Search Results
Results 301 - 350 of 1232
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Dickin D C - - 2008
Investigations of postural recovery following controlled external perturbations have provided models for healthy and pathological balance behavior. Less work, however, has investigated postural responses related to internal perturbations of the balance system. In this study, lower extremity joint (knee, or ankle) and overall fatigue of the dominant leg provided the ...
Xu Chuan-Xiang - - 2008
To investigate changes of 5-hydroxytryptamine (5-HT) and its synthesis rate-limiting enzyme tryptophan hydroxylase (TPH) in the ventral horn of spinal cord after exercise-induced fatigue, and to further discuss the mechanism of exercise-induced central fatigue at spinal level. Sixteen healthy adult Wistar rats were randomly divided into 2 groups: exercise-induced fatigue ...
Rainoldi Alberto - - 2008
Twelve endurance athletes and six power athletes performed fatiguing isokinetic knee flexions/extensions. Isokinetic torque was recorded during the exercise. Isometric torque, cortisol and lactate responses, electromyographic (EMG) mean power frequency, average rectified value, and conduction velocity were analysed before and after the isokinetic exercise to determine correlations between electrophysiological variables ...
Macdonald Jamie Hugo - - 2008
PURPOSE: Surface electromyographic (EMG) variables allow study of the electrical activity of motor units within active skeletal muscle. Recent methodological advances permit the estimation of muscle fiber-conduction velocity (MFCV) from EMG signals recorded during dynamic exercise. However, EMG responses to incremental and fatiguing cycling are poorly understood. METHODS: Twenty males ...
de Araújo Rodrigo Cappato - - 2009
The purpose of the present study was to evaluate the intra and interday reliability of surface electromyographic amplitude values of the scapular girdle muscles and upper limbs during 3 isometric closed kinetic chain exercises, involving upper limbs with the fixed distal segment extremity on stable base of support and on ...
Nummela A T - - 2008
This study investigated fatigue-induced changes in neuromuscular and stride characteristics during and immediately after the 5-km running time trial. Eighteen well-trained male distance runners performed a maximal 20-m sprint test and maximal voluntary contraction (MVC) in a leg press machine before and immediately after the 5-km running time trial. In ...
Wiles Jonathan D - - 2008
Currently, it is not possible to prescribe isometric exercise at an intensity that corresponds to given heart rates or systolic blood pressures. This might be useful in optimizing the effects of isometric exercise training. Therefore, the aim of this study was to explore the relationships between isometric exercise intensity and ...
Yamauchi Junichiro - - 2008
It is not known how the mode of exercise, dynamic and static exercises, affects the limb volume. Therefore, the purpose of this study was to investigate hand and wrist volume (HWV) after dynamic and static handgrip exercise. Nine healthy subjects (age 31.8 +/- 7.3 years; height 172.0 +/- 5.7 cm; ...
Marcora Samuele M - - 2008
Locomotor muscle fatigue, defined as an exercise-induced reduction in maximal voluntary force, occurs during prolonged exercise, but its effects on cardiorespiratory responses and exercise performance are unknown. In this investigation, a significant reduction in locomotor muscle force (-18%, P < 0.05) was isolated from the metabolic stress usually associated with ...
Dartnall Tamara J - - 2008
The purpose of this study was to determine the effect of eccentric exercise on correlated motor unit discharge (motor unit synchronization and coherence) during low-force contractions of the human biceps brachii muscle. Eight subjects (age, 25 +/- 7 yr) performed three tasks involving isometric contraction of elbow flexors while EMG ...
Puetz Timothy W - - 2008
BACKGROUND: There is growing evidence that chronic exercise is a promising intervention for combating feelings of low energy and fatigue. Although groups with well-defined medical conditions (for example cancer and heart disease) or unexplained fatigue syndromes consistently have reported improved feelings of energy and fatigue after chronic exercise, relatively few ...
Foley Teresa E - - 2008
Habitual exercise increases plasticity in a variety of neurotransmitter systems. The current review focuses on the effects of habitual physical activity on monoamine dopamine (DA) neurotransmission and the potential implication of these changes to exercise-induced fatigue. Although it is clear that peripheral adaptations in muscle and energy substrate utilization contribute ...
