Resistance Exercise Training as a Primary Countermeasure to Age-Related Chronic Disease

A single session of strength training changed plasma levels of resistin, but not leptin in overweight and obese men

Obesity has a complex multifactorial etiology and is characterized by excessive accumulation of adipose tissue. Visceral adipose tissue has deleterious effects on health because it secretes large amounts of inflammatory cytokines. Nutritional calorie restriction associated with strength training may be useful in managing chronic systemic inflammation. This study aimed to evaluate the acute effect of a single strength-training session on plasma adipokine levels in sedentary, overweight, and obese young men. This study included twelve men (Age: [34.95 ​± ​9.77] years; Height: [174.16 ​± ​3.66] centimeter [cm]; Weight: [97.83 ​± ​12.87] kilogram (kg); body mass index [BMI]: [32.30 ​± ​4.51] kg/m2), who performed a single strength training session. The strength training protocol consisted of 4 sets of 12 repetitions in the following six exercises, 45° leg press, bench press, leg extension, machine row, leg curl, and shoulder press. Blood samples were collected before, immediately after, and 1-h subsequent after strength training. The plasma levels of resistin and leptin were measured. A significant decrease in resistin levels were found 1 ​h after the strength training session if compared to levels before the training session (pre-[before] [2 390 ​± ​1 199] picograms per milliliter [pg/mL] vs post-1 h [1-h subsequent] [1 523 ​± ​798],6 ​pg/mL, p ​= ​0.002 8). The plasma leptin levels did not differ at any time point. In conclusion, a very well controlled single session of strength training significantly decreased the plasma levels of resistin without altering the concentration of leptin in overweight and obese individuals. This effect, at least in part, supports the benefits of exercise by reducing the low grade inflammation and insulin resistance in obesity.

Cardiovascular benefits of resistance exercise: It's time to prescribe

Despite the well-known health benefits of regular physical activity, sedentary behavior and physical inactivity remain a real global pandemic. Exercise is associated with increased life expectancy, improved quality of life and prevention of multiple diseases. Although less implemented in practice compared to aerobic exercise, recent evidence shows that resistance exercise (RE) is also responsible for various benefits, including improvements in body composition, control of several cardiovascular (CV) risk factors, and reduction of CV outcomes. RE increases strength and muscle mass, is effective in controlling type 2 diabetes, and improves the management of obesity, lipids, and blood pressure profiles. In this setting, clinical guidelines recommend the inclusion of RE for primary and secondary CV risk prevention, particularly in combination with aerobic exercise, in which the benefits are most pronounced. Prescription of RE should follow a methodology that includes key variables such as frequency, intensity, type, time, and progression. Despite challenges, professionals in the CV field should be familiar with RE prescription in order to maximize its referral in clinical practice. This review aims to analyze the CV effects of RE and current recommendations regarding the prescription of this type of exercise.

Does Taking a Break Matter-Adaptations in Muscle Strength and Size Between Continuous and Periodic Resistance Training

We aimed to compare the effects of periodic resistance training (RT) and continuous RT on muscle strength and size. Fifty-five healthy, untrained participants (age 32 ± 5 years) were randomized to periodic (PRT, n = 20 completed the study, 45% females) or continuous (CRT, n = 22 completed the study, 45% females) groups. PRT completed a 10-week RT, a 10-week detraining, and a second identical 10-week RT. CRT began with a 10-week non-RT, followed by a 20-week RT. RT included twice-weekly supervised whole-body RT sessions. Leg press (LP) and biceps curl (BC) one repetition maximum (1RM), countermovement jump (CMJ) height, muscle cross-sectional area (CSA) of vastus lateralis (VL), and biceps brachii (BB) using ultrasound imaging were measured twice at the beginning and every fifth week during the intervention. Both groups increased (p < 0.001) 1RM in LP and BC, CSA in VL and BB, and CMJ height with no differences between the groups. In PRT, 1RM in LP and BC, CSA in VL and BB, and CMJ height decreased during detraining (p < 0.05). During the first 5 weeks of retraining in PRT, increases in LP 1RM, and VL and BB CSA were greater than in CRT during Weeks 10-15 of their CRT (p < 0.01). PRT and CTR ended up in similar postintervention adaptations, as decreased muscle strength and size during detraining in PRT regained rapidly during retraining. Our results therefore suggest that trainees should not be too concerned about occasional short-term training breaks in their daily lives when it comes to lifelong strength training. Trial Registration: ClinicalTrials.gov identifier: NCT05553769.

Mitigating disuse-induced skeletal muscle atrophy in ageing: Resistance exercise as a critical countermeasure

The gradual deterioration of physiological systems with ageing makes it difficult to maintain skeletal muscle mass (sarcopenia), at least partly due to the presence of 'anabolic resistance', resulting in muscle loss. Sarcopenia can be transiently but markedly accelerated through periods of muscle disuse-induced (i.e., unloading) atrophy due to reduced physical activity, sickness, immobilisation or hospitalisation. Periods of disuse are detrimental to older adults' overall quality of life and substantially increase their risk of falls, physical and social dependence, and early mortality. Disuse events induce skeletal muscle atrophy through various mechanisms, including anabolic resistance, inflammation, disturbed proteostasis and mitochondrial dysfunction, all of which tip the scales in favour of a negative net protein balance and subsequent muscle loss. Concerningly, recovery from disuse atrophy is more difficult for older adults than their younger counterparts. Resistance training (RT) is a potent anabolic stimulus that can robustly stimulate muscle protein synthesis and mitigate muscle losses in older adults when implemented before, during and following unloading. RT may take the form of traditional weightlifting-focused RT, bodyweight training and lower- and higher-load RT. When combined with sufficient dietary protein, RT can accelerate older adults' recovery from a disuse event, mitigate frailty and improve mobility; however, few older adults regularly participate in RT. A feasible and practical approach to improving the accessibility and acceptability of RT is through the use of resistance bands. Moving forward, RT must be prescribed to older adults to mitigate the negative consequences of disuse atrophy.

Effects and neural mechanisms of different physical activity on major depressive disorder based on cerebral multimodality monitoring: a narrative review

Major depressive disorder (MDD) is currently the most common psychiatric disorder in the world. It characterized by a high incidence of disease with the symptoms like depressed mood, slowed thinking, and reduced cognitive function. Without timely intervention, there is a 20-30% risk of conversion to treatment-resistant depression (TRD) and a high burden for the patient, family and society. Numerous studies have shown that physical activity (PA) is a non-pharmacological treatment that can significantly improve the mental status of patients with MDD and has positive effects on cognitive function, sleep status, and brain plasticity. However, the physiological and psychological effects of different types of PA on individuals vary, and the dosage profile of PA in improving symptoms in patients with MDD has not been elucidated. In most current studies of MDD, PA can be categorized as continuous endurance training (ECT), explosive interval training (EIT), resistance strength training (RST), and mind-body training (MBT), and the effects on patients' depressive symptoms, cognitive function, and sleep varied. Therefore, the present study was based on a narrative review and included a large number of existing studies to investigate the characteristics and differences in the effects of different PA interventions on MDD. The study also investigated the characteristics and differences of different PA interventions in MDD, and explained the neural mechanisms through the results of multimodal brain function monitoring, including the intracranial environment and brain structure. It aims to provide exercise prescription and theoretical reference for future research in neuroscience and clinical intervention in MDD.

Whole body resistance training on functional outcomes of patients with Stage 4 or 5 chronic kidney disease: A systematic review

Chronic kidney disease (CKD) causes skeletal muscle wasting, resulting in reduced function and inability to live independently. This systematic review critically appraised the scientific literature regarding the effects of full-body resistance training on clinically-relevant functional capacity measures in CKD. The study population included studies of people with Stage 4 or 5 CKD and a mean age of 40+ years old. Eight databases were searched for eligible studies: Pubmed, Embase, Cochrane, CINAHL, Scopus, Web of Science, MEDLINE, and AGELINE. MeSH terms and keyword combinations were used for screening following the PRISMA conduct. Inclusion criteria were based on PICO principles and no date of publication filter was applied. The intervention was training 2 days/week of structured resistance exercises using major upper and lower muscle groups. Minimum intervention period was 7 weeks. Comparison groups maintained their habitual activity without structured exercise training. Outcome measures of interest were: 6-min walk test, grip strength, timed up-and-go test, and sit-to-stand. Eight randomized controlled trials and one nonequivalent comparison-group study fulfilled the inclusion criteria and underwent data extraction. All studies were of hemodialysis patients. The evidence indicates that full-body resistance exercise significantly improved grip strength, timed up and go and sit to stand tests; metrics associated with enhanced quality and quantity of life.

