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Maximal lactate state

Benoit Capostagno, Michael I Lambert, Robert P Lamberts
Finding the optimal balance between high training loads and recovery is a constant challenge for cyclists and their coaches. Monitoring improvements in performance and levels of fatigue is recommended to correctly adjust training to ensure optimal adaptation. However, many performance tests require a maximal or exhaustive effort, which reduces their real-world application. The purpose of this review was to investigate the development and use of submaximal cycling tests that can be used to predict and monitor cycling performance and training status...
September 2016: International Journal of Sports Physiology and Performance
Rafael Azevedo, Marcos David Silva-Cavalcante, Bruno Gualano, Adriano E Lima-Silva, Romulo Bertuzzi
PURPOSE: To examine the effects of caffeine ingestion on physiological and perceptual responses in mentally fatigued individuals. METHODS: Eight male physically active subjects completed four cycling constant-workload tests in four experimental conditions at 80 % of maximal power output: control (C), mental fatigue (MF), mental fatigue plus caffeine ingestion (5 mg/kg) (MF-CAF), and mental fatigue plus placebo (MF-PLA). The mental fatigue was induced by a continuous performance task A-X version (AX-CPT)...
September 30, 2016: European Journal of Applied Physiology
Nathan A Lewis, Colin Towey, Georgie Bruinvels, Glyn Howatson, Charles R Pedlar
Exercise causes alterations in redox homeostasis (ARH). Measuring ARH in elite athletes may aid in the identification of training tolerance, fatigued states, and underperformance. To the best of our knowledge, no studies have examined ARH in elite male and female distance runners at sea level. The monitoring of ARH in athletes is hindered by a lack of reliable and repeatable in-the-field testing tools and by the rapid turnaround of results. We examined the effects of various exercise intensities on ARH in healthy (non-over-reached) elite male and female endurance athletes using clinical point-of-care (POC) redox tests, referred to as the free oxygen radical test (FORT) (pro-oxidant) and the free oxygen radical defence (FORD) (antioxidant)...
October 2016: Applied Physiology, Nutrition, and Metabolism, Physiologie Appliquée, Nutrition et Métabolisme
Jan Boone, Kristof Vandekerckhove, Ilse Coomans, Fabrice Prieur, Jan G Bourgois
In the past two decades oxygenation responses to incremental ramp exercise, measured non-invasively by means of near-infrared spectroscopy at different locations in the body, have advanced the insights on the underpinning mechanisms of the whole-body pulmonary oxygen uptake ([Formula: see text]) response. In healthy subjects the complex oxygenation responses at the level of locomotor and respiratory muscles, and brain were simplified and quantified by the detection of breakpoints as a deviation in the ongoing response pattern as work rate increases...
September 9, 2016: European Journal of Applied Physiology
Thomas Hauser, Jennifer Adam, Henry Schulz
No abstract text is available yet for this article.
2016: Theoretical Biology & Medical Modelling
Raúl J Gazmuri, Christopher L Kaufman, Alvin Baetiong, Jeejabai Radhakrishnan
BACKGROUND: Several characteristics of the ventricular fibrillation (VF) waveform have been found predictive of successful defibrillation and hypothesized to reflect the myocardial energy state. In an open-chest swine model of VF, we modeled "average CPR" using extracorporeal circulation (ECC) and assessed the time course of coronary blood flow, myocardial metabolism, and myocardial structure in relation to the amplitude spectral area (AMSA) of the VF waveform without artifacts related to chest compression...
2016: PloS One
Jailton Gregório Pelarigo, Camila Coelho Greco, Benedito Sérgio Denadai, Ricardo Jorge Fernandes, João Paulo Vilas-Boas, David Robert Pendergast
Our purpose was to examine the swimming biophysical responses at velocities (v) of 97.5, 100 and 102.5% of the maximal lactate steady state (MLSS). Ten elite female swimmers performed three-to-five 30-min constant tests at imposed paces to determine 97.5, 100 and 102.5%MLSS v. Gas exchange, blood lactate concentration ([La-]), stroke rate (SR) and v were determined during each test. The v values at 97.5, 100 and 102.5%MLSS were 1.21±0.07, 1.24±0.07 and 1.27±0.07m.s(-1), respectively. Oxygen uptake (V̇O2) and Pulmonary ventilation (V̇E) increased as function of v...
