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Results 401 - 450 of 1231
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Benwell Nicola M NM Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Queen Elizabeth II Medical Centre, Nedlands, WA, 6009, - - 2007
During fatiguing exercise corticomotor excitability increases as force declines, which may serve to increase motor output to the exercising muscle, but paradoxically at the same time there is an increase in silent period (SP) duration which is thought to represent a build-up of intracortical inhibition. Paired-pulse TMS at long interstimulus ...
Ross Emma Z - - 2007
It is unknown whether changes in corticomotor excitability follow prolonged exercise in healthy humans. Furthermore, the role of supraspinal fatigue in decrements of force production and voluntary activation following prolonged exercise has not been established. This study investigated peripheral and central fatigue after a marathon (42.2 km) on a treadmill. ...
Stout Jeffrey R - - 2006
The purpose of this study was to examine the effects of 28 days of beta-alanine (b-Ala) and creatine monohydrate (CrM) supplementation on the onset of neuromuscular fatigue by using the physical working capacity at neuromuscular fatigue threshold (PWC(FT)) test in untrained men. Fifty-one men (mean age +/- SD = 24.5 ...
Mäestu Jarek - - 2006
The aim of this study was to investigate the concepts of electromyographic (EMG) threshold (EMGT) by integrated EMG (iEMG) signals and neuromuscular fatigue threshold (NMFT) concepts in trained male athletes. Nine competitive national-level male rowers (21.8 +/- 4.4 years; 186.2 +/- 4.6 cm; 79.6 +/- 8.4 kg) took part in ...
Moalla Wassim - - 2006
The aim of this study was to examine the time-course of and the relationships between muscle oxygenation, blood volume and myoelectrical manifestations during isometric exercise in children. Twelve healthy children aged 12.5 +/- 1.2 years (mean +/- s) performed an isometric knee extension at 50% of their maximal voluntary contraction ...
Puetz Timothy W - - 2006
The authors investigated the effect of chronic exercise on feelings of energy and fatigue using meta-analytic techniques. Chronic exercise increased feelings of energy and lessened feelings of fatigue compared with control conditions by a mean effect delta of 0.37. The effect varied according to the presence or absence of a ...
Dimitrov George V - - 2006
PURPOSE: The aim of the present study was to test the applicability and sensitivity of new electromyography (EMG) spectral indices in assessing peripheral muscle fatigue during dynamic knee-extension exercise. METHODS: Seven subjects completed 10 sets of 15 repetitions of right knee-extension exercise lifting 50% of their one-repetition maximum. Torque (T), ...
Verges Samuel - - 2007
Respiratory muscle fatigue develops during exhaustive exercise and can limit exercise performance. Respiratory muscle training, in turn, can increase exercise performance. We investigated whether respiratory muscle endurance training (RMT) reduces exercise-induced inspiratory and expiratory muscle fatigue. Twenty-one healthy, male volunteers performed twenty 30-min sessions of either normocapnic hyperpnoea (n = ...
Kindig Angela E - - 2007
ATP, by activating purinergic 2 (P2) receptors on group III and IV afferents, is thought to evoke the metabolic component of the exercise pressor reflex. Previously we have shown that injection of PPADS, a P2 receptor antagonist, into the arterial supply of skeletal muscle of decerebrated cats attenuated the responses ...
Garrandes F - - 2007
This study examined the impact of sport specificity on the time course of fatigue during maximal voluntary eccentric, concentric and isometric torque production following a submaximal isokinetic fatiguing exercise. Seven cyclists and seven triathletes performed a fatiguing exercise consisting of nine sets of 31 isokinetic concentric knee extensions at 1.05 ...
Lee Eun Ok - - 2006
Rheumatoid arthritis (RA) is a major health problem in Korea. To explore the effects of regular exercise on pain, fatigue, and disability, a descriptive study was conducted in 435 Korean patients with RA. Exercisers were defined as those who are currently exercising more than 3 times a week, for at ...
Moran Kieran A - - 2006
PURPOSE: The principle of specificity suggests that it may be beneficial to undertake plyometric drop-jump training when fatigued. However, this may increase peak-impact accelerations and therefore increase the risk of injury. The aims of the study were to determine if whole-body fatigue (i) increased peak-impact acceleration on the proximal tibia ...
