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"Critical power"

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https://www.readbyqxmd.com/read/29721605/estimation-of-critical-end-test-torque-using-neuromuscular-electrical-stimulation-of-the-quadriceps-in-humans
#1
Natalie R Janzen, Robert E Hight, Darshit S Patel, Jason A Campbell, Rebecca D Larson, Christopher D Black
Characterization of critical power/torque (CP/CT) during voluntary exercise requires maximal effort, making difficult for those with neuromuscular impairments. To address this issue we sought to determine if electrically stimulated intermittent isometric exercise resulted in a critical end-test torque (ETT) that behaved similar to voluntary CT. In the first experiment participants (n = 9) completed four bouts of stimulated exercise at a 3:2 duty cycle, at frequencies of 100, 50, 25 Hz, and a low frequency below ETT (Sub-ETT; ≤ 15 Hz)...
May 2, 2018: European Journal of Applied Physiology
https://www.readbyqxmd.com/read/29651247/application-of-the-athlete-s-performance-passport-for-doping-control-a-case-report
#2
Sergei Iljukov, Stephane Bermon, Yorck O Schumacher
The efficient use of testing resources is a key issue in the fight against doping. The longitudinal tracking of sporting performances to identify unusual improvements possibly caused by doping, so-called "athlete's performance passport" (APP) is a new concept to improve targeted anti-doping testing. In fact, unusual performances by an athlete would trigger a more thorough testing program. In the present case report, performance data is modeled using the critical power concept for a group of athletes based on their past performances...
2018: Frontiers in Physiology
https://www.readbyqxmd.com/read/29566544/the-effects-of-priming-exercise-on-the-vo2-slow-component-and-the-time-course-of-muscle-fatigue-during-very-heavy-intensity-exercise-in-humans
#3
Paulo Cesar do Nascimento Salvador, Kristopher Mendes de Souza, Ricardo Dantas de Lucas, Luiz Guilherme Antonacci Guglielmo, Benedito Sérgio Denadai
We hypothesized that prior exercise would attenuate the muscle fatigue accompanied by the VO2SC behavior during a subsequent very heavy (VH) intensity cycling exercise. Thirteen healthy male subjects performed tests to determine the critical power (CP) and W' and six square-wave bouts until 3 or 8 min, each at a work rate set to deplete 70 % W' in 8 min, with an maximal isokinetic effort (MIE) before and after the conditions without (VHCON) and with prior exercise (VHEXP), to measure the cycling peak torque decrement...
March 22, 2018: Applied Physiology, Nutrition, and Metabolism, Physiologie Appliquée, Nutrition et Métabolisme
https://www.readbyqxmd.com/read/29541334/examination-of-resistance-settings-based-on-body-weight-for-the-3-minute-all-out-critical-power-test
#4
Marlene J Schulte, Jody L Clasey, Bradley S Fleenor, Haley C Bergstrom
There are conflicting suggestions regarding the most valid resistance (3-5% of body weight) to use for the critical power (CP) 3-min all-out (CP3min ) test to estimate CP and anaerobic work capacity (AWC). The purpose of this study was to determine if the CP and AWC estimates from the CP3min test were affected by the percentage of body weight used to set the resistance on a Monark cycle ergometer. Ten recreationally trained participants (mean ± SD: Age: 22.2 ± 2.2 yrs.) completed the CP3min test at resistances of 4...
2018: International Journal of Exercise Science
https://www.readbyqxmd.com/read/29521722/effects-of-two-hours-of-heavy-intensity-exercise-on-the-power-duration-relationship
#5
Ida E Clark, Anni Vanhatalo, Stephen J Bailey, Lee J Wylie, Brett S Kirby, Brad W Wilkins, Andrew M Jones
INTRODUCTION: Changes in the parameters of the power-time relationship (critical power (CP) and W') during endurance exercise would have important implications for performance. We tested the hypotheses that CP and W', estimated using the end-test power (EP) and the work done above EP (WEP), respectively, during a the 3-min all-out test (3MT), can be reliably determined, and would be lower, after completing 2-h of heavy-intensity exercise. METHODS: In study 1, six cyclists completed a 3MT immediately following 2-h of heavy-intensity exercise on two occasions to establish the reliability of EP and WEP...
