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Abstract: Ageing affects mitochondrial integrity in skeletal muscle, and physical inactivity may further exacerbate these changes. Although mitochondrial alterations are documented in ageing and disuse independently, how disuse impacts the mitochondrial phenotype in older populations remains unclear. This work aimed to characterise how physical inactivity impacts mitochondrial function, morphology and gene expression in the skeletal muscle of older adults. Ten healthy older men (65+ years) underwent 10 days of bed rest. Skeletal muscle biopsies were collected before and after bed rest to assess mitochondrial respiration (high-resolution respirometry), H2O2 emission, mitochondrial protein expression, morphology and volume density (electron microscopy) and transcriptomic profile. Ten days of inactivity increased mitochondrial reactive oxygen species (ROS) emission under non-phosphorylating conditions but did not impair oxidative phosphorylation (OXPHOS) capacity, indicating preserved respiratory efficiency. Consistently, mitochondrial respiratory complex and supercomplex protein abundance were unchanged. Mitochondrial mass decreased, as shown by reduced mitochondrial volume density. Reduced dynamin-like protein 1 (DRP1) phosphorylation at serine 637 was observed, whereas other mitochondrial fission and fusion protein levels remained unchanged. Mitochondrial morphology remained unaltered. Transcriptomic analysis revealed >3000 differentially expressed genes, characterised by downregulation of oxidative phosphorylation genes alongside altered mitophagy, antioxidant and oxidoreductase pathways. In summary, 10-day bed rest increased mitochondrial ROS emission and reduced mitochondrial mass in older skeletal muscle despite preserved respiratory function, indicating that elevated ROS production occurs upstream of respiratory dysfunction and is potentially linked to impaired antioxidant defence and ROS clearance. These findings suggest that preserving redox balance during inactivity may be a key strategy to maintain muscle health and functional independence in ageing populations.
Keywords: skeletal muscle, mitochondria, older adults, physical inactivity, mitochondrial respiration
Published in DiRROS: 11.09.2026; Views: 56; Downloads: 40
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Abstract: Introduction: Frailty is a dynamic condition associated with increased vulnerability to adverse health outcomes in older adults. While previous research has primarily focused on deficit-based mental health factors, such as depression and loneliness, less is known about the role of positive mental health determinants, including wellbeing, resilience and social connectedness, in the development and progression of frailty. Understanding both risk and protective factors is essential for informing public health strategies aimed at promoting healthy aging. This study aims to examine the longitudinal relationship between mental health and frailty in a nationally sampled population of adults aged 50 years and older in Slovenia.Methods and analysis: This longitudinal observational cohort study will collect data at four time points over a 2-year period (January 2026-March 2028). A stratified random sample of community-dwelling adults aged 50–84 years will be drawn from the national population registry, with 5,000 individuals invited to participate in the first wave. Frailty, mental health and a set of social, psychological, and health-related factors will be assessed. Data will be analyzed using a combination of descriptive, inferential and longitudinal statistical methods to examine associations between frailty and mental health over time. Potential explanatory factors will also be explored within the longitudinal framework, and additional analyses will assess the impact of attrition. 1 Introduction
Keywords: frailty, adverse health outcomes, older adults, healthy aging
Published in DiRROS: 14.07.2026; Views: 273; Downloads: 119
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Abstract: Background: Muscle fat fraction (MFF) obtained through magnetic resonance imaging (MRI) is the gold standard for assessing muscle quality, but it is expensive and time consuming. Portable methods to examine muscles such as tensiomyography (TMG) are emerging and could enable broader screening. This study aims to examine associations between TMG-derived muscle contractile parameters and MFF in older adults with and without sarcopenia. Methods: A sample of 51 Slovenian older adults (53% females) were scanned with Dixon MRIs to evaluate muscle MFF and contractile parameters were assessed with TMG estimating delay time (Td), maximal displacement (Dm) and radial contraction velocity (Vc). Right leg vastus lateralis (VL) and biceps femoris (BF) were analyzed. Sarcopenia was defined using both European Working Group on Sarcopenia in Older People (EWGSOP2) and Sarcopenia Definition and Outcomes Consortium (SDOC) criteria. Regression models adjusted for age and sex were used to assess associations between TMG-derived contractile parameters and MFF. Results: Age- and sex-adjusted models revealed associations between increased MFF and reduced Dm (R2 = .29, p = .003) and Vc (R2 = .32, p = .002) for the VL. SDOC-classified sarcopenic individuals showed increased VL MFF (27.2% vs 22.5%, p = .019),while EWGSOP2 classified sarcopenia displayed no differences. Discussion: The study reveals that increased MFF is associated with reduced muscle contractility in VL. MFF differs between sarcopenic and non-sarcopenic groups using only SDOC criteria. Since the TMG Dm increase is regularly found in atrophic muscles after bed rest, in sarcopenic muscle MFF explains lowering of the Dm, highlighting the TMG potential for early detection of changes in aging muscle.
