scholarly journals Durée de la récupération et puissance maximale anaérobie au cours de la journée

2003 ◽  
Vol 28 (2) ◽  
pp. 213-224 ◽  
Author(s):  
Guy Falgairette ◽  
François Billaut ◽  
Sophiane Ramdani
Keyword(s):  
Peak Power ◽  
Biological Rhythms ◽  
Cycle Ergometer ◽  
Time Of Day ◽  
Total Work ◽  
Half Time ◽  
Instantaneous Power ◽  
Recovery Processes ◽  
Logarithmic Relationship ◽  
Short Time

Effects of recovery duration (2-3 s, 15 s, 30 s, 1 min, and 2 min) and time of day (9 a.m., 2 p.m., and 6 p.m.) on sprint performance were studied in 9 subjects using a cycle ergometer. The peak power (Ppeak) and the total work performed (W) were determined from changes in instantaneous power, taking into account the inertia of the flywheel. A decrease in Ppeak and W was observed after 15 s and 2-3 s recovery (p < 0.001). A logarithmic relationship (y = 3.92 ln x + 81.5; r = 0.82; n = 9) was found between Ppeak (%Ppeak of the first sprint) and the duration of the recovery (half-time = 14.3 s; SD = 7.6). Data indicated that there was no significant effect of time of day on Ppeak and W, regardless of the duration of recovery. The recovery processes occurred in a very short time and did not seem to be affected by biological rhythms. Key words: performance, diurnal variation, fatigue, ergometry, inertia

scholarly journals Influence of Hypohydration on Intermittent Sprint Performance in the Heat

2009 ◽  
Vol 4 (1) ◽  
pp. 54-67 ◽  
Author(s):  
Neil S. Maxwell ◽  
Richard W.A. Mackenzie ◽  
David Bishop
Keyword(s):  
Relative Humidity ◽  
Peak Power ◽  
Cycle Ergometer ◽  
Sprint Performance ◽  
Peak Power Output ◽  
Total Work ◽  
Physiological Strain ◽  
Metabolic Markers ◽  
Repeated Sprint ◽  
Physiological Strain Index

Purpose:To examine the effect of hypohydration on physiological strain and intermittent sprint exercise performance in the heat (35.5 ± 0.6°C, 48.7 ± 3.4% relative humidity).Methods:Eight unacclimatized males (age 23.4 ± 6.2 y, height 1.78 ± 0.04 m, mass 76.8 ± 7.7 kg) undertook three trials, each over two days. On day 1, subjects performed 90 min of exercise/heat-induced dehydration on a cycle ergometer, before following one of three rehydration strategies. On day 2, subjects completed a 36-min cycling intermittent sprint test (IST) with a -0.62 ± 0.74% (euhydrated, EUH), -1.81 (0.99)% (hypohydrated1, HYPO1), or -3.88 ± 0.89% (hypohydrated2, HYPO2) body mass defcit.Results:No difference was observed in average total work (EUH, 3790 ± 556 kJ; HYPO1, 3785 ± 628 kJ; HYPO2, 3647 ± 339 kJ, P = 0.418), or average peak power (EUH, 1315 ± 129 W; HYPO1, 1304 ± 175 W; HYPO2, 1282 ± 128 W, P = 0.356) between conditions on day 2. Total work and peak power output in the sprint immediately following an intense repeated sprint bout during the IST were lower in the HYPO2 condition. Physiological strain index was greater in the HYPO2 vs. the EUH condition, but without changes in metabolic markers.Conclusion:A greater physiological strain was observed with the greatest degree of hypohydration; however, sprint performance only diminished in the most hypohydrated state near the end of the IST, following an intense bout of repeating sprinting.

