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Results 501 - 550 of 1394
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de Araujo Gustavo Gomes - - 2007
The lactate minimum test (LACmin) has been considered an important indicator of endurance exercise capacity and a single session protocol can predict the maximal steady state lactate (MLSS). The objective of this study was to determine the best swimming protocol to induce hyperlactatemia in order to assure the LACmin in ...
Caruso John F - - 2007
INTRODUCTION: Historically, exercise performance outcomes may be predicted with anthropometric variables such as body mass. To assess body mass and resistance exercise (REX) performance variable correlations to blood lactate values, subjects performed five different workouts on two devices that do not employ gravitational resistance. One device uses flywheels to impose ...
Shi Minyi - - 2007
In addition to having health-promoting effects, exercise is considered to induce oxidative stress. To clarify whether increased oxygen consumption during exercise induces oxidative stress, we investigated the effects of aerobic exercise and anaerobic exercise on a series of oxidative damage markers. One group of subjects performed aerobic exercise and another ...
Nielsen H B - - 2007
The exponential rise in blood lactate with exercise intensity may be influenced by hepatic lactate uptake. We compared muscle-derived lactate to the hepatic elimination during 2 h prolonged cycling (62 +/- 4% of maximal O(2) uptake, (.)Vo(2max)) followed by incremental exercise in seven healthy men. Hepatic blood flow was assessed ...
Herbert, Neill A.
Restricted Item. Print thesis available in the University of Auckland Library or available through Inter-Library Loan. This thesis addresses aspects of the physiology, behaviour and anatomy of fishes in order to test the hypotheses that (i) visual performance is influenced by metabolic stress and the development of an oxygen concentrating ...
Goodwin Matthew L - - 2007
Blood lactate concentration ([La(-)](b)) is one of the most often measured parameters during clinical exercise testing as well as during performance testing of athletes. While an elevated [La(-)](b) may be indicative of ischemia or hypoxemia, it may also be a "normal" physiological response to exertion. In response to "all-out" maximal ...
Figueira Tiago R - - 2008
The aim of this study was to analyze the effects of exercise mode on the validity of onset of blood lactate accumulation (OBLA-3.5-mM fixed blood lactate concentration) to predict the work-rate at maximal lactate steady state (MLSS(work-rate)). Eleven recreationally active males (21.3+/-2.9 years, 72.8+/-6.7kg, 1.78+/-0.1m) performed randomly incremental tests to ...
Rose Elaine A - - 2007
Using a mixed-method approach, the aim of this study was to explore affective responses to exercise at intensities below-lactate threshold (LT), at-LT, and above-LT to test the proposals of the dual-mode model. These intensities were also contrasted with a self-selected intensity. Further, the factors that influenced the generation of those ...
Kulaputana Onanong - - 2007
BACKGROUND: Ginseng has been one of the most popular herbs said to improve human exercise performance. Unclear and anecdotal information is known about the effect of ginseng on lactate threshold and aerobic performance in humans. OBJECTIVE: The purpose of the present study was to investigate the effect of ginseng supplementation ...
Sargent Charli - - 2007
The lactate threshold (LT) is commonly reported as not different between sexes, yet lower blood lactate concentrations have been reported in women during submaximal exercise. The purpose of the present study was to measure the changes in plasma lactate concentration [La(-1)] in men and women during incremental cycle ergometer exercise ...
Petersen A M - - 2007
We characterized carbohydrate metabolism following activity in the American bullfrog, Rana catesbeiana, and compared whole body metabolic profiles between two seasons. Forty-eight adult male Rana catesbeiana were chronically cannulated and injected with [U-(14)C]L-lactic acid sodium salt in either summer (June) or winter (January) after acclimation for 2 weeks at 15 ...
Meyerspeer Martin - - 2007
A novel method based on interleaved localized 31P- and 1H MRS is presented, by which lactate accumulation and the accompanying changes in high energy phosphates in human skeletal muscle can be monitored simultaneously during exercise and recovery. Lactate is quantified using a localized double quantum filter suppressing the abundant lipid ...