March 8, 2018: Medicine and Science in Sports and Exercise
https://www.readbyqxmd.com/read/29520007/spatiotemporal-airy-ince-gaussian-wave-packets-in-strongly-nonlocal-nonlinear-media
#6
Xi Peng, Jingli Zhuang, Yulian Peng, DongDong Li, Liping Zhang, Xingyu Chen, Fang Zhao, Dongmei Deng
The self-accelerating Airy Ince-Gaussian (AiIG) and Airy helical Ince-Gaussian (AihIG) wave packets in strongly nonlocal nonlinear media (SNNM) are obtained by solving the strongly nonlocal nonlinear Schrödinger equation. For the first time, the propagation properties of three dimensional localized AiIG and AihIG breathers and solitons in the SNNM are demonstrated, these spatiotemporal wave packets maintain the self-accelerating and approximately non-dispersion properties in temporal dimension, periodically oscillating (breather state) or steady (soliton state) in spatial dimension...
March 8, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29515455/the-effects-of-%C3%AE-alanine-supplementation-on-muscle-ph-and-the-power-duration-relationship-during-high-intensity-exercise
#7
Matthew I Black, Andrew M Jones, Paul T Morgan, Stephen J Bailey, Jonathan Fulford, Anni Vanhatalo
Purpose: To investigate the influence of β-alanine (BA) supplementation on muscle carnosine content, muscle pH and the power-duration relationship (i.e., critical power and W'). Methods: In a double-blind, randomized, placebo-controlled study, 20 recreationally-active males (22 ± 3 y, V°O2peak 3.73 ± 0.44 L·min-1 ) ingested either BA (6.4 g/d for 28 d) or placebo (PL) (6.4 g/d) for 28 d. Subjects completed an incremental test and two 3-min all-out tests separated by 1-min on a cycle ergometer pre- and post-supplementation...
2018: Frontiers in Physiology
https://www.readbyqxmd.com/read/29489713/contributions-of-lower-body-strength-parameters-to-critical-power-and-anaerobic-work-capacity
#8
M Travis Byrd, Brian J Wallace, Jody L Clasey, Haley C Bergstrom
This study examined the contribution of lower body strength and isokinetic peak torque measures to the prediction of critical power (CP) and anaerobic work capacity (AWC). Fourteen recreationally trained males (mean ± SD age: 22.4 ± 2.5 yrs; height: 177.9 ± 7.7 cm; body mass: 84.2 ± 12.4 kg) with anaerobic training experience completed this study. The lower body strength measures included one repetition max (1RM) bilateral back squat [BSq], isokinetic peak torque at 30°·sec [PT30] and isokinetic peak torque at 240°·sec [PT240]) of the dominant leg...
February 27, 2018: Journal of Strength and Conditioning Research
https://www.readbyqxmd.com/read/29483625/new-considerations-for-hipsc-based-models-of-neuropsychiatric-disorders
#9
REVIEW
Gabriel E Hoffman, Nadine Schrode, Erin Flaherty, Kristen J Brennand
The development of human-induced pluripotent stem cells (hiPSCs) has made possible patient-specific modeling across the spectrum of human disease. Here, we discuss recent advances in psychiatric genomics and post-mortem studies that provide critical insights concerning cell-type composition and sample size that should be considered when designing hiPSC-based studies of complex genetic disease. We review recent hiPSC-based models of SZ, in light of our new understanding of critical power limitations in the design of hiPSC-based studies of complex genetic disorders...
February 26, 2018: Molecular Psychiatry
https://www.readbyqxmd.com/read/29470151/caffeine-increases-both-total-work-performed-above-critical-power-and-peripheral-fatigue-during-a-4-km-cycling-time-trial
#10
Leandro Camati Felippe, Guilherme Assuncao Ferreira, Sara Kely Learsi, Daniel Boari, Rômulo Bertuzzi, Adriano Eduardo Lima-Silva
The link between total work performed above critical power (CP) and peripheral muscle fatigue during self-paced exercise is unknown. We investigated the influence of caffeine on the total work done above CP during a 4-km cycling time trial (TT), and the subsequent consequence on the development of central and peripheral fatigue. Nine cyclists performed three constant-load exercise trials to determine CP and two 4-km TT ~75 min after oral caffeine (5 mg·kg-1 ) or cellulose (placebo) ingestion. Neuromuscular functions were assessed before and 50 min after supplementation, and 1 min after TT...