Moreau Noelle - - 2008
PURPOSE: To develop a reliable and feasible isokinetic fatigue protocol for the knee flexors and extensors in individuals with cerebral palsy (CP) who are ambulatory. METHODS: Twelve subjects with CP, 10 to 23 years old, participated in the study. The protocol consisted of repeated maximum voluntary concentric knee flexion and ...
Cheung Stephen S - - 2008
Hyperthermia, through either passive exposure or exercise in hot environments, can severely impair exercise capacity, and one primary pathway of impairment may be the neuromuscular system. This is because fatigue or reduced exercise capacity in other physiological systems ultimately terminate in an inability of the muscle to adequately generate the ...
Hoffman Jay R - - 2008
The purpose of this study was to examine the effect of 30 days of beta-alanine supplementation in collegiate football players on anaerobic performance measures. Subjects were randomly divided into a supplement (beta-alanine group [BA], 4.5 g x d(-1) of beta-alanine) or placebo (placebo group [P], 4.5 g x d(-1) of ...
Paulus David C - - 2008
During the concentric portion of the free-weight squat exercise, accelerating the mass from rest results in a fluctuation in ground reaction force. It is characterized by an initial period of force greater than the load while accelerating from rest followed by a period of force lower than the external load ...
Friedberg Fred - - 2008
BACKGROUND: Understanding how patients with chronic fatigue syndrome (CFS) recall their fatigue is important because fatigue is a core clinical dimension of this poorly understood illness. PURPOSE: This study assessed the associations between momentary fatigue ratings and weekly recall of fatigue in 71 participants with CFS. METHOD: During the three-week ...
Oliveira Anderson Souza - - 2008
The aim of this study was to determine the time to restore the biceps brachii (BB) electromyographic (EMG) activity after the biceps curl (BC) exercise, at different intensities. Ten males performed initially maximal voluntary isometric contractions (MVC) of the elbow flexors, followed by one isometric submaximal contraction at 50% MVC ...
Joosen Margot - - 2008
OBJECTIVES: Complaints of prolonged fatigue are considered as a major health problem, as it can affect daily functioning and may lead to work disability. To increase knowledge about the effectiveness of interventions focussing on fatigued patients, a study was designed to evaluate an established training programme for patients with prolonged ...
Solnik Stanisław - - 2008
A temporal analysis of electromyographic (EMG) activity has widely been used for non-invasive study of muscle activation patterns. Such an analysis requires robust methods to accurately detect EMG onset. We examined whether data conditioning, supplemented with Teager-Kaiser Energy Operator (TKEO), would improve accuracy of the EMG burst onset detection. EMG ...
Ingledew David K DK a School of Psychology , University of Wales , Bangor , - - 2008
The aim was to better understand the role of motives in exercise participation. It was hypothesised that motives influence exercise participation by influencing behavioural regulation, and that motives are themselves influenced by personality traits. Data were from a cross-sectional questionnaire survey of 252 office workers, mean age 40 years. Analysis ...
Romer Lee M - - 2008
It is commonly held that the respiratory system has ample capacity relative to the demand for maximal O(2) and CO(2) transport in healthy humans exercising near sea level. However, this situation may not apply during heavy-intensity, sustained exercise where exercise may encroach on the capacity of the respiratory system. Nerve ...
Shirasawa Hatuki - - 2009
The present study aimed to investigate differences among the soleus (Sol), medial gastrocnemius (MG) and tibialis anterior (TA) in electromyogram (EMG) activities during ambulatory condition without any moderate to high intensity exercise. From 10:00 to 17:00, seven healthy graduate students participated in EMG recordings, which included the measurements during maximal ...
Moazedi A A - - 2007
Traditional herbal medicines such as Petroselinum crispum (Parsley) have been used for treatment of intestinal disorders in Iran. To date no pharmacological evidence for their effectiveness has been reported. The aim of this study was to examine the relaxant effect of hydroalcoholic extract of Petroselinum crispum on isolated adult male ...
Dalsgaard Mads K - - 2007
Central fatigue refers to circumstances in which strength appears to be limited by the ability of the central nervous system to recruit motoneurons. Central fatigue manifests when the effort to contract skeletal muscles is intense and, thus, is aggravated when exercise is performed under stress, whereas it becomes attenuated following ...
