Search Results
Results 751 - 800 of 1436
< 11 12 13 14 15 16 17 18 19 20 21 >
Baragli P - - 2001
The aim of the present study was to test a constant blood withdrawal method (CBWM) to collect blood samples from horses during treadmill exercise. CBWM was performed in 4 Standardbreds and 5 Haflinger horses. A peristaltic pump was used to control blood aspiration from an i.v. catheter via an extension ...
Siciliano G - - 2001
The pathogenic mechanism of selective loss of motor neurones in amyotrophic lateral sclerosis (ALS) is still poorly understood. Recently, research evidence has suggested that mitochondrial dysfunction occurs in central nervous system as well as in peripheral tissues from ALS patients. The aim of our study was to indirectly investigate in ...
Evertsen F - - 2001
The training intensity may affect the monocarboxylate transporters MCT1 and MCT4 in skeletal muscle. Therefore, 20 elite cross-country skiers (11 men and nine women) trained hard for 5 months at either moderate (MIG, 60-70% of VO2max) or high intensity (HIG, 80-90%). The lactate threshold, several performance parameters, and the blood ...
Chatham J C - - 2001
The simultaneous release and uptake of lactate by the heart has been observed both in vivo and ex vivo; however, the pathways underlying these observations have not been satisfactorily explained. Consequently, the purpose of this study was to test the hypothesis that hearts release lactate from glycolysis while simultaneously taking ...
Lott M E - - 2001
We examined the effects of dynamic one-legged knee extension exercise on mean blood velocity (MBV) and muscle interstitial metabolite concentrations in healthy young subjects (n = 7). Femoral MBV (Doppler), mean arterial pressure (MAP) and muscle interstitial metabolite (adenosine, lactate, phosphate, K(+), pH, and H(+); by microdialysis) concentrations were measured ...
Bishop D - - 2001
It has been suggested that lactate concentrations may provide a guide to an optimal training intensity. However, lactate concentrations established during incremental exercise in the laboratory are not always indicative of what is occurring during constant-load exercise at the same intensity. Ideally, lactate concentrations should be measured during a training ...
Mercer T H - - 2001
This study investigated the reproducibility of blood lactate-anchored ratings of perceived exertion (RPE) in seven women of average, and seven of above average cardiorespiratory fitness, [moderate and high maximal oxygen uptake (Mod VO2max and High VO2max, respectively)]. The subjects completed a series of four exercise tests, comprising a VO2max assessment ...
Buckley J D - - 2001
A number of training adaptations in skeletal muscle might be expected to enhance lactate extraction during hyperlactataemia. The aim of the present study was to determine whether resting endurance-trained forearms exhibit an increased net lactate removal during hyperlactataemia. Six racquet-sport players attended the laboratory for two experiments, separated by 2 ...
Finsterer J - - 2001
Usually, the lactate stress test is carried under a constant, low workload maintained for 15 min, although there are indications that the lactate response to exercise is a function of the relative workload, and that a workload for only 5 min does not decrease its sensitivity. Thus, this study compared ...
Smith C G - - 2001
In cycle exercise, it has been suggested that critical power, maximal lactate steady state, and lactate turnpoint all demarcate the transition between the heavy exercise domain (in which blood lactate is elevated above resting values but remains stable over time) and the very heavy exercise domain (in which blood lactate ...
Barillet F - - 2001
Genetic analysis for mastitis resistance was studied from two data sets. Firstly, risk factors for different mastitis traits, i.e. culling due to clinical or chronic mastitis and subclinical mastitis predicted from somatic cell count (SCC), were explored using data from 957 first lactation Lacaune ewes of an experimental INRA flock ...
Väihkönen L K - - 2001
In red blood cells (RBC) of horses, both lactate-transport activity and lactate accumulation during races vary interindividually. To study whether similar variation in lactate transport is apparent also in RBCs of other racing species, blood samples were collected from 21 reindeer, 40 horses, 31 humans, and 38 dogs. Total lactate-transport ...
Grassi B - - 2001
Anecdotal observations suggest that the reduction in peak lactate accumulation in blood ([La]b peak) after exhausting exercise, in chronic hypoxia vs. normoxia, may be related to the duration of the exercise protocol, being less pronounced after short supramaximal exercise than after incremental exercise (IE) lasting several minutes. To test this ...
