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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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) ...

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 ...

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. ...

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) ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 = ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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, 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, 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, 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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...