O'Sullivan Dawn - - 2007
AIM: To measure fatigue and physical functioning in patients with end stage renal disease (ESRD) receiving haemodialysis and to investigate the relationships between fatigue and physical functioning. BACKGROUND: Fatigue and reduced physical functioning are among the most bothersome symptoms experienced by individuals receiving haemodialysis for ESRD. Research has shown that ...
Smith Jay - - 2007
OBJECTIVE: To quantify the electromyographic activity in the shoulder girdle musculature during ipsilateral kinetic chain 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 ...
Morihara Naoaki - - 2007
More than three thousand publications in the past have confirmed the efficacy of garlic for the prevention and treatment of a variety of diseases, acknowledging and validating its traditional uses. Garlic is also used for the treatment of fatigue, although the mechanism involved remain unclear. The anti-fatigue function of garlic ...
Medel Francisco J - - 2007
Highly cross-linked polyethylenes (HXLPEs) have been incorporated into the hip replacement armamentarium based on their improved wear resistance. However, two different methods of thermal treatment separate the orthopedic community as strategies to control potential long-term oxidation, and controversy remains with problems in the long-term use of acetabular liners (long-term oxidation, ...
Monga Uma - - 2007
OBJECTIVE: To show fatigue prevention and quality of life (QOL) improvement from cardiovascular exercise during radiotherapy. DESIGN: Prospective enrollment (n=21), randomized to exercise (n=11) and control groups (n=10), with pre- and post-radiotherapy between- and within-group comparisons. SETTING: Academic medical center. PARTICIPANTS: Localized prostate cancer patients undergoing radiotherapy. INTERVENTIONS: The interventional ...
Amann Markus - - 2008
During exercise, fatigue is defined as a reversible reduction in force- or power-generating capacity and can be elicited by "central" and/or "peripheral" mechanisms. During skeletal muscle contractions, both aspects of fatigue may develop independent of alterations in convective O(2) delivery; however, reductions in O(2) supply exacerbate and increases attenuate the ...
Nybo Lars - - 2008
The present review addresses mechanisms of importance for hyperthermia-induced fatigue during short intense activities and prolonged exercise in the heat. Inferior performance during physical activities with intensities that elicit maximal oxygen uptake is to a large extent related to perturbation of the cardiovascular function, which eventually reduces arterial oxygen delivery ...
Van Brussel Marco - - 2008
OBJECTIVE: To study the effects of a physical training program on exercise capacity, muscle force, and subjective fatigue levels in patients with mild to moderate forms of osteogenesis imperfecta (OI). STUDY DESIGN: Thirty-four children with OI type I or IV were randomly assigned to either a 12-week graded exercise program ...
Regueme S C - - 2007
This study examined the perceived movement velocity induced by tendon vibrations during the delayed recovery phase of a stretch-shortening cycle (SSC)-type exercise characterized by 2 to 4 days of neuromuscular and proprioceptive impairments. Seven subjects performed until exhaustion series of unilateral rebounds involving mostly the triceps surae muscle group. Fatigue ...
Goldman Myla D - - 2008
OBJECTIVE: To assess the characteristics of the 6-min walk (6MW) in multiple sclerosis (MS) subjects of varied disability, and controls. To assess the correlation of 6MW to subjective measures of fatigue, health status and ambulation using the modified fatigue impact scale (MFIS), short form-36 Health Questionnaire physical component score and ...
Regueme S C - - 2008
This study examines the static position sense from the ankle joint following a unilateral exhaustive stretch-shortening cycle (SSC)-type exercise involving mostly the triceps surae muscle group. Fatigue effects were quantified within the exercised and non-exercised leg through a maximal isometric voluntary plantarflexion test (MVC) performed immediately before (Pre) and after ...
Cook Summer B - - 2007
Resistance training at low loads with blood flow restriction (BFR) (also known as Kaatsu) has been shown to stimulate increases in muscle size and strength. It is unclear how occlusion pressure, exercise intensity, and occlusion duration interact, or which combination of these factors results in the most potent muscle stimulus. ...
