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Results 551 - 600 of 1396
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Usher-Smith Juliet A - - 2006
The combined effects of intracellular lactate and proton accumulation on cell volume, Vc, were investigated in resting Rana temporaria striated muscle fibres. Intracellular lactate and H+ concentrations were simultaneously increased by exposing resting muscle fibres to extracellular solutions that contained 20-80 mm sodium lactate. Cellular H+ and lactate entry was ...
Hanisch Frank - - 2006
BACKGROUND: Mitochondrial disorders are characterized by an accumulation of lactate and an insufficient oxygen extraction from blood during exercise. Therefore, both parameters (lactate and oxygen saturation) can be used as screening tests in mitochondrial disorders. However, conflicting results regarding sensitivities and specifities of both tests have been reported. METHOD: We ...
Tilbrook A J - - 2006
We investigated the effect of the presence and absence of lambs and suckling by lambs to attenuate activation of the hypothalamo-pituitary-adrenal (HPA) axis to isolation and restraint stress in lactating sheep. In experiment 1, blood samples were collected every 10 min from nonlactating (n = 5) and lactating (n = ...
Temfemo A - - 2006
This study investigated the effects of prior exercise on performance during a subsequent force-velocity (FV) exercise test. After determination of the individual maximal aerobic power (MAP) during maximal graded exercise testing, fifteen trained male subjects (age: 25 +/- 3 y) were randomly assigned to perform the FV exercise test without ...
Wells R M G - - 2006
Silver trevally (Pseudocaranx dentex) are highly athletic marine teleosts inhabiting the tropical waters of the Great Barrier Reef, Australia. Burst swimming increased plasma lactate from 1.6 +/- 0.4 S.D. to 21.6 +/- 3.3 mM (N = 6), among the highest values reported for functional hypoxia in fish. These data support ...
Johnson Michael A - - 2006
Ventilatory work during heavy endurance exercise has not been thought to influence systemic lactate concentration. We evaluated the effect of maximal isocapnic volitional hyperpnoea upon arterialised venous blood lactate concentration ([lac-]B) during leg cycling exercise at maximum lactate steady state (MLSS). Seven healthy males performed a lactate minimum test to ...
Ravier G - - 2006
The purpose of this study was to compare maximal accumulated oxygen deficit (MAOD) and the time course of blood markers of the anaerobic metabolism in response to exhaustive supramaximal test in two elite (international vs. national) class karate athletes. Ten male international competitors from the French national team (Int, age ...
Krieg A - - 2006
Competitive inline speedskating combines a movement pattern similar to speedskating on ice with pack-oriented competition modes known from cycling. The deep-seated body position leads to high static load and, thus, restricted blood flow within propulsive muscles. This condition may affect lactate kinetics and limit V.O (2peak). The present study compares ...
Parfitt Gaynor - - 2006
OBJECTIVES: Affective valence responses to exercise may influence adherence. According to a newly proposed dual-mode model, affective responses have been proposed to vary depending on whether exercise is undertaken above or below the anaerobic threshold. With the model in mind, the study objectives were to explore the impact of an ...
Kaya Oktay - - 2006
OBJECTIVE: There is fairly scarce information about the effects of zinc, an essential trace element, on performance. Studies concerned with the relation between zinc and exercise mostly concentrate on the distribution of this element in the body in response to exercise. The objective of the present study is to explore ...
Obara, Shigeru
OBARA, S., NIKI, T. and SATAKE, M., The First Heart sound Amplitude Has a Brealing Point and Pistive Relationshios With Blood Lactate Concentraion and Double Product in Ggraded Exercise. Abv. Exerc. Sports Physiol., Vol.11, No.1 pp.33-39, 2005. Continuous recording of heart sounds during graded exercise suggested that there might be ...
Yamauchi, Takeshi
YAMAUCHI, T. and MATSUI, N. Effect of Blood on Plasma Ammonia and Lactate Concentrations During Incremental Esercise in Men. Abv. Exerc. Sports Physiol., Vol.2, No.2 pp.71-78, 1996. This study was designed to ecalute whether extracellular ...
Shou, Guo-chiang
SHOU, G.C. and ISHIKO, T., Effect of Thermal Dehydration on Blood Lactate Accumulation During Incremental Exercise under Different Environmental Conditions. Adv. Exerc. Sports Physiol., Vol.1, No.2 pp1-7, 1995. The purpose of this study was to investigate tje levels of blood lactate (HLa) during increncetal exerice in both a hot and ...