Hogrel J Y - - 2001
BACKGROUND: The forearm exercise test is a common investigation that allows detection of some metabolic myopathies. It is not completely standardized and, when performed in ischemic conditions, may induce rhabdomyolysis in patients with glycogenosis. OBJECTIVE: To develop a standardized non-ischemic exercise test for a safe screening of patients with exercise ...
Harnish C R - - 2001
PURPOSE: Maximal lactate steady state (MLSS) is the highest exercise intensity at which blood lactate concentration (HLa) remains stable. In this study, we examined the validity of simulated 5-km and 40-km time trials (TT) as methods for estimating average speed at MLSS in cyclists. METHODS: Nine trained cyclists reported to ...
Kinugawa T - - 2001
Purine degradation occurs during strenuous muscle exercise and plasma levels of hypoxanthine (HX), purine degradation intermediate, increase. Purine nucleotide degradation has not been investigated in patients with essential hypertension (HTN). The present study determined whether purine nucleotide degradation is altered in patients with HTN. Cardiopulmonary exercise test was performed with ...
Beneke R - - 2001
BACKGROUND: Blood lactate concentration (BLC) can be used to monitor relative exercise intensity. The highest BLC representing an equilibrium between lactate production and elimination is termed maximal lactate steady state (MLSS). MLSS is used to discriminate qualitatively between continuous exercise, which is limited by stored energy, from other types of ...
Serrano M A - - 2001
Relationships between perceived exertion and blood lactate have usually been studied in laboratory or training contexts but not in competition, the most important setting in which sports performance is evaluated. The purpose of this study was to examine the relationships between psychological and physiological indices of the physical effort in ...
Fell J W - - 2001
The physiological profiles of 17 open grade (OG) and 13 reserve grade (RG) male surfboat rowers (SBR) aged 19-44 years were determined and compared. Parameters investigated included anthropometry, agility, isometric strength, flexibility, rowing ergometer performance (MT), peak VO2 and arterialised blood pH, lactate and bicarbonate. Means were compared using t-tests. ...
Cranford J L - - 2001
The relationship between sire predicted transmitting ability (PTA) for somatic cell score (SCS) and occurrence of mastitis in daughters was characterized with 304 Holsteins first freshening since 1991 in the Virginia Tech dairy herd. No direct sire selection for PTA SCS was practiced in the herd. Linear regressions of first ...
Bergmann M - - 2001
Crustacean discards experience stress during commercial fishing operations, due to increased exercise while in the trawl and aerial exposure during sorting of the catch. Physiological stress and recovery were assessed following trawling of two ecologically important decapod species, regularly discarded in the Clyde Nephrops fishery. Haemolymph samples taken from trawled ...
Vissing J - - 2001
In a double-blinded, placebo-controlled, crossover study in seven mitochondrial myopathy patients (MM), we investigated whether lowering of lactate with dichloroacetate (DCA) can improve exercise tolerance and oxidative capacity in MM. DCA lowered plasma lactate at rest and during exercise (from 10.5 +/- 2.0 to 5.0 +/- 1.6 mM; p = ...
Messonnier L - - 2001
The effects of 4 weeks of endurance training in conditions of normoxia or hypoxia on muscle characteristics and blood lactate responses after a 5-min constant-load exercise (CLE) at 90% of the power corresponding to the maximal oxygen uptake were examined at sea-level in 13 sedentary subjects. Five subjects trained in ...
Bradley K J - - 2001
The superficial supramammary lymph nodes of 54 lactating dairy cows were examined ultrasonographically with a 7.5 MHz linear transducer; each node was measured in two planes within 24 hours of recording the milk somatic cell count. In most cows, the nodes were well demarcated from the surrounding tissue. The parenchyma ...
Rodríguez E M - - 2001
Whole body oxygen consumption and some hemolymph parameters such as pH, partial pressure of gases, level of ions and lactate were measured in the estuarine crab Chasmagnathus granulata after both acute (96 h) and chronic (2 weeks) exposure to cadmium at concentrations ranging from 0.4 to 6.3 mg/l. In all ...
