Oral D-ribose supplementation has been reported to increase adenine nucleotide synthesis and exercise capacity in certain clinical populations. Theoretically, increasing adenine nucleotide availability may enhance high intensity exercise capacity. This study evaluated the potential ergogenic value of D-ribose supplementation on repetitive high-intensity exercise capacity in 19 trained males. Subjects were ...

The aim of this study was to determine whether cyclists modify the pattern of force application to become more effective during a prolonged ride to exhaustion. Twelve competitive male cyclists completed a steady-rate exercise ride to exhaustion at 80% of their maximum power output at 90 rev x min(-1) on ...

The effect of an active warm-up on maximal voluntary contraction (MVC), maximal instantaneous power output and surface EMG (sEMG) parameters was studied. Eight volunteers [mean (SD) 22 (4) years] completed two trials on the same day, one control (CO), and the other preceded by an active cycling warm-up (WU) at ...

In this article we report an experiment that examines how demand-side bidding can discipline generators in a market for electric power. First we develop a treatment without demand-side bidding; two large firms are allocated baseload and intermediate cost generators such that either firm might unilaterally withhold the capacity of its ...

The aim of this study was to investigate the metabolic and physiological responses to a laboratory-based simulated 30-min individual time-trial (ITT 30 ) in cycling at a self-selected intensity. Twelve experienced triathletes (n = 4 women) performed a progressive incremental exercise test on a cycle ergometer to determine .VO2max (52 ...

This study used a randomized, placebo-controlled, crossover design to evaluate the effects of oral ribose supplementation on short-term anaerobic performance. After familiarization, subjects performed 2 bouts of repeated cycle sprint exercise (six 10-second sprints with 60-second rest periods between sprints) in a single day. After the second exercise, bout subjects ...

A double-blind study was performed to evaluate the effects of oral creatine-pyruvate administration on exercise performance in well-trained cyclists. Endurance and intermittent sprint performance were evaluated before (pretest) and after (posttest) one week of creatine-pyruvate intake (Cr(pyr), 2 x 3.5 g x d-1, n = 7) or placebo (PL, n ...

The purpose of this study was to investigate the effect of two cycling velocities on power output and concomitant metabolic and cardiorespiratory responses to repeated all-out exercises. Mean power output (P(m)), total work ( W(tot)), total oxygen consumption (VO(2tot)) and blood lactate accumulation (delta[La](b)) were evaluated in 13 male subjects ...

Myocardial function is enhanced by endurance exercise training, but the cellular mechanisms underlying this improved function remain unclear. The ability of the myocardium to perform external work is a critical aspect of ventricular function, but previous studies of myocardial adaptation to exercise training have been limited to measurements of isometric ...

This article explores the relationship between dialogue and power in the practice of dialogue-oriented, "not-knowing" forms of therapy. It is argued that power of a dynamic and reversible kind infuses much ordinary social dialogue, and that the joint processes of power and resistance work together to render an interaction dialogical. ...

OBJECTIVE:to define with a simple test the power sustainable by older people during everyday occupations. METHODS:nine healthy subjects (65-71 years) performed two series of 5-6 trials on bicycle and arm ergometers at constant power. Throughout the exercise they reported their evaluation of the effort, referred either to perceived whole body ...

We have estimated the reliability of performance in a commonly employed exercise test consisting of repeated sprints on a cycle ergometer. Eight recreationally active young men completed a practice trial and three more trials at 3- to 6-day intervals. Each trial consisted of two bouts of 30-s maximal-effort cycling on ...

BACKGROUND: A field test consisting of 5 continuous runs at the maximum speed possible, playing the ball, starting from the centre line to the basket with a final shot, was studied in order to obtain an index of mechanical work efficiency in basketball players (micro-index=Jmec/Joxy) and evaluate the correlation between ...

PURPOSE: Previously we demonstrated that the method to reorder near-infrared spectroscopy (NIRS) parameters against crank angle could serve as a useful measure in providing circulatory dynamics and metabolic changes in a working muscle during pedaling exercise. To examine further applicability of this method, we investigated the effects of cycling experience ...

We examined the supposition that swimmers may exhibit an imbalance in bilateral arm power output during simulated swimming exercise. Ten competitive front crawl swimmers (5 males, 5 females; age 20.5+/-2.3 years; height 1.74+/-0.09 m; body mass 72.0+/-16.7 kg; 400 m freestyle swim time 278+/-20.5 s; mean +/- s) performed four ...

BACKGROUND: The aim of this study is to measure and compare the physiological characteristics and the rating of perceived exertion (RPE) in 72 high level road cyclists of 3 different categories. METHODS: These cyclists were divided in 3 groups according to their age (24 professionals, mean age 26 years, 22 ...

The purpose of this study was to examine the effect of intermittent training in a hypobaric chamber on physical exercise at sea level. Over a 10 day period, 16 male triathletes trained for 2 h each day on a cycle ergometer placed in a hypobaric chamber. Training intensity was at ...