Hadsell Darryl L - - 2006
Milk synthesis by the mammary gland declines during prolonged lactation despite the continued suckling stimulus and complete removal of mammary secretions. Although this process has been hypothesized to result from cellular aging there has been no reported analysis of aging markers in the lactating mammary gland. The goal of these ...
Stellingwerff Trent - - 2006
The aim of this study was to determine whether the decreased muscle and blood lactate during exercise with hyperoxia (60% inspired O2) vs. room air is due to decreased muscle glycogenolysis, leading to decreased pyruvate and lactate production and efflux. We measured pyruvate oxidation via PDH, muscle pyruvate and lactate ...
Ionescu Alina A - - 2006
Exercise is associated with release of inflammatory mediators in the circulation and there is evidence that the exercising muscles and tendons are sources of interleukin-6. Due to the catabolic effects of some cytokines, increased release in circulation might contribute to alterations in body composition in adults with cystic fibrosis. We ...
Messonnier L - - 2006
The purpose of the present study was to relate the training-induced alterations in lactate kinetics parameters to the concomitant changes in time to exhaustion (T(lim)) at a work rate corresponding to maximal oxygen uptake (Pa(peak)). Eight subjects performed before and after training i) an incremental exercise up to exhaustion to ...
Valeri C Robert - - 2006
Hemoglobin based oxygen carriers (HBOC) are resuspended in "excipients" consisting of Ringer's D,L-lactate containing antioxidants to prevent methemoglobin formation during storage. Investigators have reported cardiac arrhythmias following infusion of Ringer's D,L-lactate solution. Studies have shown that D-lactate stimulates human granulocytes to generate oxygen free radicals and L-lactate inhibits glycolysis. Patients ...
Sagiv Moran M The Sports Medicine and Rehabilitation Division, The Zinman College of Physical Education and Sport Sciences at the Wingate Institute , - - 2006
Backpack carriage occurs in day-to-day tasks and has applications in school, physical training, recreational activities and sports. Using metabolic cart and echocardiograph, this study determined and examined the effects of two different load carriages on left ventricular function during 30 min. of treadmill walking in healthy adolescent male subjects. Seventeen ...
McIver K L - - 2006
The purpose of these investigations was to determine if differences exist in skeletal muscle nutritive blood flow and lactate metabolism in women with fibromyalgia (FM) compared to healthy women (HC); furthermore, to determine if differences in nitric oxide-mediated systems account for any detected alterations in blood flow and lactate metabolism ...
Crisafulli Antonio - - 2006
To date, few attempts have been made to correlate cardiovascular variables to lactate threshold (L(T)). This study was designed to determine the relationship between the accumulation of blood lactate and several haemodynamic variables during exercise. Eight male volunteer cyclists performed an incremental test on an electromagnetically braked cycle-ergometer consisting of ...
Baldari C - - 2005
AIM: Optimal lactate removal was reported to occur at work-rate between 30% and 70% VO2max. However, it has been recently recommended to quantify exercise intensity not in percentage of VO2max but in relation to validated metabolic reference points such as the individual anaerobic threshold (IAT) and the individual ventilatory threshold ...
Garcin M - - 2005
The purpose of this investigation was to study effects of acetaminophen consumption on ratings of perceived exertion and estimated time limit responses at the lactate threshold. 98 young regional to national level athletes performed a graded exhausting exercise on an outdoor running track to estimate their maximal aerobic velocity and ...
Paccotti P - - 2005
Physical exercise is associated with increases of serum and salivary levels of cortisol. The concomitant increase in serum lactate has been implicated as one of the mechanisms responsible for adrenocortical activation. We evaluated the responses of serum lactate and serum and salivary cortisol to an acute bout of high-intensity isokinetic ...
Meissner T - - 2005
Exercise-induced hyperinsulinism (EIHI) is a recently described entity characterised by recurrent episodes of hypoglycaemia induced by physical exercise. The index patient for this disorder and a matched control were subjected to aerobic and anaerobic exercise tests on a cycle ergometer. Aerobic exercise was performed at an intensity of 60% of ...
