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Ventilatory threshold

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https://www.readbyqxmd.com/read/28550471/blood-lactate-accumulation-decreases-during-the-slow-component-of-oxygen-uptake-without-a-decrease-in-muscular-efficiency
#1
J M O'Connell, J M Weir, B R MacIntosh
Pulmonary oxygen uptake ([Formula: see text]) slowly increases during exercise above the anaerobic threshold, and this increase is called the slow component of [Formula: see text]. The mechanism of the increase in [Formula: see text] is assumed to be due to increasing energy cost associated with increasingly inefficient muscle contraction. We hypothesized that the increase in [Formula: see text] would be accompanied by a constant or increasing rate of accumulation of blood lactate, indicating sustained anaerobic metabolism while [Formula: see text] increased...
May 26, 2017: Pflügers Archiv: European Journal of Physiology
https://www.readbyqxmd.com/read/28538301/proposal-of-a-new-specific-cardiopulmonary-exercise-test-for-taekwondo-athletes
#2
Marcus P Araujo, Antônio C L Nóbrega, Gabriel Espinosa, Matheus R Hausen, Renata R T Castro, Pedro P Soares, Jonas L Gurgel
Araujo, MP, Nóbrega, ACL, Espinosa, G, Hausen, MR, Castro, RRT, Soares, PP, and Gurgel, JL. Proposal of a new specific cardiopulmonary exercise test for taekwondo athletes. J Strength Cond Res 31(6): 1525-1535, 2017-The objective of this study is to evaluate the cardiorespiratory variables of Taekwondo athletes while performing incremental exercise test on an ergometer using a ramp protocol and to propose a specific protocol for assessing these physiological variables during Taekwondo practice. Fourteen athletes participated in 2 incremental exercise tests: a treadmill exercise test (TREADtest) and a Taekwondo-specific exercise test (TKDtest)...
June 2017: Journal of Strength and Conditioning Research
https://www.readbyqxmd.com/read/28531336/loop-gain-predicts-the-response-to-upper-airway-surgery-in-patients-with-obstructive-sleep-apnoea-ventilatory-control-abnormalities-predict-surgical-responsiveness
#3
Simon A Joosten, Paul Leong, Shane A Landry, Scott A Sands, Philip I Terrill, Dwayne Mann, Anthony Turton, Jhanavi Rangaswamy, Christopher Andara, Glen Burgess, Darren Mansfield, Garun S Hamilton, Bradley A Edwards
Study Objectives: Upper airway surgery is often recommended to treat OSA patients who cannot tolerate continuous positive airways pressure (CPAP). However, the response to surgery is variable, potentially because it does not improve the non-anatomical factors (i.e. loop gain and arousal threshold) causing OSA. Measuring these traits clinically might predict responses to surgery. Our primary objective was to test the value of loop gain and arousal threshold to predict surgical success defined as 50% reduction in apnea-hypopnea index (AHI) and AHI <10 events/hr post-surgery...
May 22, 2017: Sleep
https://www.readbyqxmd.com/read/28528994/clinical-significance-of-the-overshoot-phenomena-of-respiratory-gas-indices-during-recovery-from-maximal-exercise-testing
#4
Yuta Takayanagi, Akira Koike, Osamu Nagayama, Arisa Nagamine, Rujie Qin, Jo Kato, Isao Nishi, Tomoko Himi, Yuko Kato, Akira Sato, Takeshi Yamashita, Kazutaka Aonuma
BACKGROUND: Overshoot phenomena of the gas exchange ratio (R:VCO2/VO2), ventilatory equivalent for O2 (VE/VO2), and end-tidal O2 pressure (PETO2) are commonly observed during recovery from maximal cardiopulmonary exercise testing (CPX). We investigated the clinical significance of the overshoots of these indices by comparing their magnitudes between healthy subjects and cardiac patients with left ventricular dysfunction. METHODS: In total, 121 subjects (73 healthy subjects and 48 cardiac patients with left ventricular ejection fraction<40%) who underwent CPX and achieved peak R≥1...
May 18, 2017: Journal of Cardiology
https://www.readbyqxmd.com/read/28522658/effect-of-fontan-geometry-on-exercise-haemodynamics-and-its-potential-implications
#5
Elaine Tang, Zhenglun Alan Wei, Kevin K Whitehead, Reza H Khiabani, Maria Restrepo, Lucia Mirabella, James Bethel, Stephen M Paridon, Bradley S Marino, Mark A Fogel, Ajit P Yoganathan
OBJECTIVE: Exercise intolerance afflicts Fontan patients with total cavopulmonary connections (TCPCs) causing a reduction in quality of life. Optimising TCPC design is hypothesised to have a beneficial effect on exercise capacity. This study investigates relationships between TCPC geometries and exercise haemodynamics and performance. METHODS: This study included 47 patients who completed metabolic exercise stress test with cardiac magnetic resonance (CMR). Phase-contrast CMR images were acquired immediately following supine lower limb exercise...
