in older women.