Efficacy of Supersets Versus Traditional Sets in Whole-Body Multiple-Joint Resistance Training: A Randomized Controlled Trial

ABSTRACT

Iversen, VM, Eide, VB, Unhjem, BJ, and Fimland, MS. Efficacy of supersets versus traditional sets in whole-body multiple-joint resistance training: A randomized controlled trial. J Strength Cond Res 38(8): 1372-1378, 2024-Time constraints often hinder exercise engagement, necessitating exploration of time-efficient resistance training methods. Superset training, where 2 exercises are performed successively with minimal rest, nearly halves session duration but is metabolically demanding, possibly reducing strength gains. In a randomized controlled trial with blinded test leaders, we examined the efficacy of supersets versus traditional sets in a full-body, multiple-joint resistance training workout on maximal strength in the trained exercises. Subjects took part in a 3-week introductory training phase before baseline testing to ensure they were thoroughly familiarized. Next, they were randomized to a superset- or a traditional-set group, performing 10 weeks of heavy multiple-joint resistance training twice per week. The exercise programs consisted of leg press, bench press, lat pull-down, and seated rows. The traditional training group had a 5.2-kg higher improvement in pull-down than the superset group (p = 0.033), and a close to significant 4.8-kg higher improvement in seated rows (p = 0.073). The improvements in leg press and bench press were quite similar for both groups (p = 0.507-0.527). There were no changes between groups in body composition outcomes (0.151-0.640), but both groups increased muscle mass and reduced fat mass (p < 0.05). In conclusion, superset training of multi-joint exercises hampered maximal strength gains somewhat compared with traditional-set training. However, there were very similar improvements in body composition, and strength gains were observed for all exercises in the superset group. Thus, whole-body, multiple-joint superset resistance training could be a viable time-saving approach.

Skeletal muscle dysfunction with advancing age

As a result of advances in medical treatments and associated policy over the last century, life expectancy has risen substantially and continues to increase globally. However, the disconnect between lifespan and 'health span' (the length of time spent in a healthy, disease-free state) has also increased, with skeletal muscle being a substantial contributor to this. Biological ageing is accompanied by declines in both skeletal muscle mass and function, termed sarcopenia. The mechanisms underpinning sarcopenia are multifactorial and are known to include marked alterations in muscle protein turnover and adaptations to the neural input to muscle. However, to date, the relative contribution of each factor remains largely unexplored. Specifically, muscle protein synthetic responses to key anabolic stimuli are blunted with advancing age, whilst alterations to neural components, spanning from the motor cortex and motoneuron excitability to the neuromuscular junction, may explain the greater magnitude of function losses when compared with mass. The consequences of these losses can be devastating for individuals, their support networks, and healthcare services; with clear detrimental impacts on both clinical (e.g., mortality, frailty, and post-treatment complications) and societal (e.g., independence maintenance) outcomes. Whether declines in muscle quantity and quality are an inevitable component of ageing remains to be completely understood. Nevertheless, strategies to mitigate these declines are of vital importance to improve the health span of older adults. This review aims to provide an overview of the declines in skeletal muscle mass and function with advancing age, describes the wide-ranging implications of these declines, and finally suggests strategies to mitigate them, including the merits of emerging pharmaceutical agents.

Dual-task training is as effective as functional training on the functional fitness of older women: a randomized clinical trial

BACKGROUND

The interest in approaches that improve older individuals' functional fitness and autonomy is increasing. However, the effects of dual-task training on older women's functional fitness and the comparison with the functional training approach are unclear. Therefore, we compared dual-task and functional training on the functional fitness of older women and the effects of three months of detraining.

METHODS

Sixty-one women performed 16 weeks of dual-task training or functional training. The functional fitness was measured pre-, post-training, and post-detraining, based on the ability to put on and take off a t-shirt, evaluating the mobility of the upper limb, standing-up from the prone position measuring the global functionality, five times sit-to-stand test to assess the lower limbs muscle power, timed up and go to measure the dynamic balance and agility, gallon-jug shelf-transfer to evaluate the global functionality emphasizing the upper limbs and 10 m walk test to analyze the gait ability.

RESULTS

Dual-task training and functional training generally provided significant small to moderate magnitude performance increases in the put on and take off a t-shirt (dual-task training: d = 0.35 / functional training: d = 0.49), five times sit-to-stand test (dual-task training: d = 0.41 / functional training: d = 0.77), timed up and go (dual-task training: d = 0.34 / functional training: d = 0.78), and gallon-jug shelf-transfer (dual-task training: d = 0.76 / functional training: d = 0.82). Only the functional training improved the 10 m walk test (d = 0.32; p = 0.013), and both groups did not change the standing-up from the prone position performance. After the detraining period, both groups kept the adaptations for the gallon-jug shelf-transfer and five times sit-to-stand test. At the same time, only the dual-task training maintained the adaptations for the put on and take off a t-shirt and the functional training for the timed up and go.

CONCLUSION

Sixteen weeks of dual-task and functional training are similarly effective in improving older women's functional fitness, maintaining their benefits even after three months of detraining.

TRIAL REGISTRATION

RBR-10ny848z ( https://ensaiosclinicos.gov.br/rg/RBR-10ny848z ).

Socioeconomic status as a potential mediator of arterial aging in marginalized ethnic and racial groups: current understandings and future directions

Cardiovascular diseases (CVDs) are the leading cause of death in the United States. However, disparities in CVD-related morbidity and mortality exist as marginalized racial and ethnic groups are generally at higher risk for CVDs (Black Americans, Indigenous People, South and Southeast Asians, Native Hawaiians, and Pacific Islanders) and/or development of traditional CVD risk factors (groups above plus Hispanics/Latinos) relative to non-Hispanic Whites (NHW). In this comprehensive review, we outline emerging evidence suggesting these groups experience accelerated arterial dysfunction, including vascular endothelial dysfunction and large elastic artery stiffening, a nontraditional CVD risk factor that may predict risk of CVDs in these groups with advancing age. Adverse exposures to social determinants of health (SDOH), specifically lower socioeconomic status (SES), are exacerbated in most of these groups (except South Asians-higher SES) and may be a potential mediator of accelerated arterial aging. SES negatively influences the ability of marginalized racial and ethnic groups to meet aerobic exercise guidelines, the first-line strategy to improve arterial function, due to increased barriers, such as time and financial constraints, lack of motivation, facility access, and health education, to performing conventional aerobic exercise. Thus, identifying alternative interventions to conventional aerobic exercise that 1) overcome these common barriers and 2) target the biological mechanisms of aging to improve arterial function may be an effective, alternative method to aerobic exercise to ameliorate accelerated arterial aging and reduce CVD risk. Importantly, dedicated efforts are needed to assess these strategies in randomized-controlled clinical trials in these marginalized racial and ethnic groups.

Exercise and Nutrition in the Mental Health of the Older Adult Population: A Randomized Controlled Clinical Trial

(1) Background: Global population aging is changing demographic structures and presents significant challenges for health systems, which must adapt to an increasingly elderly population. (2) Methods: The study employed a randomized controlled trial design with a total of 116 older adults aged 65 or older, randomly assigned to an experimental group (n = 57) undergoing a combined resistance program and Mediterranean diet program and a control group (n = 59) who did not receive any intervention. Anxiety and depression were evaluated using the Hospital Anxiety and Depression Scale (HADS), sleep quality through the Pittsburgh Sleep Quality Index (PSQI), and perceived stress using the Perceived Stress Scale (PSS). (3) Results: Statistically significant improvements (p < 0.05) were observed both within and between groups in anxiety (Cohen's d = 0.38 and 0.78, respectively), depression (Cohen's d = 0.56 and 0.18, respectively), perceived stress (Cohen's d = 0.15 and 0.39, respectively), and in the PSQI domains: subjective sleep quality (Cohen's d = 1.01 and 0.53, respectively), sleep duration (Cohen's d = 0.112 and 0.53, respectively), sleep disturbances (Cohen's d = 1.92 and 0.95, respectively), use of medications (Cohen's d = 0.34 and 0.40, respectively), and the PSQI total score (Cohen's d = 0.68 and 0.49, respectively). No significant differences were observed in sleep latency or daytime dysfunction. (4) Conclusions: The results of the present study suggest that resistance intervention may be an effective therapeutic option to improve mental health and sleep quality in older adults aged 65 or older, offering a non-pharmacological approach to improving overall well-being in this demographic.

Non-Pharmacological Strategies for Managing Sarcopenia in Chronic Diseases

This article focuses on a range of non-pharmacological strategies for managing sarcopenia in chronic diseases, including exercise, dietary supplements, traditional Chinese exercise, intestinal microecology, and rehabilitation therapies for individuals with limited limb movement. By analyzing multiple studies, the article aims to summarize the available evidence to manage sarcopenia in individuals with chronic diseases. The results strongly emphasize the role of resistance training in addressing chronic diseases and secondary sarcopenia. Maintaining the appropriate frequency and intensity of resistance training can help prevent muscle atrophy and effectively reduce inflammation. Although aerobic exercise has limited ability to improve skeletal muscle mass, it does have some positive effects on physical function. Building upon this, the article explores the potential benefits of combined training approaches, highlighting their helpfulness for overall quality of life. Additionally, the article also highlights the importance of dietary supplements in combating muscle atrophy in chronic diseases. It focuses on the importance of protein intake, supplements rich in essential amino acids and omega-3, as well as sufficient vitamin D to prevent muscle atrophy. Combining exercise with dietary supplements appears to be an effective strategy for preventing sarcopenia, although the optimal dosage and type of supplement remain unclear. Furthermore, the article explores the potential benefits of intestinal microecology in sarcopenia. Probiotics, prebiotics, and bacterial products are suggested as new treatment options for sarcopenia. Additionally, emerging therapies such as whole body vibration training, blood flow restriction, and electrical stimulation show promise in treating sarcopenia with limited limb movement. Overall, this article provides valuable insights into non-pharmacological strategies for managing sarcopenia in individuals with chronic diseases. It emphasizes the importance of a holistic and integrated approach that incorporates exercise, nutrition, and multidisciplinary interventions, which have the potential to promote health in the elderly population. Future research should prioritize high-quality randomized controlled trials and utilize wearable devices, smartphone applications, and other advanced surveillance methods to investigate the most effective intervention strategies for sarcopenia associated with different chronic diseases.

