Search Results
Results 651 - 700 of 1166
< 9 10 11 12 13 14 15 16 17 18 19 >
Slatkovska Lubomira - - 2006
This study examined the effects of menstrual cycle phase on ventilatory control. Fourteen eumenorrheic women were studied in the early follicular (FP; 1-6 days) and mid-luteal (LP; 20-24 days) phase of the menstrual cycle. Blood for the determination of arterial PCO(2) (PaCO(2)) , plasma strong ion difference ([SID]), progesterone ([P(4)]), ...
Calbet José A L - - 2006
An acute reduction of blood hemoglobin concentration ([Hb]), even when the circulating blood volume is maintained, results in lower (.)V(O(2)(max) and endurance performance, due to the reduction of the oxygen carrying capacity of blood. Conversely, an increase of [Hb] is associated with enhanced (.)V(O(2)(max) and endurance capacity, that is also ...
Snyder Eric M - - 2006
BACKGROUND: In humans, beta(2)-adrenergic receptors (beta(2)ARs) influence airway tone. There are known functional polymorphisms of the beta(2)AR, such as substitution of glycine for arginine at codon 16. We sought to determine if this variation in genotype differentially influences airway function during exercise. METHODS: Healthy subjects without asthma who were either ...
Davis James A - - 2006
Indices of ventilatory efficiency have proven useful in assessing patients with heart and lung disease. One of these indices is the slope of the ventilation (V(E)) versus carbon dioxide output (VCO(2)) relationship during cardiopulmonary exercise testing (CPET) for work rates where the relationship is linear. However, this relationship is defined ...
Vella Chantal A - - 2006
OBJECTIVE: Evidence of significant oxygen requirements for ventilation during exercise (exercise hyperpnoea) prompted the investigation into whether the oxygen cost of ventilation affects the presence of a whole-body VO(2) plateau at maximal exercise. The purposes of this study were to: (i) use isocapnic hyperpnoea trials to determine the oxygen cost ...
Davis James A - - 2006
Ventilatory efficiency is commonly defined as the level of ventilation V(E) at a given carbon dioxide output (V(CO(2) )). The slope of the V(E) versus V(CO(2) ) relationship and the lowest V(E)/V(CO(2) ) are two ventilatory efficiency indices that can be measured during cardiopulmonary exercise testing (CPET). A possible CPET ...
Kogure Akira - - 2006
OBJECTIVES: To evaluate the utility of our newly devised method (incremental stand-up exercise-load) to determine features of general endurance in hemiplegic patients. SUBJECTS/PATIENTS: Participants were 15 healthy adults and 15 hemiplegics, with 13 men and 2 women in each group. METHODS: To evaluate endurance, the subjects were required to assume ...
Rutherford John S - - 2006
In this article, a number of the results relevant to the concept of sublattices of a basic crystallographic lattice are reviewed, emphasizing particularly previously unpublished work on the algebraic aspects. A three-dimensional geometric lattice L can be considered as an infinite Abelian group under addition. A sublattice S of L, ...
von Heimburg Erna D - - 2006
There is incomplete information about how physically demanding rescue work may be. The aim therefore of this paper was to examine the physiological responses of firefighters during a simulated rescue of hospital patients and to relate the firefighters' performance to their endurance, strength and working technique. Fourteen part-time male firefighters ...
Laukkanen J A - - 2006
OBJECTIVE: To investigate the prognostic value of peak oxygen pulse, which is the amount of oxygen consumed per heart beat during exercise, and to compare the prognostic value of peak oxygen pulse and maximum oxygen uptake (Vo(2max)) with respect to coronary heart disease (CHD) and overall death. DESIGN: Prospective population-based ...
Titlestad John - - 2006
The aim of this study was to compare the physiological and psychological responses of cyclists riding on a hard tail bicycle and on a full suspension bicycle. Twenty males participated in two series of tests. A test rig held the front axle of the bicycle steady while the rear wheel ...
Kawaguchi Kotaro - - 2006
This study examined the relationship between acute cardiorespiratory and muscle oxygenation and blood volume changes during prolonged exercise. Eight healthy male volunteers (mean maximum oxygen uptake VO(2max) = 41.6 +/- 2.4 mL/kg/min) performed 60 min submaximal cycling at 50% VO(2max). Oxygen uptake VO(2) was measured by indirect spirometry, cardiac output ...
