Search Results
Results 451 - 500 of 1137
< 5 6 7 8 9 10 11 12 13 14 15 >
Roland Jeremy - - 2008
Actin dynamics (i.e., polymerization/depolymerization) powers a large number of cellular processes. However, a great deal remains to be learned to explain the rapid actin filament turnover observed in vivo. Here, we developed a minimal kinetic model that describes key details of actin filament dynamics in the presence of actin depolymerizing ...
Ramsbottom R - - 2007
The collection of primary data in laboratory classes enhances undergraduate practical and critical thinking skills. The present article describes the use of a lecture program, running in parallel with a series of linked practical classes, that emphasizes classical or standard concepts in exercise physiology. The academic and practical program ran ...
Hopker James G - - 2007
Controversy still exists in the literature as to whether cycling experience affects gross mechanical efficiency (GME). The aim of this study was to identify differences in efficiency between trained and untrained cyclists. Thirty-two participants, 16 trained (mean+/-SD: age, 33+/-4 y; height, 1.76+/-0.05 m; mass 75+/-10 kg; Wmax, 421+/-38 W; maximal ...
Tucker Ross - - 2007
Increasing inspiratory oxygen tension improves exercise performance. We tested the hypothesis that this is partly due to changes in muscle activation levels while perception of exertion remains unaltered. Eleven male subjects performed two 20-km cycling time-trials, one in hyperoxia (HI, FiO2 40%) and one in normoxia (NORM, FiO2 21%). Every ...
McNaughton Lars R - - 2007
CONTEXT: Recently, superoxygenated-water beverages have emerged as a new purported ergogenic substance. PURPOSE: This study aimed to determine the effects of superoxygenated water on submaximal endurance performance. METHODS: Eleven active male subjects, VO2max 52.6 +/- 4.8 mL . kg-1 . min-1, height 180.0 +/- 2.0 cm, weight 76.0 +/- 7.0 ...
Legaz-Arrese A - - 2007
Resistance training techniques, that increase the global power output of an exercise, exercise set and continuous sets, can optimize neuromuscular adaptation and dynamic athletic performance. An observation that is apparent during traditional resistance training is the slowing of movement velocity as fatigue increases. To perform at maximum velocity, only repetitions ...
Briñol Pablo - - 2007
In the present research, the authors examined the effect of a message recipient's power on attitude change and introduced a new mechanism by which power can affect social judgment. In line with prior research that suggested a link between power and approach tendencies, the authors hypothesized that having power increases ...
Majerczak J - - 2008
In this study, we have determined power output reached at maximal oxygen uptake during incremental cycling exercise (P(I, max)) performed at low and at high pedaling rates in nineteen untrained men with various myosin heavy chain composition (MyHC) in the vastus lateralis muscle. On separate days, subjects performed two incremental ...
Baker Daniel G - - 2007
Athletes experienced in maximal-power and power-endurance training performed 1 set of 2 common power training exercises in an effort to determine the effects of moderately high repetitions upon power output levels throughout the set. Twenty-four and 15 athletes, respectively, performed a set of 10 repetitions in both the bench throw ...
Yamaguchi Taichi - - 2007
The purpose of the present study was to clarify the acute effect of dynamic stretching exercise on muscular performance during concentric dynamic constant external resistance (DCER, formally called isotonic) muscle actions under various loads. Concentric DCER leg extension power outputs were measured in 12 healthy male students after 2 types ...
Goosey-Tolfrey Victoria L - - 2008
The purpose of this study was to determine the effect of crank length and cadence on mechanical efficiency in hand cycling. Eight wheelchair dependent, high performance athletes completed four 4-min submaximal exercise bouts at a constant power output of 90 W over the different experimental conditions (crank length, pedal rate) ...
Vogt Stefan - - 2007
Until recently, the physiological demands of cycling competitions were mostly reflected by the measurement of heart rate and the indirect estimation of exercise intensity. The purpose of this case study was to illustrate the varying power output of a professional cyclist during flat and mountain stages of a Grand Tour ...
Forbes Scott C - - 2007
The purpose of this study was to determine the effects of Red Bull energy drink on Wingate cycle performance and muscle endurance. Healthy young adults (N = 15, 11 men, 4 women, 21 +/- 5 y old) participated in a crossover study in which they were randomized to supplement with ...