February 22, 2018: Journal of Applied Physiology
https://www.readbyqxmd.com/read/29444141/the-3-min-all-out-test-is-valid-for-determining-critical-power-but-not-anaerobic-work-capacity-in-tethered-running
#11
Maria Carolina Traina Gama, Ivan Gustavo Masselli Dos Reis, Filipe Antônio de Barros Sousa, Claudio Alexandre Gobatto
The purpose of the study was to investigate if the 3-min all-out test (3MT) is valid for obtaining critical power intensity (CP) and the amount of work that can be performed above CP (W') on non-motorized treadmills in tethered running. Eight physically active individuals (24 ± 3 years; 78.3 ± 8.7 kg; 179 ± 5 cm; 9.0 ± 2.5% body fat) performed four different efforts at constant intensity to exhaustion in order to determine CP and W'. The mechanical power values obtained were subsequently plotted with their corresponding time to exhaustion (limit time) for application of three mathematical models: power hyperbolic versus time limit (Hyp), linear power versus 1/time (P vs 1/t) and linear work versus time limit (Ԏ vs t)...
2018: PloS One
https://www.readbyqxmd.com/read/29432324/classification-of-intensity-in-team-sport-activity
#12
Ted Polglaze, Cruz Hogan, Brian Dawson, Alec Buttfield, Cristian Osgnach, Leanne Lester, Peter Peeling
PURPOSE: To assess the efficacy of critical metabolic power derived from variable-speed movement for classifying intensity in team sport activity. METHODS: Elite male hockey players (n = 12) completed a series of time trials (100 yd, 400 yd, 1500 yd) and a 3-min all-out test to derive both critical speed (CS) and critical power (CP). Heart rate (HR), blood lactate (BLa) and rating of perceived exertion (RPE) were measured during each protocol. Participants (n = 10) then played 2 competitive hockey matches...
February 9, 2018: Medicine and Science in Sports and Exercise
https://www.readbyqxmd.com/read/29401192/examination-of-a-multi-ingredient-pre-workout-supplement-on-total-volume-of-resistance-exercise-and-subsequent-strength-and-power-performance
#13
Haley C Bergstrom, M Travis Byrd, Brian J Wallace, Jody L Clasey
This study examined the acute effects of a multi-ingredient pre-workout supplement on: 1) total, lower, and upper body volume of resistance exercise; and 2) the subsequent lower body strength (isokinetic leg extension and flexion), lower (vertical jump [VJ] height), upper body power (bench-throw velocity [BTv]), and cycle ergometry performance (critical power [CP] and anaerobic work capacity [AWC]). Twelve men completed baseline strength and power measures prior to two experimental visits, supplement (SUP) and placebo (PL)...
February 1, 2018: Journal of Strength and Conditioning Research
https://www.readbyqxmd.com/read/29352330/relationship-between-power-duration-parameters-and-mechanical-and-anthropometric-properties-of-the-thigh-in-elite-cyclists
#14
Mehdi Kordi, Campbell Menzies, Len Parker Simpson
PURPOSE: The curvature constant (W') and asymptote (critical power; CP) of the power-duration relationship are important parameters for explaining cycling performance. Short-duration endurance cycling events rely more heavily on the W'; however, the full mechanistic underpinning of this parameter is yet to be determined. Evidence suggests both muscle volume and muscle strength may contribute to the magnitude of W'. Therefore, the present study investigated the relationship between power-duration parameters (CP and W') and (1) anthropometric and (2) mechanical properties of thigh muscles in a sample of elite cyclists...
March 2018: European Journal of Applied Physiology
https://www.readbyqxmd.com/read/29315165/exercise-thresholds-on-trial-are-they-really-equivalent
#15
Kevin Caen, Kobe Vermeire, Jan G Bourgois, Jan Boone
PURPOSE: The interchangeable use of whole-body exercise thresholds and breakpoints (BPs) in the local oxygenation response, as measured via near-infrared spectroscopy (NIRS), has recently been questioned in scientific literature. Therefore, the present study aimed to longitudinally investigate the interrelationship of four commonly used exercise thresholds: critical power (CP), the respiratory compensation point (RCP) and BPs in muscle (m[HHb]BP) and brain (c[O2Hb]BP) oxygenation. METHODS: Nine male participants (21...