Ahmadreza Askary Ashtyani
This study aimed to compare four different tapering techniques to find out their effectiveness on hematological responses including biochemical, hematological and VO<SUB>2 </SUB>max indices. Sixty semi-professional athletes (age 20-35 years old) and with VO<SUB>2 </SUB>max 30-45 mL/kg/min were recruited in this study. The test was carried out in three steps. ...
de Carvalho Daniela Cristina Leite - - 2006
This work assessed the influence of treadmill gait training with neuromuscular electrical stimulation (NMES) on the metabolic and cardiorespiratory responses in quadriplegic subjects. The gait group (GG) (n=11) performed 6 months of treadmill training with 30-50% body weight support and with the help of physiotherapists, twice a week, allotting 20 ...
Bircher Stefan S School of Health Sciences, Nutritional Physiology Research Group, University of South Australia , Adelaide, - - 2006
The aim of this case study was to examine energy expenditure (EE) in one cyclist during an extreme endurance cycling race - the "XXAlps 2004" (2,272 km distance and 55,455 m altitude) which was completed in 5 days and 7 hours - and whether the energy deficit derives primarily from ...
L Andreacci Joseph J Department of Exercise Science, Bloomsburg University , Bloomsburg, PA, - - 2006
The purpose of this investigation was to determine the effect of intermittent sub-maximal exercise on percent body fat (%BF) estimated by leg-to-leg bioelectrical impedance analysis (LBIA) in children. Fifty-nine children (29 girls; 30 boys) mean age 9.0 ± 1.3 years participated in this study. LBIA measured %BF values were obtained ...
Bouassida Anissa A Laboratory of Cardio-Circulatory, Respiratory, Metabolic and Hormonal Adaptations to the Muscular Exercise, Faculty of Medicine Ibn El Jazzar , 4002 Sousse, - - 2006
Leptin, a hormone synthesized by fat tissue had been noted to regulate energy balance and metabolism and thus to influence body weight. The influence of acute exercise and chronic exercise training on circulating leptin and its relationship with hormonal and metabolic changes that induce energy balance are presented. Research that ...
Dusek Jeffery A - - 2006
BACKGROUND: Mind/body practices that elicit the relaxation response (RR) are currently practiced by over 30% of American adults. RR elicitation reduces volumetric oxygen consumption (VO(2)) from rest and counteracts the effects of stress, although the mechanisms mediating the RR remain unknown. This study was designed to investigate whether RR elicitation ...
Gonzalez Norberto C - - 2006
The relative contribution of genetic and environmental influences to individual exercise capacity is difficult to determine. Accordingly, animal models in which these influences are carefully controlled are highly useful to understand the determinants of intrinsic exercise capacity. Studies of systemic O(2) transport during maximal treadmill exercise in two diverging lines ...
Wilkerson Daryl P - - 2006
We hypothesised that the fundamental (Phase II) component of pulmonary oxygen uptake (VO(2)) kinetics would be significantly slower when step transitions to severe intensity cycle exercise were initiated from elevated baseline metabolic rates, and that this would be associated with evidence for a greater activation of higher-order (i.e. type II) ...
Kikkawa Takashi - - 2006
CO(2) ocean storage by which liquefied CO(2) is injected into the deep-sea to mitigate the climate change would increase the CO(2) concentrations of the surrounding seawater. The biological impacts of such dynamic CO(2) environments are, however, unknown. We examined the acute toxicity of temporally changing seawater CO(2) concentrations on juveniles ...
Higuchi Y - - 2006
Cross-sectional and comparative investigation using quadriplegics (QP) and nondisabled subjects (ND). To evaluate cardiorespiratory responses during passive walking-like exercise (PWE) in QP. National Rehabilitation Center for Persons with Disabilities in Japan. The subjects were seven male QP with complete lesion (age: 27.0 +/- 5.4, injured level: C6-C7) and six male ...
Wehrlin Jon Peter - - 2006
It has been hypothesized that one reason for decreased .VO(2max) in hypoxia could be the lower maximal exercise intensity achieved in incremental, time or distance trial tests. We hypothesized that (1).VO(2max) would be decreased at altitude even when exercising at the same absolute maximal exercise intensity as at sea level ...
Rasmussen P - - 2006
Light and moderate exercise elevates the regional cerebral blood flow by approximately 20% as determined by ultrasound Doppler sonography (middle cerebral artery mean flow velocity; MCA V(mean)). However, strenuous exercise, especially in the heat, appears to reduce MCA V(mean) more than can be accounted for by the reduction in the ...
Zhang Lan - - 2005
Aesculetin is the product of the hydrolysis reaction of aesculin. A high sensitivity and good repeatability method based on capillary electrophoresis with amperometric detection (CE-AD) was developed for simultaneous determination of aesculin and aesculetin in the hydrolysate of aesculin. Under the optimum condition: 10mmol/L KH(2)PO(4)-5mmol/L Na(2)B(4)O(7) (pH 6.0) buffer, separation ...
