Progressive Resistance Training for Concomitant Increases in Muscle Strength and Bone Mineral Density in Older Adults: A Systematic Review and Meta-Analysis

The contribution of age and sex hormones to female neuromuscular function across the adult lifespan

Neuromuscular ageing is characterized by neural and/or skeletal muscle degeneration that decreases maximal force and power. Female neuromuscular ageing occurs earlier in life compared to males, potentially due to sex hormone changes during the menopausal transition. We quantified neuromuscular function in 88 females represented equally over each decade from 18 to 80 years of age and investigated the role of decreased ovarian hormone concentrations following menopause. Neuromuscular assessment included quadriceps maximal voluntary and evoked isometric torque and surface electromyography measurements, plus one-repetition maximum leg press. Voluntary and evoked torques and one-repetition maximum decreased non-linearly with age, with accelerated reductions starting during the fourth decade. An absence of changes in volitional recruitment of existing quadriceps motor units and Ia afferent facilitation of spinal motoneurons suggests that functional decline was largely mediated by impairment in intrinsic peripheral muscle function and/or neuromuscular transmission. Maximal muscle compound action potential amplitude decreased with increasing age for rectus femoris muscle only, indicating increased vulnerability to neuromuscular degeneration compared to vastus lateralis and medialis. In postmenopausal females, some variance was explained by inter-individual differences in quadriceps tissue composition and lifestyle factors, but changes in total or free concentrations of oestradiol, progesterone and/or testosterone were included in all correlations with age-related decreases in isometric voluntary and evoked torques. We demonstrate an accelerated onset of neuromuscular degeneration of peripheral muscular origin around menopause onset associated with changes in sex hormone concentrations. Interventions aimed at mitigating declines in ovarian hormones and their subsequent effects on neuromuscular function after menopause should be further explored. KEY POINTS: Neuromuscular deterioration with age is associated with poor physical function and quality of life in older adults, but female-specific trajectories and mechanisms remain unclear. This study is the first to map neuromuscular function across each decade of the adult lifespan in 88 females from 18 to 80 years old and to examine the potential role of hormonal changes after menopause. We show an accelerated reduction in neuromuscular function, primarily of peripheral muscular origin, that occurs during the fourth decade and coincides with menopause onset. In postmenopausal females, age-related reductions in neuromuscular function can in part be explained by quadriceps lean and intramuscular fat composition, physical activity and protein intake, and sex hormone concentrations. These findings help us better understand the factors that contribute to the loss of neuromuscular function with age in females, enabling the identification of potential therapeutic interventions to prolong female health span.

Relationship between knee pain and depth-specific measures of proximal tibial subchondral bone density

BACKGROUND

Altered subchondral bone mineral density (BMD) may be a possible contributor to osteoarthritis (OA) pain. We evaluated the relation of compartment-specific proximal tibial BMD, at varying depths beneath the subchondral surface, to knee pain.

METHODS

Multicenter Osteoarthritis (MOST) study participants with knee CTs were included. A 3D imaging tool measuring BMD in relation to depth from the subchondral surface was used to assess proximal tibial subchondral BMD at depths of 0-2.5, 2.5-5.0, and 5-10 mm. Knee pain in the past 30 days was scored on a numeric rating scale (range 0-100), dichotomized at 40/100 to define the presence of at least moderate pain. We cross-sectionally evaluated the relation of subchondral BMD to the presence of knee pain using binomial regression with generalized estimating equations (to account for correlations between two knees per individual) for each compartment and depth in separate models and adjusted for age, sex, and body mass index (BMI).

RESULTS

We included 2082 participants (mean age: 61 years, 56.5% female, mean BMI: 29 kg/m2). The prevalence of moderate pain was significantly lower for each SD unit increase in average subchondral BMD, after confounder adjustment, in each compartment. The magnitude of association did not differ for increasing depths beneath the subchondral surface or between compartments.

CONCLUSION

Lower subchondral proximal tibial BMD measures were associated with the prevalence of moderate knee pain in individuals with or at risk for knee OA, without differences by depth or compartment. These findings suggest bone remodeling responses throughout subchondral bone contribute to the knee pain experience.

Sarcopenia in type 2 Diabetes mellitus among Asian populations: prevalence and risk factors based on AWGS- 2019: a systematic review and meta-analysis

BACKGROUND

Sarcopenia is increasingly recognized as a significant complication in type 2 diabetes mellitus (T2DM), yet its prevalence and risk factors in Asian populations remain incompletely understood using the updated Asian Working Group for Sarcopenia (AWGS) 2019 criteria. The present review aimed to evaluate the prevalence of sarcopenia among Asian T2DM patients and identify associated risk factors using AWGS-2019 criteria through systematic review and meta-analysis.

METHODS

A comprehensive systematic review of PubMed, SCOPUS, Crossref, Google Scholar, Semantic Scholar, and OpenAlex followed PRISMA guidelines to identify observational studies assessing the magnitude of sarcopenia in type-2 Diabetes mellitus. Random-effect models were used to estimate pooled prevalence and odds ratios (OR) for associated factors. Heterogeneity was quantified using I2 statistics and Cochran's Q test, where I2 values of 25%, 50%, and 75% indicated low, moderate, and high heterogeneity, respectively. Subgroup analyses and meta-regression explored heterogeneity sources across all studies. The quality of the studies was assessed by the Joanna Briggs Institute (JBI) criteria. Publication bias was assessed by funnel plot and Egger's test.

FINDINGS

Thirty nine studies, including approximately 19,902 participants, were analyzed. The pooled prevalence of confirmed sarcopenia was 23% (95% CI: 18%-27%, p < 0.001) among Asian T2DM patients, with notably higher rates of possible sarcopenia at 61% (95% CI: 28%-86%, p < 0.001) and lower rates of severe sarcopenia at 12.1% (95% CI: 8.4%-16.7%, p < 0.001). Regional variations showed a higher prevalence in Southeast Asia (37.46%) compared to Western Pacific (21.95%). Meta-analysis revealed significant risk factors including older age (OR: 1.13, 95% CI: 1.11-1.16, p < 0.0001), male gender (OR: 2.37, 95% CI: 1.33-4.21, p = 0.0033), hypertension (OR: 3.65, 95% CI: 1.06-12.65, p = 0.0409), diabetes duration (OR: 1.35, 95% CI: 1.05-2.13, p = 0.02), and reduced physical activity (OR: 2.54, 95% CI: 1.92-3.36, p < 0.0001). Higher BMI (OR: 0.63, 95% CI: 0.53-0.75, p < 0.0001) and better vitamin D levels (OR: 0.91, 95% CI: 0.87-0.95, p < 0.001) demonstrated protective effects. Recent studies (2023-2024) showed a higher prevalence than pre-2022 studies (27.85% vs 18.42%, p = 0.0440). DXA-based measurements yielded higher prevalence estimates than BIA-based assessments (29.86% vs 19.52%, p = 0.7121).