A Mixed Methods Feasibility Study of Machine-Based Resistance Training With Prefrail Older Adults in Residential Care: The Keeping Active in Residential Elderly Trial II

Physical activity is an effective, proactive intervention to reduce or reverse frailty and functional decline. However, uncertainty exists about the feasibility and impact of resistance training on multidimensional health in prefrail older adults in residential care. This mixed methods feasibility study assessed practicability with limited efficacy testing on health and functional outcomes. Eleven prefrail older adults participated in a 6-week progressive resistance training protocol three times per week. The intervention and measures were found to be appropriate and acceptable by those who completed the trial, with participants self-reporting improved well-being, mood, and function. Analysis identified several barriers to recruitment, including prior commitments, seasonal impact, and session timing, and offered potential solutions with further recommendations for program refinement prior to a definitive randomized controlled trial. These findings add to our understanding of prefrail older adults' preferences regarding participation in physical activity research and the perceived benefits of resistance training. This trial was registered with ClinicalTrials.gov: NCT03141879.

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.

Comparative Efficacy of Different Protein Supplements on Muscle Mass, Strength, and Physical Indices of Sarcopenia among Community-Dwelling, Hospitalized or Institutionalized Older Adults Undergoing Resistance Training: A Network Meta-Analysis of Randomized Controlled Trials

Aging-related sarcopenia exerts harmful impacts on muscle mass, strength, and physical mobility. Protein supplementation has been demonstrated to augment efficacy of resistance training (RT) in elderly. This study compared the relative effects of different protein supplements on muscle mass, strength, and mobility outcomes in middle-aged and older individuals undergoing RT. A comprehensive search of online databases was performed to identify randomized controlled trials (RCTs) examining the efficacy of protein supplement plus RT in untrained community-dwelling adults, hospitalized, or institutionalized residents who suffered acute or chronic health conditions. Network meta-analysis (NMA) was performed using a frequentist method for all analyses. Treatment effects for main outcomes were expressed as standard mean difference (SMD) with 95% confidence interval (CI). We used the surface-under-the cumulative-ranking (SUCRA) scores to rank probabilities of effect estimation among all identified treatments. Meta-regression analyses were performed to identify any relevant moderator of the treatment efficacy and results were expressed as β with 95% credible interval (CrI). We finally included 78 RCTs (5272 participants) for analyses. Among the six protein sources identified in this NMA, namely whey, milk, casein, meat, soy, and peanut, whey supplement yielded the most effective treatments augmenting efficacy of RT on muscle mass (SMD = 1.29, 95% CI: 0.96, 1.62; SUCRA = 0.86), handgrip strength (SMD = 1.46, 95% CI: 0.92, 2.00; SUCRA = 0.85), and walking speed (SMD = 0.73, 95% CI: 0.39, 1.07; SUCRA = 0.84). Participant's health condition, sex, and supplementation dose were significant factors moderating the treatment efficacy on muscle mass (β = 0.74; 95% CrI: 0.22, 1.25), handgrip strength (β = -1.72; 95% CrI: -2.68, -0.77), and leg strength (β = 0.76; 95% CrI: 0.06, 1.47), respectively. Our findings suggest whey protein yields the optimal supplements to counter sarcopenia in older individuals undergoing RT.

Comparison of low-dose maximal-intent versus controlled-tempo resistance training on quality-of-life, functional capacity, and strength in untrained healthy adults: a comparative effectiveness study

Lack of physical activity is a global issue for adults that can lead to sedentary behaviour and a higher prevalence of health complications and chronic diseases, resulting in reduced quality-of-life (QoL) and functional capacity (FC). A potential strategy to mitigate this inactivity is low-dose resistance training (RT); however, physiological, and psychological responses are limited in evidence. Twenty untrained participants aged 30-60 years old (mean ± SD age 42 ± 7 years, mass 77 ± 13 kg, stature 166 ± 8 cm; 18 females and two males) were recruited and randomly assigned to maximal velocity-intent (MI, n = 10) or controlled-tempo (CT, n = 10) RT according to CONsolidated Standards of Reporting Trials (CONSORT) guidelines. Participants attended one training session per week for 6 weeks, consisting of five sets of five repetitions at 60% of one-repetition maximum (1RM) leg press. The interventions differed only during the concentric phase, with MI group pushing with maximal intent, and CT group pushing in a time-controlled manner (3 s). Outcome measures assessed pre- and post-RT included body mass, body mass index (BMI), strength-to-mass ratio, bipedal balance, 6-minute walk test (6MWT), 30-second sit-to-stand (30s-STS), timed up and go (TUG), and leg press 1RM. Time effects were observed for all demographics and FC-related outcomes, such as identical reductions in mass and BMI (- 2%), improvements in strength-to-mass ratio (25%) leg press 1RM (22%), 6MWT (3%), and 30s-STS (14%), as well as a 9% improvement in both TUG-clockwise and anticlockwise. Results show low-dose once-weekly RT is effective in improving QoL, FC, and strength in untrained healthy adults, regardless of modality. Positive responses from participants suggest an increased likelihood of consistent participation for low-dose once-weekly RT over more intense modalities. Retrospective ClinicalTrials.gov ID (TRN): NCT06107855, 24/10/2023.

Therapeutic Quality Affects Physical Fitness Benefits of Home Exercise Interventions in Older Adults: A Systematic Review, Meta-Analysis, and Meta-Regression

BACKGROUND AND PURPOSE

The international Consensus on Therapeutic Exercise aNd Training (i-CONTENT) tool is a new instrument developed to evaluate the therapeutic quality of exercise interventions. Home-based exercise has been shown to improve physical fitness in older adults, but its effects may be influenced by therapeutic quality. The purpose of this systematic review was to describe the therapeutic quality of home-based exercise interventions for community-dwelling older adults and examine the relationship between therapeutic quality and changes in physical fitness.

METHODS

Six electronic databases and 2 clinical trial registries were searched for randomized controlled trials investigating the effects of home-based exercise on physical fitness in community-dwelling older adults (≥60 years). Therapeutic quality was evaluated using the i-CONTENT tool for items of patient selection, type of exercise, safety, type/timing of outcomes, exercise dose, and adherence. International Consensus on Therapeutic Exercise aNd Training items were used to explain heterogeneity in meta-regression analyses. Risk of bias, certainty of evidence and credibility of analyses were assessed.

RESULTS

Thirty-six trials (n = 6157 participants) were identified. Most studies (≥66.7%) had high or probably high therapeutic quality for i-CONTENT items, except exercise dose (47.2%) and adherence (16.7%). Interventions improved upper- (N = 20 trials; standardized mean difference [SMD] = 0.39; 95% CI, 0.13-0.64; low certainty of evidence) and lower-body strength (N = 28; SMD = 0.42; 95% CI, 0.08-0.77; very low certainty), and aerobic fitness (N = 8; SMD = 0.42; 95% CI, 0.08-0.77; very low certainty). For exercise dose, low- or probably low-quality studies negatively influenced effects on upper- (estimated β = -.48; P = .049; moderate credibility) and lower-body strength (estimated β = -.77; P = .048; moderate credibility). For adherence, low- or probably low-quality studies negatively influenced effects on aerobic fitness (estimated β = -.97; P = .02; low credibility).

CONCLUSIONS

Home-based exercise may improve upper- and lower-body strength, as well as aerobic fitness in older adults. However, the effectiveness of interventions is affected by inadequate dosing of exercise programs and adherence issues. Physical therapists should have the best available evidence to support their clinical decision making, especially when designing and monitoring home programs.

Advancing cancer cachexia diagnosis with -omics technology and exercise as molecular medicine

Muscle atrophy exacerbates disease outcomes and increases mortality, whereas the preservation of skeletal muscle mass and function play pivotal roles in ensuring long-term health and overall quality-of-life. Muscle atrophy represents a significant clinical challenge, involving the continued loss of muscle mass and strength, which frequently accompany the development of numerous types of cancer. Cancer cachexia is a highly prevalent multifactorial syndrome, and although cachexia is one of the main causes of cancer-related deaths, there are still no approved management strategies for the disease. The etiology of this condition is based on the upregulation of systemic inflammation factors and catabolic stimuli, resulting in the inhibition of protein synthesis and enhancement of protein degradation. Numerous necessary cellular processes are disrupted by cachectic pathology, which mediate intracellular signalling pathways resulting in the net loss of muscle and organelles. However, the exact underpinning molecular mechanisms of how these changes are orchestrated are incompletely understood. Much work is still required, but structured exercise has the capacity to counteract numerous detrimental effects linked to cancer cachexia. Primarily through the stimulation of muscle protein synthesis, enhancement of mitochondrial function, and the release of myokines. As a result, muscle mass and strength increase, leading to improved mobility, and quality-of-life. This review summarises existing knowledge of the complex molecular networks that regulate cancer cachexia and exercise, highlighting the molecular interplay between the two for potential therapeutic intervention. Finally, the utility of mass spectrometry-based proteomics is considered as a way of establishing early diagnostic biomarkers of cachectic patients.