Lepretre P-M - - 2008
To examine the fatigue response during an exhaustive heavy exercise performed under control of oxygen uptake (SS@V.O (2)Delta50) or power output (SS@pDelta50), eleven trained male subjects performed an incremental test to determine the peak of the oxygen uptake value (V.O (2peak)) and lactate threshold and two exhaustive steady-state cycling exercises ...
Lenton J P - - 2008
The purpose of this study was to determine the contributions of arm frequency and propulsion mode on the internal work during submaximal wheelchair propulsion. Twelve able-bodied participants performed a V.O (2) peak test on a wheelchair ergometer. On a separate occasion, six (4 min) submaximal exercise conditions employing two modes ...
Vogt S - - 2008
The aim of the study was to report the relationship between cadence and power developed by professional cyclists during high mountain ascents of the Tour de France. From the 10 cyclists (30 +/- 4 years, 178 +/- 8 cm, 69 +/- 6 kg) involved in the study, 108 ascents were ...
Kilduff Liam P - - 2007
PURPOSE: The ability to develop high levels of muscle power is considered an essential component of success in many sporting activities; however, the optimal load for the development of peak power during training remains controversial. The aim of the present study was to determine the optimal load required to observe ...
Casas Fernando - - 2007
MagScrew total artificial heart (TAH) external battery pack (EBP) cycle bench testing was conducted on two Wilson Greatbatch (Clarence, NY, USA) lithium ion EBPs over a period of 22 months during continuous charge and discharge cycles under a simulated TAH system current requirement. A custom electronic load was developed to ...
Edwards Lindsay M - - 2007
The existing literature suggests that crank inertial load has little effect on the responses of untrained cyclists. However, it would be useful to be aware of any possible effect in the trained population, particularly considering the many laboratory-based studies that are conducted using relatively low-inertia ergometers. Ten competitive cyclists (mean ...
Cochrane D J - - 2008
This study was designed to compare the acute effect of vibration exercise with a concentric-only activity (arm cranking) on concentric-only muscle action using an upper body isoinertial exercise. Twelve healthy, physically active men, 30.0y+/-6.1 (mean+/-S.D.); height 1.81m+/-0.06; and weight 83.4kg+/-9.7, performed four maximal prone bench pull (PBP) efforts before and ...
van der Woude Lucas H V - - 2008
PURPOSE: To evaluate external power output and physiological responses of synchronous (SYNC) and asynchronous hand cycling (ASYNC) at submaximal and peak levels of exercise. METHODS: n=9 able-bodied male subjects (age: 20.1+/-2.1 years) performed two (sub)maximal continuous hand cycle exercise tests, using the SYNC and ASYNC mode in a standardized commercial ...
Tokui Masato - - 2007
The purpose of this study was to investigate the muscular efficiency during cycling exercise under certain total power output (Ptot) or external power output (Pext) experimental conditions that required a large range of pedal rates from 40 to 120 rpm. Muscular efficiency estimated as a ratio of Ptot, which is ...
Price Michael J - - 2007
The aim of this study was to examine the effects of cadence and power output on physiological and biomechanical responses to incremental arm-crank ergometry (ACE). Ten male subjects (mean +/- SD age, 30.4 +/-5.4 y; height, 1.78 +/-0.07 m; mass, 86.1 +/-14.2 kg) undertook 3 incremental ACE protocols to determine ...
Noonan Benjamin - - 2007
PURPOSE: To examine the impact of hockey protective equipment on thermal and fluid homeostasis and power output, during a high-intensity, intermittent, exercise protocol. We hypothesized that protective equipment would increase core temperature and reduce sprint power after a simulated hockey game. METHODS: Eight men (26.8 +/- 1.7 yr) performed a ...
Erdreich Linda S - - 2007
Epidemiological studies of mobile phone use and risk of brain cancer have relied on self-reported use, years as a subscriber, and billing records as exposure surrogates without addressing the level of radiofrequency (RF) power output. The objective of this study was to measure environmental, behavioral and engineering factors affecting the ...