Toumi Hechmi - - 2006
The purpose of the present study was to compare vertical jump performance after 2 different fatigue protocols. In the first protocol, subjects performed consecutive sets of 10 repetitions of stretch-shortening cycle (SSC) contractions. In the second protocol, successive sets of 10 repetitions of isometric contractions were performed for 10 s ...
Verges Samuel - - 2006
High-intensity exercise can induce diaphragm fatigue which can, in turn, limit exercise performance. We investigated whether expiratory muscles fatigue similarly during exhaustive exercise. Eleven healthy male volunteers cycled to exhaustion at 85% maximal power. Before, immediately after exercise, and after 30 and 60 min of recovery, the nerve roots supplying ...
Brunello E - - 2006
Structural and mechanical changes occurring in the myosin filament and myosin head domains during the development of the isometric tetanus have been investigated in intact frog muscle fibres at 4 degrees C and 2.15 microm sarcomere length, using sarcomere level mechanics and X-ray diffraction at beamline ID2 of the European ...
Tran Quan T - - 2006
The purpose of this study was to examine the effects of different methods of measuring training volume, controlled in different ways, on selected variables that reflect acute neuromuscular responses. Eighteen resistance-trained males performed three fatiguing protocols of dynamic constant external resistance exercise, involving elbow flexors, that manipulated either time-under-tension (TUT) ...
Minetto M A - - 2006
Exercise stimulates the release of interleukin-6 (IL-6). Aims of the study were to: (a) analyse the IL-6 response to exercise in power (n = 7) and endurance athletes (n = 13); (b) determine the effects of the IL-6 production on mechanical and myoelectric fatigue; (c) evaluate the relationship between IL-6 ...
Skurvydas A - - 2006
AIM: The purpose of this study was to establish the main differences between men (M) and adolescents (A) (males) in metabolic fatigue and damage induced by exercise performed at maximal intensity. METHODS: Healthy A (age 13.4 0.6 years, n = 12) and healthy adult M (age 25.4 1.7 years, n ...
Coventry Evan - - 2006
BACKGROUND: The forces that are imposed on the body due to landings must be attenuated primarily in the lower extremity. Muscles assist in the absorption of these forces, and it has been shown that a fatigued muscle decreases the body's ability to attenuate shock from running. The purpose of the ...
Biagini Maria Rosa MR Department of Clinical Pathophysiology, Gastroenterology Unit, University of Florence, Viale Morgagni 85 50134, Firenze, - - 2006
To evaluate the myoelectric manifestations of peripheral fatigability in patients with primary biliary cirrhosis in comparison to healthy subjects. Sixteen women with primary biliary cirrhosis without comorbidity and 13 healthy women matched for age and body mass index (BMI) completed the self-reported questionnaire fatigue impact scale. All subjects underwent surface ...
Hug François - - 2006
During exhaustive incremental pedaling exercises, root mean square or amplitude of integrated electromyographic values exhibits a nonlinear increase, i.e., the so-called electromyographic threshold (EMG(Th)). As proposed by various authors, this EMG(Th) could be used as a complementary indicator of the aerobic-anaerobic transition in physiological evaluations. However, most of these studies ...
Baker-Fulco Carol J - - 2006
PURPOSE: To determine whether creatine (Cr) supplementation improves muscle performance during exposure to acute hypobaric hypoxia. METHODS: Seven healthy men (28 +/- 6 yr, mean +/- SD) performed submaximal intermittent static knee contractions interspersed with maximal voluntary contractions (MVCs) every minute to exhaustion (approximately 50% of rested MVC force) in ...
Royal Kylie A - - 2006
The aim of this study was to assess the effects of fatigue on decision making and goal shooting skill in water polo. Fourteen junior elite male players (age 17.2 +/- 0.5 years; mass 84.2 +/- 7.6 kg; height 1.85 +/- 0.05 m) completed four sets of eight repetitions of an ...
McKenna Michael J - - 2006
Reactive oxygen species (ROS) have been linked with both depressed Na(+),K(+)-pump activity and skeletal muscle fatigue. This study investigated N-acetylcysteine (NAC) effects on muscle Na(+),K(+)-pump activity and potassium (K(+)) regulation during prolonged, submaximal endurance exercise. Eight well-trained subjects participated in a double-blind, randomised, crossover design, receiving either NAC or saline ...
Benwell Nicola M NM Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Queen Elizabeth II Medical Centre, Nedlands, WA 6009, Australia. - - 2006
We have previously shown that following a period of unimanual fatiguing exercise, there is a reduction in primary sensorimotor cortex (SM1) activation with movement of either the fatigued or the non-fatigued hand by Benwell et al. (Exp Brain Res 167:160-164, 2005). In the present study we have investigated whether this ...