Sara Fagnété - - 2006
The physical and physiological behavior of sickle cell trait carriers (AS) is somewhat equivocal under strenuous conditions, although this genetic abnormality is generally considered to be a benign disorder. The occurrence of incidents and severe injuries in AS during exercise might be explained, in part, by the lactic acidosis due ...
Kilding Andrew E - - 2005
INTRODUCTION: The maximum lactate steady state (MLSS) represents the highest intensity of exercise at which a balance exists between the rate of lactate production and the rate of lactate clearance. The MLSS is an important determinant of endurance exercise performance but its determination, which involves 4-5 laboratory visits, is labor-intensive ...
Gröhn Y T - - 2005
The objective of this study was to estimate the effects of clinical mastitis (CM) (both with and without specific pathogen identification) occurring in different stages of lactation on length of herd life in two New York State dairy farms. The 2,697 cows in the study were followed for one lactation ...
Kato Takahide - - 2005
The present study examined the effects of hypercapnia on changes in blood pH, plasma lactate and ammonia due to exhaustive exercise. Six male subjects underwent exercise of increasing intensity until exhaustion: (1) breathing air = MAX (maximal exercise), or (2) under hypercapnia (HC: 21% O(2), 6% CO(2)) that had been ...
Li Jia - - 2005
OBJECTIVE: We assessed the causes of imbalance of oxygen transport by continuously measuring oxygen consumption (VO2) during hypothermic cardiopulmonary bypass (CPB) in pigs. METHODS: Six pigs (17.2+/-1.6 kg) underwent hypothermic (32 degrees C) CPB for 180 min with 120 min of aortic crossclamping (ACC). An AMIS 2000 mass spectrometer was ...
Dekerle J - - 2005
Critical power and critical swimming speed (CSS) are mathematically defined as intensities that could theoretically be maintained indefinitely without exhaustion. Several investigations have been conducted to attribute a physiological meaning to these variables, but results in swimming remain equivocal. Thus, the purpose of this study was to compare CSS with ...
Vissing John - - 2005
BACKGROUND: Muscle phosphoglycerate mutase deficiency (PGAMD) is a rare, recessively inherited metabolic myopathy that affects one of the last steps of glycolysis. Clinically, PGAMD resembles muscle phosphorylase deficiency (McArdle disease) and phosphofructokinase deficiency (PFKD). However, it is unknown whether PGAMD is associated with a second-wind phenomenon during exercise, as in ...
Doutreleau Stéphane - - 2005
The purpose of this study was to determine, in heart failure patients (HF), whether acute or chronic L-arginine supplementation (LAS) might delay the ventilatory threshold (VT) and whether chronic LAS might reduce exercise-induced plasma lactate increase. HF patients undertook 4 cardiopulmonary bicycle exercises tests. The first 3 were maximal without ...
McMorris T - - 2005
OBJECTIVES: To examine how exercise at moderate and maximal intensities affects performance on a choice response time, whole body psychomotor task. METHODS: Subjects (n = 12) were tested on a three-choice response time task, after rest and after exercise at 70% and 100% maximum power output (W*max). The dependent variables ...
Beneke Ralph - - 2005
Whether age-related differences in blood lactate concentrations (BLC) reflect specific BLC kinetics was analyzed in 15 prepubescent boys (age 12.0 +/- 0.6 yr, height 1.54 +/- 0.06 m, body mass 40.0 +/- 5.2 kg), 12 adolescents (16.3 +/- 0.7 yr, 1.83 +/- 0.07 m, 68.2 +/- 7.5 kg), and 12 ...
Zavorsky Gerald S - - 2005
OBJECTIVE: The purpose was to determine whether arterialized fingertip blood-gas samples are comparable to arterial samples at rest and at exercise. DESIGN: Repeated measures, with subjects serving as their own controls. SETTING: Department of Anesthesia, Montreal General Hospital, Montreal, Quebec, Canada, (January to April 2004). PARTICIPANTS: Fifteen healthy men (age ...
Meredith Carolyn - - 2005
Each year, reports occur of deaths in individuals, while struggling against physical restraint. The mechanism of these deaths remains unclear. This study aimed to determine the effect of wrist restraint on cardiorespiratory function during maximal exercise. Twelve healthy volunteers underwent 3 incremental maximal exercise tests on a cycle ergometer. In ...
