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Results 551 - 600 of 1183
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Atkinson Greg - - 2007
We aim to summarise the impact and mechanisms of work-rate pacing during individual cycling time trials (TTs). Unlike time-to-exhaustion tests, a TT provides an externally valid model for examining how an initial work rate is chosen and maintained by an athlete during self-selected exercise. The selection and distribution of work ...
Xavier Priya - - 2007
This study investigates the ability of EEG in identifying apnea/hypopnea events. A preliminary study was performed on 13 subjects (ages: 49.08+/-8.82) previously diagnosed with OSA. Power spectral analysis was performed and centered on apnea/hypopnea event terminations. The normalized power changes between the frequency bands delta, theta, alpha and sigma were ...
Baker Julien S - - 2007
The purpose of this study was to compare power outputs and blood lactate concentrations ([La-]B) following 30 s of maximal cycle ergometry when resistive forces were derived from total-body mass (TBM) or fat-free mass (FFM). Differences (P < 0.05) in peak power output (PPO), pedal velocity (PV) and resistive forces ...
Gao Y-C - - 2007
AFP, CEA, CA125 and CA19-9 are commonly used serum tumour markers (TMs) in clinical practice, although their quantification by immunoassay may be influenced by pre-analytical sample handling. Though the effect of repetitive freeze-thaw cycles is generally recognized, it is not clear in detail. The present study measured (CLIA) these TMs ...
Mahler Donald A - - 2007
BACKGROUND: The purpose of the study was to examine the responsiveness of a computerized system whereby the patient reports spontaneously any change in the intensity of breathlessness during exercise. The hypotheses were that hypercapnia would increase and hyperoxia would decrease the slope of power production-breathlessness ratings compared with a control ...
Impellizzeri Franco M - - 2007
Mountain biking is a popular outdoor recreational activity and an Olympic sport. Cross-country circuit races have a winning time of approximately equal 120 minutes and are performed at an average heart rate close to 90% of the maximum, corresponding to 84% of maximum oxygen uptake (VO2max). More than 80% of ...
Harnish Chris - - 2007
Numerous researchers have studied the physiological responses to seated and standing cycling, but actual field data are sparse. One open issue is the preferred cadence of trained cyclists while hill climbing. The purpose of this study, therefore, was to examine the affect of cycling position on economy and preferred cadence ...
Olivier Anne-Hélène - - 2007
Neuroscientific approaches have provided an important invariant linking kinematics and geometry in locomotion: a power law controls the relation between radius of curvature and velocity of the trajectory followed. However, these trajectories are predefined and cyclic. Consequently, they cannot be considered as fully natural. We investigate whether this relationship still ...
Osada T - - 2006
AIM: Blood flow in peripheral conduit arteries during steady-state, dynamic exercise, can be estimated noninvasively with Doppler ultrasound, by measuring the conduit arterial diameter and the mean blood velocity averaged over consecutive cardiac beat-by-beat cycles (BB(cycle)) or muscle contraction-relaxation cycles (CR(cycle)). The precise impact fluctuations in the 1-BB(cycle)- or 1-CR(cycle)-rate ...
Huo Ming - - 2006
The purpose of this study was to obtain the optimal pedaling rate in bicycle ergometer exercise by measuring probe reaction time, which is a good indicator of attention demand, by changing workloads and pedaling rates, and to discuss the relevant rhythm of lower limb movement. Subjects were 19 healthy men ...
Ebert Tammie R - - 2006
PURPOSE: To quantify the power-output demands of men's road-cycling stage racing using a direct measure of power output. METHODS: Power-output data were collected from 207 races over 6 competition years on 31 Australian national male road cyclists. Subjects performed a maximal graded exercise test in the laboratory to determine maximum ...
Atkinson G - - 2007
We investigated the acceptability of power variation during a cycling time trial (TT) with simulated uphill and downhill sections. Seven cyclists first completed an 800-kJ self-paced TT on a simulated flat course. An 800-kJ TT course with four sections of uphill/downhill was then modeled. Each section involved 100 kJ of ...