Bjørgaas M - - 2005
AIM: The aim of this study is to investigate the relationship between pedometer-registered activity, aerobic capacity (VO(2 max)) and self-reported activity and fitness in patients with type 2 diabetes before and after a 12-week exercise programme. METHODS: Twenty-nine men with type 2 diabetes (age=57.4 (7.8) years, BMI=31.7 (2.8) kg/m(2)) underwent ...
de Carvalho D C L - - 2005
The analysis of oxygen uptake (VO(2)) and energy consumption in quadriplegics after 6 months of treadmill gait with neuromuscular electrical stimulation (NMES). To compare metabolic responses in quadriplegics after 6 months of treadmill training, with NMES (30-50% body weight relief), with quadriplegics who did not perform gait. Ambulatory of University ...
Astorino Todd A - - 2005
Runners Advantage (RA) creatine (Cr) serum has been marketed to increase running performance. To test this claim, cross-country runners completed baseline testing (BASE), an outdoor 5,000-m run followed by treadmill Vo(2)max testing on the same day. Subjects repeated testing after ingesting 5 ml of RA (n = 13) containing 2.5 ...
Malek Moh H - - 2005
The purposes of this study were to (a) determine if the mathematical model used to estimate the physical working capacity at the oxygen consumption threshold (PWC(VO(2))) and physical working capacity at the heart rate threshold (PWC(HRT)) for cycle ergometry could be applied to treadmill running; (b) propose new fatigue thresholds ...
Edge Johann - - 2005
PURPOSE: We compared the effects of high-intensity interval (HIT) and moderate-intensity continuous (MIT) training (matched for total work) on changes in repeated-sprint ability (RSA) and muscle metabolism. METHODS: Pre- and posttraining, VO(2peak), lactate threshold (LT), and RSA (5 x 6-s sprints, every 30 s) were assessed in 20 females. Before ...
Ohuchi Hideo - - 2005
We evaluated how Paco(2) and respiratory variables relate during and after exercise and derived a new noninvasive estimation of Paco(2) in children and postoperative patients with congenital heart disease. We randomly selected 8 subjects from each of three categorized groups from our previous studies: 15 control subjects (8 to 21 ...
Lador Frédéric - - 2006
We tested whether the kinetics of systemic O(2) delivery (QaO(2)) at exercise start was faster than that of lung O(2) uptake (Vo(2)), being dictated by that of cardiac output (Q), and whether changes in Q would explain the postulated rapid phase of the Vo(2) increase. Simultaneous determinations of beat-by-beat (BBB) ...
West Sacha J - - 2006
The aim of this study was to differentiate the role of raised plasma adrenaline (Adr) concentrations from sympathoadrenal activation associated with moderate-intensity exercise, on muscle activation, cardiopulmonary responses, fuel metabolism, and ratings of perceived exertion (RPE) during low-intensity exercise. Two groups of subjects (MOD, n=6; LOW, n=7) cycled on two ...
Hättenschwiler Stephan - - 2006
Populations of the annual hemiparasites Melampyrum pratense L. and Melampyrum sylvaticum L. were studied at the treeline in the Swiss Alps after 3 years of in situ CO(2) enrichment. The total density of Melampyrum doubled to an average of 44 individuals per square meter at elevated CO(2) compared to ambient ...
Dodd Jonathan D - - 2006
To evaluate whether respiratory factors limit exercise capacity in patients with mild cystic fibrosis (CF) lung disease (mean FEV(1) = 76 +/- 7.7% predicted) we stressed the respiratory system of seven patients using added dead space (V(D)). Primary outcomes were exercise duration (Ex(dur)) and maximal oxygen uptake (VO(2max)). Dyspnoea/leg-discomfort were ...
Impellizzeri F M - - 2005
OBJECTIVES: To examine the relations between maximal and submaximal indices of aerobic fitness and off road cycling performance in a homogeneous group of high level mountain bikers. METHODS: 12 internationally competitive mountain bikers completed the study. Maximum oxygen uptake (Vo(2max)), peak power output (PPO), power output (PO), and oxygen uptake ...
Ferretti Guido - - 2005
At exercise steady state, the lower the arterial oxygen saturation (SaO(2)), the lower the O(2) return (QvO(2)). A linear relationship between these variables was demonstrated. Our conjecture is that this relationship describes a condition of predominant sympathetic activation, from which it is hypothesized that selective beta1-adrenergic blockade (BB) would reduce ...