Deghorain Marie - - 2007
Lactobacillus plantarum produces peptidoglycan precursors ending in D-lactate instead of D-alanine, making the bacterium intrinsically resistant to vancomycin. The ligase Ddl of L. plantarum plays a central role in this specificity by synthesizing D-alanyl-D-lactate depsipeptides that are added to the precursor peptide chain by the enzyme MurF. Here we show ...
Provent Peggy - - 2007
The glutamate-glutamine shuttle requires a flux of fixed N from neurons to astrocytes. The suggestion that some or all of this N is ammonium has received support from reports that ammonium (as NH(4)(+)) rapidly enters astrocytes. Ammonium might also help control astrocyte energy metabolism by increasing lactate production. If ammonium ...
Otte Johannes A - - 2007
Gastric exercise tonometry is a functional diagnostic test in chronic gastrointestinal ischemia. As maximal exercise can cause false-positive tests, exercise buildup should be controlled to remain submaximal. We evaluated three parameters for monitoring and adjusting exercise levels (heart rate [HR], respiratory quotient [RQ], and serial lactate measurements) in 178 tests ...
Debray François-Guillaume - - 2007
BACKGROUND: Although the blood lactate-to-pyruvate (L:P) molar ratio is used to distinguish between pyruvate dehydrogenase deficiency (PDH-D) and other causes of congenital lactic acidosis (CLA), its diagnostic accuracy for differentiating between these 2 types of CLA has not been evaluated formally. METHODS: We conducted a retrospective study of all patients ...
Lowinsohn Denise - - 2007
An amperometric l-lactate biosensor was fabricated by confining lactate oxidase in a Prussian Blue-modified electrode with a Nafion membrane. The detector was assembled in a flow injection apparatus and operated at -0.1 V. Conditions for optimal electrode response were determined by investigating the influence of the amount of immobilized enzyme, ...
Solligård E - - 2007
The aim of this prospective study was to determine the feasibility of intestinal endoluminal microdialysis as a new method for clinical monitoring of the adequacy of splanchnic perfusion in the large bowel. A microdialysis catheter for continuous lactate, glycerol, glucose and pyruvate measurements attached to a tonometric catheter was placed ...
Rovira S - - 2007
BACKGROUND: Normal response to different types of exercise needs to be established before performance, training level, or exercise intolerance can be assessed. OBJECTIVES: The aim of this research was to describe the hematologic and biochemical changes that dogs undergo during an agility competition. METHODS: Fifteen dogs were subjected to an ...
Hadsell Darryl - - 2007
In most species the functional activity of the mammary gland during lactation follows a biphasic developmental pattern. This pattern starts with a rapid increase in milk output that occurs with secretory activation and continues with a more gradual increase until the point of peak lactation is reached. Following this gain-of-function ...
Mc Naughton L - - 2007
AIM: The aim of this work was to determine the ergogenic effects of a nucleotide supplement on the metabolic and immune responses to short term high intensity exercise in volunteer, trained, male subjects. METHODS: Thirty moderately trained male subjects were randomly divided into 3 equal sized groups, control (C), placebo ...
Messonnier Laurent - - 2007
We examine the influence of the cytosolic and membrane-bound contents of carbonic anhydrase (CA; CAII, CAIII, CAIV, and CAXIV) and the muscle content of proteins involved in lactate and proton transport [monocarboxylate transporter (MCT) 1, MCT4, and Na(+)/H(+) exchanger 1 (NHE1)] on work capacity during supramaximal exercise. Eight healthy, sedentary ...
Alvarenga R L - - 2007
Bioelectrical Impedance Spectroscopy (BIS) is a noninvasive technology with potential application to study exercise physiology as body composition and estimation of maximal oxygen uptake. The aim of the study was to compare the power at lactate threshold (WLT) obtained using blood lactate concentration (BLC) with the power at lactate threshold ...
Gustafsson J - - 2007
OBJECTIVE: Microdialysis can be used to monitor carbohydrate metabolism and lipolysis in adipose tissue. This method, however, does not discriminate between local metabolite production and delivery from other tissues. Our aim was to study glucose metabolism by direct delivery of 13C-labelled glucose into adipose tissue by microdialysis. MATERIAL AND METHODS: ...
