Search Results
Results 401 - 450 of 1266
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Wergel-Kolmert U - - 1999
The day-to-day variation in oxygen consumption (VO2) and energy expenditure (EE) during horizontal treadmill walking was measured using indirect calorimetry in 20 female adolescents (mean age 17.3 years). Two different walking speeds were used: 5 km h-1 and an individually convenient speed of 3.0 km h-1 (mean). The two sets ...
van Eeden S F - - 1999
The pulmonary vascular bed is an important reservoir for the marginated pool of leukocytes that can be mobilized by exercise or catecholamines. This study was designed to determine the phenotypic characteristics of leukocytes that are mobilized into the circulation during exercise. Twenty healthy volunteers performed incremental exercise to exhaustion [maximal ...
Brunner-La Rocca H P - - 1999
OBJECTIVE: To investigate whether oxygen uptake (VO2) kinetics during low intensity exercise are related to clinical signs, symptoms, and neurohumoral activation independently of peak oxygen consumption in chronic heart failure. DESIGN: Comparison of VO2 kinetics with peak VO2, neurohormones, and clinical signs of chronic heart failure. SETTING: Tertiary care centre. ...
Chicharro J L - - 1999
A blood lactate concentration of 4 mmol x l-1 (OBLA) is frequently used as an indicator of the maximal steady state of lactate (MLSS) for workload planning in training programs. The aim of the present investigation was to compare several metabolic parameters determined at OBLA and at a fixed heart ...
James D V - - 1999
Elevated oxygen uptake (VO2) during moderate-intensity running following a bout of interval running training has been studied previously. To further investigate this phenomenon, the VO2 response to high-intensity exercise was examined following a bout of interval running. Well-trained endurance runners were split into an experimental group [maximum oxygen uptake, VO2max ...
Armstrong N - - 1999
The aim of this study was to examine the maturation responses of young people to submaximal treadmill exercise. Body mass was controlled using both the conventional ratio standard and allometric modelling. Ninety-seven boys and 97 girls with a mean age of 12.2 years completed a discontinuous, incremental exercise test to ...
Hoogeveen A R - - 1999
The purpose of this study was to investigate the validity of the ventilatory response during incremental exercise as indication of endurance performance during prolonged high-intensity exercise under field test conditions in elite cyclists. The ventilatory threshold (VT) was assessed in 14 male elite cyclists (age 22.4+/-3.4 years, height 181+/-6 cm, ...
Kiens B - - 1999
We measured the content of long-chain fatty acids (LCFA) in biopsies obtained from the vastus lateralis muscle in humans at rest and after different exercise intensities. Nine volunteers exercised at 65% of maximal oxygen uptake (VO2 max) for 40 min and at 90% of VO2 max for another 15 min ...
Bergman B C - - 1999
We evaluated the hypotheses that endurance training increases relative lipid oxidation over a wide range of relative exercise intensities in fed and fasted states and that carbohydrate nutrition causes carbohydrate-derived fuels to predominate as energy sources during exercise. Pulmonary respiratory gas-exchange ratios [(RER) = CO2 production/O2 consumption (VO2)] were determined ...
Ramos-Barbón D D Department of Medicine, Royal Victoria Hospital, McGill University, Montreal, Quebec, - - 1999
Peak exercise oxygen consumption (peak VO2), which is considered an indicator of prognosis in advanced heart failure, is currently being used as a major criterion in many centers for the selection of candidates for heart transplantation. Available studies suggest that patients with peak VO2 < 14 mL/min/kg have improved survival ...
Bader D S - - 1999
To evaluate whether individualized ramp protocols may be better than step protocols in patients > or = 60 years of age referred for exercise testing, peak cardiopulmonary responses and accuracy in prediction of oxygen uptake (VO2) for individualized ramp and step protocols (Bruce or modified Bruce) were compared. Twenty-four subjects ...
Irita K - - 1999
Little attention has been paid to oxygen demand/supply balance during the cooling phase of cardiopulmonary bypass (CPB). We examined the changes in systemic oxygen utilization caused by the initiation of deep hypothermic CPB. METHODS: We calculated the changes in systemic oxygen consumption (VO2) and its related parameters in 5 patients ...