Smith Jay - - 2006
OBJECTIVE: To quantify the electromyographic activity in the shoulder girdle musculature during scapulothoracic exercises performed in a shoulder immobilizer in asymptomatic men. DESIGN: Descriptive. SETTING: Motion analysis laboratory at a tertiary care center. PARTICIPANTS: Five asymptomatic male volunteers ages 24 to 32 years. INTERVENTION: Fine-wire (supraspinatus, infraspinatus, upper subscapularis) and ...
Meeusen Romain - - 2006
It is clear that the cause of fatigue is complex, influenced by events occurring in both the periphery and the central nervous system. Work conducted over the last 20 years has focused on the role of brain serotonin and catecholamines in the development of fatigue, and the possibility that manipulation ...
Saey Didier - - 2006
Contractile fatigue is associated with exercise intolerance in patients with chronic obstructive pulmonary disease (COPD). Contractile fatigue may be assessed by quantifying the decline in strength after a fatiguing protocol but this may pose practical problems. The purpose of this study was to investigate the relationship between the decline in ...
Kinugasa R - - 2006
The purpose of our study was to determine the effect of vascular occlusion on neuromuscular activation and/or the energy metabolic characteristics of the quadriceps femoris (QF) muscles during muscle contractions. Seven men participated in the study. An occlusion cuff was attached to the proximal end of the right thigh, so ...
Hart Joseph M JM University of Virginia, Department of Orthopaedic Surgery,Charlottesville, VA, USA. - - 2006
A neuromuscular relationship exists between the lumbar extensor and quadriceps muscles during fatiguing exercise. However, this relationship may be different for persons with low back pain (LBP). To compare quadriceps inhibition after isometric, fatiguing lumbar extension exercise between persons with a history of LBP and control subjects. A 2 x ...
Bowman Thomas G TG School of Health Science and Human Performance, Lynchburg College, Lynchburg, VA, USA. - - 2006
Muscular fatigue impedes sensorimotor function and may increase the risk of shoulder injury during activity. The effects of fatigue on the sensorimotor system of the shoulder have been studied with various results. Deceleration times have been used to study neuromuscular control of the shoulder; however, no studies involving the effects ...
Smith J Chadwick - - 2006
Previously, we showed that artificial rearing using the "pup in a cup" model results in decreased tongue activity and caused some minor alterations in the tongue retrusor musculature. However, the artificial rearing time frame previously chosen was brief (11 days). The purpose of the present investigation was to extend the ...
Amann Markus - - 2006
Changing arterial oxygen content (C(aO(2))) has a highly sensitive influence on the rate of peripheral locomotor muscle fatigue development. We examined the effects of C(aO(2)) on exercise performance and its interaction with peripheral quadriceps fatigue. Eight trained males performed four 5 km cycling time trials (power output voluntarily adjustable) at ...
Kavanagh Justin J - - 2006
The purpose of this study was to examine how inducing fatigue of the 1) lumbar erector spinae and 2) cervical erector spinae (CES) muscles affected the ability to maintain head stability during walking. Triaxial accelerometers were attached to the head, upper trunk, and lower trunk to measure accelerations in the ...
Jaskólska Anna - - 2007
The aim of this study was to compare mechanomyogram (MMG) recorded by a condenser microphone (MIC) and an accelerometer (ACC) during submaximal isometric, concentric and eccentric contractions in 14 males. The maximal voluntary force (MVC) of the biceps brachii was measured. The subjects were asked to do short duration isometric, ...
Delliaux S - - 2006
OBJECTIVE: To study alterations in muscle function combining physiological, electrophysiological and metabolic measurements in patients receiving a statin at various dosages during long-term therapy. MATERIAL: A 3-month (D0, D30 and D90) longitudinal physiological and electrophysiological muscle study was performed in 26 patients receiving 10, 40 or 80 mg/day atorvastatin. METHOD: ...
Saggini R - - 2006
AIM: Chronic fatigue syndrome (CFS) is an illness characterised by disabling fatigue of uncertain aetiology and other nonspecific symptoms. Typically CFS patients complain of a severe fatigue made worse by exercise, with a consistent reduction of working activity. A physical deconditioning could explain CFS features as well as a neuromuscular ...
