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Results 101 - 150 of 1170
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Guenette Jordan A - - 2010
There is evidence that female athletes may be more susceptible to exercise-induced arterial hypoxemia and expiratory flow limitation and have greater increases in operational lung volumes during exercise relative to men. These pulmonary limitations may ultimately lead to greater levels of diaphragmatic fatigue in women. Accordingly, the purpose of this ...
Rasmussen P - - 2010
Maximal exercise may be limited by central fatigue defined as an inability of the central nervous system to fully recruit the involved muscles. This study evaluated whether a reduction in the cerebral oxygen-to-carbohydrate index (OCI) and in the cerebral mitochondrial oxygen tension relate to the ability to generate a maximal ...
Cui Jian - - 2010
The role adenosine plays in evoking the exercise pressor reflex in humans remains controversial. We hypothesized that localized forearm adenosine receptor blockade would attenuate muscle sympathetic nerve activity (MSNA) responses to fatiguing handgrip exercise in humans. Blood pressure (Finometer), heart rate, and MSNA from the peroneal nerve were assessed in ...
Cerri Gabriella - - 2010
OBJECTIVE: Primary biliary cirrhosis (PBC), a female-predominant autoimmune liver disease, is commonly associated with fatigue, a sensation of weariness from physical activity. In healthy subjects, motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) increase in amplitude during fatiguing exercise and decrease after the exercise due to post-contraction cortical ...
Long Joy L - - 2010
STUDY DESIGN: Prospective, single-group, repeated-measures design. OBJECTIVES: To evaluate electromyographic (EMG) signal amplitude in the supraspinatus, infraspinatus, and deltoid muscles during pendulum exercises and light activities in a group of healthy subjects. BACKGROUND: There are numerous rehabilitation protocols used after rotator cuff repair. One of the most commonly used exercises ...
Jones D E J - - 2010
OBJECTIVES: To examine muscle acid handling following exercise in chronic fatigue syndrome (CFS/ME) and the relationship with autonomic dysfunction. DESIGN: Observational study. SETTING: Regional fatigue service. SUBJECTS & INTERVENTIONS: Chronic fatigue syndrome (n = 16) and age and sex matched normal controls (n = 8) underwent phosphorus magnetic resonance spectroscopy ...
Fauth McKenzie L - - 2010
The reliability of electromyographic (EMG) data has been examined for isometric and slow dynamic tasks, but little is known about the repeatability of this data for ballistic movements. The purpose of this study was to examine the within-session, trial-to-trial reliability of a variety of quadriceps and hamstrings muscles during isometric ...
Nijs J J Department of Human Physiology, Faculty of Physical Education & Physiotherapy, Vrije Universiteit Brussel, Brussels, Belgium. - - 2010
Too vigorous exercise or activity increase frequently triggers postexertional malaise in people with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), a primary characteristic evident in up to 95% of people with ME/CFS. The present study aimed at examining whether two different types of exercise results in changes in health status, circulating elastase ...
Hollingsworth Kieren G KG Newcastle Magnetic Resonance Centre, Newcastle University, - - 2010
Upon exercise, primary biliary cirrhosis (PBC) is associated with significant acidosis in peripheral muscle with recovery rate from acidosis strongly associating with fatigue. PBC patients describe particular problems with repeat exercise describing subsequent exercise episodes being limited by perceived effects of the first. We modelled this effect by exploring kinetics ...
Brazaitis Marius - - 2010
We tested the hypothesis that improved physiological symptoms of passively induced heat acclimation (HA) might impair the impact of hyperthermia on central fatigue and consequently cause greater peripheral fatigue. Subjects in the experimental group (7 males and 6 females) completed seven sessions of HA involving passive heating of the lower ...
White Andrea T - - 2010
Chronic fatigue syndrome (CFS) patients often report symptom flare (SF) for >24 h after moderate exercise (post-ex). We hypothesized that SF is linked to increases in circulating cytokines and CD40 Ligand (CD40L). In 19 CFS patients and 17 controls, mental and physical fatigue and pain symptom ratings were obtained together ...
Mileva Katya N - - 2010
This study was conducted to investigate whether the low-frequency (5-Hz) oscillatory vibration-like stimulus, purported to be delivered by exercising with Flexi-bar, acutely affects muscle activation and maximal voluntary contraction (MVC) force. Nine healthy men participated in 2 trials, separated by at least 1 week, during which 4 x 30-second sets ...