Kusenbach G - - 1999
Patients with cystic fibrosis (CF) have been shown to exhibit impaired oxygen uptake (VO2) kinetics independent of their physical fitness. This study investigated whether oxygen supplementation improves VO2 kinetics in CF as determined by cycle ergometry at submaximal exercise intensities using a pseudo-random binary sequence exercise test i.e. a simultaneous ...
Edwards A M - - 1999
The aim of the study was to examine whether a measure of oxygen uptake (VO2) kinetics could differentiate between 12 elite male endurance (3000-10,000 m) runners and 12 elite male sprint (100-400 m) runners using a pseudo random binary sequence (PRBS) exercise protocol. All exercise tests were performed on an ...
Le Gallais D - - 1999
Previous studies have reported respiratory, cardiac and muscle changes at rest in triathletes 24 h after completion of the event. To examine the effects of these changes on metabolic and cardioventilatory variables during exercise, eight male triathletes of mean age 21.1 (SD 2.5) years (range 17-26 years) performed an incremental ...
Petrella R J - - 1999
This study examined the effect of the phenylalkylamine calcium channel blocker verapamil, on resting left ventricular (LV) function and O2 uptake rate (VO2) during exercise at maximal and submaximal work rates. Nine older hypertensive (71 years; OH), 10 older sedentary normotensive (69 years; OS), 10 older active (71 years; OA) ...
Jones M A MA Department of Movement Science and Physical Education, University of Liverpool, - - 1998
The primary aim was to assess cardiovascular responses of expert and novice subjects to kung fu techniques. It was hypothesised that experienced subjects would demonstrate improved economy of movement during the techniques, evidenced by reduced exercise intensity. a comparative design was established utilising two groups; experienced (group E), and novice ...
Friedlander A L - - 1998
We examined the effects of exercise intensity and training [12 wk, 5 days/wk, 1 h, 75% peak oxygen consumption (VO2 peak)] on lipolysis and plasma free fatty acid (FFA) flux in women (n = 8; 24.3 +/- 1.6 yr). Two pretraining trials (45 and 65% of VO2 peak) and two ...
Gurney A B - - 1998
This study was designed to investigate the effects of detraining that occurred during an 8 week period of muscular inactivity following a 12 week training program of artificial computerized functional electrical stimulation cycle ergometry (CFES LE) and arm ergometry. Six spinal cord injured male individuals were followed through an 8 ...
Bernard O - - 1998
During high-intensity running, the oxygen uptake (VO2) kinetics is characterised by a slow component which delays the attainment of the steady-state beyond the 3rd min of exercise. To assess if the aerobic energy cost of running measured at the 3rd min (C3) adequately reflects the variability of the true aerobic ...
Phillips W T - - 1998
The purpose of this pilot study was to compare the contribution of upper body musculature to VO2 with and without concurrent leg FES (LFES). Eight subjects with spinal cord injury, lesion levels range C6-T12, performed upper body exercise (UBE) during no LFES (NOS), LFES at 40 mA (LOS), and 80 ...
MacDonald M J - - 1998
We tested the hypothesis that the slower increase in alveolar oxygen uptake (VO2) at the onset of supine, compared with upright, exercise would be accompanied by a slower rate of increase in leg blood flow (LBF). Seven healthy subjects performed transitions from rest to 40-W knee extension exercise in the ...
Hebestreit H - - 1998
The objective of this study was to compare the O2 uptake (VO2) kinetics at the onset of heavy exercise in boys and men. Nine boys, aged 9-12 yr, and 8 men, aged 19-27 yr, performed a continuous incremental cycling task to determine peak VO2 (VO2 peak). On 2 other days, ...
Hjeltnes N - - 1998
Individuals with cervical spinal cord lesions are characterised by markedly decreased aerobic capacity, accompanied by increased risk of developing cardiovascular disease. The aim of this study was to evaluate the effects of a primary rehabilitation programme that included three sessions of arm cycling per week on the endurance capacity in ...
Green H J - - 1998
Muscle biopsies were performed on the vastus lateralis muscle prior to and during a high-resistance training (HRT) programme in order to examine the effects of hypertrophy on sarcoplasmic reticulum Ca2+ ATPase activity at rest and during exercise. In six male untrained volunteers (peak aerobic power, Vo2 peak = 3.39 +/- ...
