The physiological impact of high?intensity interval training in octogenarians with comorbidities

BackgroundDeclines in cardiorespiratory fitness (CRF) and fat-free mass (FFM) with age are linked to mortality, morbidity and poor quality of life. High-intensity interval training (HIIT) has been shown to improve CRF and FFM in many groups, but its efficacy in the very old, in whom comorbidities are present is undefined. We aimed to assess the efficacy of and physiological/metabolic responses to HIIT, in a cohort of octogenarians with comorbidities (e.g. hypertension and osteoarthritis).MethodsTwenty-eight volunteers (18 men, 10 women, 81.2 ± 0.6 years, 27.1 ± 0.6 kg·m−2) with American Society of Anaesthesiology (ASA) Grade 2–3 status each completed 4 weeks (12 sessions) HIIT after a control period of equal duration. Before and after each 4 week period, subjects underwent body composition assessments and cardiopulmonary exercise testing. Quadriceps muscle biopsies (m. vastus lateralis) were taken to quantify anabolic signalling, mitochondrial oxidative phosphorylation, and cumulative muscle protein synthesis (MPS) over 4-weeks.ResultsIn comorbid octogenarians, HIIT elicited improvements in CRF (anaerobic threshold: +1.2 ± 0.4 ml·kg−1·min−1, P = 0.001). HIIT also augmented total FFM (47.2 ± 1.4 to 47.6 ± 1.3 kg, P = 0.04), while decreasing total fat mass (24.8 ± 1.3 to 24 ± 1.2 kg, P = 0.0002) and body fat percentage (33.1 ± 1.5 to 32.1 ± 1.4%, P = 0.0008). Mechanistically, mitochondrial oxidative phosphorylation capacity increased after HIIT (i.e. citrate synthase activity: 52.4 ± 4 to 67.9 ± 5.1 nmol·min−1·mg−1, P = 0.005; membrane protein complexes (C): C-II, 1.4-fold increase, P = 0.002; C-III, 1.2-fold increase, P = 0.03), as did rates of MPS (1.3 ± 0.1 to 1.5 ± 0.1%·day−1, P = 0.03). The increase in MPS was supported by up-regulated phosphorylation of anabolic signalling proteins (e.g. AKT, p70S6K, and 4E-BP1; all P < 0.05). There were no changes in any of these parameters during the control period. No adverse events were reported throughout the study.ConclusionsThe HIIT enhances skeletal muscle mass and CRF in octogenarians with disease, with up-regulation of MPS and mitochondrial capacity likely underlying these improvements. HIIT can be safely delivered to octogenarians with disease and is an effective, time-efficient intervention to improve muscle mass and physical function in a short time frame

Relationship between employees\' safety climate and safety performance with respect to mediating effect of safety knowledge and safety motivation in Sarcheshmeh copper complex

Introduction: The present study aimed to investigate the relationship between safety climate and safety performance with respect to the mediating effect of safety knowledge and safety motivation.   Material and method: The study population was a sample of 354 subjects chosen by Cochran formula among all 4252 employee in Sarcheshmeh copper complex in Rafsanjan, 2015. The participants were selected according to stratified random sampling. Data collection was done by four questionnaires (safety climate, safety knowledge, safety motivation, and safety performance).The Cronbach's alpha and composite reliability (CR) were used to evaluate the reliability of the study tools and the coefficient of all variables were acceptable with values of higher than 0.8. Moreover, validity of the questionnaires was confirmed by convergent validity and divergent validity, R-square, effect size (f2), and Q2 criterion. The Average Variance Extracted (AVE) was greater than 0.4 which is relatively acceptable. The obtained data were analyzed using SmartPLS software.    Result: Kolmogorov-Smirnov test was used to investigate the normality status of variables distribution. Furthermore, Structural Equations Method (SEM) was adopted to test the research hypotheses.The results confirmed all the research hypothesis and showed safety climate direct effect on safety performance. Moreover, safety motivation and safety knowledge have mediating role in the relationship between safety climate and safety performance. Safety motivation can also mediate the relationship between safety knowledge and safety performance.   Conclosion: Overall, it is recommended to improve safety climate, considering its influencing components. Employees' safety knowledge and safety motivation should also be promoted. Additionally, it is recommended to determine other personal and organizational parameters and include them into the model. By determining the mediating variables, their role in the safety performance can be investigated

Biochemical pathways of sarcopenia and their modulation by physical exercise: A narrative review

Aging is a complex process characterized by progressive multisystem derangement predisposing individuals to increased risk of developing negative health outcomes. Sarcopenia is the age-related decline of muscle mass and function/strength and represents a highly prevalent correlate of aging. Several factors have been indicated to play a role in the onset and progression of sarcopenia; however, its pathophysiology is still unclear. Physical exercise is to date one of the few strategies able to improve muscle health in old age through multiple metabolic and transcriptional adaptations. Although the benefits of different exercise modalities on the function and structure of aged myocytes is acknowledged, the cellular and molecular mechanisms underlying such effects are not yet fully identified. Here, we briefly overview the current knowledge on the biochemical pathways associated with the onset and progression of sarcopenia. We subsequently describe the effects of exercise on relevant signaling pathways involved in sarcopenia pathophysiology

Healthy ageing: The natural consequences of good nutrition\u2014A conference report

Many countries are witnessing a marked increase in longevity and with this increased lifespan and the desire for healthy ageing, many, however, suffer from the opposite including mental and physical deterioration, lost productivity and quality of life, and increased medical costs. While adequate nutrition is fundamental for good health, it remains unclear what impact various dietary interventions may have on prolonging good quality of life. Studies which span age, geography and income all suggest that access to quality foods, host immunity and response to inflammation/infections, impaired senses (i.e., sight, taste, smell) or mobility are all factors which can limit intake or increase the body\u2019s need for specific micronutrients. New clinical studies of healthy ageing are needed and quantitative biomarkers are an essential component, particularly tools which can measure improvements in physiological integrity throughout life, thought to be a primary contributor to a long and productive life (a healthy \u201clifespan\u201d). A framework for progress has recently been proposed in a WHO report which takes a broad, person-centered focus on healthy ageing, emphasizing the need to better understand an individual\u2019s intrinsic capacity, their functional abilities at various life stages, and the impact by mental, and physical health, and the environments they inhabit. \ua9 The Author(s) 2018