Roelands Bart - - 2010
The scientific evidence is reviewed for the involvement of the brain monoamines serotonin, dopamine and noradrenaline (norepinephrine) in the onset of fatigue, in both normal and high ambient temperatures. The main focus is the pharmacological manipulations used to explore the central fatigue hypothesis. The original central fatigue hypothesis emphasizes that ...
Sander Mikael - - 2010
Static isometric exercise increases muscle sympathetic nerve activity (MSNA) and mean arterial pressure, both of which can be maintained at the conclusion of the exercise by occlusion of the arterial supply [postexercise ischemia (PEI)]. To identify the cortical and subcortical sites involved, and to differentiate between central command and reflex ...
Mallor Fermin - - 2010
The purpose of this study was to analyze exercise-induced leg fatigue during a dynamic fatiguing task by examining the shapes of power vs. time curves through the combined use of several statistical methods: B-spline smoothing, functional principal components and (supervised and unsupervised) classification. In addition, granulometric size distributions were also ...
Wilkinson Daniel J - - 2010
This review addresses the ammonia fatigue theory in light of new evidence from exercise and disease studies and aims to provide a view of the role of ammonia during exercise. Hyperammonemia is a condition common to pathological liver disorders and intense or exhausting exercise. In pathology, hyperammonemia is linked to ...
Green Jackson G - - 2010
Isometric contractions, such as occurring during rock climbing, occlude blood flow to the active musculature. The ability to maximize forearm blood flow between such contractions is a likely determinant of intermittent handgrip performance. This study aimed to test the hypothesis that intermittent isometric handgrip performance is improved by 2 common ...
Stone Marcus B - - 2010
Though clinical observations and laboratory data provide some support for the neuromuscular imbalance theory of the genesis of exercise-associated muscle cramps, no direct evidence has been published. The purpose of this study was to determine the effect of local muscle fatigue on the threshold frequency of an electrically induced muscle ...
Hedayatpour N - - 2010
An increase to above-baseline levels of electromyography (EMG) mean power spectral frequency (MPF) has been observed previously during muscle recovery following fatiguing contractions and has been explained by membrane hyperpolarization due to increased activation of the Na+-K+ pump. It is hypothesized that this membrane mechanism is impaired by muscle fiber ...
VanNess J Mark - - 2010
Postexertional malaise (PEM) is a defining characteristic of chronic fatigue syndrome (CFS) that remains a source of some controversy. The purpose of this study was to explore the effects of an exercise challenge on CFS symptoms from a patient perspective. This study included 25 female CFS patients and 23 age-matched ...
Davis J Mark - - 2010
Quercetin, a natural polyphenolic flavonoid substance present in a variety of food plants, has been shown in vitro and in animal studies to have widespread health and performance benefits resulting from a combination of biological properties, including antioxidant and anti-inflammatory activity, as well as the ability to increase mitochondrial biogenesis. ...
Chmura Jan - - 2010
During aerobic exercise with increasing intensities choice reaction time (CRT) progressively shortens up to 60-80% of maximal workload, and then it rapidly increases. The aim of this study was to determine whether workload associated with the shortest CRT operationally called "the psychomotor fatigue threshold" is related to the metabolic response ...
Patterson Sarah A - - 2010
Typical models of stroke rehabilitation usually direct minimal resources for ongoing maintenance beyond discharge. However, there is increasing recognition of the benefits of community-based rehabilitation to maintain physical function and health in frail and disabled clients. A stroke maintenance exercise group was established to provide long-term care for stroke survivors. ...
Arnold Meaghan - - 2010
The primary aim was to find out if exercise reduces cancer-related fatigue in hospitalised oncology patients. Controlled trials of fatigue outcomes after exercise in hospitalised oncology patients were obtained by searching electronic databases. Two reviewers completed data extraction and quality assessment independently. Standardised mean differences and 95% confidence intervals (CI) ...
Ross Emma Z - - 2010
PURPOSE: To examine alterations in muscle contractile properties, cortical excitability, and voluntary activation as a consequence of 20 d of repetitive endurance cycling within a 22-d period. METHODS: Eight well-trained male cyclists completed 20 prolonged cycling stages interspersed by two rest days (days 9 and 17), which replicated the 2007 ...
McBride Jeffrey M - - 2010
The purpose of the current investigation was to assess the effect of an acute bout of whole body vibration (WBV) exercise on muscle force output and motor neuron excitability. Nineteen recreationally trained college-aged males were randomly assigned to a WBV (n = 10) or a sham (S, n = 9) ...