INTERPRETATION

Sarcopenia affects nearly one-quarter of Asian T2DM patients, with significant regional variations. Age, male gender, hypertension, and physical inactivity were key risk factors, while maintaining a healthy BMI and good nutrition appeared protective. These findings emphasize the importance of regular screening and early intervention strategies, particularly for high-risk patients.

Exercise for Postmenopausal Bone Health - Can We Raise the Bar?

PURPOSE OF REVIEW

This review summarises the latest evidence on effects of exercise on falls prevention, bone mineral density (BMD) and fragility fracture risk in postmenopausal women, explores hypotheses underpinning exercise-mediated effects on BMD and sheds light on innovative concepts to better understand and harness the skeletal benefits of exercise.

RECENT FINDINGS

Multimodal exercise programs incorporating challenging balance exercises can prevent falls. Emerging clinical trial evidence indicates supervised progressive high-intensity resistance and impact training (HiRIT) is efficacious in increasing lumbar spine BMD and is safe and well-tolerated in postmenopausal women with osteoporosis/osteopenia. There remains uncertainty regarding durability of this load-induced osteogenic response and safety in patients with recent fractures. Muscle-derived myokines and small circulating extracellular vesicles have emerged as potential sources of exercise-induced muscle-bone crosstalk but require validation in postmenopausal women. Exercise has the potential for multi-modal skeletal benefits with i) HiRIT to build bone, and ii) challenging balance exercises to prevent falls, and ultimately fractures. The therapeutic effect of such exercise in combination with osteoporosis pharmacotherapy should be considered in future trials.

Comparison of trabecular bone microarchitecture between older males with and without a running habit: A cross-sectional study

Objectives

Despite its prevalence among seniors, the impact of running on trabecular bone microarchitecture, especially in weight-bearing sites, remains relatively unexplored. This cross-sectional study aimed to investigate the impact of habitual running on bone health, specifically bone mineral density (BMD) and trabecular bone microarchitecture, in male older adults.

Methods

Twenty-five male recreational runners aged between 50 and 75 years old were recruited in this study (RUN; average running experience 7.5 ± 6.0 years, average monthly running volume 217 ± 120 km), and 25 age matched sedentary older males served as controls (CON). Dual-energy X-ray absorptiometry was used to obtain bone mineral density (BMD) measures at whole-body, bilateral proximal femur as well as lumbar spine for all participants. Magnetic resonance imaging was used to obtain trabecular bone microarchitectural parameters at distal femur and distal tibia for all participants.

Results

Findings revealed no significant difference in BMD between groups for all measured sites (all p > 0.05; d range 0.013-0.540). However, runners displayed higher bone volume fraction and trabecular thickness at the distal tibia (p = 0.012 and 0.001; 95 % CI of MD [-0.030, -0.004] and [-0.013, -0.004]; d = 0.739 and 1.034, respectively) and higher trabecular thickness at the distal femur (p = 0.002; 95 % CI of MD [-0.010, -0.002]; d = 0.907).

Conclusions

This study provides critical insights into the relationship between running and bone health in older adults, suggesting regular recreational running may positively influence trabecular bone microarchitecture, potentially enhancing bone strength and reducing fracture risk. These findings pave the way for future research to develop evidence-based exercise recommendations for an aging population.

Effects of resistance training, Yijinjing and Baduanjin exercise with oral caltrate D on bone mineral density and bone metabolism in older women: a randomised controlled trial

BACKGROUND

The literature lacks studies comparing the effects of traditional Chinese exercises, Qigong Yijinjing (YJJ) and Baduanjin (BDJ), with resistance training (RT) on bone mineral density (BMD) and bone metabolism in older adults.

OBJECTIVE

This study investigated the effects of regular RT, YJJ, and BDJ exercises training, combined with oral Caltrate D supplementation, on lumbar spine and proximal femur BMD and serum bone metabolism indices in older women.

METHODS

Eighty-four older women were randomly divided into the RT group (RG, n = 21), YJJ group (YG, n = 22), BDJ group (BG, n = 21) and control group (CG, n = 20). These groups performed the assigned exercises for 24 weeks (3 times/week, 60 min/time). The BMD of the lumbar L2-4 and proximal femur, as well as serum bone metabolism indices, were measured using dual-energy X-ray absorptiometry and an automatic chemiluminescence apparatus, respectively.

RESULTS

At week 24, compared to the CG, the RG, YG, and BG had significantly higher BMD and procollagen type I N-terminal propeptide (PINP) levels in the lumbar L2-4 region (BMD: p = 0.049, p = 0.016, p = 0.040; PINP: p = 0.026, p = 0.029, p = 0.020), and lower β-carboxy-terminal cross-linked telopeptide of type 1 collagen (β-CTX) levels (p = 0.001, p = 0.012, p = 0.042). Intragroup comparison between baseline and week 24 data revealed that in RG, YG, and BG, lumbar L2-4 BMD (RG: p = 0.036, YG: p = 0.002, BG: p = 0.022) and PINP (RG: p = 0.020, YG: p = 0.001, BG: p = 0.001) increased, whereas β-CTX (RG: p = 0.003, YG: p < 0.001, BG: p = 0.008) decreased.

CONCLUSIONS

RT, YJJ and BDJ combined with Caltrate D for 24 weeks can increase lumbar BMD, increase the bone formation marker PINP and decrease the bone resorption marker β-CTX in older women but had no significant effect on the BMD of the proximal femur. YJJ and BDJ had the same effect on improving BMD in the older adults as RT with the same exercise cycle and frequency.

SIRT1 and exercise-induced bone metabolism: a regulatory nexus

Regular exercise positively influences bone health, enhances bone density and strength, and reduces the risk of osteoporosis. Silent information regulator of transcription 1 (SIRT1) is a deacetylase that plays a pivotal role in the regulation of various biological processes. In this review, we explore the role of SIRT1 in modulating bone metabolism in response to exercise. SIRT1 regulates crucial cellular processes, including inflammation, aging, autophagy, and oxidative stress, in bone cells such as bone marrow mesenchymal stem cells, osteoblasts, and osteoclasts, in response to exercise-induced stimuli. Notably, exercise influences bone metabolism by modulating muscle metabolism and neurotransmitters, with SIRT1 acting as a key mediator. A comprehensive understanding of SIRT1's regulatory mechanisms will facilitate a deeper exploration of the principles underlying exercise-induced improvements in bone metabolism, ultimately providing novel insights into the treatment of bone metabolic disorders.

Physical activity and handgrip strength in patients with mild, moderate and severe haemophilia: Impacts on bone quality and lean mass

BACKGROUND

Patients with haemophilia (PwH) might be restricted in physical activity (PA) depending on the severity phenotype. It is well-known that PA affects overall health including bone quality. This study aims to evaluate the level of PA within the different haemophilia severity phenotypes and to elaborate on the interplay of PA in regard to bone quality (bone mineral density (BMD) and trabecular bone score (TBS)) as well as lean mass.

METHODS

This investigation was part of a large prospective single-center cohort study examining the relation between haemophilia and osteoporosis registered at clinicaltrials.gov (ID: NCT04524481). PwH underwent a dual x-ray screening using Horizon™ to examine BMD, TBS, and lean mass. Step activity was tracked electronically for seven consecutive days after clinical examination, supported by a self-reported activity diary for seven days. Handgrip strength was examined as an overall fitness proxy.