Can resistance training improve mental health outcomes in older adults? A systematic review and meta-analysis of randomized controlled trials

Purpose This systematic review and meta-analysis aimed to analyze the effects of resistance training (RT) and to compare the different RT prescriptions, sample characteristics, and mental health outcomes (depressive and anxiety symptoms) in older adults. Methods All studies that were available on 28th April 2023. For the analysis of intervention effects on depressive and anxiety symptoms, standardized mean differences and standard errors were calculated. Meta-analyses using random-effects models, employing robust variance meta-regression for multilevel data structures, with adjustments for small samples. Results For depressive symptoms, the mean effect was - 0.94 (95 %CI: -1.45 - -0.43, P< 0.01, I2= 93.4 %), and for anxiety symptoms, the mean effect was -1.33 (95 %CI: -2.10 - -0.56, P< 0.01, I2= 92.3 %). The mean effect was -0.51 (95 %CI: -0.67 - -0.35, P< 0.01, I2= 36.7 %) for older adults without mental disorders, and those with mental disorders the mean effect was ES= -2.15 (95 %CI: -3.01 - - 1.29, P< 0.01, I2= 91.5 %). Conclusion RT was able to improve mental health outcomes in individuals with and without mental disorders, and some RT characteristics influenced the effect of RT on mental health.

Preoperative Body Composition Correlates with Postoperative Muscle Volume and Degeneration after Total Hip Arthroplasty

Impaired muscle recovery after total hip arthroplasty (THA) may affect gait and activities of daily living. Bioelectrical impedance analysis (BIA) can assess body composition and muscle volume, and computed tomography (CT) can assess muscle volume and the fatty degeneration of muscle. This study aimed to explore the effectiveness of BIA, and the correlation between preoperative body composition and postoperative muscle volume and degeneration after THA using BIA and CT. Thirty-eight patients who underwent THA and had BIA and CT performed pre- and postoperatively were retrospectively assessed. The BIA-derived measurements of preoperative body composition (fat mass index, fat-free mass index, and phase angle) were correlated with the CT-derived measurements (pre- and postoperative muscle volume and gluteus maximus and quadriceps Hounsfield Units of the affected hip). The preoperative fat mass index negatively correlated with the postoperative muscle volume of the gluteus maximus (p = 0.02) and quadriceps (p < 0.001) and the Hounsfield Units of the gluteus maximus (p = 0.03) and quadriceps (p = 0.03). The preoperative fat-free mass index positively correlated with the postoperative muscle volume of the quadriceps (p = 0.02). The preoperative phase angle positively correlated with the postoperative muscle volume of the quadriceps (p = 0.001) and the Hounsfield Units of the gluteus maximus (p = 0.03) and quadriceps (p = 0.001). In patients who underwent THA, preoperative body composition correlated with postoperative muscle volume and the fatty degeneration of the affected lower limb. Preoperative body composition may help predict postoperative muscle volume and fatty degeneration and thus, postoperative recovery.

Pathogenesis and comprehensive treatment strategies of sarcopenia in elderly patients with type 2 diabetes mellitus

Sarcopenia and diabetes are two age-related diseases that are common in the elderly population, and have a serious effect on their general health and quality of life. Sarcopenia refers to the progressive loss of muscle mass, strength and function, whereas diabetes is a chronic disease characterized by elevated blood sugar levels. The comorbidity of sarcopenia and diabetes is particularly concerning, as people with diabetes have a higher risk of developing sarcopenia due to the combination of insulin resistance, chronic inflammation and reduced physical activity. In contrast, sarcopenia destroyed blood sugar control and exacerbated the development of people with diabetes, leading to the occurrence of a variety of complications. Fortunately, there are a number of effective treatment strategies for sarcopenia in people with diabetes. Physical exercise and a balanced diet with enough protein and nutrients have been proved to enhance the muscular quality and strength of this population. Additionally, pharmacological therapies and lifestyle changes can optimize blood sugar control, which can prevent further muscle loss and improve overall health outcomes. This review aims to summarize the pathogenesis and comprehensive treatment strategies of sarcopenia in elderly patients with type 2 diabetes, which help healthcare professionals recognize their intimate connection and provide a new vision for the treatment of diabetes and its complications in this population. Through early identification and comprehensive treatment, it is possible to improve the muscle function and general quality of life of elderly with diabetes and sarcopenia.

The Plateau in Muscle Growth with Resistance Training: An Exploration of Possible Mechanisms

It is hypothesized that there is likely a finite ability for muscular adaptation. While it is difficult to distinguish between a true plateau following a long-term training period and short-term stalling in muscle growth, a plateau in muscle growth has been attributed to reaching a genetic potential, with limited discussion on what might physiologically contribute to this muscle growth plateau. The present paper explores potential physiological factors that may drive the decline in muscle growth after prolonged resistance training. Overall, with chronic training, the anabolic signaling pathways may become more refractory to loading. While measures of anabolic markers may have some predictive capabilities regarding muscle growth adaptation, they do not always demonstrate a clear connection. Catabolic processes may also constrain the ability to achieve further muscle growth, which is influenced by energy balance. Although speculative, muscle cells may also possess cell scaling mechanisms that sense and regulate their own size, along with molecular brakes that hinder growth rate over time. When considering muscle growth over the lifespan, there comes a point when the anabolic response is attenuated by aging, regardless of whether or not individuals approach their muscle growth potential. Our goal is that the current review opens avenues for future experimental studies to further elucidate potential mechanisms to explain why muscle growth may plateau.

Conserved and species-specific transcriptional responses to daily programmed resistance exercise in rat and mouse

Mice are often used in gain or loss of function studies to understand how genes regulate metabolism and adaptation to exercise in skeletal muscle. Once-daily resistance training with electrical nerve stimulation produces hypertrophy of the dorsiflexors in rat, but not in mouse. Using implantable pulse generators, we assessed the acute transcriptional response (1-h post-exercise) after 2, 10, and 20 days of training in free-living mice and rats using identical nerve stimulation paradigms. RNA sequencing revealed strong concordance in the timecourse of many transcriptional responses in the tibialis anterior muscles of both species including responses related to "stress responses/immediate-early genes, and "collagen homeostasis," "ribosomal subunits," "autophagy," and "focal adhesion." However, pathways associated with energy metabolism including "carbon metabolism," "oxidative phosphorylation," "mitochondrial translation," "propanoate metabolism," and "valine, leucine, and isoleucine degradation" were oppositely regulated between species. These pathways were suppressed in the rat but upregulated in the mouse. Our transcriptional analysis suggests that although many pathways associated with growth show remarkable similarities between species, the absence of an actual growth response in the mouse may be because the mouse prioritizes energy metabolism, specifically the replenishment of fuel stores and intermediate metabolites.

Effects of resistance training on muscular strength, endurance, body composition and functional performance among sarcopenic patients: a systematic review

Background

Sarcopenia, a gradual loss of muscle mass and strength associated with ageing, contributes to a decline in physical abilities, increase in disability and frailty and loss of functional independence. This functional deterioration which comes with ageing, can be slowed in pace with exercise.

Objective

The objective of the current review was to thoroughly search for literature assessing impact of RT on physical performance, body composition, muscle strength and endurance in sarcopenic elderly patients.

Methods

PubMed, Scopus, Web of Science, and PEDro databases were brought in use for a thorough search for articles published from 2010 to 2023. Two researchers independently retrieved data from studies that complied with the inclusion and exclusion criteria, while they also evaluated quality of the evidence.

Results

In total, 14 studies with 742 patients with mean age of 72.4 ± 9.22 years were included in the analysis for this review. Results indicate, RT improves body composition (p = 0.001), functional performance (p 0.001), postural stability (p = 0.005) and muscle strength (p 0.001) in elderly sarcopenic patients.

Conclusion

A promising intervention for the management of sarcopenia is RT. To yield RT's positive effects, a well-designed prescription is the need of the hour, just like it is with other treatment strategies.

Resistance exercise protects mice from protein-induced fat accretion

Low-protein (LP) diets extend the lifespan of diverse species and are associated with improved metabolic health in both rodents and humans. Paradoxically, many athletes and bodybuilders consume high-protein (HP) diets and protein supplements, yet are both fit and metabolically healthy. Here, we examine this paradox using weight pulling, a validated progressive resistance exercise training regimen, in mice fed either an LP diet or an isocaloric HP diet. We find that despite having lower food consumption than the LP group, HP-fed mice gain significantly more fat mass than LP-fed mice when not exercising, while weight pulling protected HP-fed mice from this excess fat accretion. The HP diet augmented exercise-induced hypertrophy of the forearm flexor complex, and weight pulling ability increased more rapidly in the exercised HP-fed mice. Surprisingly, exercise did not protect from HP-induced changes in glycemic control. Our results confirm that HP diets can augment muscle hypertrophy and accelerate strength gain induced by resistance exercise without negative effects on fat mass, and also demonstrate that LP diets may be advantageous in the sedentary. Our results highlight the need to consider both dietary composition and activity, not simply calories, when taking a precision nutrition approach to health.

A deep learning system to monitor and assess rehabilitation exercises in home-based remote and unsupervised conditions

In the domain of physical rehabilitation, the progress in machine learning and the availability of cost-effective motion capture technologies have paved the way for innovative systems capable of capturing human movements, automatically analyzing recorded data, and evaluating movement quality. This study introduces a novel, economically viable system designed for monitoring and assessing rehabilitation exercises. The system enables real-time evaluation of exercises, providing precise insights into deviations from correct execution. The evaluation comprises two significant components: range of motion (ROM) classification and compensatory pattern recognition. To develop and validate the effectiveness of the system, a unique dataset of 6 resistance training exercises was acquired. The proposed system demonstrated impressive capabilities in motion monitoring and evaluation. Notably, we achieved promising results, with mean accuracies of 89% for evaluating ROM-class and 98% for classifying compensatory patterns. By complementing conventional rehabilitation assessments conducted by skilled clinicians, this cutting-edge system has the potential to significantly improve rehabilitation practices. Additionally, its integration in home-based rehabilitation programs can greatly enhance patient outcomes and increase access to high-quality care.