Sumida K D - - 2001
The effects of endurance training (running 40 m/min grade for 60 min, 5 days/wk for 8 wk) on skeletal muscle lactate removal was studied in rats by utilizing the isolated hindlimb perfusion technique. Hindlimbs were perfused (single-pass) with Krebs-Henseleit bicarbonate buffer, fresh bovine erythrocytes (hematocrit approximately 30%), 10 mM lactate, ...
Arbel R - - 2001
A field trial was conducted to examine the effect of extended calving interval (CI) on production and profitability of high yielding cows (n = 937). First insemination was performed at 154 and 93 d postpartum (pp), for treatment and control primiparous cows, respectively, and at 124 and 71 d pp ...
Pinnington H - - 2001
Clough et al. (1997) reported that 95% of lactate values obtained using an Accusport analyser may be up to 2.6 mM below or 2.1 mM above YSI 2300 analyser values over the range 0-16 mM. This variability is substantial and unsuitable for research purposes, The objectives of this study were ...
Pyne D B - - 2001
PURPOSE: To determine whether lactate profiling could detect changes in discrete aspects of endurance fitness in world-ranked swimmers during a season. METHODS: Eight male and four female Australian National Team swimmers aged 20--27 yr undertook a 7 x 200-m incremental swimming step test on four occasions over an 8-month period ...
Heenan A P - - 2001
OBJECTIVE: To study the effects of human pregnancy on metabolic and respiratory responses to maximal cycle ergometer testing and to test the hypothesis that the respiratory exchange ratio at maximal exercise and peak postexercise lactate concentration are lower in the pregnant compared with the nonpregnant state and that these effects ...
Cooper R A - - 2001
OBJECTIVE: This study investigated the blood lactate accumulation during two wheelchair-racing protocols. During exercise, energy is required, which causes metabolism to increase and blood lactate to accumulate. Proper training can reduce the amount of blood lactate accumulation and increase tolerance to blood lactate accumulation during aerobic exercise. METHODS: Eleven male ...
Lan C - - 2001
Tai Chi Chuan (TCC) is a popular Chinese conditioning exercise, however, its exercise intensity remains controversial. The objective of this study was to determine the exercise intensity of Yang TCC by measuring heart rate (HR) responses and oxygen consumption (VO2) during practice. Fifteen men aged 39.9 +/- 9.5 yrs (range ...
Tomlin D L - - 2001
A strong relationship between aerobic fitness and the aerobic response to repeated bouts of high intensity exercise has been established, suggesting that aerobic fitness is important in determining the magnitude of the oxidative response. The elevation of exercise oxygen consumption (VO2) is at least partially responsible for the larger fast ...
Hollmann W - - 2001
At the Third Pan-American Congress of Sport Physicians in Chicago in 1959 we reported the physiological and clinical significance of the spiroergometric determination of the aerobic-anaerobic turnover point for judging the performance of sick and healthy persons for the first time. In this context a distinction was made between a ...
Coen B - - 2001
The present study was designed in order to examine the objectivity and reliability of the individual anaerobic threshold (IAT) as well as its resistance against several interfering factors: missing exhaustion, preliminary exercise, longer step duration, and lower speed increment. 87 male and 24 female runners and triathletes were examined. They ...
Bosquet L - - 2001
Many physiological markers vary similarly during training and overtraining. This is the case for the blood lactate concentration ([La-]b), since a right shift of the lactate curve is to be expected in both conditions. We examined the possibility of separating the changes in training from those of overtraining by dividing ...
Castillo M - - 2001
BACKGROUND AND PURPOSE: Decreases in N-acetyl aspartate (NAA) as seen by proton MR spectroscopy are found in hippocampal sclerosis, and elevated levels of lipids/lactate have been observed after electroconvulsive therapy. Our purpose was to determine whether increased levels of lipids/lactate are found in patients with acute seizures of hippocampal origin. ...
Baldari C - - 2000
BACKGROUND: The individual anaerobic threshold (IAT) is defined (18) as the highest metabolic rate where blood lactate (La) concentrations are maintained at a steady-state during prolonged exercise. Stegmann et al.'s (18) method to detect IAT, using La-performance relationship during incremental graded exercise, is based on the assumption that La is ...