RESULTS

Data of 223 patients with either mild (N = 45), moderate (N = 46), or severe (N = 132) haemophilia A or B, aged 43.6 ± 15.6 years were analyzed. There was no significant difference in objective (p = 0.162) and subjective (p = 0.459) PA levels between severity phenotypes. The most frequent type of PA in all severities was walking (n = 72, 53.3%) and cycling (n = 60, 44.4%). Step activity positively correlated with TBS (rho = 0.202, p = 0.005) and lean mass positively correlated with BMD (rho = 0.309, p < 0.001). Handgrip strength correlated with BMD (rho = 0.361, p < 0.001) as well as TBS (rho = 0.221, p = 0.021) and lean mass (rho = 0.287, p = 0.003).

CONCLUSION

PA does not differ significantly between the severity phenotypes. The majority of PwH in all severity phenotypes performed low-impact PA, which is most likely insufficient to positively affect BMD. However, handgrip strength correlates with BMD and TBS. Despite restrictions in movement function or reduced BMD, it is of major importance to promote PA to maintain a healthy or even increase bone quality.

Repetition-dependent acutecardiopulmonary responses during intensity-matched squats in males

The 'strength-endurance continuum' is a key concept in strength training (ST). Although cardiopulmonary responses have seldom been reported in conjunction with ST, this repeated-measurement study examined acute blood pressure and haemodynamic responses continuously depending on the number of repetitions but without changing the intensity. Fifteen healthy male participants (21.6 (2.0) years; mean (SD)) performed an incremental exercise test and a 3-repetition maximum test (3-RM) on a Smith machine. They were then randomly assigned to three ST sessions involving 10, 20 and 30 repetitions at 50% of their 3-RM. Blood pressure (vascular unloading technique) and cardiopulmonary responses (spirometry and impedance cardiography) were continuously monitored. Heart rate (121 (10) vs. 139 (22) vs. 153 (13) bpm, P = 0.001, respectively), cardiac output (10.4 (1.9) vs. 13.6 (3.8) vs. 14.6 (3.1) L/min, P = 0.001, respectively) and diastolic blood pressure (113 (8) vs. 116 (21) vs. 135 (22) mmHg, P = 0.001, respectively) increased in the training sessions with higher repetitions. Stroke volume, systolic blood pressure and end-diastolic volume indicated no change in peak values between training sessions. Total peripheral resistance (13.6 (2.8) vs. 11.3 (3.6) vs. 11.2 (3.1) mmHg min/L, P = 0.002, respectively) was significantly lower with 20 and 30 repetitions, while oxygen uptake (V ̇ O 2 ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}}}$ : 15.5 (1.9) vs. 20.5 (4.1) vs. 20.6 (4.4) mL/min/kg, P = 0.001, respectively) was significantly higher. ST of moderate intensity with an exhausting number (>20) of repetitions induces strong haemodynamic responses, especially high cardiac afterload and a compensatory heart rate acceleration, which may also create a strong stimulus for cardiopulmonary adaptation.

The regular effects of concurrent aerobic and resistance exercise on global cognition in healthy elderly populations: A systematic review with meta-analysis of randomized trials

Aerobic and resistance exercises are widely recognized as essential for preserving and enhancing cognitive function. However, the effects of concurrent exercise on cognition in older adults remain unclear. This systematic review sought to evaluate the regular effects of concurrent aerobic and resistance training on global cognition in healthy older adults. A comprehensive search was conducted across PubMed, Web of Science, EMBASE, Google Scholar, Cochrane Library, and CNKI up to July 2024. Randomized controlled trials involving healthy older adults aged ≥65 years that assessed the cognitive effects of concurrent exercise were included. The methodological quality of the included studies was evaluated using the PEDro scale. Meta-analyses were performed using a random-effects model, and heterogeneity was quantified with the I2 statistic. The initial search identified 13,533 records, ultimately including 12 studies in the meta-analysis, which involved 2557 participants. The meta-analysis revealed non-significant effects of concurrent exercise on global cognition (SMD = 0.12, 95 % CI: -0.08 to 0.33, p = 0.200). The subgroup analysis indicated that concurrent exercise cannot enhance global cognition compared to active controls (SMD = -0.03, 95 % CI: -0.23 to 0.18, p = 0.80), but it does show significant improvement compared to passive controls (SMD = 0.35, 95 % CI: 0.14 to 0.56, p < 0.001). Moderate heterogeneity was observed (I2 = 49.9 %), and sensitivity analyses confirmed the stability of the results. No significant publication bias was identified. While concurrent exercise was effective in improving global cognition in healthy older adults, the improvements were not superior to active control conditions. Future research should investigate optimal training combinations and sequences to maximize cognitive benefits.

Factors, mechanisms and improvement methods of muscle strength loss

Muscle strength is a crucial aspect of muscle function, essential for maintaining normal physical activity and quality of life. The global aging population coupled with the increasing prevalence of muscle disorders and strength loss, poses a remarkable public health challenge. Understanding the mechanisms behind muscle strength decline is vital for improving public health outcomes. This review discusses recent research advancements on muscle strength loss from various perspectives, including factors contributing to muscle strength decline, the signaling pathways involved in the deterioration of muscle function, and the methods for assessing muscle strength. The final section explores the influence of exercise stimulation and nutrition on muscle strength.

Machine-Based Resistance Training Improves Functional Capacity in Older Adults: A Systematic Review and Meta-Analysis

Background/Objectives: Resistance training (RT) can improve the functional performance of older adults, maintaining independence and quality of life. It has been proposed that training interventions should implement exercises associated with the movements needed in everyday life. However, this strength training philosophy presents challenges, specifically to older adults, and the use of resistance machines might present an efficacious alternative. The aim of this systematic review and meta-analysis was to explore the impact of machine-based RT on strength and functional capacity in older adults. Methods: The inclusion criteria were for strength training interventions to be a minimum of 6 weeks, using only resistance machines, with pre- and post-intervention measurements of functional capacity of either a timed up-and-go and/or a sit-to-stand test, and including healthy older adults (>60 years). Results: Following the screening, 17 articles met the inclusion criteria for the systematic review, 15 of which were included in the meta-analysis for functional outcomes (n = 614 participants), and 11 of which were included in the meta-analysis for strength outcomes (n = 511 participants). Analyses revealed significant standardized mean change in favor of machine-based RT for functional outcomes (0.72, 95% CIs 0.39 to 1.07) and strength outcomes (0.71, 95% CIs 0.34 to 1.08) compared to control conditions (functional = 0.09, 95% CIs - 0.1 to 0.28, strength = 0.1, 95% CIs - 0.05 to 0.24). Substantial heterogeneity was noted in the manipulation of RT variables and the magnitude of effects between studies. Conclusions: The data presented support the idea that significant strength and functional performance outcomes are attainable using uncomplicated, machine-based RT.