PURPOSE: To assess the effects of the Rotor (ROT), a new pedaling system that makes each pedal independent from the other so that cranks are no longer fixed at 180 degrees, on endurance cycling performance. METHODS: Following a randomized design, eight subjects (noncyclists; age (mean +/- SEM): 22 +/- 1 ...

The purpose of this study was to examine the effects of cold-water immersion on power output, heart rate, and time to peak power in 10 well-trained cyclists. The Compu-trainer Professional Model 8001 computerized stationary trainer was used to evaluate maximum power, average power, and time to peak power during a ...

The aim of this study was to employ neuro-fuzzy logic and regression calculations to determine the accuracy of prediction of the power output ( P) of the maximal lactate steady-state (MLSS) on a cycle ergometer calculated from the results of incremental tests. A group of 17 male and 17 female ...

The mechanical efficiency of cycling with a new pedal-crank prototype (PP) was investigated during an incremental test on a stationary cycloergometer. The efficiency values were compared with those obtained, in the same experimental conditions and with the same subjects, by using a standard pedal-crank system (SP). The main feature of ...

PURPOSE: This study was designed to examine the effects of cycling position (seated or standing) during level-ground and uphill cycling on gross external efficiency (GE) and economy (EC). METHODS: Eight well-trained cyclists performed in a randomized order five trials of 6-min duration at 75% of peak power output either on ...

We hypothesised that: (1) the maximal lactate steady state (MLSS), critical power (CP) and electromyographic fatigue threshold (EMG(FT)) occur at the same power output in cycling exercise, and (2) exercise above the power output at MLSS (P-MLSS) results in continued increases in oxygen uptake (VO(2)), blood lactate concentration ([La]) and ...

To determine the optimal pedalling rate that minimises both the oxygen consumption (fV(O2,min)) and the energy cost of cycling (f(Cr,min)), 22 male subjects were asked to cycle on an ergometer on five occasions of 4 min each at a constant power output of 150 W and at pedalling rates of ...

Critical power (CP) is a theoretical construct derived from a series of constant load tests to failure. Many studies have examined the methodological limitations of deriving CP, but few studies have examined the responses to exercise at CP in well-trained individuals. The purpose of the present study was to examine ...

This study examined the relationships between VO2max, power maintenance and oxygen consumption during intense intermittent work. Female recreational soccer players were assigned to either a low aerobic power group (LOW, n = 6, mean (SD) VO2max = 34.4 (2.4) mL.kg(-1)min(-1) or to a moderate aerobic power group (MOD, n = ...

The ability to generate peak power is central for performance in many sports. Currently two distinct resistance training methods are used to develop peak power, the heavy weight/slow velocity and light weight/fast velocity regimes. When using the light weight/fast velocity power training method it was proposed that peak power would ...

The aim of this study was to assess reliability of the Ariel Computerized Exercise System (ACES) "multifunction exerciser". Twenty-three healthy women completed three sets, three repetitions each, of maximal isokinetic supine bench press at two different velocities, slow (10/s) and moderate (25/s). The following performance parameters were studied: peak and ...

Vibration exercise (VbX) is a new type of physical training to increase muscle power. The present study was designed to assess the influence of whole-body VbX on metabolic power. Specific oxygen uptake (sVO(2)) was assessed, testing the hypotheses that sVO(2) increases with the frequency of vibration (tested in 10 males) ...

The aim of this study was to compare the cardiorespiratory and efficiency responses between upper (T(UBE)) and lower (T(LBE)) body exercises at the same relative power outputs and with spontaneously chosen crank (SCCR) or pedal (SCPR) rates. Twelve participants performed exercise bouts set at 20, 40, 60 and 80% of ...

The kinematics of plaice (Pleuronectes platessa, L=22.1 cm) and cod (Gadus morhua, L=25.0 cm, where L is total fish length) swimming at various speeds at the bottom and lifted to heights, h, of 10, 50 and 100 mm by a thin-wire grid were measured. For cod, tailbeat frequency, amplitude, body ...

This study analysed external power output and physiologic responses in 5 individuals with paraplegia during 40 minutes of electrical stimulation leg cycle exercise. Cycling was performed on a motor-driven isokinetic ergometer that enabled precise determinations of power output. Electrical stimulation was increased to 120-140 mA within the first 5 minutes ...

The power coefficient k decreases along evolution in an allometric relationship between the oxygen consumption rate and the body mass of animals. This theoretical study investigated the role of the power coefficient k and its behavior along evolution. The animals were organized in three groups according to the values of ...

The Wingate Anaerobic Test (WAnT) is generally used to evaluate anaerobic cycling performance, but knowledge of the metabolic profile of WAnT is limited. Therefore the energetics of WAnT was analysed with respect to working efficiency and performance. A group of 11 male subjects [mean (SD), age 21.6 (3.8) years, height ...