Olek Robert A - - 2005
In this work, we investigated the influence of NADH on the redox state of myoglobin and the roles of pyruvate and lactate in this process. NADH increased the autoxidation rate of myoglobin. Both a drop in pH and partial deoxygenation markedly stimulated the autoxidation process and the influence of NADH. ...
Moorcroft A J - - 2005
The purpose of this study was to investigate symptoms, lactate accumulation and limiting factors at peak exercise in cystic fibrosis (CF) patients. In total, 104 CF adults attending an adult CF centre and 27 controls performed progressive cycle ergometry to a symptom-limited maximum. Measurements taken at peak exercise included: heart ...
Kashihara Koji - - 2005
The duration of the enhancement of choice reaction task efficiency by physical exercise at lactate threshold was studied. After healthy male students completed the exercise or nonexercise (control) period for 10 min., they performed a three-choice reaction task for 20 min. The mean heart rate during the choice reaction task ...
Burmeister Jason J - - 2005
A newly developed multisite array microelectrode for in vivo measurements of L-lactate is presented. The resulting microelectrode is composed of three functional layers. First, Nafion is used to repel interfering electroactive anions, such as ascorbate. Second, L-lactate oxidase immobilized onto the recording sites is used to convert L-lactate to hydrogen ...
Binzoni Tiziano - - 2005
It is demonstrated, that the bioenergetic model combined with the mathematical constraints determined by the experimental knowledge of the aerobic metabolism and the Lohmann reaction dictates the exact lactate (La)-time relationship during exercise. The theory predicts that La is necessarily produced (above the resting baseline), even during extremely low work ...
Nagy Peter - - 2005
The occurrence of spontaneous ovulation in dromedaries was examined in two separate studies including 20 non-lactating, barren and 12 lactating dromedaries, respectively. Lactating camels were milked twice a day with an automatic bucket milking machine. Ovarian activity was monitored by repeated ultrasonography. Blood samples for progesterone were collected daily or ...
Dubé Michael P - - 2005
Plasma lactate measurements are typically performed in real time, limiting their usefulness in multicenter or longitudinal studies. To determine the stability of lactate specimens, blood was drawn in sodium fluoride/potassium oxalate tubes from 13 volunteers before and after 5 min of handgrip exercise to intentionally increase lactate concentrations. Plasma was ...
Koch H J - - 2005
Nineteen healthy volunteers were exposed to a standardized exercise test at sea level (SLa), at an altitude of 1700 m before (1700a) and after a moderate 10-day mountain training (1700b), with a final control four weeks later at sea level (SLb). Vital signs, blood lactate and arterial oxygen saturation were ...
Scott Christopher B - - 2005
Whole-body energy expenditure for heavy/severe exercise is currently accounted for by either: (1) anaerobic and oxygen uptake measures during exercise where recovery energy expenditure is omitted; or (2) oxygen uptake during, and an EPOC (excess post-exercise oxygen consumption), measure following exercise where substrate level phosphorylation during exercise is considered part ...
Valenza Franco - - 2005
Lactate measurement in the critically ill has been traditionally used to stratify patients with poor outcome. However, plasma lactate levels are the result of a finely tuned interplay of factors that affect the balance between its production and its clearance. When the oxygen supply does not match its consumption, organisms ...
Moorcroft A J - - 2004
BACKGROUND: Short term studies of exercise training have shown benefits in cystic fibrosis. Transferring exercise programmes to the community and sustaining them long term is a challenge for the patient. The effectiveness of an individualised unsupervised home based exercise programme was examined in adults with cystic fibrosis over a 1 ...
Rosendal Lars - - 2004
Local metabolic changes are suggested to be involved in muscle pain development in humans. Nineteen women with chronic work-related trapezius myalgia (TM) and 20 healthy female controls (CON) were studied during baseline rest, 20 min repetitive low-force exercise, and 120 min recovery. Interstitial serotonin (5-HT), glutamate, lactate, pyruvate, and blood ...
Banaschak S - - 2005
To investigate the potential for estimating the time since death by monitoring the evolution of different metabolites in brain tissue by (1)H-MRS, an animal model using pig heads was established. The maximum examination interval was 3 weeks. Within this time interval spectra revealed different compositions of metabolites, including metabolites observed ...
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