Keywords: sarcopenia, contractile parameters, tensiomyography, muscle fat fraction, muscle function, older adults
Published in DiRROS: 23.03.2026; Views: 417; Downloads: 337
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Abstract: Background: Sarcopenia, the progressive decline in skeletal muscle mass and function, is a major public health concern linked to falls, hospitalization and loss of independence among older adults. Initially defined by reduced muscle mass, later also by reduced muscle strength and function, it is now recognized that standard diagnostic tools do not fully capture complexity of sarcopenia. Tensiomyography (TMG) is a non-invasive method that assesses skeletal muscle contractile parameters, which undergo change with aging and sarcopenia. The aims of this exploratory study are to determine whether TMG could be a method for contractile parameters assessment in sarcopenia classification and to evaluate the relationship between TMG-derived parameters and sarcopenia classification tests. Methods: We included 654 older adults (70.6% women) and included demographics, sarcopenia classification (EWGSOP2, SDOC), muscle strength (handgrip strength, five sit-to-stand), TMG of three leg muscles, muscle mass (bioimpedance), and physical performance (gait speed, timed up-and-go). MANOVA was used to analyze contractile properties and due to low agreement between classifications, we used both classifications. A partial correlation for each sex was conducted to determine the associations between sarcopenia classification tests and TMG-derived parameters of delay time (Td), contraction time (Tc), radial displacement (Dm) and contraction velocity (Vc), controlling for age. Results: One-way MANOVA confirmed difference between sarcopenic and nonsarcopenic participants according to EWGSOP2 and SDOC classifications in TMG-derived contractile parameters in all three muscles, Td was consistently longer and Dm consistently lower in sarcopenic individuals. Post-hoc univariate tests further demonstrated specific differences due to sarcopenia presence. Ageadjusted partial correlations were weak to moderate, ranging between −0.430 and 0.369. Conclusion: Sarcopenic individuals exhibited longer Td and Tc, and smaller Dm, though not consistently across all muscles. Td was longer in all three muscles, reflecting electromechnical delays linked to aging. Dm was consistently lower, suggesting increased muscle stiffness. Correlations between TMG parameters and sarcopenia classification tests indicated that shorter Td and Tc, higher Dm, and greater Vc were associated with higher muscle volume, muscle strength and performance. The findings indicate that TMG parameters may be associated with neuromuscular degeneration and sarcopenia, supporting further exploration of muscle- and sex-specific differences.
Keywords: tensiomyography, muscle function, older adults, sarcopenia, seniors
Published in DiRROS: 04.02.2026; Views: 797; Downloads: 378
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Abstract: Background and objectives This is a protocol for a living systematic review and meta-analysis. This review will assess the effects of state-of-the-art exercise interventions designed to promote functional mobility. Therefore, after identifying all potential interventions, we will use the F.I.T.T. principles (frequency, intensity, time, type) as well as the physical and health status of the participants as moderators to analyse the mechanisms for the positive benefits of exercise interventions. The main research questions are: Which exercise types are most beneficial for improving functional mobility in various populations of older adults? Which physical exercise characteristics in terms of frequency, intensity, time and duration will achieve the greatest benefit in terms of the defined outcomes, i.e, the functional mobility of older adults? Methods The systematic literature research according to PRISMA guidelines will search databases like MEDLINE, APA Psych-Info and Web of Science. Inclusion criteria are: healthy older people ≥ 50 years, randomized-controlled trials including exercise intervention and a walking or mobility assessments (eg., TUG, SPPB) as an outcome measure. A preliminary search revealed more than 33,000 hits that will be screened by pairs of independent reviewers. The results will be summarized according to the effects regarding functional mobility and potential dose-response relations via respective meta-analysis. Conclusion The systematic review will comprise the knowledge of the existing literature with regards to the effects of the physical activity interventions compared to an active or inactive control group. We will summarize the effects with respect to the F.I.T.T.. They provide a foundation for structuring an optimal exercise training program. If possible, we will also compare interventions from the different categories (eg. cardiovascular, resistance, motor-coordinative, multicomponent or mind-body exercise) as a network analysis and report the influence of moderator variables. Based on the results evidence-based guidelines following GRADE for physical exercise interventions to improve functional mobility in older adults will be provided. Functional mobility of older adults is a crucial determinant of health and independence. Mobility can reverse or delay age-related health issues and promote independence, while immobility or limitations in mobility (such as difficulty rising from a chair, balance problems, or reduced walking capacity) can cause or increase dependency. This underscores the significance of fostering mobility among the growing population of older adults. The development of tailored exercise programs targeting the independence of older adults is one of the motivators for the improvement of crucial policy action areas described by WHO in the Equity Policy Tool, namely ʻliving conditionsʼ and ʻsocial and human capitalʼ (WHO, 2019). The key outcomes related to functional mobility in older age include gait, walking capacity, and balance. Additionally, aspects of life-space mobility, such as the overall walking distance within the environment, are significant factors that characterize mobility in older adults. Exercise can be seen as a preventive measure, so that, without adequate physical activity levels, the ageing process may be associated with premature development of disease and dysfunction. However, different training types will enhance outcomes of functional mobility via specific pathways. For example, walking capacity has an endurance and a strength component. Accordingly, aerobic training will improve walking capacity by enhancing cardio-respiratory fitness, as shown within different clinical trials with older patient cohorts. Resistance training helps to increase muscle strength in the lower limb, which increases gait stability. However, recent literature reviews showed that a combination of both interventions might be more sufficient to gain most benefits on walking capacity. This review will systematically assess the effects of state-of-the-art exercise interventions designed to promote mobility. The ultimate aim is to provide evidence-based guidelines for the optimal type and dose of exercise to preserve and enhance functional mobility in diverse populations of older adults
Keywords: functional mobility, older adults, exercise programs, systematic review
Published in DiRROS: 10.03.2025; Views: 1170; Downloads: 787
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