Muscle metabolites and performance during high-intensity, intermittent exercise

1998 ◽  
Vol 84 (5) ◽  
pp. 1687-1691 ◽  
Author(s):  
Mark Hargreaves ◽  
Michael J. McKenna ◽  
David G. Jenkins ◽  
Stuart A. Warmington ◽  
Jia L. Li ◽  
...  
Keyword(s):  
Exercise Performance ◽  
Peak Power ◽  
Intermittent Exercise ◽  
Exercise Bout ◽  
Creatine Phosphate ◽  
Cycle Ergometer ◽  
Total Work ◽  
Muscle Lactate ◽  
The Third ◽  
And Performance

Six men were studied during four 30-s “all-out” exercise bouts on an air-braked cycle ergometer. The first three exercise bouts were separated by 4 min of passive recovery; after the third bout, subjects rested for 4 min, exercised for 30 min at 30–35% peak O2 consumption, and rested for a further 60 min before completing the fourth exercise bout. Peak power and total work were reduced ( P < 0.05) during bout 3 [765 ± 60 (SE) W; 15.8 ± 1.0 kJ] compared with bout 1 (1,168 ± 55 W, 23.8 ± 1.2 kJ), but no difference in exercise performance was observed between bouts 1 and 4 (1,094 ± 64 W, 23.2 ± 1.4 kJ). Before bout 3, muscle ATP, creatine phosphate (CP), glycogen, pH, and sarcoplasmic reticulum (SR) Ca2+ uptake were reduced, while muscle lactate and inosine 5′-monophosphate were increased. Muscle ATP and glycogen before bout 4 remained lower than values before bout 1( P < 0.05), but there were no differences in muscle inosine 5′-monophosphate, lactate, pH, and SR Ca2+ uptake. Muscle CP levels before bout 4 had increased above resting levels. Consistent with the decline in muscle ATP were increases in hypoxanthine and inosine before bouts 3 and 4. The decline in exercise performance does not appear to be related to a reduction in muscle glycogen. Instead, it may be caused by reduced CP availability, increased H+ concentration, impairment in SR function, or some other fatigue-inducing agent.

scholarly journals Time-of-Day Effects on Anaerobic Power and Concentration of Selected Hormones in Blind Men

2021 ◽  
Vol 18 (17) ◽  
pp. 9353
Author(s):  
Tomasz Pałka ◽  
Przemysław Pajor ◽  
Anna Katarzyna Tyka ◽  
Wanda Pilch ◽  
Agata Cebula ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Circadian Rhythm ◽  
Peak Power ◽  
Anaerobic Power ◽  
Time Of Day ◽  
Control Group ◽  
Anaerobic Performance ◽  
Diurnal Changes ◽  
Total Work ◽  
Blind Person

Knowledge of the circadian rhythm of the blind person and diurnal changes in anaerobic power and hormones concentration can create the possibility of individualising physical training. The aim of the study was to examine the time-of-day effects on anaerobic performance and the concentration of selected hormones. The measurements were performed at two different times of the day (10:00 a.m., 10:00 p.m.) in blind men at the age of 20–25 years old. The experiment group was chosen by using repeated hormonal tests four times a day so that each selected patient had a sleep/wake cycle even of 24 h. Anaerobic peak power and total work were tested in an anaerobic sprint test, and the concentration of growth hormone, testosterone, cortisol, and melatonin was determined. In blind men, the hormonal response was not driven by the photoperiod as in the control group. In the blind group, at 10:00 p.m., anaerobic peak power and total work results were significantly higher than at 10:00 a.m. and negatively correlated with melatonin levels. No such correlation was found in the control group.

Conditional Ground-Motion Model for Damaging Characteristics of Near-Fault Ground Motions Based on Instantaneous Power

2020 ◽  
Vol 110 (6) ◽  
pp. 2828-2842
Author(s):  
Esra Zengin ◽  
Norman Abrahamson
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Accurate Estimation ◽  
Spectral Acceleration ◽  
Motion Model ◽  
Velocity Pulse ◽  
Near Fault ◽  
Instantaneous Power ◽  
Ground Motion Model ◽  
Short Time

