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"Critical power"

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
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
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
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
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
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
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
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
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
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
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
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
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 V̇O2peak and peak power output (PPO). Each participant completed four constant work-rate (CWR) arm-cranking tests at 90-120% PPO in both environmental conditions...
December 13, 2017: Respiratory Physiology & Neurobiology
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
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
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
Daniel A Keir, Felipe Mattioni Maturana, Juan M Murias
No abstract text is available yet for this article.
November 21, 2017: Applied Physiology, Nutrition, and Metabolism, Physiologie Appliquée, Nutrition et Métabolisme
Ricardo Dantas de Lucas
No abstract text is available yet for this article.
November 21, 2017: Applied Physiology, Nutrition, and Metabolism, Physiologie Appliquée, Nutrition et Métabolisme
Jan Boone, Jan G Bourgois
No abstract text is available yet for this article.
December 2017: Medicine and Science in Sports and Exercise
Hawbeer Salam, Samuele M Marcora, James G Hopker
PURPOSE: Time to exhaustion (TTE) tests used in the determination of critical power (CP) and curvature constant (W') of the power-duration relationship are strongly influenced by the perception of effort (PE). This study aimed to investigate whether manipulation of the PE alters the CP and W'. METHODS: Eleven trained cyclists completed a series of TTE tests to establish CP and W' under two conditions, following a mentally fatiguing (MF), or a control (CON) task...
January 2018: European Journal of Applied Physiology
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