Chronic disease multimorbidity and substance use among African American men: veteran-non-veteran differences

OBJECTIVES

The purpose of the study was to explore the extent to which prior military service may moderate the relationship between chronic disease multimorbidity and substance use among African American men in the United States.

DESIGN

Data for this cross-sectional study was downloaded from the 2016 -2019 United States (US) National Survey on Drug Use and Health. We estimated three survey-weighted multivariable logistic regression models, where use of each of the following substances served as the dependent variables: illicit drugs, opioids, and tobacco. Differences in these outcomes were examined along two primary independent variables: veteran status and multimorbidity (and an interaction term for these variables). We also controlled for the following covariates: age, education, income, rurality, criminal behavior, and religiosity.

RESULTS

From the 37,203,237 (weighted N) African American men in the sample, approximately 17% reported prior military service. Veterans with ≥ 2 chronic diseases had higher rates of illicit drug use (aOR = 1.37, 95% CI = 1.01, 1.87; 32% vs. 28%) than non-veterans with ≥ 2 chronic diseases. Non-veterans with one chronic disease had higher rates of tobacco use (aOR = 0.80, 95% CI = 0.69, 0.93; 29% vs. 26%) and opioid misuse (aOR = 0.49, 95% CI = 0.36, 0.67; 29% vs. 18%) than veterans with one chronic disease.

DISCUSSION

Chronic disease multi-morbidity appears to be a context in which African American veterans may be at greater risk for certain undesirable health behaviors than African American non-veterans and at lower risk for others. This may be due to exposure to trauma, difficulty accessing care, socio-environmental factors, and co-occurring mental health conditions. These complex interactions may contribute to higher rates of SUDs among African American veterans compared to African American non-veterans.

Effects of blood-flow restricted exercise versus conventional resistance training in musculoskeletal disorders-a systematic review and meta-analysis

OBJECTIVE

To compare the effect of low-load blood flow restricted resistance training (BFR-RT) versus high-load resistance training (HL-RT) on muscle strength, muscle mass, physical function, patient-reported outcomes, and adherence to training in clinical musculoskeletal populations.

DATA SOURCES

Web of Science, Cochrane Central, Medline, Embase, SportDiscus was searched on the 30th May 2022.

REVIEW METHODS

This study was conducted as a systematic review and meta-analysis. Randomized Controlled Trials (RCTs) were included if they (i) included patients, (ii) comprised of a BFR-RT intervention protocol and a group who performed HL-RT (≥ 70%1RM) for at least eight exercise sessions, and (iii) involved at least 1 exercise that targeted the lower limbs. The Cochrane Risk of Bias tool was used to evaluate the risk of bias. The meta-analyses were performed using a random effects model with an adjustment to the confidence interval.

RESULTS

Seven RCTs comprising 303 participants (BFR-RT: n = 151; HL-RT: n = 152) were identified. HL-RT and BFR-RT showed similar gains in dynamic (1-10RM) knee extensor strength and leg press strength, quadriceps cross sectional area, sit-to-stand performance, and patient reported pain and function. There was a moderate effect favoring BFR-RT for increasing maximal isometric knee extensor strength. The grading of certainty in evidence was low-to-very low for all outcome variables.

CONCLUSION

This systematic review and meta-analysis extends our current knowledge about BFR-RT and HL-RT as equally effective exercise methods for inducing gains in maximal muscle strength in healthy populations, by now also comprising patients suffering from various clinical musculoskeletal conditions. The certainty in the estimates was low-to-very low, prompting the inclusion of future higher-quality trials.

TRIAL REGISTRATION

PROSPERO ID (CRD42022337173). Registered June 18th 2022.

Implementation and Core Components of a Multimodal Program including Exercise and Nutrition in Prevention and Treatment of Frailty in Community-Dwelling Older Adults: A Narrative Review

Increasing disability-free life expectancy is a crucial issue to optimize active ageing and to reduce the burden of evitable medical costs. One of the main challenges is to develop pragmatic and personalized prevention strategies in order to prevent frailty, counteract adverse outcomes such as falls and mobility disability, and to improve quality of life. Strong evidence reports the effectiveness of exercise interventions to improve various physical parameters and muscle function that are cornerstones of frailty. Other findings also suggest that the interactions between nutrition and physical exercise with or without health behavior promotion prevent the development of frailty. Multimodal programs, including structured exercise, adequate dietary intervention and health behavior promotion, appear increasingly consensual. However, in order for implementation in real-life settings, some pitfalls need to be addressed. In this perspective, structuring and tailoring feasible, acceptable and sustainable interventions to optimize exercise training responses are essential conditions to warrant short, medium and long-term individual benefits. The different components of exercise programs appear to be fairly consensual and effective. However, specific composition of the programs proposed (frequency, intensity, type, time, volume and progressiveness) have to be tailored to individual characteristics and objectives in order to improve exercise responses. The intervention approaches, behavioral strategies and indications for these programs also need to be refined and framed. The main objective of this work is to guide the actions of healthcare professionals and enable them to widely and effectively implement multimodal programs including exercise, nutrition and behavioral strategies in real-life settings.

Monitoring Resistance Training in Real Time with Wearable Technology: Current Applications and Future Directions

Resistance training is an exercise modality that involves using weights or resistance to strengthen and tone muscles. It has become popular in recent years, with numerous people including it in their fitness routines to ameliorate their strength, muscle mass, and overall health. Still, resistance training can be complex, requiring careful planning and execution to avoid injury and achieve satisfactory results. Wearable technology has emerged as a promising tool for resistance training, as it allows monitoring and adjusting training programs in real time. Several wearable devices are currently available, such as smart watches, fitness trackers, and other sensors that can yield detailed physiological and biomechanical information. In resistance training research, this information can be used to assess the effectiveness of training programs and identify areas for improvement. Wearable technology has the potential to revolutionize resistance training research, providing new insights and opportunities for developing optimized training programs. This review examines the types of wearables commonly used in resistance training research, their applications in monitoring and optimizing training programs, and the potential limitations and challenges associated with their use. Finally, it discusses future research directions, including the development of advanced wearable technologies and the integration of artificial intelligence in resistance training research.

The potential protective effects of pre-injury exercise on neuroimmune responses following experimentally-induced traumatic neuropathy: a systematic review with meta-analysis

Pre-clinical evidence shows that neuropathy is associated with complex neuroimmune responses, which in turn are associated with increased intensity and persistence of neuropathic pain. Routine exercise has the potential to mitigate complications of future nerve damage and persistence of pain through neuroimmune regulation. This systematic review aimed to explore the effect of pre-injury exercise on neuroimmune responses, and other physiological and behavioural reactions following peripheral neuropathy in animals. Three electronic databases were searched from inception to July 2022. All controlled animal studies assessing the influence of an active exercise program prior to experimentally-induced traumatic peripheral neuropathy compared to a non-exercise control group on neuroimmune, physiological and behavioural outcomes were selected. The search identified 17,431 records. After screening, 11 articles were included. Meta-analyses showed that pre-injury exercise significantly reduced levels of IL-1β (SMD: -1.06, 95% CI: -1.99 to -0.13, n=40), but not iNOS (SMD: -0.71 95% CI: -1.66 to 0.25, n=82). From 72 comparisons of different neuroimmune outcomes at different anatomical locations, vote counting revealed reductions in 23 pro-inflammatory and increases in 6 anti-inflammatory neuroimmune outcomes. For physiological outcomes, meta-analyses revealed that pre-injury exercise improved one out of six nerve morphometric related outcomes (G-ratio; SMD: 1.95, 95%CI: 0.77 to 3.12, n=20) and one out of two muscle morphometric outcomes (muscle fibre cross-sectional area; SMD: 0.91, 95%CI: 0.27 to 1.54, n=48). For behavioural outcomes, mechanical allodynia was significantly less in the pre-injury exercise group (SMD -1.24, 95%CI: -1.87 to -0.61) whereas no overall effect was seen for sciatic function index. Post hoc subgroup analysis suggests that timing of outcome measurement may influence the effect of pre-injury exercise on mechanical allodynia. Risk of bias was unclear in most studies, as the design and conduct of the included experiments were poorly reported. Preventative exercise may have potential neuroprotective and immunoregulatory effects limiting the sequalae of nerve injury, but more research in this field is urgently needed.

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

OBJECTIVE

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

DATA SOURCES

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

STUDY SELECTION

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

DATA EXTRACTION

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

DATA SYNTHESIS

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

CONCLUSIONS

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

Resistance training prescription for muscle strength and hypertrophy in healthy adults: a systematic review and Bayesian network meta-analysis

OBJECTIVE

To determine how distinct combinations of resistance training prescription (RTx) variables (load, sets and frequency) affect muscle strength and hypertrophy.

DATA SOURCES

MEDLINE, Embase, Emcare, SPORTDiscus, CINAHL, and Web of Science were searched until February 2022.

ELIGIBILITY CRITERIA

Randomised trials that included healthy adults, compared at least 2 predefined conditions (non-exercise control (CTRL) and 12 RTx, differentiated by load, sets and/or weekly frequency), and reported muscle strength and/or hypertrophy were included.

ANALYSES

Systematic review and Bayesian network meta-analysis methodology was used to compare RTxs and CTRL. Surface under the cumulative ranking curve values were used to rank conditions. Confidence was assessed with threshold analysis.