Sato Tomoaki - - 2010
Increased night work is an important issue because of its implications on workers' health, safety and performance. This study examined the effects of brief hourly exercise as a countermeasure against the adverse effects of night work, especially for workers requiring sustained attention while working in a prolonged sitting posture. During ...
Scalise Anna - - 2010
OBJECTIVE: Dopaminergic pathways are most likely involved in the pathophysiology of restless legs syndrome (RLS). In previous investigations, an alteration of cortical excitability was suggested to be related to a dopaminergic dysfunction in RLS. The purpose of our study was to compare practice-dependent plasticity in RLS patients before and after ...
Nybo Lars - - 2010
Exercise-induced hyperthermia is associated with central fatigue as indicated by an impaired ability to sustain maximal motor activation during prolonged voluntary efforts. Therefore, exercise in hot environments challenges not only to the cardiorespiratory and locomotive systems but also to the brain. However, exercise with superimposed hyperthermia is not only a ...
Tseng Benjamin Y - - 2010
Background and Purpose. Post-Stroke Fatigue (PSF) is a prevalent yet commonly neglected issue that impacts daily functions and quality of life in people post-stroke. To date no studies have attempted to validate a clinically-feasible and reliable instrument to quantify PSF. We developed the Visual Analog Fatigue Scale (VAFS) to eliminate ...
Costa Marcelo V MV Group of Study and Research in Neuromuscular System and Exercise, CEFE - State University of Londrina (UEL), PR, - - 2010
Frequency domain analyses of changes in electromyographic (EMG) signals over time are frequently used to assess muscle fatigue. Fourier based approaches are typically used in these analyses, yet Fourier analysis assumes signal stationarity, which is unlikely during dynamic contractions. Wavelet based methods of signal analysis do not assume stationarity and ...
Camata Thiago V TV Group of Study and Research in Neuromuscular System and Exercise, CEFE - State University of Londrina (UEL), PR, Brazil. - - 2010
Frequency domain analyses of changes in electromyographic (EMG) signals over time are frequently used to assess muscle fatigue. Fourier based approaches are typically used in these analyses, yet Fourier analysis assumes signal stationarity, which is unlikely during dynamic contractions. Wavelet based methods of signal analysis do not assume stationarity and ...
Peixoto Luciana Roberta Tenorio LR School of Medicine of the University of Brasília, DF, Brazil. - - 2010
Despite growing interest in the behavior of electromyographic signals during muscle fatigue, few studies investigate fatigue recovery. In this work, we use surface electromyographic signals to determine the recovery time after isometric fatigue of the biceps brachii muscle in 90° flexion of the non-dominant elbow. Sixty volunteers were arranged into ...
de Jesus Igor Ramathur Telles IR Biomedical Engineering Program, COPPE, Federal University of Rio de Janeiro, P. O. Box 68.510, 21941-972, Brazil. - - 2010
The parameters commonly employed for muscular fatigue (MF) analysis, the mean frequency (F(mean)) and median frequency (F(median)) of surface EMG (SEMG) spectra, did not present consistent results for exercises performed at low to moderate intensities. For overcoming this limitation, the present study proposes the use of principal component (PC) analysis ...
Dantas José L JL Group of Study and Research in Neuromuscular System and Exercise, CEFE - State University of Londrina (UEL), PR, - - 2010
Frequency domain analyses of changes in electromyographic (EMG) signals over time are frequently used to assess muscle fatigue. Fourier based approaches are typically used in these analyses, yet Fourier analysis assumes signal stationarity, which is unlikely during dynamic contractions. Wavelet based methods of signal analysis do not assume stationarity and ...
Hart Joseph M JM Department of Human Services, University of Virginia, Charlottesville, VA, United States. - - 2010
A relationship exists between muscles of the lumbar spine and those of the lower extremity where the quadriceps become more inhibited after lumbar paraspinal. The purpose of this experiment was to compare surface electromyography (sEMG) total frequency content after lumbar paraspinal fatiguing exercise. 50 subjects performed fatiguing lumbar extension exercise ...
Leal Junior Ernesto Cesar Pinto - - 2010
We wanted to test if pre-exercise muscle irradiation with 904 nm laser affects the development of fatigue, blood lactate levels and creatine kinase (CK) activity in a rat model with tetanic contractions. Thirty male Wistar rats were divided into five groups receiving either one of four different laser doses (0.1, ...