Eves Neil D - - 2005
Our previous work showed that breathing low density gases during exercise with the self-contained breathing apparatus (SCBA) improves maximal ventilation (V(E)) and maximal oxygen consumption (VO(2)max). This suggests that the SCBA limits exercise by adding a resistive load to breathing. In this study we compared VO(2)max with and without the ...
Martin David T - - 2005
This case describes the physiological maturation from ages 21 to 28 yr of the bicyclist who has now become the six-time consecutive Grand Champion of the Tour de France, at ages 27-32 yr. Maximal oxygen uptake (Vo(2max)) in the trained state remained at approximately 6 l/min, lean body weight remained ...
Stuessi Christoph - - 2005
We hypothesised that L: -carnitine could accelerate recovery from exhaustive exercise since increased blood L: -carnitine concentrations elicit a vasodilation in isolated animal vessels as well as in patients with peripheral vascular or coronary artery disease during exercise. Twelve subjects received either 2 g L: -carnitine or a placebo in ...
Sabapathy Surendran - - 2005
PURPOSE: An increased recruitment of type II muscle fibers has been suggested as a major cause of the slow component of O(2) uptake (VO(2)) kinetics. Furthermore, the rise in plasma ammonia (NH(3)) during high-intensity exercise, where a slow component is observed, has been associated with the activation of type II ...
Seiler Stephen - - 2005
PURPOSE: To investigate the effect of rest duration on self-selected intensity, physiological responses, and RPE during a standardized, high-intensity interval training prescription. SUBJECTS: Nine well-trained male runners (VO(2max) 71 +/- 4 mL.kg(-1).min(-1)) performed three treadmill interval training sessions running at constant 5% incline. Six 4-min work bouts with either 1-, ...
Jones Andrew M - - 2005
The purpose of this paper is to provide an introduction to the study of oxygen uptake (VO(2)) dynamics or kinetics. Following the onset of exercise, both muscle and pulmonary VO(2) rise in a near-exponential fashion towards the anticipated "steady-state" VO(2) demand. However, it can take 2-4 min, or even longer ...
Walsh Brandon - - 2005
At the onset of constant-load exercise, pulmonary oxygen uptake (VO(2)) exhibits a monoexponential increase, following a brief time delay, to a new steady state. To date, the specific factors controlling VO(2) onset kinetics during the transition to higher rates of work remain largely unknown. To study the control of respiration ...
Hajoglou Amanda - - 2005
PURPOSE: This study was designed to determine the effect of warm-up on 3-km cycling time trial (TT) performance, and the influence of accelerated VO(2) kinetics on such effect. METHODS: Eight well-trained road cyclists, habituated to 3-km time trials, performed randomly ordered 3-km TT after a) no warm-up (NWU), b) easy ...
Likens Gene E - - 2005
A highly significant second-order polynomial relation between SO(2) emissions and SO(4)(2-) concentrations during 1970-2000 (r(2)= 0.80, p= <0.001), and a linear relation between NO(x) and NO(3)(-) concentrations during 1991-2000 (r(2)= 0.67, p= 0.004) in bulk precipitation were found for the Hubbard Brook Experimental Forest, NH based on emissions from a ...
Aliverti A - - 2005
To determine the effects of exercise with expiratory flow-limitation (EFL) on systemic O(2) delivery, seven normal subjects performed incremental exercise with and without EFL at approximately 0.8 l s(-1) (imposed by a Starling resistor in the expiratory line) to determine maximal power output under control (W'(max,c)) and EFL (W'(max,e)) conditions. ...
Wilkerson Daryl P - - 2005
We hypothesized that 4 weeks of recombinant human erythropoietin (RhEPO) treatment would result in a significant increase in haemoglobin concentration ([Hb]) and arterial blood O(2)-carrying capacity and that this would (1) increase peak pulmonary oxygen uptake during ramp incremental exercise, and (2) speed kinetics during 'severe'-, but not 'moderate'- or ...
Banerjee Prithwish - - 2005
This investigation evaluated training responses to prolonged electrical muscle stimulation (EMS) in sedentary adults. Fifteen healthy subjects (10 men, 5 women) with a sedentary lifestyle completed a 6-wk training program during which they completed an average of 29 1-h EMS sessions. The form of EMS used by the subjects was ...
Womack Christopher J - - 2006
This study sought to compare fibrinolytic responses to exercise above lactate threshold (LT) to longer-duration, equicaloric exercise below LT. Fifteen males performed cycle ergometer tests above (77% VO(2)peak) and below LT (41% VO(2)peak) to comparatively evaluate tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) responses. tPA activity significantly (P ...
< 9 10 11 12 13 14 15 16 17 18 19 >