RESULTS

The strength network included 178 studies (n=5097; women=45%). The hypertrophy network included 119 studies (n=3364; women=47%). All RTxs were superior to CTRL for muscle strength and hypertrophy. Higher-load (>80% of single repetition maximum) prescriptions maximised strength gains, and all prescriptions comparably promoted muscle hypertrophy. While the calculated effects of many prescriptions were similar, higher-load, multiset, thrice-weekly training (standardised mean difference (95% credible interval); 1.60 (1.38 to 1.82) vs CTRL) was the highest-ranked RTx for strength, and higher-load, multiset, twice-weekly training (0.66 (0.47 to 0.85) vs CTRL) was the highest-ranked RTx for hypertrophy. Threshold analysis demonstrated these results were extremely robust.

CONCLUSION

All RTx promoted strength and hypertrophy compared with no exercise. The highest-ranked prescriptions for strength involved higher loads, whereas the highest-ranked prescriptions for hypertrophy included multiple sets.

PROSPERO REGISTRATION NUMBER

CRD42021259663 and CRD42021258902.

The Effect of Feedback on Resistance Training Performance and Adaptations: A Systematic Review and Meta-analysis

BACKGROUND

Augmented feedback is often used during resistance training to enhance acute physical performance and has shown promise as a method of improving chronic physical adaptation. However, there are inconsistencies in the scientific literature regarding the magnitude of the acute and chronic responses to feedback and the optimal method with which it is provided.

OBJECTIVE

This systematic review and meta-analysis aimed to (1) establish the evidence for the effects of feedback on acute resistance training performance and chronic training adaptations; (2) quantify the effects of feedback on acute kinematic outcomes and changes in physical adaptations; and (3) assess the effects of moderating factors on the influence of feedback during resistance training.

METHODS

Twenty studies were included in this systematic review and meta-analysis. This review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Four databases were searched, and studies were included if they were peer-reviewed investigations, written in English, and involved the provision of feedback during or following dynamic resistance exercise. Furthermore, studies must have evaluated either acute training performance or chronic physical adaptations. Risk of bias was assessed using a modified Downs and Black assessment tool. Multilevel meta-analyses were performed to quantify the effects of feedback on acute and chronic training outcomes.

RESULTS

Feedback enhanced acute kinetic and kinematic outputs, muscular endurance, motivation, competitiveness, and perceived effort, while greater improvements in speed, strength, jump performance, and technical competency were reported when feedback was provided chronically. Furthermore, greater frequencies of feedback (e.g., following every repetition) were found to be most beneficial for enhancing acute performance. Results demonstrated that feedback improves acute barbell velocities by approximately 8.4% (g = 0.63, 95% confidence interval [CI] 0.36-0.90). Moderator analysis revealed that both verbal (g = 0.47, 95% CI 0.22-0.71) and visual feedback (g = 1.11, 95% CI 0.61-1.61) were superior to no feedback, but visual feedback was superior to verbal feedback. For chronic outcomes, jump performance might have been positively influenced (g = 0.39, 95% CI - 0.20 to 0.99) and short sprint performance was likely enhanced (g = 0.47, 95% CI 0.10-0.84) to a greater extent when feedback is provided throughout a training cycle.

CONCLUSIONS

Feedback during resistance training can lead to enhanced acute performance within a training session and greater chronic adaptations. Studies included in our analysis demonstrated a positive influence of feedback, with all outcomes showing superior results than when no feedback is provided. For practitioners, it is recommended that high-frequency, visual feedback is consistently provided to individuals when they complete resistance training, and this may be particularly useful during periods of low motivation or when greater competitiveness is beneficial. Alternatively, researchers must be aware of the ergogenic effects of feedback on acute and chronic responses and ensure that feedback is standardised when investigating resistance training.

Examining the Interaction between Exercise, Gut Microbiota, and Neurodegeneration: Future Research Directions

Physical activity has been demonstrated to have a significant impact on gut microbial diversity and function. Emerging research has revealed certain aspects of the complex interactions between the gut, exercise, microbiota, and neurodegenerative diseases, suggesting that changes in gut microbial diversity and metabolic function may have an impact on the onset and progression of neurological conditions. This study aimed to review the current literature from several databases until 1 June 2023 (PubMed/MEDLINE, Web of Science, and Google Scholar) on the interplay between the gut, physical exercise, microbiota, and neurodegeneration. We summarized the roles of exercise and gut microbiota on neurodegeneration and identified the ways in which these are all connected. The gut-brain axis is a complex and multifaceted network that has gained considerable attention in recent years. Research indicates that gut microbiota plays vital roles in metabolic shifts during physiological or pathophysiological conditions in neurodegenerative diseases; therefore, they are closely related to maintaining overall health and well-being. Similarly, exercise has shown positive effects on brain health and cognitive function, which may reduce/delay the onset of severe neurological disorders. Exercise has been associated with various neurochemical changes, including alterations in cortisol levels, increased production of endorphins, endocannabinoids like anandamide, as well as higher levels of serotonin and dopamine. These changes have been linked to mood improvements, enhanced sleep quality, better motor control, and cognitive enhancements resulting from exercise-induced effects. However, further clinical research is necessary to evaluate changes in bacteria taxa along with age- and sex-based differences.

Does Therapeutic Exercise Support Improvement in Cognitive Function and Instrumental Activities of Daily Living in Patients with Mild Alzheimer's Disease? A Randomized Controlled Trial

This randomized controlled trial aims to investigate the effect of 12 weeks of therapeutic exercise on cognitive function and daily activities in patients with mild Alzheimer's disease (AD). A total of 171 patients with mild AD from the Amarousion Day Care Center of the Alzheimer Society of Athens and the Athens General Hospital "G. Gennimatas" were randomly divided into three groups. Group A (aerobic and resistance exercise, n = 57), group B (resistance exercise, n = 57), and group C (control group, n = 57). Group A followed a weekly program consisting of 5 days with 30 min walking and 3 days with resistance exercises for about 45 min. Group B followed only a resistance exercise program, the same as group A. Group C did not participate in any exercise program. After the intervention, cognitive function was assessed with the Cognitive Examination-Revised (ACE-R), Trail Making Test A-B (TMT A-B), and Digit Span Test Forward and Backward (DST F-B) and daily activities with the instrumental activities of daily living scale (IADLs). A significant intervention effect was observed for all outcome measures (global cognitive function and instrumental activities of daily living). ANCOVA Bonferroni corrected post hoc tests revealed that the aerobic and resistance group improved compared to the control group on all measurement scales. The resistance group also showed an improvement compared to the control group. No significant effects were found between the aerobic and resistance group and the resistance group in any of the outcome measures.

Acute effects of different exercise forms on executive function and the mechanism of cerebral hemodynamics in hospitalized T2DM patients: a within-subject study

Objective

This study aimed to investigate the acute effects of aerobic exercise (AE), resistance exercise (RE), and integrated concurrent exercise (ICE; i.e., AE plus RE) on executive function among hospitalized type 2 diabetes mellitus (T2DM) inpatients, and the mechanism of cerebral hemodynamics.

Methods

A within-subject design was applied in 30 hospitalized patients with T2DM aged between 45 and 70 years in the Jiangsu Geriatric Hospital, China. The participants were asked to take AE, RE, and ICE for 3 days at 48-h intervals. Three executive function (EF) tests, namely, Stroop, More-odd shifting, and 2-back tests, were applied at baseline and after each exercise. The functional near-infrared spectroscopy brain function imaging system was used to collect cerebral hemodynamic data. The one-way repeated measurement ANOVA was used to explore training effects on each test indicator.

Results

Compared with the baseline data, the EF indicators have been improved after both ICE and RE (p < 0.05). Compared with the AE group, the ICE and RE groups have demonstrated significant improvements in inhibition (ICE: MD = - 162.92 ms; RE: MD = -106.86 ms) and conversion functions (ICE: MD = -111.79 ms; RE: MD = -86.95 ms). Based on the cerebral hemodynamic data, the beta values of brain activation in executive function related brain regions increased after three kinds of exercise, the EF improvements after the ICE showed synchronous activation of blood flow in the dorsolateral prefrontal cortex (DLPFC), the frontal polar (FPA) and orbitofrontal cortex (OFC), the improvement of inhibitory function after RE displayed synchronous activation of DLPFC and FPA, and AE mainly activates DLPFC. The HbO₂ concentration in the pars triangularis Broca's area increased significantly after AE, but the EF did not improve significantly.

Conclusion

The ICE is preferred for the improvements of executive function in T2DM patients, while AE is more conducive to the improvements of refresh function. Moreover, a synergistic mechanism exists between cognitive function and blood flow activation in specific brain regions.