Roseguini B T - - 2007
In this study, we evaluated the validity of a sharp increase in pulse deficit (PD) as a noninvasive index for estimation of the first lactate threshold (LT (1)) in healthy individuals with various levels of aerobic fitness. Three groups of healthy male subjects participated in the study: 15 sedentary individuals, ...
Lacerda Ana Cristina R - - 2007
The purpose of this study was to investigate the effects of acute heat exposure at thermal balance on high-intensity performance during sprint cycle exercise. Nine healthy male subjects were tested in three different, well-controlled environments in an environmental chamber: T (22 degrees C, 65% RH), H1 (30 degrees C, 55% ...
Green Alexander L - - 2007
For almost one hundred years, the exact role of human brain structures controlling the cardiorespiratory response to exercise ('central command') has been sought. Animal experiments and functional imaging studies have provided clues, but the underlying electrophysiological activity of proposed relevant neural sites in humans has never been measured. In this ...
Hatfield Disa L - - 2006
The purpose of this study was to determine the impact of a very slow (VS) velocity and a self-selected volitional (VOL) velocity at varying intensities on repetition number, peak force, peak power, and total volume in the squat and shoulder press exercises. On separate testing days, 9 resistance trained men ...
Dawes Helen - - 2006
PURPOSE: To examine factors affecting cycling exercise performance in individuals with acquired brain injury. METHODS: Thirty individuals with acquired brain injury and 18 sedentary controls (SC) participated. Heart rate, bicycle power output and rating of perceived exertional (RPE) were recorded, throughout incremental cycle ergometer exercise. The SC group and 18 ...
Antón M M - - 2007
The aim of this study was to determine physiological, anthropometric, biomechanical and hormonal variables related to road flat and uphill climb performance. Eighteen elite level amateur road cyclists (21.1 +/- 3.8 yrs), homogeneous with regard to time trial performance (coefficient of variation: 2.9-5.2 %), were measured for frontal area (FA), ...
Havenetidis Konstadinos - - 2006
This study assessed the effect of incorrect calculation of power output measurement on the ergogenic properties of creatine. Fifteen males performed repeated Wingate anaerobic tests, under baseline, placebo, and creatine conditions. Statistics showed significant differences (p < 0.05) following creatine-supplemented conditions compared with placebo conditions, whereas no significant differences existed ...
Hurst Howard Thomas - - 2006
The purpose of this study was to assess the power output of field-based downhill mountain biking. Seventeen trained male downhill cyclists (age 27.1 +/- 5.1 years) competing nationally performed two timed runs of a measured downhill course. An SRM powermeter was used to simultaneously record power, cadence, and speed. Values ...
Sarre G - - 2007
The main aim of the present paper was to address the validity of a methodology proposed in a previous paper [Li L, Baum BS. Electromechanical delay estimated by using electromyography during cycling at different pedaling frequencies. J Electromyogr Kinesiol 2004;14(6):647-52], aimed at determining the electromechanical delay from pedaling exercise performed ...
Tucker R - - 2006
To analyse the power output measured during a self-paced 20-km cycling time trial, during which power output was free to vary, in order to assess the level and characteristics of the variability in power output that occurred during the exercise bout. Eleven well-trained cyclists performed a 20-km cycling time trial, ...
McGawley K - - 2006
The present study examined the reliability of work and power measures during a 5 x 6-s cycle ergometer test of repeated-sprint ability. Nine, well-trained, female soccer players performed five, 5 x 6-s repeated-sprint tests on a front-access cycle ergometer on separate days. Sprints were separated by 24 s of active ...
Mendez-Villanueva Alberto - - 2007
The purpose of this study was to examine the reproducibility in measures of power output during a 6-s, maximal cycling sprint test. Eleven healthy, moderately-trained males (mean+/-S.D.; age=19+/-1 year; height=181.5+/-6.2 cm; mass=76.9+/-9.5 kg; peak oxygen uptake 54.9+/-6.1 mL kg(-1)min(-1)) performed a 6-s standing sprint on a front-access cycle ergometer on ...
Trinity Joel D - - 2006
INTRODUCTION: Insight regarding the fluctuations in neuromuscular function among athletes during a taper is lacking. PURPOSE: This study examined the time course of changes in maximal mechanical power (Pmax), torque at power maximum (T), velocity at power maximum (V), and swim performance (m x s(-1)) that occur during the taper. ...