ABSTRACT The velocity pulse in near-fault ground motions has been used as a key characteristic of damaging ground motions. Characterization of the velocity pulse involves three parameters: presence of the pulse, period of the pulse, and amplitude of the pulse. The basic concept behind the velocity pulse is that a large amount of seismic energy is packed into a short time, leading to larger demands on the structure. An intensity measure for near-fault ground motions, which is a direct measure of the amount of energy arriving in short time, called instantaneous power (IP (T1)), is defined as the maximum power of the bandpass-filtered velocity time series measured over a time interval of 0.5T1, in which T1 is the fundamental period of the structure. The records are bandpass filtered in the period band (0.2T1−3T1) to remove the frequencies that are not expected to excite the structure. Zengin and Abrahamson (2020) showed that the drift is better correlated with the IP (T1) than with the velocity pulse parameters for records scaled to the same spectral acceleration at T1. A conditional ground-motion model (GMM) for the IP is developed based on the 5%-damped spectral acceleration at T1, the earthquake magnitude, and the rupture distance. This conditional GMM can be used for record selection for near-fault ground motions that captures the key features of velocity pulses and can lead to a better representation of the median and variability of the maximum interstory drift. The conditional GMM can also be used in a vector hazard analysis for spectral acceleration (T1) and IP (T1) that can be used for more accurate estimation of drift hazard and seismic risk.

Improvements in exercise performance: effects of carbohydrate feedings and diet

1987 ◽  
Vol 62 (3) ◽  
pp. 983-988 ◽  
Author(s):  
P. D. Neufer ◽  
D. L. Costill ◽  
M. G. Flynn ◽  
J. P. Kirwan ◽  
J. B. Mitchell ◽  
...  
Keyword(s):  
Muscle Glycogen ◽  
Exercise Performance ◽  
Cycle Ergometer ◽  
Serum Glucose ◽  
O2 Consumption ◽  
Total Work ◽  
Vo2 Max ◽  
Fed State ◽  
Performance Effects ◽  
Muscle Glycogen Concentration

In an effort to determine the effects of carbohydrate (CHO) feedings immediately before exercise in both the fasted and fed state, 10 well-trained male cyclists [maximum O2 consumption (VO2 max), 4.35 +/- 0.11 l/min)] performed 45 min of cycling at 77% VO2 max followed by a 15-min performance ride on an isokinetic cycle ergometer. After a 12-h fast, subjects ingested 45 g of liquid carbohydrate (LCHO), solid carbohydrate confectionery bar (SCHO), or placebo (P) 5 min before exercise. An additional trial was performed in which a high-CHO meal (200 g) taken 4 h before exercise was combined with a confectionery bar feeding (M + SCHO) immediately before the activity. At 10 min of exercise, serum glucose values were elevated by 18 and 24% during SCHO and LCHO, respectively, compared with P. At 0 and 45 min no significant differences were observed in muscle glycogen concentration or total use between the four trials. Total work produced during the final 15 min of exercise was significantly greater (P less than 0.05) during M + SCHO (194,735 +/- 9,448 N X m), compared with all other trials and significantly greater (P less than 0.05) during LCHO and SCHO (175,204 +/- 11,780 and 176,013 +/- 10,465 N X m, respectively) than trial P (159,143 +/- 11,407 N X m). These results suggest that, under conditions when CHO stores are less than optimal, exercise performance is enhanced with the ingestion of 45 g of CHO 5 min before 1 h of intense cycling.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of the Monark Wingate Ergometer by Direct Measurement of Resistance and Velocity

2001 ◽  
Vol 26 (6) ◽  
pp. 543-558 ◽  
Author(s):  
Brian R. Macintosh ◽  
Shirley N. Bryan ◽  
Peter Rishaug ◽  
Stephen R. Norris
Keyword(s):  
Peak Power ◽  
Anaerobic Power ◽  
Constant Load ◽  
Cycle Ergometer ◽  
Moment Of Inertia ◽  
Power Moment ◽  
Correct Calculation ◽  
Load Tests ◽  
The Moment ◽  
Direct Measures