Hildebrand A - - 2000
The purpose of this study was to investigate the distribution of lactate in plasma and red blood cells (RBC) in capillary blood during and after incremental exercise. We measured capillary plasma lactate and whole blood lactate of 10 subjects during incremental treadmill running and the first 20 min of recovery. ...
Parolin M L - - 2000
During the onset of exercise in hypoxia, the increased lactate accumulation is associated with a delayed activation of pyruvate dehydrogenase (PDH; Parolin ML, Spreit LL, Hultman E, Hollidge-Horvat MG, Jones NL, and Heigenhauser GJF. Am J Physiol Endocrinol Metab 278: E522-E534, 2000). The present study investigated whether activation of PDH ...
Murakami M - - 2000
The purpose of this study was to measure O2 consumption of nonexercising skeletal muscles (VO2nonex) at rest and after aerobic exercise and to investigate the stimulant factors of O2 consumption. In experiment 1, we measured the resting metabolic rate of the finger flexor muscles in seven healthy males by 31P-magnetic ...
Collomp K - - 2000
To assess the eventual effects of acute oral salbutamol intake on performance and metabolism during submaximal exercise, nine healthy volunteers completed two cycling trials at a power corresponding to 80-85% VO2max, after either placebo (Pla) or salbutamol (Sal, 6 mg) treatment, according to a double-blind randomized protocol. Blood samples were ...
Baldwin J - - 2000
PURPOSE: This study examined the effect of training status and relative exercise intensity on physiological responses to endurance exercise in humans. METHODS: Seven endurance trained (TR: peak oxygen uptake [VO2peak] = 65.8 +/- 2.4 mL x kg(-1) min(-1)) and six untrained (UT: VO2peak = 46.2 +/- 1.9 mL x kg(-1) ...
Ogino K - - 2000
1. We evaluated the plasma ammonia response to constant exercise at different intensities. Ten healthy male volunteers were asked to perform constant exercise for 15 min at five different intensities: 80, 90, 100, 110 and 120% of their ventilatory threshold (VT). Blood concentrations of lactate, ammonia and hypoxanthine were measured ...
Roecker K - - 2000
The so-called excess-CO2 in physical exertion results stoichiometrically directly from the quantity of protons bound in bicarbonate buffering. This situation is used in determining the ventilatory threshold (VT). However, the extent to which the degree and increase characteristics of excess-CO2 can be used as an equivalent to blood lactate concentrations ...
Trueblood N A - - 2000
Nicotinic acid (niacin) has been shown to decrease myocyte injury. Because interventions that lower the cytosolic NADH/NAD(+) ratio improve glycolysis and limit infarct size, we hypothesized that 1) niacin, as a precursor of NAD(+), would lower the NADH/NAD(+) ratio, increase glycolysis, and limit ischemic injury and 2) these cardioprotective benefits ...
Lajoie C - - 2000
Changes in physiological variables during a 60-min continuous test at maximal lactate steady state (MLSS) were studied using highly conditioned cyclists (1 female and 9 males, aged 28.3 +/- 8.1 years). To determine power at MLSS, we tested at 8-min increments and interpolated the power corresponding to a blood lactate ...
Solberg E E - - 2000
OBJECTIVE: To compare the efficacy in runners of two relaxation techniques with regard to exercise reactivity and recovery after exercise. METHODS: Thirty one adult male runners were studied prospectively for six months in three groups practising either meditation (n = 11) or autogenic training (n = 11) or serving as ...
Eydoux N - - 2000
We investigated the effects of a single bout of non-exhaustive exercise (25 m x min(-1), 10% grade, for 30 min) on the initial rates of lactate uptake in rat skeletal muscle sarcolemmal vesicles and the monocarboxylate transporter 1 (MCT1) content in isolated hindlimb muscles in relation to the exercise-induced oxidative ...
Claessen C C Department of Internal Medicine, University Hospital Gasthuisberg, Leuven, - - 2000
Endurance sports require a variety of physiological adaptations. To examine the structural and functional heart adaptations and their hemodynamic implications in triathletes. A group of 52 male triathletes was compared with a control group of 22 healthy male nonathletes. All of the subjects were given a bidimensional cardiac Doppler echocardiography ...
< 11 12 13 14 15 16 17 18 19 20 21 >