Love John A - - 2006
The purpose of this case study was to report data from a clinical evaluation of an individual with fascioscapulohumeral muscular dystrophy (FSHMD) while using a manual wheelchair versus the same wheelchair fitted with pushrim activated power-assisted wheelchair hubs (PAPAW). An individual with FSHMD was tested for change in heart rate ...
Suriano R - - 2007
The aim of this study was to investigate the effect of constant versus variable power output cycling exercise on subsequent high-intensity, running performance. Eight triathletes completed two testing sessions (in a random order), which required the subjects to perform 30 min of cycling at either, a constant power output (90% ...
Peveler Willard W - - 2006
The amount of adenosine triphosphate (ATP) stored in the muscle available for immediate use is limited, and once used, must be resynthesized in the muscle. Ribose, a naturally occurring pentose sugar, helps resynthesize ATP for use in muscles. There have been claims that ribose supplements increase ATP levels and improve ...
MacRae Holden S H - - 2006
We investigated whether 6 wk of antioxidant supplementation (AS) would enhance 30 km time trial (TT) cycling performance. Eleven elite male cyclists completed a randomized, double-blind, cross-over study to test the effects of twice daily AS containing essential vitamins plus quercetin (FRS), and AS minus quercetin (FRS-Q) versus a baseline ...
Mullineaux David R - - 2006
The appropriateness of normalizing data, as one method to reduce the effects of a covariate on a dependent variable, should be evaluated. Using ratio, 0.67-nonlinear, and fitted normalizations, the aim of this study was to investigate the relationship between ground reaction force variables and body mass (BM). Ground reaction forces ...
Wallman Karen E - - 2007
Many overweight and obese individuals have difficulty in performing aerobic fitness tests that require maximal exertion. Therefore, the purpose of this study was to investigate the reliability of the Aerobic Power Index (API) submaximal aerobic exercise test, as well as associated variables consisting of oxygen uptake (mlkg(-1)min(-1)) and ratings of ...
Busso Thierry - - 2006
A mathematical model of performance describing aerobic and anaerobic energy production during exercise was applied to middle-distance running data from world records (WR) and from a group of elite runners (NL). The model is based on the assumption that, above a critical power (Pc), a continuous rate of anaerobic energy ...
Matsuura Ryouta - - 2006
The purpose of this study was to determine whether neuromuscular activation is affected by blood lactate concentration (La) and the level of oxygen uptake immediately before a cycling sprint (preVO(2)). The tests consisted of ten repeated cycling sprints for 10 sec with 35-sec (RCS(35)) and 350-sec recovery periods (RCS(350)). Peak ...
Bentley David J - - 2007
The purpose of this study was to compare the affects of drafting or a reduction of exercise intensity during swimming on the power output sustained (P(mean)) during a subsequent cycle time trial (TT). In addition the relationship between peak power output (PPO) and P(mean) generated during the cycle TT after ...
Majerczak J - - 2006
The aim of this study was to examine the relationship between the content of various types of myosin heavy chain isoforms (MyHC) in the vastus lateralis muscle and pulmonary oxygen uptake during moderate power output incremental exercise, performed at low and at high pedalling rates. Twenty one male subjects (mean ...
Jokubkiene L - - 2006
OBJECTIVES: To describe changes in endometrial and subendometrial volume and vascularity during the normal menstrual cycle using three-dimensional (3D) power Doppler ultrasonography. METHODS: Fourteen healthy volunteers, 24-44 years old with regular menstrual cycles, underwent serial transvaginal 3D power Doppler ultrasound examinations of the uterus on cycle day 2, 3 or ...
Farina Dario - - 2007
The aim of the study was to investigate the correlation between myosin heavy chain (MHC) composition, lactate threshold (LT), maximal oxygen uptake VO2max, and average muscle fiber conduction velocity (MFCV) measured from surface electromyographic (EMG) signals during cycling exercise. Ten healthy male subjects participated in the study. MHC isoforms were ...