Smekal Gerhard - - 2007
PURPOSE: Numerous investigations have reported changes in metabolic and cardiorespiratory responses associated with the menstrual cycle. We examined whether variables commonly used in exercise testing are influenced by menstrual cycle phases. METHODS: Nineteen eumenorrheic women performed two incremental tests to voluntary exhaustion on a cycle ergometer during two different phases ...
Temfemo A - - 2007
The purpose of the present study was to determine whether there are any differences in power output (PO) and/or quadriceps muscle (Quad) activity between black African and Caucasian football players during a force-velocity (fv) exercise test, which consisted of performing maximal 6-s sprints against an increasing load. Each subject started ...
Folland Jonathan P - - 2008
Sodium phosphate loading has been reported to increase maximal oxygen uptake (6-12%), however its influence on endurance performance has been ambiguous. The aim of this study was to examine the influence of sodium phosphate loading on laboratory 16.1 km cycling time-trial performance. Six trained male cyclists (V O(2) peak, 64.1+/-2.8 ...
Lacour Jean-René - - 2007
To assess whether the ability to demonstrate a plateau in oxygen consumption VO2 could be related to adaptation to exercise, the data obtained over a period of 10 years on 94 elite oarsmen who had participated in annual testing were re-evaluated. The test consisted in an incremental step protocol until ...
James David V B - - 2007
The aim of this study was to compare optimization and correction procedures for the determination of peak power output during friction-loaded cycle ergometry. Ten male and 10 female sports students each performed five 10-s sprints from a stationary start on a Monark 864 basket-loaded ergometer. Resistive loads of 5.0, 6.5, ...
Korff Thomas - - 2007
PURPOSE: To optimize endurance cycling performance, it is important to maximize efficiency. Power-measuring cranks and force-sensing pedals can be used to determine the mechanical effectiveness of cycling. From both a coaching and basic science perspective, it is of interest if a mechanically effective pedaling technique leads to greater efficiency. Thus, ...
Muraki Satoshi - - 2007
This study investigated cardiorespiratory responses and muscle oxygenation during prolonged electrical stimulation (ES)-evoked leg cycling in individuals with paraplegia (PARA). Four PARA and 6 able-bodied (AB) persons participated in this study. Subjects performed 10 min of passive cycling and 40 min of active cycling (PARA, ES cycling; AB, voluntary cycling) ...
Cormie Prue - - 2007
PURPOSE: The purpose of this investigation was to compare the impact of power training and strength-power training on the load-power relationship in the jump squat. METHODS: Twenty-six recreationally trained male subjects were randomly assigned to either a power training group (P; N=10), a strength-power training group (SP; N=8), or a ...
Coleman D A - - 2007
The study aim was to consider the use of a motorised treadmill as a cycling ergometry system by assessing predicted and recorded power output values during treadmill cycling. Fourteen male cyclists completed repeated cycling trials on a motorised treadmill whilst riding their own bicycle fitted with a mobile ergometer. The ...
Minahan C - - 2007
The purpose of this study was to evaluate the relationship between anaerobic power and capacity. Seven men and seven women performed a 30-s Wingate Anaerobic Test on a cycle ergometer to determine peak power, mean power, and the fatigue index. Subjects also cycled at a work rate predicted to elicit ...
Lepers R - - 2008
The aim of this study was to determine whether or not variable power cycling produced greater neuromuscular fatigue of knee extensor muscles than constant power cycling at the same mean power output. Eight male triathletes (age: 33+/-5 years, mass: 74+/-4 kg, VO2max: 62+/-5 mL kg(-1) min(-1), maximal aerobic power: 392+/-17 ...
Hoffman Jay R - - 2007
The purpose of this study was to compare nutritionally enriched JavaFit coffee (JF) to commercially available decaffeinated coffee (P) with regard to impact on endurance and anaerobic power performance in a physically active, college-aged population. Ten subjects (8 men, 2 women) performed two 30-second Wingate anaerobic power tests and 2 ...
Thomas Gwendolyn A - - 2007
National Collegiate Athletic Association Division I athletes were tested to determine the load at which maximal mechanical output is achieved. Athletes performed power testing at 30, 40, 50, 60, and 70% of individual 1 repetition maximum (1RM) in the squat jump, bench press, and hang pull exercises. Additionally, hang pull ...