Low, but Not High, Pulsating Fluid Shear Stress Affects Matrix Extracellular Phosphoglycoprotein Expression, Mainly via Integrin β Subunits in Pre-Osteoblasts

Matrix extracellular phosphoglycoprotein (Mepe), present in bone and dentin, plays important multifunctional roles in cell signaling, bone mineralization, and phosphate homeostasis. Mepe expression in bone cells changes in response to pulsating fluid shear stress (PFSS), which is transmitted into cells through integrin-based adhesion sites, i.e., α and β subunits. Whether and to what extent PFSS influences Mepe expression through the modulation of integrin α and/or β subunit expression in pre-osteoblasts is uncertain. Therefore, we aimed to test whether low and/or high PFSS affects Mepe expression via modulation of integrin α and/or β subunit expression. MC3T3-E1 pre-osteoblasts were treated with ± 1 h PFSS (magnitude: 0.3 Pa (low PFSS) or 0.7 Pa (high PFSS); frequency: 1 Hz). Single integrin fluorescence intensity in pre-osteoblasts was increased, but single integrin area was decreased by low and high PFSS. Expression of two integrin α subunit-related genes (Itga1 and Itga5 2) was increased by low PFSS, and one (Itga5 2) by high PFSS. Expression of five integrin β subunit genes (Itgb1, Itgb3, Itgb5, Itgb5 13, and Itgb5 123) was increased by low PFSS, and three (Itgb5, Itgb5 13, and Itgb5 123) by high PFSS. Interestingly, Mepe expression in pre-osteoblasts was only modulated by low, but not high, PFSS. In conclusion, both low and high PFSS affected integrin α and β subunit expression in pre-osteoblasts, while integrin β subunit expression was more altered by low PFSS. Importantly, Mepe gene expression was only affected by low PFSS. These results might explain the different ways that Mepe-induced changes in pre-osteoblast mechanosensitivity may drive signaling pathways of bone cell function at low or high impact loading. These findings might have physiological and biomedical implications and require future research specifically addressing the precise role of integrin α or β subunits and Mepe during dynamic loading in bone health and disease.

Determinants of bone mineral density in various regions of the skeleton among smokers and non-smokers: the role of physical activity

Background

The adult human skeleton is composed of cortical and cancellous bone. The proportions of these two types of bone tissue differ in various parts of the skeleton. The aim of this cross-sectional study was to quantify the determinants of bone mineral density (BMD) and bone mineral content in various regions of interest (ROIs) in smokers and never-smokers.

Methods

In this study, 4,332 bone scans of three regions of interest (ROIs) were analyzed: the forearm (distal and proximal), femur, and lumbar spine. Body composition and bone parameters were measured using dual-energy X-ray absorptiometry. Smoking was measured using the Global Adult Tobacco Survey questionnaire. Body mass index (BMI) was calculated, and physical activity (PA) was characterized by the metabolic equivalent of task (MET).

Results

Among women, the interaction between PA (positive β coefficient) and smoking (negative β coefficient) was a significant predictor of BMD in the distal and proximal forearm (adj. R2 = 0.40 and R2 = 0.58; p < 0.001). The interaction of three variables-age, smoking (negative β), and MET (positive β)-was significant for total hip BMD (adj. R2 = 0.54; p < 0.001). The interaction between BMI and MET (positive β) and smoking (negative β) was significant for BMD in the lumbar spine (adj. R2 = 0.62; p < 0.001). In men, the interaction between MET (positive β) and smoking (negative β) was significant for BMD in the forearm and lumbar spine (adj. R2 = 0.44, R2 = 0.46, and R2 = 0.49; p < 0.01). Smoking alone was a significant negative predictor of total hip BMD (adj. R2 = 0.34; p < 0.001).

Conclusion

Among both women and men, never-smokers had significantly better bone parameters than smokers. Smoking was a significant negative predictor for BMD in the various ROIs in both women and men. Physical activity was a significant positive predictor of BMD, with a strong association with bone parameters.

Assessing the Clinical Effectiveness of an Exergame-Based Exercise Training Program Using Ring Fit Adventure to Prevent and Postpone Frailty and Sarcopenia Among Older Adults in Rural Long-Term Care Facilities: Randomized Controlled Trial

BACKGROUND

Frailty and sarcopenia are geriatric syndromes of increasing concern and are associated with adverse health outcomes. They are more prevalent among long-term care facility (LTCF) users than among community dwellers. Exercise, especially multicomponent and progressive resistance training, is essential for managing these conditions. However, LTCFs, particularly in rural areas, face challenges in implementing structured exercise programs due to health care professional shortages. Moreover, older adults often become bored with repetitive exercise training and may lose interest over time. The Nintendo Switch Ring Fit Adventure (RFA) exergame is a novel exergame that combines resistance, aerobic, and balance exercises and offers a potential solution by boosting motivation in an immersive manner and reducing staff intervention needs.

OBJECTIVE

We aimed to evaluate the clinical effectiveness of an exergame-based exercise training program delivered via RFA (exergame-RFA) in improving muscle mass and functional performance among older adult LTCF users.

METHODS

This was a randomized controlled trial conducted from August 2022 to September 2023 and involved older adult LTCF users (aged ≥60 y) in rural southern Taiwan. Participants were randomized into an intervention group (exergame-RFA plus standard care) or a control group (standard care alone). The intervention, conducted seated with arm fit skills and trunk control exercises using the RFA, lasted 30 minutes twice weekly over 12 weeks. The primary outcomes measured were the Study of Osteoporotic Fractures index (serving as an indicator of frailty status) and the diagnostic criteria for sarcopenia (appendicular skeletal muscle mass index, handgrip strength, and gait speed). The secondary outcomes included functional performance (box and block test as well as maximum voluntary isometric contraction of the dominant upper extremity), muscle condition (muscle thickness measured using ultrasonography), activities of daily living (Kihon checklist), health-related quality of life (Short Form Health Survey-36), and cognitive function (brain health test). We used an intention-to-treat analysis, incorporating a simple imputation technique in statistical analysis. A mixed ANOVA, with time as a within-participant factor and intervention as a between-participant factor, was used to compare the training effects on outcomes.

RESULTS

We recruited 96 individuals, of whom 60 (62%) underwent randomization. Of these 60 participants, 55 (92%) completed the study. Significant group×time interactions were observed in the intervention group in all primary outcomes (all P<.001, except P=.01 for handgrip strength) and most secondary outcomes, including maximum voluntary isometric contraction of the biceps (P=.004) and triceps brachii (P<.001) muscles, biceps muscle thickness measured using ultrasonography (P<.001), box and block test (P<.001), Kihon checklist (physical function: P=.01, mood status: P=.003, and total: P=.003), and brain health test (P<.001).

CONCLUSIONS

The exergame-RFA intervention significantly improved muscle mass, strength, and functional performance among older adult users of rural LTCFs, offering a novel approach to addressing frailty and sarcopenia.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05360667; https://clinicaltrials.gov/study/NCT05360667.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.3389/fmed.2022.1071409.

