Search results for "229"
showing 10 items of 1572 documents
Neural Activation During Submaximal Contractions Seems More Reflective of Neuromuscular Ageing than Maximal Voluntary Activation
2016
International audience; This study aimed at testing the hypothesis that differences in neural activation strategy during submaximal but not maximal plantarflexions exist between young and older men. Eleven young men (YM, 26 +/- 4 years) and thirteen old men (OM, 76 +/- 3 years) volunteered for the investigation. Maximal voluntary torque (MVT) was 38.2%, lower (p < 0.001) in OM than in YM, while voluntary activation was equivalent (similar to 97%). The relationship between the interpolated twitch torque and the voluntary torque (IT-VT relationship) was composite (curvilinear + exponential) for both age-groups. However, the OM showed accentuated concavity, as attested by the occurrence of the…
Universal spectral profile and dynamic evolution of muscle activation: A hallmark of muscle type and physiological state
2020
The skeletal muscle is an integrated multicomponent system with complex dynamics of continuous myoelectrical activation of various muscle types across time scales to facilitate muscle coordination among units and adaptation to physiological states. To understand the multiscale dynamics of neuromuscular activity, we investigated spectral characteristics of different muscle types across time scales and their evolution with physiological states. We hypothesized that each muscle type is characterized by a specific spectral profile, reflecting muscle composition and function, that remains invariant over time scales and is universal across subjects. Furthermore, we hypothesized that the myoelectr…
Physical activity, mood and the functioning of daily living
2009
We studied whether factors related to type of sport participated in as young adults and level of and changes in physical activity later in life predict changes in mood as well as functioning during a 6-year follow-up. A cohort of male Finnish former athletes (N = 504), referents (N = 349) was followed up for changes in physical activity, in relation to subsequent self-reported mood and functioning of daily living in 1985, 1995, and 2001. The mean age of the cohort was 68.6 years in 2001. Multinomial logistic regression analysis was used to assess changes in mood and functioning between 1995 and 2001 in relation to baseline values and changes in exposure variables and covariates. A low level…
The involvement of ankle muscles in maintaining balance in the upright posture is higher in elderly fallers
2016
International audience; The purpose of this study was to determine whether the mechanical contribution of ankle muscles in the upright stance differed among young adults (YA) (n = 10, age: similar to 24.3), elderly non-fallers (ENF) (n = 12, age: similar to 77.3) and elderly fallers (EF) (n = 20, age: similar to 80.7). Torque and electromyographic (EMG) activity were recorded on the triceps surae and tibialis anterior during maximum and submaximum contractions in the seated position. EMG activity was also recorded in subjects standing still. Plantar flexor (PF) and dorsal flexor (DF) torques generated in the upright posture were estimated from the torque-EMG relationship obtained during sub…
The effect of resistance training programs on lean body mass in postmenopausal and elderly women: a meta-analysis of observational studies
2021
AbstractAging and menopause are associated with morphological and functional changes which may lead to loss of muscle mass and therefore quality of life. Resistance training (RT) is an effective training mode to increase muscle mass. We reviewed the existing literature to identify studies implementing RT protocols and evaluating muscle hypertrophy exclusively in healthy, postmenopausal and elderly women. Participants’ age range was comprised between 50 and 80 years. The primary outcome observed was muscle hypertrophy. Fat mass was also evaluated, if available. PubMed and Web of Science were the screened database, and original articles written in English and published from 2000 up to 2020 we…
The Effect of Moderate- Versus High-Intensity Resistance Training on Systemic Redox State and DNA Damage in Healthy Older Women
2018
This study investigated effects of a 16-week progressive resistance training program (RTP) with elastic bands at two different intensities on systemic redox state, DNA damage, and physical function in healthy older women. Methods: Participants were randomly assigned to the high-intensity group (HIGH; n = 39), moderate-intensity group (MOD; n = 31), or control group (CG; n = 23). The exercise groups performed an RTP twice a week with three to four sets of 6 (HIGH) or 15 (MOD) repetitions of six overall body exercises at a perceived exertion rate of 8–9 on the OMNI-Resistance Exercise Scale for use with elastic bands. Thiol redox state was determined by reduced glutathione (GSH), oxidized gl…
Quantifying Dynamic Balance in Young, Elderly and Parkinson's Individuals: A Systematic Review
2018
Introduction: Falling is one of the primary concerns for people with Parkinson's Disease and occurs predominately during dynamic movements, such as walking. Several methods have been proposed to quantify dynamic balance and to assess fall risk. However, no consensus has been reached concerning which method is most appropriate for examining walking balance during unperturbed and perturbed conditions, particularly in Parkinson's Disease individuals. Therefore, this systematic review aimed to assess the current literature on quantifying dynamic balance in healthy young, elderly and Parkinson's individuals during unperturbed and perturbed walking. Methods: The PubMed database was searched by ti…
The effect of aquatic exercise on physical functioning in the older adult: a systematic review with meta-analysis
2015
Background ageing and sedentary behaviour cause negative changes in the neuromuscular systems of healthy older adults resulting in a decrease in physical functioning. Exercising in water (aquatic exercise, AE) has been shown to be effective at improving physical functioning in this population; however, no systematic review with meta-analysis has been published. Purpose to investigate the effect of AE on physical functioning in healthy older adults compared to control or land-based exercise (LE) through a systematic review with meta-analysis of randomised controlled trials. Data sources Medline, Embase, Cinahl, PEDro, SPORTDiscus, Web of Science, Cochrane Library, published before 31st Decem…
Physical activity is associated with better global cognition and frontal function in overweight/obese older adults with metabolic syndrome
2019
Background There is epidemiological evidence of an association between the metabolic syndrome (MetS), a cluster of cardiovascular risk factors related to central adiposity and insulin resistance, and cognitive impairment and dementia. On the other hand, there is evidence for a beneficial effect of physical activity on cognitive outcomes in older adult populations. In a cross-sectional study, we evaluated the relationship between aerobic physical activity and cognition in a cohort of overweight/obese older adults with MetS at risk for dementia. Cognitive function was assessed in a subsample of 82 subjects (men 55–75 y; women 60–75 y), with MetS and a BMI ≥27 to < 40 kg/m2 enrolled in the PRE…
Ankle and knee extensor muscle effort during locomotion in young and older athletes : Implications for understanding age-related locomotor decline
2019
AbstractAge-related reduction in muscle force generation capacity is similarly evident across different lower limb muscle groups, yet decline in locomotor performance with age has been shown to depend primarily on reduced ankle extensor muscle function. To better understand why ageing has the largest detrimental effect on ankle joint function during locomotion, we examined maximal ankle and knee extensor force development during a two-leg hopping test in older and young men, and used these forces as a reference to calculate relative operating efforts for the knee and ankle extensors as participants walked, ran and sprinted. We found that, across locomotion modes in both age groups, ankle ex…