Bentley David J - - 2007
Physiological variables, such as maximum work rate or maximal oxygen uptake (VO2max), together with other submaximal metabolic inflection points (e.g. the lactate threshold [LT], the onset of blood lactate accumulation and the pulmonary ventilation threshold [VT]), are regularly quantified by sports scientists during an incremental exercise test to exhaustion. These ...
Garatachea Nuria - - 2006
The purpose of this investigation was to determine if the critical swimming velocity (CSV), defined as the theoretical maximal swimming velocity that could be maintained for a long period of time without exhaustion, corresponds to the exercise intensity at onset blood lactate accumulation (OBLA), and if it could be utilized ...
Manchado Fúlvia de Barros Fde - - 2006
The aim of this study was to describe a double-bout exercise test for non-exhaustive aerobic capacity determination in swimming rats. Adult rats were submitted to 4 swimming tests at different intensities (4%, 6%, 7%, and 8% of body mass), with intervals of 48 h between them. Two exercise bouts of ...
Gondim Fernando José - - 2007
Maximal blood lactate steady state concentration (MLSS) and anaerobic threshold (AT) have been shown to accurately predict long distance events performance and training loads, as well, in human athletes. Horse endurance races can take up to 160 km and, in practice, coaches use the 4 mM blood lactate concentration, a ...
Bentley D J - - 2007
The purpose of this study was to compare plasma markers of metabolic stress and other physiological parameters during prolonged endurance exercise of different intensity in trained subjects possessing a "high" or "low" lactate threshold (LT) expressed as a percentage (%) of peak power output (PPO). Fifteen trained male cyclists completed ...
Apple J K - - 2006
Holstein steer calves (n = 25) were used to evaluate the effects of treadmill exercise (TME) on blood metabolite status and formation of dark-cutting beef. Calves were blocked by BW (156 +/- 33.2 kg) and assigned randomly within blocks to 1 of 5 TME treatments arranged in a 2 x ...
Larson Abigail J - - 2006
This study attempted to quantify the difference in heart rate and exercise stage at which blood lactate threshold (T(bla)) occurs using 3 different modes of exercise: running, double poling (DP) on roller skis, and skating (SK) on roller skis. Nine elite collegiate cross-country ski racers (4 men, 5 women) served ...
Cavus Erol - - 2006
OBJECTIVE: Direct measurement of brain tissue oxygenation (PbtO2) is established during spontaneous circulation, but values of PbtO2 during and after cardiopulmonary resuscitation (CPR) are unknown. The purpose of this study was to investigate: (1) the time-course of PbtO2 in an established model of CPR, and (2) the changes of cerebral ...
Duffield Rob - - 2007
This study examined the relationship between the V O(2) response, particularly the slow component (SC), muscle metabolite changes and performance during very-heavy exhaustive exercise. Sixteen active females performed a graded exercise test to determine V O(2peak) and the lactate threshold followed 48h later by a constant-load cycle test to exhaustion ...
Garcin M - - 2006
The purpose was to identify the most predictive parameters for perceived exertion and estimated time limit responses at the velocity corresponding to the lactate concentration threshold. The former scale concerns the subject's current status (how hard he feels the exercise currently is) whereas the latter scale deals with a subjective ...
Denton James - - 2006
The purpose of this study was to investigate and compare the acute kinematic, kinetic, and blood lactate responses to continuous and intraset rest loading schemes that differed in terms of rest frequency but not total rest duration. Nine male subjects performed an isoinertial bench press task (6 repetition maximum load) ...
Crisafulli Antonio - - 2006
To verify the relationship between exercise intensity and post-exercise haemodynamics, we studied haemodynamic and lactate responses during 10 min following 3 bicycle tests. Two tests were performed for 3 min at 70% and 130% of the workload corresponding to anaerobic threshold (70% W(at) and 130% W(at) tests), and 1 was ...