Hughes M G - - 2006
Although repeated sprint tests are relatively common, there have been few investigations of repeated sprint exercise using non-motorised treadmill ergometry. The purpose of this study was to determine the reliability of a repeated sprint procedure using this apparatus. Ten healthy, active males, performed three repeated sprint tests (six repetitions of ...
Scano Giorgio - - 2006
The energy expenditure required by the respiratory muscles during exercise is a function of their work rate, cost of breathing, and efficiency. During exercise, ventilatory requirements increase further exacerbating the potential imbalance between inspiratory muscle load and capacity. High level of exercise intensity in conjunction with contracting respiratory muscles is ...
Moynihan Audrey T - - 2006
OBJECTIVE: The purpose of this study was to investigate the effects of leptin on human uterine contractility in vitro. STUDY DESIGN: Biopsies of human myometrium were obtained at elective cesarean section (n = 18). Dissected myometrial strips suspended under isometric conditions, undergoing spontaneous and oxytocin-induced contractions, were exposed to cumulative ...
Smith Robyn M - - 2006
OBJECTIVE: To determine the impact of a single exercise session on function, fatigue, and sensory symptoms for people with multiple sclerosis (MS). DESIGN: This pilot study was designed as a before-after trial. Demographic and response-to-exercise measures were taken before exercise, repeated immediately after exercise, and followed up again 24 hours ...
Carlson L E - - 2006
Chronic cancer-related fatigue in otherwise asymptomatic post-allogeneic hematopoietic stem cell transplant (HSCT) patients is common and debilitating. This pilot study investigated whether patients with no clinical or psychological abnormalities but severe fatigue would respond to an individually adapted aerobic exercise program. Participants were 12 patients (eight male, and four female ...
Desbrosses Kévin - - 2006
PURPOSE: To investigate i) whether neural activation dependence on muscle length is preserved with neuromuscular fatigue and ii) whether fatigue induced by a maximal isometric exercise is muscle length dependent. METHODS: Twelve male subjects performed two fatiguing quadriceps muscle exercises: FS is the fatigue carried out at short muscle length ...
Dempsey Jerome A - - 2006
We briefly review the evidence for a hypothesis, which links the ventilatory response to heavy intensity, sustained exercise-to-exercise performance limitation in health. A key step in this linkage is a respiratory muscle fatigue-induced metaboreflex, which increases sympathetic vasoconstrictor outflow, causing reduced blood flow to locomotor muscles and locomotor muscle fatigue. ...
Thickbroom Gary W - - 2006
OBJECTIVE: To determine if task performance and fatiguability during repeated low-level contractions of an intrinsic hand muscle differ in a group of MS subjects compared with a control group, and what central changes accompany the development of fatigue and the period of recovery, whether these measures are related to subjective ...
Oskouei Ali E - - 2006
There is substantial evidence that the steady-state isometric force following active muscle stretch is greater than the corresponding isometric force for sub-maximal and maximal electrically induced contractions, and for maximal voluntary contractions (MVC). This so-called force enhancement (FE) has not been investigated systematically for sub-MVC. Recently, we found that FE ...
Romer Lee M - - 2006
1. Reductions in arterial O(2) saturation (-5% to -10%S(a)o(2) below rest) occur over time during sustained heavy-intensity exercise in a normoxic environment, caused primarily by the effects of acid pH and increased temperature on the position of the HbO(2) dissociation curve. 2. We prevented the desaturation incurred during exercise at ...
Aujouannet Yannick A - - 2006
The present study aimed to investigate the effects of a high-intensity swim test among top-level swimmers on (i) the spatial and temporal parameters of both the stroke and the 3-D fingertip pattern and (ii) the mechanical, muscular, and physiological parameters. Ten male international swimmers performed a 4 x 50 m ...
Van Beekvelt Mireille C P - - 2006
The initial temporary weakness that occurs in autosomal-recessive generalized myotonia diminishes with repetitive contractions. Physiological understanding of this phenomenon is incomplete. The underlying hypothesis of our study was that the "warming-up" phenomenon relates to the exercise-related activation of Na(+)-K(+)-ATPase. Three patients performed isometric exercise of the brachioradialis muscle on two ...
Iridiastadi H - - 2006
Localized muscle fatigue has received growing attention as a potential design variable and exposure metric in research towards prevention of musculoskeletal disorders in the workplace. While fatigue during sustained static work has been investigated extensively, effects during tasks comprising work-rest cycles are less clear. Work-rest models for static intermittent work ...
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