Search results for "Output"
showing 10 items of 381 documents
The effect of fatigue on store and re-use of elastic energy in slow and fast types of human skeletal muscle
1986
Stretch-shortening exercises are characterized by enhancement of performance when compared to the work output performed in shortening conditions. There is evidence that fast subjects are unable to re-use great amounts of elastic energy during stretch-shortening cycles performed with slow stretching speed and large stretching length. In the present study, 14 subjects possessing different fibre types in m. vastus lateralis performed vertical jumps with and without preliminary countermovement and with large angular displacement and slow stretching speed The jumping tests were executed before and immediately after fatigue induced by short intense exercises (60 s of continuous rebound jumping). …
Neuromuscular Adaptations to Different Modes of Combined Strength and Endurance Training
2014
The present study investigated neuromuscular adaptations between same-session combined strength and endurance training with 2 loading orders and different day combined training over 24 weeks. 56 subjects were divided into different day (DD) combined strength and endurance training (4-6 d·wk(-1)) and same-session combined training: endurance preceding strength (E+S) or vice versa (S+E) (2-3 d·wk(-1)). Dynamic and isometric strength, EMG, voluntary activation, muscle cross-sectional area and endurance performance were measured. All groups increased dynamic one-repetition maximum (p<0.001; DD 13±7%, E+S 12±9% and S+E 17±12%) and isometric force (p<0.05-0.01), muscle cross-sectional area (p<0.0…
Muscle activation during cycling at different cadences: Effect of maximal strength capacity
2007
International audience; The purpose of this study was to examine the influence of maximal strength capacity on muscle activation, during cycling, at three selected cadences: a low cadence (50 rpm), a high cadence (110 rpm) and the freely chosen cadence (FCC). Two groups of trained cyclists were selected on the basis of the different maximal isokinetic voluntary contraction values (MVCi) of their lower extremity muscles as follow: Fmin (lower MVCi group) and Fmax (higher MVCi group). All subjects performed three 4-min cycling exercises at a power output corresponding to 80 % of the ventilatory threshold under the three cadences. Neuromuscular activity of vastus lateralis (VL), rectus femoris…
Effect of pedalling rates on physiological response during endurance cycling
2001
International audience; This study was undertaken to examine the effect of different pedalling cadences upon various physiological responses during endurance cycling exercise. Eight well-trained triathletes cycled three times for 30 min each at an intensity corresponding to 80% of their maximal aerobic power output. The first test was performed at a freely chosen cadence (FCC); two others at FCC-20% and FCC +20%, which corresponded approximately to the range of cadences habitually used by road racing cyclists. The mean (SD) FCC, FCC-20% and FCC + 20% were equal to 86 (4), 69 (3) and 103 (5) rpm respectively. Heart rate (HR), oxygen uptake (VO2), minute ventilation (VE) and respiratory excha…
Syncope and collapse in acute pulmonary embolism.
2016
Abstract Background Syncope and collapse (= presyncope) are 2 symptoms of pulmonary embolism (PE), which are suspected of being connected with poorer outcome, regardless of haemodynamic instability. However, pathomechanisms are not completely understood. We aimed to investigate these pathomechanisms in regard to blood pressure and heart rate of syncope/collapse in PE. Methods We performed a retrospective study of consecutive PE patients, who were treated in the Internal Medicine Department. Patients with and without syncope/collapse were compared. Regression models for associations between syncope/collapse and blood pressure, heart rate and shock index (SI) were computed. Moreover we calcul…
Clinical and haemodynamic effects of ketanserin in lean and obese hypertensive patients.
1990
Systemic and central haemodynamics were evaluated in 10 lean and 10 obese hypertensive patients (World Health Organization stage I – II) after treatment for 8 weeks with a serotoninergic antagonist, such as ketanserin. Blood pressure and heart rate were recorded and first-pass radionuclide angiocardiography was performed to determine cardiac output, cardiac index and ejection fraction of the left ventricle; total peripheral resistance was also calculated. In both obese and lean patients, ketanserin significantly reduced diastolic ( P < 0.05) and mean ( P < 0.005) blood pressure but no significant changes in systolic blood pressure, cardiac output, cardiac index and ejection fraction …
Noninvasive Hemodynamic Measurements During Neurosurgical Procedures in Sitting Position.
2017
Neurosurgical procedures in sitting position need advanced cardiovascular monitoring. Transesophageal echocardiography (TEE) to measure cardiac output (CO)/cardiac index (CI) and stroke volume (SV), and invasive arterial blood pressure measurements for systolic (ABPsys), diastolic (ABPdiast) and mean arterial pressure (MAP) are established monitoring technologies for these kind of procedures. A noninvasive device for continuous monitoring of blood pressure and CO based on a modified Penaz technique (volume-clamp method) was introduced recently. In the present study the noninvasive blood pressure measurements were compared with invasive arterial blood pressure monitoring, and the noninvasive…
Breathing 100% oxygen during water immersion improves postimmersion cardiovascular responses to orthostatic stress
2016
Abstract Physiological compensation to postural stress is weakened after long‐duration water immersion (WI), thus predisposing individuals to orthostatic intolerance. This study was conducted to compare hemodynamic responses to postural stress following exposure to WI alone (Air WI), hyperbaric oxygen alone in a hyperbaric chamber (O 2 HC), and WI combined with hyperbaric oxygen (O 2 WI), all at a depth of 1.35 ATA, and to determine whether hyperbaric oxygen is protective of orthostatic tolerance. Thirty‐two healthy men underwent up to 15 min of 70° head‐up tilt (HUT) testing before and after a single 6‐h resting exposure to Air WI ( N = 10), O 2 HC ( N = 12), or O 2 WI ( N = 10). Heart …
Left ventricular diastolic filling alterations in subjects with mitral valve prolapse: A Doppler echocardiographic study
1993
To assess left ventricular diastolic filling in mitral valve prolapse (MVP), we studied 22 patients with idiopathic MVP and 22 healthy controls matched for sex, age, body surface area and heart rate. A two-dimensional, M-mode and Doppler echocardiographic examination was performed to exclude any cardiac abnormalities. The two groups had similar diastolic and systolic left ventricular volumes, left ventricle mass and ejection fraction. Doppler measurements of mitral inflow were: E and A areas (the components of the total flow velocity-time integral in the early passive period of ventricular filling, E; and the late active period of atrial emptying, A), the peak E and A velocities (cm.s-1), a…
Lymphocyte beta-adrenergic receptors in young subjects with peripheral or central obesity: relationship with central haemodynamics and left ventricul…
1994
This study was designed to evaluate total (t) and surface (s) β-adrenergic receptor (BAR) density and their relationship with central haemodynamics and left ventricular function in young subjects with central or peripheral obesity. A total of 31 obese subjects (BMI ≥30.5 kg. m−2 for males and >27.3 kg. m−2 for females) aged less than 40 years and without other risk factors for cardiovascular diseases (smoking, hypertension, diabetes and lipid abnormalities) were studied. Nine had peripheral obesity and 22 central obesity according to WHR values; there were 20 lean controls (BMI <25 kg. m−2 for males and <24.7 kg. m−2 for females). Casual (c) and 24 h ambulatory mean blood pressures (MBP-24 …