Acute Resistance Exercise Modifies Extracellular Vesicle miRNAs Targeting Anabolic Gene Pathways: A Prospective Cohort Study

BACKGROUND

Resistance training confers numerous health benefits that are mediated in part by circulating factors. Toward an enhanced molecular understanding, there is growing interest in a class of signaling biomarkers called extracellular vesicles (EV). EVs support physiological adaptations to exercise by transporting their cargo (e.g., microRNA (miRNA)) to target cells. Previous studies of changes in EV cargo have focused on aerobic exercise, with limited data examining the effects of resistance exercise. We examined the effect of acute resistance exercise on circulating EV miRNAs and their predicted target pathways.

METHODS

Ten participants (5 men; age, 26.9 ± 5.5 yr; height, 173.4 ± 10.5 cm; body mass, 74.0 ± 11.1 kg; body fat, 25.7% ± 11.6%) completed an acute heavy resistance exercise test (AHRET) consisting of six sets of 10 repetitions of back squats using 75% one-repetition maximum. Pre-/post-AHRET, EVs were isolated from plasma using size exclusion chromatography, and RNA sequencing was performed. Differentially expressed miRNAs between pre- and post-AHRET EVs were analyzed using Ingenuity Pathway Analysis to predict target messenger RNAs and their target biological pathways.

RESULTS

Overall, 34 miRNAs were altered by AHRET ( P < 0.05), targeting 4895 mRNAs, with enrichment of 175 canonical pathways ( P < 0.01), including 12 related to growth/metabolism (p53, IGF-I, STAT3, PPAR, JAK/STAT, growth hormone, WNT/β-catenin, ERK/MAPK, AMPK, mTOR, and PI3K/AKT) and 8 to inflammation signaling (TGF-β, IL-8, IL-7, IL-3, IL-6, IL-2, IL-17, IL-10).

CONCLUSIONS

Acute resistance exercise alters EV miRNAs targeting pathways involved in growth, metabolism, and immune function. Circulating EVs may serve as significant adaptive signaling molecules influenced by exercise training.

Effectiveness of Mobile-Based Progressive and Fixed Physical Activity on Depression, Stress, Anxiety, and Quality of Life Outcomes Among Adults in South Korea: Randomized Controlled Trial

BACKGROUND

Depression acts as a significant obstacle to the overall well-being of individuals. Given the significant consequences, timely recognition and proactive steps to manage symptoms of depression become essential. Such actions not only reduce personal distress but also play a crucial role in reducing its far-reaching impact on society as a whole.

OBJECTIVE

In response to this concern, the objective of this study was to explore the use of mobile-based interventions as a possible remedy. More specifically, this study aimed to investigate the effectiveness of 2 types of physical activity (PA), progressive and fixed, within a mobile-based app on depression, perceived stress, anxiety, physical health, and psychological health, aiming to contribute to the optimization of mental health benefits.

METHODS

Participants (N=60; mean age 25.29, SD 6.10 years) were recruited using a combination of web-based and offline methods, and the study lasted for 8 weeks. The baseline and posttest questionnaires were administered to all participants. The participants were randomly assigned to 1 of the 3 groups: progressive group (n=20; performing mobile-based progressive PA), fixed group (n=20; performing mobile-based fixed intensity PA), and control group C (n=20). Data analysis involved comparing scores between the experimental and control groups using a one-way ANOVA, paired sample t tests (2-tailed), and repeated measures ANOVA with a 3 (group)×2 (time) design.

RESULTS

The findings revealed significant improvements in mental health indicators among participants engaged in both fixed and progressive PA groups compared with the control group. However, the fixed PA group demonstrated more significant reductions in symptoms. Specifically, the progressive PA group showed significant reductions in depression (F1,36=6.941; P=.01; ηp2=0.16) and perceived stress (F1,36=5.47; P=.03; ηp2=0.13), while the fixed PA group exhibited significant reductions in depression (F1,37=5.36; P=.03; ηp2=0.12), perceived stress (F1,37=7.81; P=.008; ηp2=0.17), and general anxiety disorder (F1,37=5.45; P=.03; ηp2=0.13) compared with the control group.

CONCLUSIONS

This study underscores the potential of mobile-based PA in improving mental health outcomes. The findings offer significant insights for mental health professionals and researchers aiming to optimize mental well-being through innovative mobile therapies.

TRIAL REGISTRATION

Clinical Research Information Service KCT0009100; https://tinyurl.com/mr33fmur.

Physical Activity and Oxidative Stress in Aging

Biological aging, characterized by changes in metabolism and physicochemical properties of cells, has an impact on public health. Environment and lifestyle, including factors like diet and physical activity, seem to play a key role in healthy aging. Several studies have shown that regular physical activity can enhance antioxidant defense mechanisms, including the activity of enzymes such as superoxide dismutase (SOD), catalase, and glutathione peroxidase. However, intense or prolonged exercise can also lead to an increase in reactive oxygen species (ROS) production temporarily, resulting in oxidative stress. This phenomenon is referred to as "exercise-induced oxidative stress". The relationship between physical activity and oxidative stress in aging is complex and depends on various factors such as the type, intensity, duration, and frequency of exercise, as well as individual differences in antioxidant capacity and adaptation to exercise. In this review, we analyzed what is reported by several authors regarding the role of physical activity on oxidative stress in the aging process as well as the role of hormesis and physical exercise as tools for the prevention and treatment of sarcopenia, an aging-related disease. Finally, we reported what has recently been studied in relation to the effect of physical activity and sport on aging in women.

Effects of resistance training on sleep quality and disorders among individuals diagnosed with cancer: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Sleep disorders are often complained by cancer patients and can last years after the end of therapies, leading to different negative consequences. Non-pharmacological strategies such as exercise interventions may be considered to counteract this phenomenon. The literature supports the beneficial effects of aerobic training (AT), while evidence on resistance training (RT) is scarce. Accordingly, our systematic review aims to investigate the potential novel effect of RT on sleep outcomes in cancer survivors.

METHODS

The literature search was conducted on MEDLINE (Pubmed), Web of Science, Scopus, and Cochrane Central Register of Controlled Trials databases, including only randomized controlled trials (RCTs). The screening procedure was conducted using the web-based software COVIDENCE. Sleep outcomes assessed through self-reported questionnaires or objective sleep measurements were extracted from RCTs recruiting cancer survivors of any age and gender, on or off treatment. The risk of bias (RoB) for each study was assessed using the Cochrane RoB 2 tool for RCTs. Meta-analytic syntheses were performed on sleep quality and insomnia.

RESULTS

A total of 21 studies were included in the review. Considering the mean percentage differences of all studies combined, promising positive results were found after combined aerobic and resistance exercise program (COMB) for sleep quality (-19%) and sleep disturbance (-17.3%). The meta-analysis results showed significant improvement for both sleep quality and insomnia (d = 0.28, SE: 0.11, Z = 2.51, p < 0.01, 95% CI: 0.07-0.49 and d = 0.43, SE: 0.20, Z = 2.18, p = 0.029, 95% CI: 0.07-0.49, respectively).

CONCLUSION

RT interventions of 60 minutes per session, performed 2-3 times a week for 12 weeks, with exercise intensity ranging from 60% to 80% of one-repetition maximum can be administered to cancer survivors, aiming to improve sleep outcomes.

