Fiogbé, E, Vassimon-Barroso, V, Catai, AM, de Melo, RC, Quitério, RJ, Porta, A, and Takahashi, ACdM. Complexity of knee extensor torque: effect of aging and contraction intensity. J Strength Cond Res 35(4): 1050–1057, 2021—Assessing the knee extensors' torque complexity in older adults is relevant because these muscles are among the most involved in functional daily activities. This study aimed to investigate the effects of aging and isometric contraction intensity on knee extensor torque complexity. Eight young (24 ± 2.8 years) and 13 old adults (63 ± 2.8 years) performed 3 maximal (maximum voluntary contraction [MVC], duration = 10 seconds) and submaximal isometric contractions (SICs, targeted at 15, 30, and 40% of MVC, respectively) of knee extensors. Torque signals were sampled continuously, and the metrics of variability and complexity were calculated basing on the SIC torque data. The coefficient of variation (CV) was used to quantify the torque variability. The torque complexity was determined by calculating the corrected approximate entropy (CApEn) and sample entropy (SampEn) and its normalized versions (NCApEn and NSampEn). Young subjects produced greater isometric torque than older adults, and the CV was similar between both groups except at the highest force level (40% MVC) where young subjects' value was higher. The major novel finding of this investigation was that although the knee extensor torque complexity is reduced in older adults, its relationship with contraction intensity is similar to young subjects. This means that despite the age-related decrease of the interactions between the components of the neuromuscular system, the organization of force control remains preserved in older adults, at least up to just below the force midrange.

Aim Frailty syndrome is related to decreased physiological complexity, functional capacity and cognition. Physical exercise has been suggested to slow down and reverse this syndrome. However, evidence of its effectiveness is not as straightforward as conventionally admitted, as there is a lack of trials with rigorous methodology. The purpose of this study was to describe the Pre‐Frail Multicomponent Training Intervention protocol. Methods Cardiovascular, motor control and neuromuscular systems of pre‐frail older adults will be assessed by measuring the complexity of the output of these systems. Functional capacity and cognition will be assessed by specific tools. A 16‐week training protocol will be carried out on three alternate days, with 60‐min sessions, and combining aerobic, muscle strength, flexibility and balance exercises. The objective of this intervention is to improve the cardiovascular, motor control and neuromuscular systems, as well as functional capacity and cognition of pre‐frail older adults. The assessment of these systems will be carried out using gold standard devices. Results The results of the present study might allow clinical and functional support for the evaluation of the variables analyzed. Conclusion This protocol is easily reproducible and requires low‐cost materials, thus the Pre‐Frail Multicomponent Training Intervention could be a therapeutic strategy for pre‐frail older adults. Geriatr Gerontol Int 2019; 19: 684–689.

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Background: Frailty syndrome is characterized by a marked reduction in physiological reserves and a clinical state of vulnerability to stress. Torque complexity analysis could reveal changes in the musculoskeletal systems that are the result of having the syndrome. Objective: The aim of this study was to evaluate the complexity of submaximal isometric knee extensor torque in frail, pre-frail, and non-frail older adults. A secondary aim was to analyze the torque complexity behavior in different force levels in each group. Methods: A cross-sectional study was conducted. Forty-two older adults were divided into three groups: non-frail (n = 15), pre-frail (n = 15), and frail (n = 12). The data collected included body composition, five times sit-to-stand test, walking speed, and isometric knee extensor torque at 15, 30, and 40% of maximal voluntary contraction. The knee extensor torque variability was evaluated by coefficient of variation, and the torque complexity was evaluated by approximate entropy and sample entropy. Results: The frail group presented a reduction in body mass and peak torque value compared to the non-frail group. Also, the frail group showed worse physical performance (on the five times sit-to-stand test and walking speed) compared to the pre-frail and non-frail groups. In addition, the frail older adults showed reduced torque complexity compared to the non-frail group. Finally, the association between torque complexity and force levels remained similar in all groups. Conclusion: Torque complexity is reduced in the presence of frailty syndrome.

The WAET protocol improved the cardiac autonomic modulation of patients with CAD and can be considered as exercise training strategy in cardiac rehabilitation programs.

Background and Purpose: The identification of altered gait and its progression over time is important to gaining a better understanding of the clinical aspects of mild cognitive impairment (MCI) in older adults. The aim of the present systematic review was to determine changes in gait variables over time among older adults with MCI. Methods: The PubMed, Web of Science, Scopus, and Science Direct databases were searched for relevant articles using the following keywords and Medical Subject Headings: Aged AND “Mild cognitive impairment” AND (gait OR locomotion). A hand search was also performed of the reference lists of the selected articles in an attempt to find additional records. The following were the inclusion criteria: longitudinal studies and clinical trials involving a control group without intervention; samples of individuals 65 years or older; and characterization of gait using a single or dual task. Results and Discussion: The initial search led to the retrieval of 6979 studies, 9 of which met the inclusion criteria. The duration of follow-up among the studies ranged from 6 months to 2 years. Most trials investigated gait speed. Other gait variables were step length, time required to walk a given distance, and mean weekly gait speed. Altered gait progressed in older adults with MCI. The main alterations were gait speed and variability in daily number of steps in follow-up periods lasting more than 1 year. No significant changes in gait variables were found in shorter follow-up periods (up to 6 months). Conclusions: The progression of gait changes in older adults with MCI has been underinvestigated. MCI leads to reduced gait speed in longer follow-up periods. Such information can contribute to the determination of motor interventions for older adults with MCI, especially in the early stages.

Função autonômica cardíaca e nível de atividade física de pacientes com doença arterial coronariana Cardiac autonomic function and level of physical activity in patients with coronary artery disease

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