October 2016: Human Movement Science
Giuliano Bolondi, Federico Mocchegiani, Roberto Montalti, Daniele Nicolini, Marco Vivarelli, Lesley De Pietri
Liver transplantation represents a fundamental therapeutic solution to end-stage liver disease. The need for liver allografts has extended the set of criteria for organ acceptability, increasing the risk of adverse outcomes. Little is known about the early postoperative parameters that can be used as valid predictive indices for early graft function, retransplantation or surgical reintervention, secondary complications, long intensive care unit stay or death. In this review, we present state-of-the-art knowledge regarding the early post-transplantation tests and scores that can be applied during the first postoperative week to predict liver allograft function and patient outcome, thereby guiding the therapeutic and surgical decisions of the medical staff...
July 14, 2016: World Journal of Gastroenterology: WJG
Dominik P Guensch, Gobinath Nadeshalingam, Kady Fischer, Aurelien F Stalder, Matthias G Friedrich
BACKGROUND: Oxygenation-sensitive (OS) Cardiovascular Magnetic Resonance (CMR) is a promising utility in the diagnosis of heart disease. Contrast in OS-CMR images is generated through deoxyhemoglobin in the tissue, which is negatively correlated with the signal intensity (SI). Thus, changing hematocrit levels may be a confounder in the interpretation of OS-CMR results. We hypothesized that hemodilution confounds the observed signal intensity in OS-CMR images. METHODS: Venous and arterial blood from five pigs was diluted with lactated Ringer solution in 10 % increments to 50 %...
2016: Journal of Cardiovascular Magnetic Resonance
Bibiano Madrid, Flávio Oliveira Pires, Jonato Prestes, Denis César Leite Vieira, Tyler Clark, Eduard Tiozzo, John E Lewis, Carmen S Grubert Campbell, Herbert Gustavo Simões
The maximal lactate steady state is the gold standard for evaluating aerobic capacity; however, it is time-consuming. The lactate minimum protocol is an easier alternative, but is not feasible and still expensive. This study investigated whether the rating of perceived exertion of 13 is an accurate predictor of lactate minimum and maximal lactate steady state intensities. Eleven physically active men performed three tests: (1) incremental exercise with workloads based on rating of perceived exertion of 10, 13, and 16 (experimental protocol - denominated RPE-13 test), (2) lactate minimum, and (3) maximal lactate steady state...
February 2016: Perceptual and Motor Skills
Jean-Paul Richalet
The adrenergic system is part of a full array of mechanisms allowing the human body to adapt to the hypoxic environment. Triggered by the stimulation of peripheral chemoreceptors, the adrenergic centers in the medulla are activated in acute hypoxia and augment the adrenergic drive to the organs, especially to the heart, leading to tachycardia. With prolonged exposure to altitude hypoxia, the adrenergic drive persists, as witnessed by elevated blood concentrations of catecholamines and nerve activity in adrenergic fibers...
2016: Advances in Experimental Medicine and Biology
Xu Steven Xu, Charles J Ryan, Kim Stuyckens, Matthew R Smith, Fred Saad, Thomas W Griffin, Youn C Park, Margaret K Yu, Peter De Porre, An Vermeulen, Italo Poggesi, Partha Nandy
BACKGROUND AND OBJECTIVES: Recent analysis revealed strong associations between prostate-specific antigen (PSA) dynamics and overall survival (OS) in metastatic castration-resistant prostate cancer (mCRPC) and supported PSA dynamics as bridging surrogacy endpoints for clinical benefit from treatment with abiraterone acetate plus prednisone. This analysis aimed to investigate the abiraterone exposure-PSA dynamics relationship in mCRPC. METHODS: Abiraterone pharmacokinetics-PSA models were constructed using data from the COU-AA-301 (chemotherapy-pretreated) and COU-AA-302 (chemotherapy-naïve) trials comparing abiraterone acetate 1000 mg/day plus prednisone 5 mg twice daily with prednisone alone in mCRPC...
June 21, 2016: Clinical Pharmacokinetics
Ralph Beneke, Renate M Leithäuser
The maximal lactate steady state (MLSS) depicts the highest blood lactate concentration (BLC) that can be maintained over time without a continual accumulation at constant prolonged workload. In cycling, no difference in the MLSS was combined with lower power output related to peak workload (IMLSS) at 100 than at 50 revolutions per minute (RPM). MLSS coincides with a respiratory exchange ratio (RER) close to 1. Recently, at incremental exercise, an RER of 1 was found at similar workload and similar intensity but higher BLC at 100 compared with 50RPM...