Tripp Brady L - - 2007
Research indicates that upper extremity fatigue hampers sensorimotor system acuity. However, no investigators have observed recovery of upper extremity acuity after fatigue. To observe recovery of active position reproduction acuity in overhead throwers after a throwing-fatigue protocol. Single-session, repeated-measures design. University musculoskeletal laboratory. Sixteen healthy collegiate baseball players (age = ...
Pozehl Bunny - - 2008
BACKGROUND: Physiological benefits of exercise training for heart failure (HF) patients have been demonstrated, however little is known about the effects of training on the symptoms of fatigue and dyspnea. AIM: The purpose of this study was to examine HF symptoms of fatigue and dyspnea in response to a 24-week ...
Felici Francesco - - 2009
Surface myoelectric signal changes occurring during sustained isometric contractions have been extensively studied with quantitative surface electromyography (sEMG) and are described by means of some sEMG global variables in time and frequency domain (such as the median power spectral frequency). Recently, the possibility of studying local muscle O(2) saturation during ...
Rupp Thomas - - 2008
Near-infrared spectroscopy (NIRS) allows non-invasive monitoring of central and peripheral changes in oxygenation during exercise and may provide valuable insight into the factors affecting fatigue. This study aimed to explore the changes in oxygenation of prefrontal cortex and active muscle tissue as limiting factors of incremental exercise performance in trained ...
Bieuzen F - - 2008
The aim of this study was to investigate the effect of concentric or eccentric fatiguing exercise on cycling pattern. Eleven well trained cyclists completed three sessions of cycling (control cycling test [CTRL], cycling following concentric [CC] or eccentric [ECC] knee contractions) at a mean power of 276.8 +/- 26.6 Watts. ...
Giske Liv - - 2008
The pathogenesis of widespread pain and fibromyalgia (FM) is unknown. Altered responses from the hypothalamus-pituitary-adrenal axis, sympathetic nervous system and muscular system have been suggested as being of importance. The present study was undertaken to determine: (i) whether the sympathoadrenal response to repetitive isometric contractions until exhaustion is altered in ...
Streckis Vytautas - - 2007
Performance in high-intensity exercise is dependent on the ability to activate motor units. The main aim of this study was to test the hypothesis that adult men and women (age 19-27 years) are able to maintain higher levels of voluntary activation (VA) in knee extensor muscles than boys and girls ...
Schneider Carole M - - 2007
This investigation determined the cardiopulmonary function and fatigue alterations in male cancer survivors during treatment as well as following treatment utilizing similar exercise assessment protocols and individualized, prescriptive exercise interventions. The study included 45 male cancer survivors that were referred by local oncologists. Following a comprehensive screening and physical examination, ...
Vangelakoudi A - - 2007
Laser sailors have to tolerate fatiguing contractions of the lower-body muscles for prolonged periods. The aims of the present study were (1) to evaluate the difference between top-ranked and club sailors, in their capacity to resist fatigue during sustained isometric and maximal power exercise, and (2) to examine the relationships ...
Spurway Neil C - - 2007
The literature indicates that the heart rate of a planing-dinghy sailor, in winds of 4 - 5 m . s(-1), is in the range seen in aerobic athletes, yet oxygen consumption (VO(2)) is roughly half that of the same individual cycling at that heart rate. Thus, although upper-body dynamic activity ...
Batista Mauro A B - - 2007
Postactivation potentiation (PAP) is defined as a short-term increase in voluntary muscle activation following a previous conditioning activity (CA). Controversy about PAP is mostly attributed to the characteristics of the CA and the training status of the subjects. While some studies have found that PAP can be induced by series ...
Meeusen Romain - - 2007
It is clear that the cause of fatigue is complex, influenced by both events occurring in the periphery and the central nervous system (CNS). It has been suggested that exercise-induced changes in serotonin (5-HT), dopamine (DA), and noradrenaline (NA) concentrations contribute to the onset of fatigue during prolonged exercise. Serotonin ...
Damon Bruce M BM Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee 37232, USA. - - 2007
The time course of exercise-induced T(2)-weighted signal intensity (SI) changes contains an initial rise, early dip, and secondary rise. The purposes of this study were to test the hypothesis that the secondary rise occurs earlier during more intense contractions, and to determine the contribution of BOLD contrast to the SI ...
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