January 8, 2018: Medicine and Science in Sports and Exercise
https://www.readbyqxmd.com/read/29247712/effects-of-normobaric-hypoxia-on-upper-body-critical-power-and-anaerobic-working-capacity
#16
Michael B La Monica, David H Fukuda, Tristan M Starling-Smith, Ran Wang, Jay R Hoffman, Jeffrey R Stout
PURPOSE: To evaluate the effects of moderate normobaric hypoxia on the parameters of the work-time relationship in the upper body. METHODS: Twenty-one recreationally active men completed a graded exercise test in both normobaric hypoxia (H) and normoxia (N) to exhaustion on an arm ergometer to determine V̇O2 peak and peak power output (PPO). Each participant completed four constant work-rate (CWR) arm-cranking tests at 90-120% PPO in both environmental conditions...
February 2018: Respiratory Physiology & Neurobiology
https://www.readbyqxmd.com/read/29244861/reliability-of-the-parameters-of-the-power-duration-relationship-using-maximal-effort-time-trials-under-laboratory-conditions
#17
Christoph Triska, Bettina Karsten, Bernd Heidegger, Bernhard Koller-Zeisler, Bernhard Prinz, Alfred Nimmerichter, Harald Tschan
The purpose of this study was to assess the reliability of critical power (CP) and the total amount of work accomplished above CP (W´) across repeated tests using ecologically valid maximal effort time-trials (TT) under laboratory conditions. After an initial incremental exercise test, ten well-trained male triathletes (age: 28.5 ± 4.7 years; body mass: 73.3 ± 7.9 kg; height: 1.80 ± 0.07 m; maximal aerobic power [MAP]: 329 ± 41 W) performed three testing sessions (Familiarization, Test I and Test II) each comprising three TT (12, 7, and 3 min with a passive recovery of 60 min between trials)...
2017: PloS One
https://www.readbyqxmd.com/read/29233666/emg-amplitude-fatigue-threshold-and-time-to-task-failure-a-meta-analysis
#18
REVIEW
J Matt McCrary, Bronwen J Ackermann, Mark Halaki
OBJECTIVES: Electromyographic (EMG) fatigue threshold (EMGFT ) is utilised as a correlate of critical power, torque, and force thresholds that establishes a theoretical exercise intensity-the power, torque, or force at which the rate of change of EMG amplitude (ΔEM¯G) is zero-below which neuromuscular fatigue is negligible and unpredictable. Recent studies demonstrating neuromuscular fatigue below critical thresholds raise questions about the construct validity of EMGFT . The purpose of this analysis is to evaluate the construct validity of EMGFT by aggregating ΔEM¯G and time to task failure (Tlim ) data...
November 11, 2017: Journal of Science and Medicine in Sport
https://www.readbyqxmd.com/read/29203319/critical-power-how-different-protocols-and-models-affect-its-determination
#19
Felipe Mattioni Maturana, Federico Y Fontana, Silvia Pogliaghi, Louis Passfield, Juan M Murias
In cycling, critical power (CP) and work above CP (W') can be estimated through linear and nonlinear models. Despite the concept of CP representing the upper boundary of sustainable exercise, overestimations may be made as the models possess inherent limitations and the protocol design is not always appropriate. OBJECTIVES: To measure and compare CP and W' through the exponential (CPexp ), 3-parameter hyperbolic (CP3-hyp ), 2-parameter hyperbolic (CP2-hyp ), linear (CPlinear ), and linear 1/time (CP1/time ) models, using different combinations of TTE trials of different durations (approximately 1-20min)...
November 29, 2017: Journal of Science and Medicine in Sport
https://www.readbyqxmd.com/read/29161112/reply-to-discussion-of-can-measures-of-critical-power-precisely-estimate-the-maximal-metabolic-steady-state-is-it-still-necessary-to-compare-critical-power-to-maximal-lactate-steady-state-when-is-it-appropriate-to-compare-critical-power-to-maximal-lactate-steady
#20
Daniel A Keir, Felipe Mattioni Maturana, Juan M Murias
No abstract text is available yet for this article.
January 2018: Applied Physiology, Nutrition, and Metabolism, Physiologie Appliquée, Nutrition et Métabolisme
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