June 1, 2016: International Journal of Sports Physiology and Performance
Clévia Santos Passos, Rosemara Silva Ribeiro, Thiago Santos Rosa, Rodrigo Vanerson Passos Neves, Fernando Costa, Milton Ginoza, Mirian Aparecida Boim
INTRODUCTION: Phalaris canariensis L. (Pc), known as birdseed, is rich in tryptophan. The aqueous extract of Pc (AEPc) treatment reduced systolic blood pressure (SBP) in spontaneously hypertensive rats (SHR) via mechanisms mediated by the tryptophan metabolizing enzyme indoleamine 2,3-dioxygenase (IDO). Hypertension is a risk factor to cardiovascular and renal diseases. Considering that physical exercise improves hypertension and cardiovascular function, the aim of this study was to evaluate whether the benefits of exercise (Ex) would be enhanced by concomitant AEPc treatment (400 mg·kg·d p...
October 2016: Medicine and Science in Sports and Exercise
Shimin Li, Edward Kim, Joseph A Bonanno
Maintenance of corneal hydration is dependent on the active transport properties of the corneal endothelium. We tested the hypothesis that lactic acid efflux, facilitated by buffering, is a component of the endothelial fluid pump. Rabbit corneas were perfused with bicarbonate-rich (BR) or bicarbonate-free (BF) Ringer of varying buffering power, while corneal thickness was measured. Perfusate was collected and analyzed for lactate efflux. In BF with no added HEPES, the maximal corneal swelling rate was 30.0 ± 4...
July 1, 2016: American Journal of Physiology. Cell Physiology
Benoit Capostagno, Michael I Lambert, Robert P Lamberts
Finding the optimal balance between high training loads and recovery is a constant challenge for cyclists and their coaches. Monitoring improvements in performance and levels of fatigue is recommended in order to correctly adjust training to ensure optimal adaptation. However, many performance tests require a maximal or exhaustive effort, which reduces their real-world application. The purpose of this review was to investigate the development and use of submaximal cycling tests which can be used to predict and monitor cycling performance and training status...
May 18, 2016: International Journal of Sports Physiology and Performance
Thiago S Rosa, Herbert G Simões, Marcelo M Rogero, Milton R Moraes, Benedito S Denadai, Ricardo M Arida, Marília S Andrade, Bruno M Silva
Severe obesity affects metabolism with potential to influence the lactate and glycemic response to different exercise intensities in untrained and trained rats. Here we evaluated metabolic thresholds and maximal aerobic capacity in rats with severe obesity and lean counterparts at pre- and post-training. Zucker rats (obese: n = 10, lean: n = 10) were submitted to constant treadmill bouts, to determine the maximal lactate steady state, and an incremental treadmill test, to determine the lactate threshold, glycemic threshold and maximal velocity at pre and post 8 weeks of treadmill training...
2016: Frontiers in Physiology
Patrick Wahl, Maximilian Sanno, Karoline Ellenberg, Hosea Frick, Ezra Böhm, Björn Haiduck, Jan-Peter Goldmann, Silvia Achtzehn, Gert-Peter Brüggemann, Joachim Mester, Wilhelm Bloch
To examine the effects of aqua-cycling (AC) vs. passive-recovery (P) on performance, markers of muscle damage, delayed onset of muscle soreness (DOMS), and the persons perceived physical state (PEPS) after 300 counter movement jumps (CMJ).20 male participants completed 300 CMJ. Afterwards, they were randomly assigned to either the P-group or the AC-group, the latter performing 30 min of AC. Before, directly after the 300 CMJ, after the recovery session, and up to 72h post, performance of leg extensor muscles, damage markers, the PEPS and DOMS were measured...
April 23, 2016: Journal of Strength and Conditioning Research
I Llodio, E M Gorostiaga, I Garcia-Tabar, C Granados, L Sánchez-Medina
This study aimed to predict the velocity corresponding to the maximal lactate steady state (MLSSV) from non-invasive variables obtained during a maximal multistage running field test (modified University of Montreal Track Test, UMTT), and to determine whether a single constant velocity test (CVT), performed several days after the UMTT, could estimate the MLSSV. Within 4-5 weeks, 20 male runners performed: 1) a modified UMTT, and 2) several 30 min CVTs to determine MLSSV to a precision of 0.25 km·h(-1)...
June 2016: International Journal of Sports Medicine
Joshua Christen, Carl Foster, John P Porcari, Richard P Mikat
PURPOSE: The session RPE (sRPE) has gained popularity as a "user friendly" method for evaluating internal training load. sRPE has historically been obtained 30-min following exercise. This study evaluated the effect of post-exercise measurement time on sRPE following steady-state and interval cycle exercise. METHODS: Well-trained subjects (N=15) (VO2max=51+4 & 36+4 (cycle ergometer) for men & women, respectively) completed counterbalanced 30-min steady-state and interval training bouts...
March 21, 2016: International Journal of Sports Physiology and Performance
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