Effects of Supplementation with Microalgae Extract from Phaeodactylum tricornutum (Mi136) to Support Benefits from a Weight Management Intervention in Overweight Women

BACKGROUND

Microalgae like Phaeodactylum tricornutum (PT) contain the carotenoid, fucoxanthin, which has been purported to promote fat loss, lower blood lipids, and improve glucose management. This study examined whether dietary supplementation with microalgae extracts from PT containing 4.4 mg/d of fucoxanthin affects changes in body composition or health markers in overweight women during an exercise and diet intervention.

MATERIALS AND METHODS

A total of 37 females (28.6 ± 7.9 years, 80.2 ± 14.9 kg, 29.6 ± 3.8 kg/m², 41.4 ± 4.2% fat) fasted for 12 h, donated a fasting blood sample, completed health and mood state inventories, and undertook body composition, health, and exercise assessments. In a counterbalanced, randomized, and double-blind manner, participants ingested a placebo (PL), or microalgae extract of Phaeodactylum tricornutum standardized to 4.4 mg of fucoxanthin (FX) for 12 weeks while participating in a supervised exercise program that included resistance-training and walking (3 days/week) with encouragement to accumulate 10,000 steps/day on remaining days of the week. The diet intervention involved reducing energy intake by about -300 kcal/d (i.e., ≈1400-1600 kcals/d, 55% carbohydrate, 30% fat, 15% protein) to promote a -500 kcal/d energy deficit with exercise. Follow-up testing was performed at 6 and 12 weeks. A general linear model (GLM) with repeated measures statistical analysis was used to analyze group responses and changes from baseline with 95% confidence intervals.

RESULTS

Dietary supplementation with microalgae extract from PT containing fucoxanthin for 12 weeks did not promote additional weight loss or fat loss in overweight but otherwise healthy females initiating an exercise and diet intervention designed to promote modest weight loss. However, fucoxanthin supplementation preserved bone mass, increased bone density, and saw greater improvements in walking steps/day, resting heart rate, aerobic capacity, blood lipid profiles, adherence to diet goals, functional activity tolerance, and measures of quality of life. Consequently, there appears to be some benefit to supplementing microalgae extract from PT containing fucoxanthin during a diet and exercise program. Registered clinical trial #NCT04761406.

The Effect of Resistance Training with Outdoor Fitness Equipment on the Body Composition, Physical Fitness, and Physical Health of Middle-Aged and Older Adults: A Randomized Controlled Trial

This study examined the effect of outdoor-fitness-equipment-based resistance training on the health parameters of middle-aged and older adults, as well as analyzing the effect of age on the results found. A total of 149 volunteers were randomly assigned to the training (TG) and control (CG) groups. The TG performed two weekly sessions of resistance training for 8 weeks using outdoor fitness equipment, while the CG continued with their regular daily activities. Body composition was measured using DXA, and the maximal isometric voluntary contraction in knee extension, elbow flexion, and hand grip were assessed, along with the 4 m walk test, the Timed Up and Go Test, and the Short Form 36 Health Survey Questionnaire. The TG showed a significant increase in the lean mass index (p = 0.002) and maximal isometric voluntary contraction in both legs (p < 0.001) and arms (p < 0.001), as well as in physical functioning (p < 0.001) and the role physical dimension (p = 0.006) of the Short Form 36 Health Survey Questionnaire, compared to the CG, which showed a decrease in all these variables. In addition, the TG showed a greater decrease in fat mass (p < 0.001), fat mass index (p = 0.003), and the Timed Up and Go Test (p < 0.001) than the CG. Age conditioned the evolution of most of the variables analyzed (p < 0.05). In conclusion, resistance training with outdoor fitness equipment may be useful for improving the health of middle-aged and older adults, although age is a factor that could influence the adaptations found.

The Interconnection Between Muscle and Bone: A Common Clinical Management Pathway

Often observed with aging, the loss of skeletal muscle (sarcopenia) and bone (osteoporosis) mass, strength, and quality, is associated with reduced physical function contributing to falls and fractures. Such events can lead to a loss of independence and poorer quality of life. Physical inactivity (mechanical unloading), especially in older adults, has detrimental effects on the mass and quality of bone as well as muscle, while increases in activity (mechanical loading) have positive effects. Emerging evidence suggests that the relationship between bone and muscle is driven, at least in part, by bone-muscle crosstalk. Bone and muscle are closely linked anatomically, mechanically, and biochemically, and both have the capacity to function with paracrine and endocrine-like action. However, the exact mechanisms involved in this crosstalk remain only partially explored. Given older adults with lower bone mass are more likely to present with impaired muscle function, and vice versa, strategies capable of targeting both bone and muscle are critical. Exercise is the primary evidence-based prevention strategy capable of simultaneously improving muscle and bone health. Unfortunately, holistic treatment plans including exercise in conjunction with other allied health services to prevent or treat musculoskeletal disease remain underutilized. With a focus on sarcopenia and osteoporosis, the aim of this review is to (i) briefly describe the mechanical and biochemical interactions between bone and muscle; (ii) provide a summary of therapeutic strategies, specifically exercise, nutrition and pharmacological approaches; and (iii) highlight a holistic clinical pathway for the assessment and management of sarcopenia and osteoporosis.

Associations of dietary oxidative balance score with femur osteoporosis in postmenopausal women: data from the National Health and Nutrition Examination Survey

We used data from the NHANES to explore associations of DOBS with femur BMD and osteoporosis in postmenopausal women. We found that DOBS was positively associated with femur BMD and negatively associated with the risk of osteoporosis in postmenopausal women.

PURPOSE

The study aimed to investigate the relationship between dietary oxidative balance score (DOBS) and the risk of osteoporosis in American postmenopausal women.

METHODS

A total of 3043 participants were included in this study. The linear relationship between DOBS and femur BMD was evaluated using a weighted multivariate linear regression model. The association between DOBS and the risk of osteoporosis was assessed using a weighted logistic regression model, with odds ratios (ORs) and 95% confidence intervals (CIs) calculated. Moreover, the relationship was further characterized through smooth curve fitting (SCF) and weighted generalized additive model (GAM) analysis.

RESULTS

After adjusting for all covariates, the weighted multivariable linear regression models showed a positive correlation between DOBS and femur BMD. Moreover, the weighted logistic regression model demonstrated that compared to the first tertile of DOBS, the highest tertile of DOBS was significantly associated with a lower risk of osteoporosis, with ORs of 0.418 (95% CI, 0.334, 0.522) for individuals under the age of 70 and 0.632 (95% CI, 0.506, 0.790) for individuals aged 70 or above. Similar trends were also observed in SCF and GAM models.

CONCLUSION

The present study indicated that postmenopausal women with a higher DOBS have a lower risk of femur osteoporosis. This finding may highlight the potential protective role of an antioxidant-rich diet for the bones of the postmenopausal population. Moreover, DOBS may also be a valuable tool in identifying individuals with osteoporosis. Screening and early intervention for osteoporosis may be essential for postmenopausal women with low DOBS.