Kumar Raj T S - - 2006
BACKGROUND: spasticity following stroke is common, but clinical measurement is difficult and inaccurate. The most common measure is the modified Ashworth scale (MAS) which grades resistance to passive movement (RPM), but its validity is unclear. AIM: to assess the validity of the MAS. METHODS: spasticity was clinically graded using MAS ...
Mora-Rodriguez Ricardo - - 2006
PURPOSE: This study was conducted to determine the effect of high pedaling cadences on maximal cycling power output (W(max)). METHODS: Nine well-trained cyclists performed a continuous, incremental cycle-ergometer test to exhaustion (25 W increases every 3 min) either at 80, 100, or 120 rpm on three different occasions. RESULTS: W(max) ...
Goosey-Tolfrey V - - 2006
Participation in wheelchair sports such as tennis and rugby enables people with quadriplegia to compete both individually and as a team at the highest level. Both sports are dominated by frequent, intermittent, short term power demands superimposed on a background of aerobic activity. To gain physiological profiles of highly trained ...
Abbiss Chris R - - 2006
INTRODUCTION: A nonlinear dynamic systems model has previously been proposed to explain pacing strategies employed during exercise. PURPOSE: This study was conducted to examine the pacing strategies used under varying conditions during the cycle phase of an Ironman triathlon. METHODS: The bicycles of six well-trained male triathletes were equipped with ...
Bessot N - - 2007
The aim of this study was to examine the pedal rate and chronobiological impacts on muscle activity pattern and propulsive force production during cycling. Ten male competitive cyclists performed at 06:00 and 18:00 h a submaximal exercise on a cycle ergometer at a power output which elicited 50% of their ...
Davranche Karen - - 2006
The aim of this study was to examine the facilitating effects of physical exercise on the reaction process. Eleven participants with specific expertise in decision-making sports performed a choice reaction time task during moderate sub-maximal exercise (90% of their ventilatory threshold power). Participants were tested at rest and while cycling. ...
Smith P M - - 2006
This study examined the effects of variations in crank rate on physiological responses during submaximal arm ergometry. Fifteen non-specifically trained male subjects volunteered to participate in this study. Each subject undertook a discontinuous arm crank ergometry test (30, 50, 70, 90 W) on three separate occasions using crank rates of ...
Okudan N - - 2006
AIM: The aim of the present study was to investigate the relationships between critical power (CP), maximal aerobic power and the anaerobic threshold and whether exercise time to exhaustion and work at the CP can be used as an index in the determination of endurance. METHODS: An incremental maximal cycle ...
Micklewright D - - 2006
Performance and metabolic profiles of the Wingate Anaerobic Test (WAnT) were compared between a mechanically resisted (ME) and an electro-magnetically braked (EE) cycle ergometer. Fifteen healthy subjects (24.0+/-3.5 years, 180.5+/-6.1 cm, 75.4+/-11.9 kg) performed a WAnT on ME, and EE 3 days apart. Performance was measured as peak power (PP), ...
Samozino Pierre - - 2006
The purpose of this study was to investigate the interactions between cadence and power output effects on cycling efficiency. Fourteen healthy subjects performed four constant power output-tests (40, 80, 120 and 160 W) in which the cadence varied in five bouts from 40 to 120 rpm. Gross efficiency (GE) was ...
Lawton Trent W - - 2006
The purpose of this study was to determine the change in weight training repetition power output as a consequence of interrepetition rest intervals. Twenty-six elite junior male basketball and soccer players performed bench presses using a 6 repetition maximum (6RM) load. The power output for each repetition was recorded using ...
Roussel-Debet Sylvie - - 2006
For 10 years, (14)C measurements have been performed around French nuclear power plant sites, both in zones influenced and zones not influenced by gaseous releases. Examining the results from these measurements in the terrestrial environment shows that the discharges have a very slight impact on the radiocarbon level (with a ...
Bessot N - - 2006
The aim of this study was to examine the supposed influence of pedal rate on the diurnal fluctuation of the time to exhaustion from high-intensity exercise. Eleven male cyclists performed three tests at 06:00 h and three at 18:00 h at a free pedal rate (FPR) and two imposed pedal ...
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