The purpose of this study was to assess the accuracy of the new basket-loaded Wingate ergometer introduced by Monark (Model 834E). Velocity was measured directly from the pedal switch while tension was measured with transducers on each end of the brake lacing. Moment of inertia of the flywheel was determined and accounted for in the calculation of power. Constant load tests (39.24 to 98.1 N), were done at pedaling speeds from 80 to 140 r•min−1 (flywheel angular velocity = 30-50 rad•s−1). The load transmitted to the lacing at the front and back of the flywheel was 95.5 ± 0.8% (mean ± SEM) and 6.71 ± 0.8%, respectively, of the load in the basket. Thus, the resultant tension (front minus back) was on average 88.8 ± 0.57% of the applied load. The velocity recorded by the Monark Wingate Ergometer computer program (MWECP) was the same (100.4 ± 1.56%) as that determined from the pedal switch directly. Five male mountain bikers performed a 30-s all-out test. Peak power calculated by MWECP (1181 ± 55W) was always higher (p < .01) than that calculated from direct measures of tension and velocity (1102 ± 66W), when not taking into account the moment of inertia. These experiments suggest that the basket-loaded Monark Wingate ergometer does not provide a correct calculation of power because of incomplete load transmission to the flywheel. Key words: power, anaerobic power, moment of inertia, cycle ergometer

scholarly journals To Jump or Cycle? Monitoring Neuromuscular Function in Rugby Union Players

2017 ◽  
Vol 12 (5) ◽  
pp. 690-696 ◽  
Author(s):  
Gregory Roe ◽  
Joshua Darrall-Jones ◽  
Kevin Till ◽  
Padraic Phibbs ◽  
Dale Read ◽  
...  
Keyword(s):  
Peak Power ◽  
Neuromuscular Function ◽  
Cycle Ergometer ◽  
Rugby Union ◽  
Flight Time ◽  
Neuromuscular Fatigue ◽  
Future Research ◽  
Mean Power ◽  
Training Block ◽  
Cycle Ergometer Test

Purpose:To evaluate changes in performance of a 6-s cycle-ergometer test (CET) and countermovement jump (CMJ) during a 6-wk training block in professional rugby union players.Methods:Twelve young professional rugby union players performed 2 CETs and CMJs on the 1st and 4th mornings of every week before the commencement of daily training during a 6-wk training block. Standardized changes in the highest score of 2 CET and CMJ efforts were assessed using linear mixed modeling and magnitude-based inferences.Results:After increases in training load during wk 3 to 5, moderate decreases in CMJ peak and mean power and small decreases in flight time were observed during wk 5 and 6 that were very likely to almost certainly greater than the smallest worthwhile change (SWC), suggesting neuromuscular fatigue. However, only small decreases, possibly greater than the SWC, were observed in CET peak power. Changes in CMJ peak and mean power were moderately greater than in CET peak power during this period, while the difference between flight time and CET peak power was small.Conclusion:The greater weekly changes in CMJ metrics in comparison with CET may indicate differences in the capacities of these tests to measure training-induced lower-body neuromuscular fatigue in rugby union players. However, future research is needed to ascertain the specific modes of training that elicit changes in CMJ and CET to determine the efficacy of each test for monitoring neuromuscular function in rugby union players.

scholarly journals No Influence of Nonivamide-nicoboxil on the Peak Power Output in Competitive Sportsmen

2021 ◽  
Author(s):  
Theresa Schörkmaier ◽  
Yvonne Wahl ◽  
Christian Brinkmann ◽  
Wilhelm Bloch ◽  
Patrick Wahl
Keyword(s):  
Power Output ◽  
Peak Power ◽  
Near Infrared ◽  
Endurance Performance ◽  
Cycle Ergometer ◽  
Muscle Oxygenation ◽  
Peak Power Output ◽  
Exercise Tests ◽  
Hypoxic Conditions ◽  
Placebo Cream

AbstractRecent studies have shown that the oxygenated hemoglobin level can be enhanced during rest through the application of nonivamide-nicoboxil cream. However, the effect of nonivamide-nicoboxil cream on oxygenation and endurance performance under hypoxic conditions is unknown. Therefore, the purpose of this study was to investigate the effects of nonivamide-nicoboxil cream on local muscle oxygenation and endurance performance under normoxic and hypoxic conditions. In a cross-over design, 13 athletes (experienced cyclists or triathletes [age: 25.2±3.5 years; VO2max 62.1±7.3 mL·min−1·kg−1]) performed four incremental exercise tests on the cycle ergometer under normoxic or hypoxic conditions, either with nonivamide-nicoboxil or placebo cream. Muscle oxygenation was recorded with near-infrared spectroscopy. Capillary blood samples were taken after each step, and spirometric data were recorded continuously. The application of nonivamide-nicoboxil cream increased muscle oxygenation at rest and during different submaximal workloads as well as during physical exhaustion, irrespective of normoxic or hypoxic conditions. Overall, there were no significant effects of nonivamide-nicoboxil on peak power output, maximal oxygen uptake or lactate concentrations. Muscle oxygenation is significantly higher with the application of nonivamide-nicoboxil cream. However, its application does not increase endurance performance.