Nutritional strategies to optimise musculoskeletal health for fall and fracture prevention: Looking beyond calcium, vitamin D and protein

Falls and osteoporotic fractures are a major public health problem, particularly among older adults. A third of individuals aged 65 years and over fall at least once each year, with up to 20 % of these resulting in serious injury, including fracture. In conjunction with regular exercise, the importance of diet for musculoskeletal health has largely focused upon calcium, vitamin D, and protein, particularly in the context of preventing falls and fractures. Whilst there is evidence for the benefits of these nutrients for musculoskeletal health, other aspects of the diet remain largely underexplored. For example, vegetables are rich sources of macro- and micronutrients that are essential for muscle function and bone health, which are key factors in the prevention of falls and fractures. Recent work has highlighted the importance of nutrients such as vegetable-derived nitrate and vitamin K1 in optimising muscle strength, physical function, and bone quality. In the context of dietary patterns, vegan/plant-based diets have recently gained popularity due to perceived health benefits, animal welfare, or to tackle climate change. The elimination and/or substitution of animal-based products for plant foods (without careful planning and/or expert dietary guidance) could, however, have long-term negative musculoskeletal consequences; a trend uncovered by recent evidence. Within the overarching theme of nutrition for fall and fracture prevention in older populations, the aim of this review is to (i) summarise the current evidence for calcium, vitamin D and protein; (ii) describe the importance of vegetables and selected nutrients, such as nitrate and vitamin K1, for muscle function and bone structural integrity; and (iii) highlight current evidence around different dietary patterns (e.g., plant-based, diet quality, data driven approaches) and their impact on musculoskeletal health.

Effects of a self-determination theory-based physical activity programme for postmenopausal women with rheumatoid arthritis: A randomized controlled trial

AIMS

The study aimed to develop and evaluate the effects of a self-determination theory-based, nurse-led, physical activity programme for postmenopausal women with rheumatoid arthritis.

METHODS

Between December 2019 and April 2020, this randomized controlled trial recruited 62 postmenopausal women with rheumatoid arthritis from a university-affiliated hospital in South Korea. The intervention group participated in a self-determination theory-based, nurse-led, physical activity programme that consisted of Tai Chi-based physical activity, a supportive psychosocial strategy, and interactive counselling for 16 weeks, and the control group continued to undergo their usual care.

RESULTS

There were statistically significant group-by-time interactions in physical activity and perceived sarcopenia, which favoured the intervention group. Additionally, the intervention group showed significant improvements in the perceived therapeutic efficacy of physical activity, grip strength, walking speed, disease activity score, and health-related quality of life.

CONCLUSIONS

The programme developed in this study can be an effective and feasible approach for postmenopausal women with rheumatoid arthritis in improving physical activity, selected osteosarcopenic outcomes, and health-related quality of life. Further research is required to investigate the long-term effects of this theory-based programme for postmenopausal women in diverse settings.

Resistance training alters body composition in middle-aged women depending on menopause - A 20-week control trial

BACKGROUND

Resistance training (RT) is effective in counteracting the age- and menopause-related loss of muscle mass (MM) and strength in middle-aged women (40-60 years). Research on RT with free weights is limited in pre- and post-menopausal women. Based on this, a 20-week training intervention was conducted with this population to investigate the effects of systematic RT with free weights on strength capacity and body composition.

METHOD

Forty-one healthy women (52.0 ± 3.6 years) participated in this study. After 10-week control phase (no RT, T0-T1) followed by a 10-week intervention phase (T1-T2) with RT twice a week and 6-8 sets of each muscle per week. Subjects were randomly assigned to a low-intensity (50% 1-RM) or moderate-intensity (75% 1-RM) RT group and divided into pre-menopausal and post-menopausal according to their hormone profile. Fat-free mass (FFM), MM, fat mass (FM), muscle thickness (Vastus lateralis (VL), Rectus femoris (RF), Triceps brachii (TB)), grip strength, 1-RM squat and bench press were assessed before and after each phase. Statistical analysis was performed using a linear mixed model to account for fixed (time and group) and random (individual) effects.

RESULTS

A total of 31 women successfully completed the study. No injuries occurred during the intervention. Significant increases in 1-RM squat and bench press were observed in all groups. No interaction effect was observed for the strength parameters. In pre-menopausal women, FFM, MM and RF muscle thickness increased significantly, while VL showed a trend. These effects were not present in post-menopausal women regardless of RT intensity.

CONCLUSION

RT with free weight is safe and effective for middle-aged women to increase 1-RM. Hypertrophy effects were found exclusively in pre-menopausal women. To achieve hypertrophy and/or body composition changes in post-menopausal women, larger training volumes (> 6-8 sets/muscle per week) are likely required.

Exercise metabolism and adaptation in skeletal muscle

Viewing metabolism through the lens of exercise biology has proven an accessible and practical strategy to gain new insights into local and systemic metabolic regulation. Recent methodological developments have advanced understanding of the central role of skeletal muscle in many exercise-associated health benefits and have uncovered the molecular underpinnings driving adaptive responses to training regimens. In this Review, we provide a contemporary view of the metabolic flexibility and functional plasticity of skeletal muscle in response to exercise. First, we provide background on the macrostructure and ultrastructure of skeletal muscle fibres, highlighting the current understanding of sarcomeric networks and mitochondrial subpopulations. Next, we discuss acute exercise skeletal muscle metabolism and the signalling, transcriptional and epigenetic regulation of adaptations to exercise training. We address knowledge gaps throughout and propose future directions for the field. This Review contextualizes recent research of skeletal muscle exercise metabolism, framing further advances and translation into practice.

Influence of resistance training on muscle architecture in older adults: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Resistance training (RT) consists of planned exercise programs to increase muscle strength capacity through neural and structural adaptations, such as changes in the geometric arrangement of muscle fibers. This study aimed to analyze the influence of RT on muscle architecture in older people.

METHODS

This PROSPERO-registered systematic review and meta-analysis (identification number CRD42022340477) followed the PRISMA guidelines. Four electronic databases were searched for eligible randomized controlled trials (RCTs) that observed older individuals submitted to RT programs that reported muscle architecture outcomes.

RESULTS

Seventeen RCTs met the eligibility criteria with a total of 488 participants. The main results of the meta-analysis showed that RT interventions had a significant effect on the thickness of the medial gastrocnemius (SMD = 0.12; 95% CI: - 0.07 to 0.17; p < 0.00001; I2 = 0%).

CONCLUSION

Based on available evidence, studies included in this review showed improvement in maximum isometric force, pennation angle, fascicle length, thickness, and muscle activation after RT interventions. In turn, the meta-analysis suggested a potential for improving the thickness of the medial gastrocnemius after the intervention. However, any clinical implications drawn from the analyses should be interpreted with caution, as these findings are substantially limited due to a low number of included studies and a potential heterogeneity between studies.