Mitochondrial transplantation as a possible therapeutic option for sarcopenia

With advancing age, the skeletal muscle phenotype is characterized by a progressive loss of mass, strength, and quality. This phenomenon, known as sarcopenia, has a negative impact on quality of life and increases the risk of morbidity and mortality in older adults. Accumulating evidence suggests that damaged and dysfunctional mitochondria play a critical role in the pathogenesis of sarcopenia. Lifestyle modifications, such as physical activity, exercise, and nutrition, as well as medical interventions with therapeutic agents, are effective in the management of sarcopenia and offer solutions to maintain and improve skeletal muscle health. Although a great deal of effort has been devoted to the identification of the best treatment option, these strategies are not sufficient to overcome sarcopenia. Recently, it has been reported that mitochondrial transplantation may be a possible therapeutic approach for the treatment of mitochondria-related pathological conditions such as ischemia, liver toxicity, kidney injury, cancer, and non-alcoholic fatty liver disease. Given the role of mitochondria in the function and metabolism of skeletal muscle, mitochondrial transplantation may be a possible option for the treatment of sarcopenia. In this review, we summarize the definition and characteristics of sarcopenia and molecular mechanisms associated with mitochondria that are known to contribute to sarcopenia. We also discuss mitochondrial transplantation as a possible option. Despite the progress made in the field of mitochondrial transplantation, further studies are needed to elucidate the role of mitochondrial transplantation in sarcopenia. KEY MESSAGES: Sarcopenia is the progressive loss of skeletal muscle mass, strength, and quality. Although the specific mechanisms that lead to sarcopenia are not fully understood, mitochondria have been identified as a key factor in the development of sarcopenia. Damaged and dysfunctional mitochondria initiate various cellular mediators and signaling pathways, which largely contribute to the age-related loss of skeletal muscle mass and strength. Mitochondrial transplantation has been reported to be a possible option for the treatment/prevention of several diseases. Mitochondrial transplantation may be a possible therapeutic option for improving skeletal muscle health and treating sarcopenia. Mitochondrial transplantation as a possible treatment option for sarcopenia.

Physiological Responses and Adaptations to Lower Load Resistance Training: Implications for Health and Performance

Resistance training is a method of enhancing strength, gait speed, mobility, and health. However, the external load required to induce these benefits is a contentious issue. A growing body of evidence suggests that when lower load resistance training [i.e., loads < 50% of one-repetition maximum (1RM)] is completed within close proximity to concentric failure, it can serve as an effective alternative to traditional higher load (i.e., loads > 70% of 1RM) training and in many cases can promote similar or even superior physiological adaptations. Such findings are important given that confidence with external loads and access to training facilities and equipment are commonly cited barriers to regular resistance training. Here, we review some of the mechanisms and physiological changes in response to lower load resistance training. We also consider the evidence for applying lower loads for those at risk of cardiovascular and metabolic diseases and those with reduced mobility. Finally, we provide practical recommendations, specifically that to maximize the benefits of lower load resistance training, high levels of effort and training in close proximity to concentric failure are required. Additionally, using lower loads 2-3 times per week with 3-4 sets per exercise, and loads no lower than 30% of 1RM can enhance muscle hypertrophy and strength adaptations. Consequently, implementing lower load resistance training can be a beneficial and viable resistance training method for a wide range of fitness- and health-related goals.

Exercise with a wearable hip-assist robot improved physical function and walking efficiency in older adults

Wearable assistive robotics has emerged as a promising technology to supplement or replace motor functions and to retrain people recovering from an injury or living with reduced mobility. We developed delayed output feedback control for a wearable hip-assistive robot, the EX1, to provide gait assistance. Our purpose in this study was to investigate the effects of long-term exercise with EX1 on gait, physical function, and cardiopulmonary metabolic energy efficiency in elderly people. This study used parallel experimental (exercise with EX1) and control groups (exercise without EX1). A total of 60 community-dwelling elderly persons participated in 18 exercise intervention sessions during 6 weeks, and all participants were assessed at 5 time points: before exercise, after 9 exercise sessions, after 18 sessions, and 1 month and 3 months after the last session. The spatiotemporal gait parameters, kinematics, kinetics, and muscle strength of the trunk and lower extremities improved more after exercise with EX1 than in that without EX1. Furthermore, the effort of muscles over the trunk and lower extremities throughout the total gait cycle (100%) significantly decreased after exercise with EX1. The net metabolic energy costs during walking significantly improved, and functional assessment scores improved more in the experimental group than in the control group. Our findings provide evidence supporting the application of EX1 in physical activity and gait exercise is effective to improve age-related declines in gait, physical function, and cardiopulmonary metabolic efficiency among older adults.

Resistance exercise acutely elevates dynamic cerebral autoregulation gain

Dynamic cerebral autoregulation (dCA) describes the regulation of cerebral blood flow (CBF) in response to fluctuations in systemic blood pressure (BP). Heavy resistance exercise is known to induce large transient elevations in BP, which are translated into perturbations of CBF, and may alter dCA in the immediate aftermath. This study aimed to better quantify the time course of any acute alterations in dCA after resistance exercise. Following familiarisation to all procedures, 22 (14 male) healthy young adults (22 ± 2 years) completed an experimental trial and resting control trial, in a counterbalanced order. Repeated squat-stand manoeuvres (SSM) at 0.05 and 0.10 Hz were used to quantify dCA before, and 10 and 45 min after four sets of ten repetition back squats at 70% of one repetition maximum, or time matched seated rest (control). Diastolic, mean and systolic dCA were quantified by transfer function analysis of BP (finger plethysmography) and middle cerebral artery blood velocity (transcranial Doppler ultrasound). Mean gain (p = 0.02; d = 0.36) systolic gain (p = 0.01; d = 0.55), mean normalised gain (p = 0.02; d = 0.28) and systolic normalised gain (p = 0.01; d = 0.67) were significantly elevated above baseline during 0.10 Hz SSM 10-min post resistance exercise. This alteration was not present 45 min post-exercise, and dCA indices were never altered during SSM at 0.05 Hz. dCA metrics were acutely altered 10 min post resistance exercise at the 0.10 Hz frequency only, which indicate changes in the sympathetic regulation of CBF. These alterations recovered 45 min post-exercise.

A systematic review of sarcopenia prevalence and associated factors in people living with human immunodeficiency virus

People living with human immunodeficiency virus (HIV) (PLWH) appear to be at an increased risk of sarcopenia, which can have a devastating effect on their life due to consequences such as physical disability, poor quality of life, and finally death. This systematic review examined sarcopenia prevalence and its associated factors in PLWH. A systematic search was conducted using the keywords in the online databases including Scopus, PubMed, Web of Science, Embase and Cochrane databases from the dates of inception up to May 2022. The retrieved articles underwent a two-step title/abstract and full-text review process, and the eligible papers were selected and included in the qualitative synthesis. Data relating to the study population, purpose of study, gender, age, race, body mass index, medical history, paraclinical results and antiretroviral therapy as associated factors of sarcopenia were extracted. In addition, the prevalence of sarcopenia in PLWH and its promoting and reducing factors were also extracted. We reviewed the 14 related studies for identifying of sarcopenia prevalence and its associated factors in PLWH. The total number of PLWH in all the reviewed studies was 2592. There was no criterion for the minimum number of people with HIV and the lowest number of PLWH was 27, and the highest number was 860. Some studies reported a significantly higher prevalence of sarcopenia in HIV-infected individuals compared with HIV-negative controls as follows: 24.2-6.7%, 15-4% and 10-6%, respectively. We showed that, age (30-50 years), being female, >5 years post-HIV diagnosis, multiple vertebral fractures, cocaine/heroin use and lower gamma-glutamyl transferase level were the main promoting factors of sarcopenia. Higher educational level, employment, physical exercise, calf circumference >31 cm, and gait speed >0.8 m/s were also factors to reduce sarcopenia. Sarcopenia prevalence in PLWH is higher than HIV-negative population. Given the importance and prevalence of sarcopenia among PLWH and its associated consequences (i.e., mortality and disability), determining its risk factors is of great importance.

Frequency, intensity and duration of muscle strengthening activity and associations with mental health

OBJECTIVES

Despite growing emphasis on the benefits of physical activity for promoting mental health, inclusion of muscle-strengthening (MS) (e.g., body-weight exercises, resistance machines) activities is limited. Notably, few studies collectively assess MS behavioural frequency, duration, and intensity. To address the gap, the current study examined associations between frequency (days), intensity (rating of perceived exertion in relation to repetitions in reserve [RPE/RIR]), and duration (minutes per typical session) of MS activities on anxiety, depression, and mental well-being.

METHOD

A cross-sectional study of 601 participants (Mean age = 30.92 years [SD = 12.70]; 57.7 % female) across Ireland was conducted. Participants completed a self-report questionnaire containing MS instruments previously used, or adapted from valid and reliable measures (i.e., International Physical Activity Questionnaire IPAQ, RPE/RIR), alongside, the Generalized Anxiety Disorder-7 (GAD-7), Patient Health Questionnaire-8 (PHQ-8) and the Mental Health Continuum- Short Form (MHC-SF). A multivariate regression model was tested in MPLUS, using dummy coding for MS frequency in relation to no activity (i.e., 0-days) non-adherence (i.e., 1-day), adherence (i.e., 2-days) and enhanced adherence (i.e., ≥3 days) to the MS public health guidelines, with the mental health variables representing the dependent variables. Intensity and duration were specified in the model as continuous variables; gender and age were included as statistical controls.

RESULTS

Three or more days engaged in MS activities was associated with fewer anxiety (β = -0.12, p < .05) and depression (β = -0.14, p < .01) symptoms. Increased intensity had a negative association with anxiety (β = -0.10, p < .05) and depression (β = -0.15, p < .001). Unexpectedly, adherence to the MS guidelines (2-days) did not predict any of the mental health outcomes, whereas 1-day of MS activity was associated with fewer depression symptoms (β = -0.11). No effects were observed for mental well-being, and MS duration exerted a null effect across all mental health outcomes.

CONCLUSION

Higher frequency and intensity of MS activities may protect against anxiety and depression symptoms. Doing some MS activities (at least 1-day) is likely more beneficial than none for depression. Evidence-based, MS interventions may help curb mental illness rates, and future longitudinal, intervention-based research could consider inclusion of MS frequency, intensity and duration variables to enhance efforts to identify at-risk groups and trends within physical activity and mental illness surveillance.

