Search Results
Results 351 - 400 of 1170
< 3 4 5 6 7 8 9 10 11 12 13 >
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 ...
Maruyama Atsuo - - 2006
OBJECTIVE: Central fatigue is the inability of central commands to recruit maximum evocable muscle force during voluntary contraction. Here, we investigate how fatigue affects the inhibitory circuits of the motor cortex. METHODS: MEPs, short interval intracortical inhibition (SICI) and intracortical facilitation (ICF) were evaluated using a paired pulse transcranial magnetic ...
Crenshaw A G - - 2006
We investigated the effects of active versus passive pauses implemented during computer mouse work on muscle oxygenation and EMG of the forearm extensor carpi radialis muscle, and on wrist position sense. Fifteen healthy female subjects (age: 19-24 years) performed a 60-min mouse-operated computer task, divided into three 20 min periods, ...
Gobbo Massimiliano - - 2006
The purpose of the study was to verify, by means of torque and mechanomyogram (MMG) compared analysis, the validity of MMG as a tool to investigate the contractile changes due to localized muscular fatigue induced by stimulation protocols usually employed for sport training and rehabilitation programs. Ten healthy sedentary subjects ...
Cox Carla E - - 2006
OBJECTIVES: To determine changes in common urinary markers of hydration maintained by the drivers (mushers) during a wilderness endurance event in the arctic and to determine water turnover in this select group of individuals. STUDY DESIGN: During this descriptive study, data was systematically collected on hydration, water turnover, changes in ...
Lyons Mark - - 2006
Despite the acknowledged importance of fatigue on performance, ecologically sound studies investigating fatigue and its effects on sport-specific skills are surprisingly limited. The aim of this study was to investigate the effects of moderate and high-intensity localized muscle fatigue on passing performance in soccer. Twenty physically active male college students ...
Vigouroux Laurent - - 2006
The aim of this study was to characterize forearm muscle fatigue identified by the decrease in electromyogram median frequency and/or fingertip force during intermittent exercise. Nine elite climbers (international competitive level, USA 5.14a on sight) and ten non-climbers were instructed to maintain a fingertip force of 80% of their maximal ...
Blomstrand Eva - - 2006
Several factors have been identified to cause peripheral fatigue during exercise, whereas the mechanisms behind central fatigue are less well known. Changes in the brain 5-hydroxytryptamine (5-HT) level is one factor that has been suggested to cause fatigue. The rate-limiting step in the synthesis of 5-HT is the transport of ...
Fernstrom John D - - 2006
Brain tryptophan (TRP) concentrations and serotonin (5HT) synthesis and release increase during running. This increase in 5HT function may promote central fatigue and contribute to suboptimal physical performance. The rise in brain TRP is reputed to result from exercise-induced elevations in serum nonesterified fatty acid (NEFA) concentrations, which dissociate TRP ...
Seki Kazuhiko - - 2007
We investigated the effects of immobilization on the maximal motoneuronal firing rate recorded from the first dorsal interosseous (FDI) during voluntary isometric contraction. In five human subjects, the middle finger, index finger, and thumb were immobilized for 1 week in a fiber-glass cast, which kept FDI in a shortened position. ...
Taylor Bryan J - - 2006
The abdominal muscles have been shown to fatigue in response to voluntary isocapnic hyperpnea using direct nerve stimulation techniques. We investigated whether the abdominal muscles fatigue in response to dynamic lower limb exercise using such techniques. Eleven male subjects [peak oxygen uptake (VO2 peak) = 50.0 +/- 1.9 (SE) ml.kg(-1).min(-1)] ...
Shibuya Kenichi - - 2006
The purpose of this study was to examine the effect of fatigue resulting from exhaustive pinching exercise on frontal and motor cortex activity. Eight healthy subjects (four male and four female) participated in the present study. All subjects performed at 70% of maximal voluntary contraction (MVC) pinching exercise until reaching ...
< 3 4 5 6 7 8 9 10 11 12 13 >