James C Roger - - 2010
The purpose of the study was to investigate the effects of two fatigue protocols on landing performance. A repeated measures design was used to examine the effects of fatigue and fatigue protocol on neuromuscular and biomechanical performance variables. Ten volunteers performed non-fatigued and fatigued landings on two days using different ...
Marino F E - - 2011
The study of human fatigue stretches back centuries and remains a significant part of medical and social discourse. In the exercise sciences fatigue is routinely related to the ability to produce muscle force or to the recovery from force decrements. However, the study of fatigue has by virtue of the ...
Paillard T - - 2010
Fatiguing exercise of the quadriceps femoris muscle degrades postural control in human subjects. The aim of this work was to compare the effects of the fatigue of the quadriceps femoris induced by voluntary muscular contraction (VC), and by electrical stimulation (ES) superimposed onto voluntary muscular contraction (VC+ES), on postural control ...
Zafeiridis Andreas - - 2010
This study examined fatigue profile during intermittent exercise in 10 men with mild to moderate mental retardation (MR) and 10 men without mental retardation (C). They performed 4 x 30s maximal knee extensions and flexions with 1-min rest on an isokinetic dynamometer. Peak torque of flexors (PTFL) and extensors (PTEX), ...
Piitulainen Harri - - 2010
High-density surface electromyography was used to examine whether gross sarcolemmal function is impaired in m. biceps brachii after intensive eccentric elbow flexor exercise, when measured at wide range of isometric contraction levels. Root mean square (RMS), mean power frequency (MNF) and mean muscle fibre conduction velocity (CV) were calculated before ...
Wen Guo - - 2009
Acetylcholinesterase is the enzyme that terminates neurotransmission by hydrolyzing the acetylcholine released by the motoneurons at the neuromuscular junctions. Although acetylcholinesterase has been studied for almost a century, the underlying relationship between exercise-induced fatigue and acetylcholinesterase activity at the synaptic cleft is not clear. The purpose of this study was ...
Camic Clayton L - - 2010
The purposes of this investigation were twofold: (1) to determine if the model used for estimating the physical working capacity at the fatigue threshold (PWC(FT)) from electromyographic (EMG) amplitude data could be applied to the frequency domain of the signal to derive a new fatigue threshold for cycle ergometry called ...
Hunter Angus M - - 2009
The aim of this study was to determine if inducing metabolic alkalosis would alter neuromuscular control after 50 min of standardized submaximal cycling. Eight trained male cyclists (mean age 32 years, s = 7; [Vdot]O(2max) 62 ml . kg(-1) x min(-1), s = 8) ingested capsules containing either CaCO(3) (placebo) ...
Hedayatpour Nosratollah - - 2009
: Eccentric contractions induce muscle fiber damage that is associated with a decreased capacity to generate voluntary force and increased fiber membrane permeability. Changes in fiber membrane permeability results in cell depolarization that is expected to have an effect on the action potential propagation velocity of the muscle fibers. : ...
Wood Lisa J - - 2009
To review evidence that muscle-derived interleukin-6 (IL-6) mediates some of the beneficial effects of exercise on cancer treatment-related fatigue (CTRF). Electronic nursing, psychology, and medicine databases. Fatigue is a common and often debilitating symptom associated with cancer treatment. Although the molecular mechanisms underlying CTRF have yet to be fully elucidated, ...
Nishijima Y - - 2010
This study aims at determining the applicability of a segment weight dynamic movement (SWDM) method as an alternative for normalizing gait EMGs in comparison with the conventional isometric maximal voluntary contraction (MVC) method. The SWDM method employs reference exercises, each being a dynamic, repetitive movement of a joint under the ...
Vianna Lauro C - - 2009
The purpose of the present study was to determine the relative importance of peripheral feedback from mechanically (mechanoreflex) and metabolically (metaboreflex) sensitive muscle afferents and central signals arising from higher centers (central command) to the exercise-induced increases in regional cerebral perfusion. To accomplish this, anterior cerebral artery (ACA) mean blood ...
Buss Tomasz - - 2010
PURPOSE: The study was focused on the influence of the kinesitherapy on fatigue and the quality of life in the terminal hospice cancer patients. PATIENTS AND METHODS: Forty-nine patients were included into the study and divided into experimental group A (with kinesitherapy) with 30 subjects and control group B (without ...
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