Exercise and cardiovascular health: A state-of-the-art review

Cardiovascular (CV) disease (CVD) is the leading cause of global morbidity and mortality, and low levels of physical activity (PA) is a leading independent predictor of poor CV health and associated with an increased prevalence of risk factors that predispose to CVD development. In this review, we evaluate the benefits of exercise on CV health. We discuss the CV adaptations to exercise, focusing on the physiological changes in the heart and vasculature. We review the impact and benefits of exercise on specific CV prevention, including type II diabetes, hypertension, hyperlipidemia, coronary artery disease, and heart failure, in addition to CVD-related and all-cause mortality. Lastly, we evaluate the current PA guidelines and various modes of exercise, assessing the current literature for the effective regimens of PA that improve CVD outcomes.

Intensity-dependent cardiopulmonary response during and after strength training

Whereas cardiopulmonary responses are well understood in endurance training, they are rarely described in strength training. This cross-over study examined acute cardiopulmonary responses in strength training. Fourteen healthy male strength training-experienced participants (age 24.5 ± 2.9 years; BMI 24.1 ± 2.0 kg/m²) were randomly assigned into three strength training sessions (three sets of ten repetitions) with different intensities (50%, 62,5%, and 75% of the 3-Repetition Maximum) of squats in a smith machine. Cardiopulmonary (impedance cardiography, ergo-spirometry) responses were continuously monitored. During exercise period, heart rate (HR 143 ± 16 vs. 132 ± 15 vs. 129 ± 18 bpm, respectively; p < 0.01; η²_p 0.54) and cardiac output (CO: 16.7 ± 3.7 vs. 14.3 ± 2.5 vs. 13.6 ± 2.4 l/min, respectively; p < 0.01; η²_p 0.56) were higher at 75% of 3-RM compared to those at the other intensities. We noted similar stroke volume (SV: p = 0.08; η²_p 0.18) and end-diastolic volume (EDV: p = 0.49). Ventilation (V_E) was higher at 75% compared to 62.5% and 50% (44.0 ± 8.0 vs. 39.6 ± 10.4 vs. 37.6 ± 7.7 l/min, respectively; p < 0.01; η²_p 0.56). Respiration rate (RR; p = .16; η²_p 0.13), tidal volume (VT: p = 0.41; η²_p 0.07) and oxygen uptake (VO₂: p = 0.11; η²_p 0.16) did not differ between intensities. High systolic and diastolic blood pressure were evident (62.5% 3-RM 197 ± 22.4/108.8 ± 13.4 mmHG). During the post-exercise period (60 s), SV, CO, V_E, VO_2, and VCO₂ were higher (p < 0.01) than during the exercise period, and the pulmonary parameters differed markedly between intensities (V_E p < 0.01; RR p < 0.01; VT p = 0.02; VO₂ p < 0.01; VCO₂ p < 0.01). Despite the differences in strength training intensity, the cardiopulmonary response reveals significant differences predominantly during the post-exercise period. Intensity-induced breath holding induces high blood pressure peaks and cardiopulmonary recovery effects after exercise.

Effects of home-based bodyweight squat training on neuromuscular properties in community-dwelling older adults

BACKGROUND

It is important to investigate neural as well as muscle morphological adaptations to evaluate the effects of exercise training on older adults.

AIMS

This study was aimed to investigate the effects of home-based bodyweight squat training on neuromuscular adaptation in older adults.

METHODS

Twenty-five community-dwelling older adults (77.7 ± 5.0 years) were assigned to squat (SQU) or control (CON) groups. Those in the SQU group performed 100 bodyweight squats every day and the others in the CON group only performed daily activities for 4 months. Maximum knee extension torque and high-density surface electromyography during submaximal contraction were assessed. Individual motor units (MUs) were identified and divided into relatively low or high-recruitment threshold MU groups. Firing rates of each MU group were calculated. The muscle thickness and echo intensity of the lateral thigh were assessed using ultrasound. As physical tests, usual gait speed, timed up and go test, grip strength, and five-time chair stand test were performed.

RESULTS

While no improvements in muscle strength, muscle thickness, echo intensity, or physical tests were noted in either group, the firing rate of relatively low recruitment threshold MUs significantly decreased in the SQU group after intervention.

CONCLUSIONS

These results suggest that low-intensity home-based squat training could not improve markedly muscle strength or physical functions even if high-repetition and high frequency exercise, but could modulate slightly neural activation in community-dwelling older adults.

Rehabilitation of Older Adults with Sarcopenia: From Cell to Functioning

The 20th and 21st centuries have witnessed a substantial increase in human life expectancy and in the number of men and women aged 60 years and older. Aging is associated with a large number of health conditions, including sarcopenia, which has been the subject of important research in the past 30 years. Sarcopenia is characterized by an age-related loss of muscle mass, weakness, and impaired physical performance. The condition can be diagnosed with a combination of measurements of these three elements. The precise definition of sarcopenia and the selection of optimal assessment methods have changed significantly in the past 20 years; nonetheless, the prevalence of sarcopenia in the general older population is in the range of 5-15%. Molecular and cellular events at the muscle cell level impact the size and quality of muscles (force adjusted for size). The active and passive mechanical properties of single muscle fibers are altered by changes in the structure and function of various cellular elements. Systemic factors such as inflammation, loss of hormonal influence, and deleterious lifestyle choices also contribute to sarcopenia. The consequences of sarcopenia include many adverse effects such as impairments in activities of daily living, falls, loss of independence, and increased mortality. Several rehabilitative interventions have been tested, and the safest and most effective is the use of progressive resistance exercise. An increase in dietary protein intake has synergistic effects. Future research should focus on a consensus definition of sarcopenia, identification of the best assessment methods, understanding of biological mechanisms, and testing of innovative interventions.

'A Lot of People Just Go for Walks, and Don't Do Anything Else': Older Adults in the UK Are Not Aware of the Strength Component Embedded in the Chief Medical Officers' Physical Activity Guidelines-A Qualitative Study

Strength recommendations have been embedded within the UK's Chief Medical Officers' physical activity guidelines since 2011. In 2019, they were given a more prominent position in the accompanying infographic. However, there is limited evidence that these recommendations have been successful in their population-wide dissemination. This study aimed to explore the engagement of community-dwelling older adults with the guidelines to date and to gain a nuanced understanding of the awareness, knowledge, and action that older adults take to fulfil strength recommendations. A total of fifteen older adults living in the UK participated in one online interview. A general inductive approach was used to generate themes from the data. There were four major themes that were found. 1. The strength component of the physical activity guidelines, 2. Barriers, 3. Motivators, and 4. Solutions. No participants were aware of the strength guidelines. When they were asked what activities they used to fulfil the 'build strength on at least two-days-per-week' criteria, walking, yoga, and Pilates were the most common responses. Ageism and strength training misconceptions were major barriers to participation in strengthening exercise. Older adults were much less aware of the benefits of building strength and strength training participation when compared to aerobic activities, so motivators to participation were generally not specific to strength training. Finally, there are several ways that practitioners can overcome the barriers to strength training participation. Solutions to improving the uptake and adherence to strength training participation are likely to be more successful when they include opportunities for social interaction, ability-appropriate challenge, and provide both short- and long-term benefits.