Takaki H - - 1998
The transient response of oxygen uptake (VO2) to submaximal exercise, known to be abnormal in patients with cardiovascular disorders, can be useful in assessing the functional status of the cardiocirculatory system, however, a method for evaluating it accurately has not yet been established. As an alternative approach to the conventional ...
Friedlander A L - - 1998
We examined the hypothesis that glucose flux was directly related to relative exercise intensity both before and after a 12-wk cycle ergometer training program [5 days/wk, 1-h duration, 75% peak O2 consumption (VO2 peak)] in healthy female subjects (n = 17; age 23.8 +/- 2.0 yr). Two pretraining trials (45 ...
Zoładź J J Department of Physiology and Biochemistry, AWF, Kraków, Poland. - - 1998
Five healthy non-smoking men, aged 22.2 +/- 0.8 years (mean SD), VO2 max 50.2 +/- 6.2 ml.min-1.kg-1) performed two 6 minutes constant power output (PO) bouts of cycling at 70 rev.min-1, separated by a 20 minutes of rest. The power output during the first bout of exercise corresponded to 40% ...
Yamasaki M - - 1998
The purpose of this study was to elucidate the main physical factor(s) affecting cardiorespiratory responses during maximal arm cranking exercise in patients with paraplegia. Peak oxygen uptake (peak Vo2), peak pulmonary ventilation (peak VE) and peak heart rate (peak HR) were measured during maximal arm cranking exercise in 28 Japanese ...
Tordi N - - 1998
The effects of a 6 weeks interval training with a wheelchair ergometer on the power and endurance of the upper limbs (UL) were studied in ten young able-bodied males. All subjects performed a maximal progressive test (10 W/2 min) on a wheelchair ergometer to measure the ventilation (VE), respiratory exchanges ...
Epstein S K - - 1998
Exercise limitation in cirrhosis is typically attributed to a cirrhotic myopathy (without impaired oxygen utilization) and/or a cardiac chronotropic dysfunction. We performed symptom-limited cardiopulmonary exercise testing in 19 cirrhotics without confounding variables (cardiopulmonary disease, beta blockade, anemia, smoking). Twelve concurrently exercised patients without cirrhosis and with normal resting pulmonary function ...
Belardinelli R - - 1998
The aim of the present study was to determine the kinetics of recovery of muscle oxygenation (MO) from comparable levels of exercise in chronic heart failure (CHF) patients and normal subjects and to relate MO kinetics to the level of exercise intolerance. The rationale is based on the observation that ...
Harms C A - - 1998
We have recently demonstrated that changes in the work of breathing during maximal exercise affect leg blood flow and leg vascular conductance (C. A. Harms, M. A. Babcock, S. R. McClaran, D. F. Pegelow, G. A. Nickele, W. B. Nelson, and J. A. Dempsey. J. Appl. Physiol. 82: 1573-1583, 1997). ...
Vaquero A F - - 1998
Peak oxygen consumption (peak VO2) has become a critical component in the evaluation of heart transplant recipients (HTR). In these patients, peak VO2 remains low after cardiac transplantation mainly because of persisting peripheral limitations in the working muscles. Muscular electrical stimulation, on the other hand, has been shown to enhance ...
Putman C T - - 1998
Muscle metabolism, including the role of pyruvate dehydrogenase (PDH) in muscle lactate (Lac-) production, was examined during incremental exercise before and after 7 days of submaximal training on a cycle ergometer [2 h daily at 60% peak O2 uptake (VO2 max)]. Subjects were studied at rest and during continuous steady-state ...
Lucía A - - 1998
The purpose of this study was to compare the physiological responses of professional and elite road cyclists during an incremental cycle ergometer test. Twenty-five elite cyclists (EC; 23+/-1 yr) and 25 professional cyclists (PC; 25+/-2yr) performed a ramp protocol (increases of 25 W x min(-1)) during which the following parameters ...
Jones S - - 1998
OBJECTIVE: To examine the submaximal and maximal indices of the exercise response of patients with hypertrophic cardiomyopathy. DESIGN AND SETTING: Prospective examination of cardiopulmonary responses to ramp exercise test of a consecutive group of patients with hypertrophic cardiomyopathy attending a cardiomyopathy outpatient clinic. METHODS: 50 patients aged 12 to 76 ...