Maximal concentric one repetition maximum half-squat (1RM(HS)), bench-press (1RM(BP)), power-load curves during concentric actions with loads ranging from 30% to 100% of 1RM(HS) and 1RM(BP)were examined in 70 male subjects divided into five groups: weightlifters (WL, n=11), handball players (HP, n=19), amateur road cyclists (RC, n=18), middle-distance runners (MDR, n=10) ...

PURPOSE: Differences in gross mechanical efficiency between experienced and inexperienced wheelchair users may be brought about by differences in propulsion technique. The purpose of this experiment was to study changes in propulsion technique (defined by force application, left-right symmetry, intercycle variability, and timing) and gross mechanical efficiency during a 3-wk ...

Researchers evaluated the effectiveness of an experimental seat that was designed to prevent perineal numbness and possibly erectile dysfunction in male bicyclists. A trial of the device among 15 experienced cyclists measured perineal sensation after a 1-hour stationary cycling session on a standard seat followed several days later by the ...

The aim of this study was to compare the effect of taking bisoprolol (B), a highly beta(1)-selective adrenoceptor antagonist to that of a placebo (P) on maximal lactate steady state (MLSS), which reflects the transition from oxidative to partially anaerobic metabolism. Ten healthy male subjects [mean (SD) age 23 (3) ...

The purposes of this study were to apply the linear power versus inverse of time relationship to high-intensity upper-body exercise and to assess the repeatability of the parameters critical power (CP) and anaerobic working capacity (AWC), using limits of agreement (Bland and Altman 1986). Sixteen active male subjects (aged 20-34 ...

Different species of animals require different cardiac performance and, in turn, their cardiac muscle exhibits different properties. A comparative approach can reveal a great deal about the mechanisms underlying myocardial contraction. Differences in myocardial Ca(2+) handling between fish and mammals suggest a greater energy cost of activation in fish. Further, ...

Using an improved Peronnet-Thibault model to analyse the maximal power available during exercise, it was found that a 3rd-order relaxation process for the decreasing dynamics of aerobic power can describe accurately the data available for world track records and aerobic-to-total energy ratio (ATER). It was estimated that the time-scales for ...

The aim of the present study was to compare the physiological responses during arm exercises when the crank rate was chosen spontaneously (TS) or set at +/- 20 % (T-20, T+ 20) of the spontaneously chosen crank rate (SCCR). Eight physical education male students, aged 22 +/- 3.2 years, performed ...

There is a disparity in the information about the heritability of the response of muscle anaerobic metabolism to exercise and the use of explosive power, as well as a lack of information concerning the genetic determinants of this form of work, as measured using different specific physical tests. We applied ...

During growth and maturation, the study of very brief high-intensity exercise has not received the same attention from researchers as, for instance, aerobic function. In anaerobic tasks or sports events such as sprint cycling, jumping or running, the children's performance is distinctly lower than that of adults. This partly reflects ...

The effect of different muscle shortening velocity was studied during cycling at a pedalling rate of 60 and 120 rev.min(-1) on the [K+]v in humans. Twenty-one healthy young men aged 22.5+/-2.2 years, body mass 72.7+/-6.4 kg, VO2 max 3.720+/-0.426 l. min(-1), performed an incremental exercise test until exhaustion. The power ...

The objective of this study was to quantify the difference in mechanical efficiency and user power generation between traditional manual wheelchairs and a pushrim activated power assisted wheelchair (PAPAW). Ten manual wheelchair users were evaluated in a repeated measures design trial with and without the PAPAW for propulsion efficiency. Subjects ...

The aim of this study was to assess the influence of three imposed crank rates on the attainment of peak oxygen consumption (VO2peak) and other physiological responses during incremental arm crank ergometry. Twenty physically active, although non-specifically trained, males volunteered for the study. They completed an exercise protocol using an ...

We examine whether the rate of delivery of photons from a UV radiation source has an effect on the inactivation of spores. We directly compare the output of a high-peak-power UV laser source at 248 nm to a low-power continuous lamp source (254 nm) in the inactivation of Bacillus subtilis ...

OBJECTIVES: To compare the submaximal exercise capacity of polio subjects with postpoliomyelitis syndrome (PPS) and without (non-PPS) with that of healthy control subjects, to investigate the relationship of this capacity with maximal short-term power and quadriceps strength, and to evaluate movement economy. DESIGN: Cross-sectional survey. SETTING: University hospital. PARTICIPANTS: Forty-three ...

PURPOSE: To determine the relationship between maximum workload (W(peak)), the workload at the onset of blood lactate accumulation (W(OBLA)), the lactate threshold (W(LTlog)) and the D(max) lactate threshold, and the average power output obtained during a 90-min (W(90-min)) and a 20-min (W(20-min)) time trial (TT) in a group of well-trained ...