Sex Effect on Catecholamine Responses to Sprint Exercise in Adolescents and Adults

2007 ◽  
Vol 19 (2) ◽  
pp. 132-144 ◽  
Author(s):  
Maïtel Botcazou ◽  
Christophe Jacob ◽  
Arlette Gratas-Delamarche ◽  
Sophie Vincent ◽  
Danièle Bentué-Ferrer ◽  
...  
Keyword(s):  
Peak Power ◽  
Tanner Stage ◽  
Cycle Ergometer ◽  
Fat Free Mass ◽  
Plasma Catecholamine ◽  
Plasma Adrenaline ◽  
Sex Effect ◽  
Sprint Exercise ◽  
Stage 4 ◽  
Adolescents And Adults

The purpose of this study was to clarify the effect of sex on plasma catecholamine responses to sprint exercise in adolescents and adults. Thirty-six untrained participants took part in this study—9 girls and 10 boys (Tanner Stage 4) and 9 women and 8 men. Each participant performed a 6-s sprint test on a cycle ergometer. Plasma adrenaline (A) and noradrenaline (NA) concentrations were determined successively at rest (A0 and NA0), immediately after the 6-s sprint test (AEX and NAEX), and after 5 min of recovery (A5 and NA5). Peak power, expressed in absolute values or relative to body weight and fat-free mass, was significantly higher in boys than in girls and higher in men than in women (p < .001). No sex effect was observed in AEX in the adolescents, but the NA increase was significantly higher in boys in response to the 6-s sprint (p < .05). In adults, no sex difference was found in NAEX, but AEX was significantly higher in men than in women (p < .05). NAEX was significantly higher in women than in girls (p < .05), and AEX was significantly higher in men than in boys (p < .01). The results of this study suggest that male and female adolescents and young adults might exhibit different catecholamine responses to sprint exercise.

A Prediction Model for Peak Power Output From Different Incremental Exercise Tests

2006 ◽  
Vol 1 (2) ◽  
pp. 122-136 ◽  
Author(s):  
Hans Luttikholt ◽  
Lars R. McNaughton ◽  
Adrian W. Midgley ◽  
David J. Bentley
Keyword(s):  
Power Output ◽  
Peak Power ◽  
Cycle Ergometer ◽  
Incremental Exercise ◽  
Peak Power Output ◽  
Exercise Tests ◽  
Male Athletes ◽  
Power Profile ◽  
Wide Range ◽  
Level Of Agreement

Context:There is currently no model that predicts peak power output (PPO) thereby allowing comparison between different incremental exercise test (EXT) protocols. In this study we have used the critical power profile to develop a mathematical model for predicting PPO from the results of different EXTs.Purpose:The purpose of this study was to examine the level of agreement between actual PPO values and those predicted from the new model.Methods:Eleven male athletes (age 25 ± 5 years, VO2max 62 ± 8 mL · kg–1 · min–1) completed 3 laboratory tests on a cycle ergometer. Each test comprised an EXT consisting of 1-minute workload increments of 30 W (EXT30/1) and 3-minute (EXT25/3) and 5-minute workload increments (EXT25/5) of 25 W. The PPO determined from each test was used to predict the PPO from the remaining 2 EXTs.Results:The differences between actual and predicted PPO values were statistically insignificant (P > .05). The random error components of the limits of agreement of ≤30 W also indicated acceptable levels of agreement between actual and predicted PPO values.Conclusions:Further data collection is necessary to confirm whether the model is able to predict PPO over a wide range of EXT protocols in athletes of different aerobic and anaerobic capacities.

Sign in / Sign up

Export Citation Format

Share Document