Peterlin M F - - 1998
OBJECTIVE: To determine if a single, over-the-counter dose of the H1 antagonist chlorpheniramine maleate (CM) alters total peripheral resistance (TPR) and oxygen uptake (VO2) during submaximal exercise. DESIGN: The study was a prospective, longitudinal, double-blind, random crossover analysis of the cardiovascular and respiratory responses to a single bout of moderately ...
Grappe F - - 1998
Three positions are generally used by cyclists: upright posture (UP), dropped posture (DP) and aero posture (AP). They determine different angles of trunk flexion which could be associated with physiological changes. The purpose of this study was to analyse the effect of these rider positions on ventilatory and metabolic variables. ...
Regensteiner J G - - 1998
Persons with type II diabetes mellitus (DM), even without cardiovascular complications have a decreased maximal oxygen consumption (VO2 max) and submaximal oxygen consumption (VO2) during graded exercise compared with healthy controls. We evaluated the hypothesis that change in the rate of VO2 in response to the onset of constant-load exercise ...
Prieur F - - 1998
PURPOSE: The validity of oxygen uptake in hyperoxia (FIO2 = 30%) measured by an automated system (MedGraphics, CPX/D system) was assessed during the simulation of gas exchanges during exercise with a mechanical system and during submaximal exercise by human subjects. METHODS: The simulation system reproduced a stable and accurate VO2 ...
Odland L M - - 1998
To investigate the regulation of intramuscular fuel selection, we measured the malonyl-CoA (M-CoA) content in human skeletal muscle at three exercise power outputs [35, 65, and 90% maximal rate of O2 consumption (VO2 max)]. Four males and four females cycled for 10 min at one power output on three separate ...
Jacobsen D J - - 1998
OBJECTIVES: To evaluate the slow component of VO2 in persons of different fitness levels exercising at different intensities and the contribution of proposed mediators to the slow component of VO2 using equations from the literature. EXPERIMENTAL DESIGN: Cross-sectional. SETTING: University. PARTICIPANTS: Low (N = 15) and high (N = 15) ...
Bile A - - 1998
The aim of the present study was to assess blood lactate concentrations ([LA], mmol x L(-1)) and oxygen uptake (VO2, L x min(-1), mL x kg(-1) x min(-1)) during incremental exercise in subjects with sickle cell trait (SCT) only, i.e., sedentary subjects with SCT without anemia and/or associated alpha thalassemia. ...
James D V - - 1998
Eight male endurance runners [mean+/-(SD): age 25 (6) years; height 1.79 (0.06) m; body mass 70.5 (6.0) kg; % body fat 12.5 (3.2); maximal oxygen consumption (VO2max 62.9 (1.7) ml x kg(-1) x min(-1)] performed an interval training session, preceded immediately by test 1, followed after 1 h by test ...
Hayashi N - - 1998
The effect of delayed vagal activity withdrawal on cardiorespiratory responses at an increase in workload was examined. Eleven volunteers (21 +/- 3 yr, 66 +/- 4 kg) performed cycle ergometer exercise at a work rate corresponding to 80% of ventilatory threshold after 3 min of unloaded cycling. Facial stimulation was ...
Millet G Y - - 1998
OBJECTIVE: To examine the effect of an increase in roller ski rolling resistance on the physiological and upper body demands of roller skiing with the V2-alternate technique. METHODS: Nine highly skilled cross-country skiers roller skied at three paced speeds on a flat oval loop using roller skis with high (HiR) ...
Granton J T - - 1998
STUDY OBJECTIVES: To determine if oxygen consumption/oxygen delivery (VO2/DO2) relationships derived using calorimetry (which are not influenced by shared measurement error) agreed with those obtained using the pulmonary artery (PA) catheter alone. To evaluate three strategies to reduce the influence of shared measurement error to determine if agreement between the ...
Walsh T S - - 1998
We have investigated the effect of N-acetylcysteine on hemodynamic variables, oxygen delivery (DO2), oxygen consumption (VO2), and oxygen extraction in patients with fulminant hepatic failure using independent methods of determining DO2 and VO2, thereby eliminating the effect of mathematical coupling, which may have biased previous studies. In 11 patients with ...
Hsi W L - - 1998
The purpose of the study was to establish standards for cardiopulmonary responses to exercise in healthy Chinese subjects in Taiwan. One hundred and five sedentary healthy subjects, 55 men and 50 women aged between 20 and 75 years, were tested. They pedalled a cycle ergometer with the work rate increased ...
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