Assessment of lifestyle "vital signs" in healthcare settings

Unhealthy lifestyles, such as maintenance of poor diets and physical inactivity, are a powerful driver of disease-producing risk factors and chronic illnesses. This has led to an increasing call to assess adverse lifestyle factors in healthcare settings. This approach could be aided by designating health-related lifestyle factors as "vital signs" that can be recorded during patient visits. Just such an approach has been used for assessing patients' smoking habits since the 1990s. In this review, we assess the rationale for addressing six other health-related lifestyle factors, beyond smoking, in patient care settings: physical activity (PA), sedentary behavior (SB), participation in muscle strengthening exercises, mobility limitations, diet, and sleep quality. For each domain, we evaluate the evidence that supports currently proposed ultra-short screening tools. Our analysis indicates strong medical evidence to support the use of one to two-item screening questions for assessing patients' PA, SB, muscle strengthening activities, and presence of "pre-clinical" mobility limitations. We also present a theoretical basis for measuring patients' diet quality through use of an ultrashort dietary screen, based on evaluation of healthy food intake (fruits/vegetables) and unhealthy food intake (high consumption of highly processed meats and/or consumption of sugary foods and beverages) and a proposed evaluation of sleep quality using a single-item screener. The result is a 10-item lifestyle questionnaire that is based on patient self-report. As such, this questionnaire has the potential to be employed as a practical tool for assessing health behaviors in clinical care settings without impairing the normal workflow of healthcare providers.

National survey of Australian cardiac rehabilitation programmes: does current exercise programming adhere to evidence-based guidelines and best practice?

Objectives

The efficacy of exercise-based cardiac rehabilitation (CR) for patient outcomes is well established, with better outcomes when delivery meets recommended guidelines. The aim of this study was to assess how well Australian practice aligns with national CR guidelines for exercise assessment and prescription.

Method

This cross-sectional online survey was distributed to all 475 publicly listed CR services in Australia and consisted of four sections: (1) Programme and client demographics, (2) aerobic exercise characteristics, (3) resistance exercise characteristics and (4) pre-exercise assessment, exercise testing and progression.

Results

In total, 228 (54%) survey responses were received. Only three of five Australian guideline recommendations were consistently reported to be followed in current CR programmes: assessment of physical function prior to exercise (91%), prescription of light-moderate exercise intensity (76%) and review of referring physician results (75%). Remaining guidelines were commonly not implemented. For example, only 58% of services reported an initial assessment of resting ECG/heart rate, and only 58% reported the concurrent prescription of both aerobic and resistance exercise, which may have been influenced by equipment availability (p<0.05). Exercise-specific assessments such as muscular strength (18%) and aerobic fitness (13%) were uncommonly reported, although both were more frequent in metropolitan services (p<0.05) or when an exercise physiologist was present (p<0.05).

Conclusions

Clinically relevant deficits in national CR guideline implementation are common, potentially influenced by location, exercise supervisor and equipment availability. Key deficiencies include the lack of concurrent aerobic and resistance exercise prescription and infrequent assessment of important physiological outcomes including resting heart rate, muscular strength and aerobic fitness.

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.

Handgrip strength in older adults with chronic diseases from 27 European countries and Israel

BACKGROUND/OBJECTIVES

Understanding the association of deconditioned strength with the most prevalent chronic diseases in older adults and inferring possible interventional strategies is of utmost importance. We aimed to investigate the association between handgrip strength and chronic diseases in a large representative European population of adults over the age of 50 years.

SUBJECTS/METHODS

Individuals aged 50 or older residing in 27 European countries and Israel participated in this cross-sectional study. Data on prior or current chronic disease and handgrip strength were retrieved from the 7th wave of Survey of Health, Ageing and Retirement in Europe (SHARE). We tested associations using binary logistic regression adjusted for potential confounders.

RESULTS

Based on data from 73,463 participants, the examined diseases showed a negative association with handgrip strength in the fully adjusted model. Participants from the highest tertile of handgrip strength had particularly lower odds for Parkinson ((Adjusted odds ratio (AOR) = 0.42 [95% Confidence Interval = 0.32-0.56])), stroke (AOR = 0.51 [95% Confidence Interval = 0.44-0.59], and emotional disorders ((Adjusted odds ratio (AOR) = 0.51 [95% Confidence Interval = 0.45-0.58])) compared with participants with the lowest level of handgrip strength in the fully adjusted model.

CONCLUSIONS

There is a negative association between handgrip strength and a wide range of chronic diseases. Evaluating handgrip strength in this population may provide a valuable clinical measure and a simple preventive strategy in relation to these diseases. The present findings support the use of resistance training for the prevention of specific chronic conditions, particularly Parkinson, stroke and emotional disorders.

Fiber-Type Shifting in Sarcopenia of Old Age: Proteomic Profiling of the Contractile Apparatus of Skeletal Muscles

The progressive loss of skeletal muscle mass and concomitant reduction in contractile strength plays a central role in frailty syndrome. Age-related neuronal impairments are closely associated with sarcopenia in the elderly, which is characterized by severe muscular atrophy that can considerably lessen the overall quality of life at old age. Mass-spectrometry-based proteomic surveys of senescent human skeletal muscles, as well as animal models of sarcopenia, have decisively improved our understanding of the molecular and cellular consequences of muscular atrophy and associated fiber-type shifting during aging. This review outlines the mass spectrometric identification of proteome-wide changes in atrophying skeletal muscles, with a focus on contractile proteins as potential markers of changes in fiber-type distribution patterns. The observed trend of fast-to-slow transitions in individual human skeletal muscles during the aging process is most likely linked to a preferential susceptibility of fast-twitching muscle fibers to muscular atrophy. Studies with senescent animal models, including mostly aged rodent skeletal muscles, have confirmed fiber-type shifting. The proteomic analysis of fast versus slow isoforms of key contractile proteins, such as myosin heavy chains, myosin light chains, actins, troponins and tropomyosins, suggests them as suitable bioanalytical tools of fiber-type transitions during aging.

Effect of Exercise Using an Exoskeletal Hip-Assist Robot on Physical Function and Walking Efficiency in Older Adults

Robotic technology has developed rapidly in recent years, and several robotic devices have been applied to improve physical, sensory, intellectual, psychological, and social functioning in the elderly and people with disabilities. In this study, we investigated the effects of EX1-assisted exercise in various environments on physical function, muscle strength, and walking efficiency in older adults. We designated four experimental conditions and randomly assigned participants to one of four groups: A (overground walking without an EX1), B (overground walking using the resistance mode of EX1), C (stair ascent using the assistance mode of EX1), and Group D (inclined treadmill walking using the assistance mode of EX1). A total of 60 community-dwelling elderly persons participated in 10 exercise intervention sessions for 4 weeks, and all participants were assessed before and after the exercise intervention. Physical function was measured by the 10-meter walk test for self-selected velocity (10MWT-SSV), short physical performance battery (SPPB), Berg balance scale (BBS), timed up and go (TUG), functional reach test (FRT), geriatric depression scale-short form (GDS-SF), and muscle strength of trunk and lower extremity. Cardiopulmonary metabolic energy efficiency was measured using a portable telemetric gas analyzer system. A significant increase in the 10MWT-SSV and TUG test was observed in groups B, C, and D. A statistically significant improvement in the SPPB and FRT was seen only in group D, and GDS-SF scores decreased significantly after exercise with an EX1 in groups B and D. Trunk and lower limb muscle strength increased more in the groups that exercised with EX1 assistance than those without an EX1, particularly in group B. The net metabolic energy costs and energy expenditure measurement during walking significantly improved in exercise groups C and D. The findings in this study support the application of the EX1 to physical activity and exercise to improve age-related changes in physical function, muscle strength, and walking efficiency among older adults. In addition, personalized exercise programs using different modes and training environments with an EX1 can enhance physical performance and walking efficiency in the elderly.

Twist2-expressing cells reside in human skeletal muscle and are responsive to aging and resistance exercise training

Skeletal muscle is maintained and repaired by sub-laminar, Pax7-expressing satellite cells. However, recent mouse investigations have described a second myogenic progenitor population that resides within the myofiber interstitium and expresses the transcription factor Twist2. Twist2-expressing cells exclusively repair and maintain type IIx/b muscle fibers. Currently, it is unknown if Twist2-expressing cells are present in human skeletal muscle and if they function as myogenic progenitors. Here, we perform a combination of single-cell RNA sequencing analysis and immunofluorescence staining to demonstrate the identity and localization of Twist2-expressing cells in human skeletal muscle. Twist2-expressing cells were identified to be anatomically and transcriptionally comparable to fibro-adipogenic progenitors (FAPs) and lack expression of typical satellite cell markers such as Pax7. Comparative analysis revealed that human and mouse Twist2-expressing cells were highly transcriptionally analogous and resided within the same anatomical structures in vivo. Examination of young and aged skeletal muscle biopsy samples revealed that Twist2-positive cells are more prevalent in aged muscle and increase following 12-weeks of resistance exercise training (RET) in humans. However, the quantity of Twist2-positive cells was not correlated with indices of muscle mass or muscle fiber cross-sectional area (CSA) in young or older muscle, and their abundance was surprisingly, negatively correlated with CSA and myonuclear domain size following RET. Taken together, we have identified cells expressing Twist2 in human skeletal muscle which are responsive to aging and exercise. Further examination of their myogenic potential is warranted.