Bertucci William - - 2007
The aim of our study was to compare crank torque profile and perceived exertion between the Monark ergometer (818 E) and two outdoor cycling conditions: level ground and uphill road cycling. Seven male cyclists performed seven tests in seated position at different pedaling cadences: (a) in the laboratory at 60, ...
Fischer Heléne - - 2007
AMP deaminase (AMPD) deficiency is an inherited disorder of skeletal muscle found in approximately 2% of the Caucasian population. Although most AMPD-deficient individuals are asymptomatic, a small subset has exercise-related cramping and pain without any other identifiable neuromuscular complications. This heterogeneity has raised doubts about the physiological significance of AMPD ...
Subudhi Andrew W - - 2007
To determine if fatigue at maximal aerobic power output was associated with a critical decrease in cerebral oxygenation, 13 male cyclists performed incremental maximal exercise tests (25 W/min ramp) under normoxic (Norm: 21% Fi(O2)) and acute hypoxic (Hypox: 12% Fi(O2)) conditions. Near-infrared spectroscopy (NIRS) was used to monitor concentration (microM) ...
Smith Paul M - - 2007
The main aim of this study was to determine whether the use of an imposed or freely chosen crank rate would influence submaximal and peak physiological responses during arm crank ergometry. Fifteen physically active men participated in the study. Their mean age, height, and body mass were 25.9 (s = ...
Hulleman Michiel - - 2007
PURPOSE: Athletes occasionally follow pacing patterns that seem unreasonably aggressive compared with those of prerace performances, potentially because of the motivation provided by competition. This study evaluated the effect of extrinsic motivation on cyclists' time trial performance. METHODS: Well-trained recreational cyclists (N=7) completed four 1500-m laboratory time trials including a ...
Baker Julien S - - 2007
The purpose of this study was to compare the exercise performance and postexercise recovery of 8 male subjects using four different maximal high-intensity intermittent cycle ergometry protocols. Resistive forces were calculated by multiplying fat-free mass (FFM) or total-body mass (TBM) by 0.75 g.kg(-1). Rest periods between successive sprints were 30 ...
Gale Jesse - - 2007
OBJECTIVE: This study assessed the effect of removing artifacts from workplace electroencephalography (EEG) recordings on power spectra and the consequent interpretation of changes in alertness. METHODS: EEG was recorded for 27 air traffic controllers on the night shifts of four roster cycles. On two of the four night shifts, each ...
Hoot Nathan R - - 2007
STUDY OBJECTIVE: We quantified the potential for monitoring current and near-future emergency department (ED) crowding by using 4 measures: the Emergency Department Work Index (EDWIN), the National Emergency Department Overcrowding Scale (NEDOCS), the Demand Value of the Real-time Emergency Analysis of Demand Indicators (READI), and the Work Score. METHODS: We ...
Bieuzen F - - 2007
The purpose of this study was to examine the relationship between strength capacity and preferred and optimal cadence in well trained cyclists. Eighteen cyclists participated in this study. Each subject completed three sessions. The initial session was to evaluate the maximal isokinetic voluntary contraction level of lower limb. The second ...
Banerjee Subrata - - 2007
This paper describes the design and implementation of a single axis DC attraction type suspension system, where a platform (vehicle structure) of around 14 kg mass is made to remain suspended at the desired operating gap under a ferromagnetic guide-way. The prototype has four electromagnetic actuators of attraction type and ...
González-Haro Carlos - - 2007
To assess which of the equations used to estimate mechanical power output for a wide aerobic range of exercise intensities gives the closest value to that measured with the SRM training system. Thirty four triathletes and endurance cyclists of both sexes (mean (SD) age 24 (5) years, height 176.3 (6.6) ...
Carpes F P - - 2007
AIM: This study investigated the pedaling asymmetry during a 40-km cycling time-trial (TT). METHODS: Six sub-elite competitive male cyclists pedaled a SRM Training Systems cycle ergometer throughout a simulated 40-km TT. A SRM scientific crank dynamometer was used to measure the bilateral crank torque (N.m) and pedaling cadence (rpm). All ...
< 5 6 7 8 9 10 11 12 13 14 15 >