Levy Bruno - - 2006
PURPOSE OF REVIEW: The conventional view in severe sepsis or septic shock is that most of the lactate that accumulates in the circulation is due to cellular hypoxia and the onset of anaerobic glycolysis. A number of papers have suggested that lactate formation during sepsis is not due to hypoxia. ...
Chen Jia-Xu - - 2007
This study was designed to investigate the effect of acute and chronic high-intensity treadmill exercise on changes in plasma lactate and brain neuropeptide (NPY), leucine-enkephalin (L-ENK), and dynorphin A(1-13) (DYN A(1-13)). Avidin-biotin complex (ABC) immunohistochemistry and image pattern analysis were used to observe the effect of chronic (total 7 weeks) ...
Dascombe B J - - 2007
The purpose of this investigation was to assess the reliability of the i-STAT clinical portable analyser and CG(4)(+) cartridge measures of blood pH, partial pressures of O(2) (pO(2)) and CO(2) (pCO(2)), bicarbonate ([HCO(3)(-)]), base excess (BE), total carbon dioxide (TCO(2)), oxygen saturation (sO(2)) and blood lactate ([BLa(-)]) at various exercise ...
Irving Brian A - - 2006
PURPOSE: To examine the utility of the Borg (6-20) and adult OMNI walk/run (0-10) ratings of perceived exertion (RPE) scales as markers of the blood lactate response to exercise. METHODS: Thirty-six (26 females and 10 males) individuals with the metabolic syndrome (mean+/-SEM: age, 45.8+/-2.0 yr; height, 168.4+/-1.3 cm; weight, 100.4+/-3.6 ...
Bicalho R C - - 2006
The objectives of the study were to evaluate the effects of digit amputation and arthrodesis surgery performed in the field on culling and milk production during the early postsurgical period. Cows from 3 commercial dairy farms in New York State were recruited for the study. A total of 49 cows ...
Caruso John F - - 2006
INTRODUCTION: A flywheel ergometer has been devised which employs gravity-independent inertial resistance. Concentric and eccentric actions, which are integral to weight-bearing and ambulation activities, may be done on this ergometer. However, blood lactate responses to exercise on the ergometer by contractile mode and training volume are unknown. METHODS: Workout order ...
Rasmussen Peter - - 2006
Regulation of cerebral blood flow during physiological activation including exercise remains unknown but may be related to the arterial lactate-to-pyruvate (L/P) ratio. We evaluated whether an exercise-induced increase in middle cerebral artery mean velocity (MCA Vmean) relates to the arterial L/P ratio at two plasma lactate levels. MCA Vmean was ...
Liesegang A - - 2007
During gestation and lactation, an increased demand for calcium (Ca) due to the development of fetal skeleton and excretion via milk is observed. The higher need for Ca is met by an augmented mobilisation of Ca from bones and by an increased absorption from the intestines. The main influence on ...
Dalsgaard Mads K - - 2006
The metabolic response to brain activation in exercise might be expressed as the cerebral metabolic ratio (MR; uptake O2/glucose + 1/2 lactate). At rest, brain energy is provided by a balanced oxidation of glucose as MR is close to 6, but activation provokes a 'surplus' uptake of glucose relative to ...
Peinado Pedro J B - - 2006
OBJECTIVE: To study acid-base status during a constant-load treadmill test at exercise levels close to the maximum lactate steady-state. DESIGN: Two tests were performed: one maximal and one steady-state at a load corresponding to the mean of the two ventilatory thresholds observed in the first test. SETTING: University Sports Science ...
Chudalla R - - 2006
To evaluate the relationship between lactate release and [lac](art) and to investigate the influence of the catecholamines on the lactate release, 14 healthy men [age 25+/-3 (SE) year] were studied by superimposing cycle on forearm exercise, both at 65% of their maximal power reached in respective incremental tests. Handgrip exercise ...
Hanisch Frank - - 2006
BACKGROUND: The nonischemic forearm exercise test (NIFET) has been shown to be as effective as the classic ischemic forearm exercise test (IFET) in the diagnosis of patients with McArdle disease. Recently, the lactate increase normalized to the mechanical energy production in NIFET was suggested to have a intermediate sensitivity and ...
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 ...
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