May 18, 2017: Heart: Official Journal of the British Cardiac Society
https://www.readbyqxmd.com/read/28511024/cardiopulmonary-exercise-testing-and-surgery
#6
Paul O Older, Denny Zh Levett
The surgical patient population is increasingly elderly and comorbid and poses challenges to perioperative physicians. Accurate pre-operative risk stratification is important to direct perioperative care. Reduced aerobic fitness is associated with increased post-operative morbidity and mortality. Cardiopulmonary exercise testing is an integrated and dynamic test that gives an objective measure of aerobic fitness or functional capacity and identifies the cause of exercise intolerance. Cardiopulmonary exercise testing provides an individualized estimate of patient risk that can be used to predict post-operative morbidity and mortality...
May 16, 2017: Annals of the American Thoracic Society
https://www.readbyqxmd.com/read/28510504/cardiopulmonary-exercise-testing-basics-of-methodology-and-measurements
#7
Alessandro Mezzani
Cardiopulmonary exercise testing adds measurement of ventilation and volume of oxygen uptake and exhaled carbon dioxide to routine physiological and performance parameters obtainable from conventional exercise testing, furnishing an all-round vision of the systems involved in both oxygen transport from air to mitochondria and its utilization during exercise. Peculiarities of cardiopulmonary exercise testing methodology are the use of ramp protocols and calibration procedures for flow meters and gas analyzers...
May 16, 2017: Annals of the American Thoracic Society
https://www.readbyqxmd.com/read/28492701/short-term-intensive-training-attenuates-the-exercise-induced-interaction-of-mono-1-2-cells-and-platelets-after-coronary-bypass-in-cardiac-patients
#8
Shu-Chun Huang, Mei-Kuen Wong, Pyng-Jing Lin, Feng-Chun Tsai, Jaw-Ji Chu, Meng-Yu Wu, Tieh-Cheng Fu, Jong-Shyan Wang
The interaction between platelets and monocytes plays a critical role in the pathogenesis and progression of cardiovascular diseases. This study investigated how short-term intensive training (SIT) influences monocyte subset characteristics and exercise-induced monocyte and platelet aggregates (MPAs) following elective coronary bypass (CABG) in cardiac patients. Forty-nine patients hospitalised for CABG were randomised into SIT (N=26) and conventional training (CT, N=23) groups. The SIT subjects underwent supervised aerobic training at 80~120 % of the ventilatory anaerobic threshold based on sub-maximal exercise tests performed 7 days post-CABG for 20 sessions with two sessions/day and 30 min/session, which were completed within four weeks after surgery...
May 11, 2017: Thrombosis and Haemostasis
https://www.readbyqxmd.com/read/28492238/association-of-oxygen-uptake-at-ventilatory-threshold-with-risk-of-incident-hypertension-a-long-term-prospective-cohort-study
#9
S K Kunutsor, S Kurl, J A Laukkanen
No abstract text is available yet for this article.
May 11, 2017: Journal of Human Hypertension
https://www.readbyqxmd.com/read/28471041/an-investigation-into-the-relationship-between-heart-rate-variability-and-the-ventilatory-threshold-in-healthy-moderately-trained-males
#10
Andrew Grannell, Giuseppe De Vito
BACKGROUND: During incremental exercise, heart rate variability (HRV) has been shown to display distinct stabilization and inflection points, which have been used to indirectly detect the ventilatory threshold (VT). METHODS: Ten moderately trained males (26·5 ± 5·9 years: VO2peak 48·7 ± 4·1 ml min(-1 ) kg(-1) ) performed an incremental test on a cycle ergometer until volitional exhaustion with both R-R intervals and respiratory indices recorded. HRV was quantified using both nonlinear (Poincare plot; short-term variability SD1) and spectral analysis of the R-R intervals (high-frequency component; HFp)...
May 4, 2017: Clinical Physiology and Functional Imaging
https://www.readbyqxmd.com/read/28470411/sexual-dimorphism-in-heart-rate-recovery-from-peak-exercise
#11
Goncalo Vilhena de Mendonca, Carolina Teodósio, Paula Marta Bruno
PURPOSE: There is lack of consensus on whether sex, per se, affects heart rate recovery (HRR). To discriminate between the role of sex and that of cardiovascular fitness on HRR, we compared two groups of male and female participants matched for age and peak oxygen uptake (VO2peak) percentile. METHODS: Forty healthy individuals with above-average cardiovascular fitness (VO2peak >50th percentile), aged 18-27 years (23 men; 17 women), performed maximal cycle-ergometer tests with cardiorespiratory measurements...
May 3, 2017: European Journal of Applied Physiology
https://www.readbyqxmd.com/read/28442632/effect-of-aerobic-exercise-training-on-ventilatory-efficiency-and-respiratory-drive-in-obese-subjects
#12
Mehdi Chlif, Anis Chaouachi, Said Ahmaidi
BACKGROUND: Obese patients show a decline in exercise capacity and diverse degrees of dyspnea in association with mechanical abnormalities, increased ventilatory requirements secondary to the increased metabolic load, and a greater work of breathing. Consequently, obese patients may be particularly predisposed to the development of respiratory muscle fatigue during exercise. The aim of this study was to assess inspiratory muscle performance during incremental exercise in 19 obese male subjects (body mass index 41 ± 6 kg/m(2)) after aerobic exercise training using the noninvasive, inspiratory muscle tension-time index (TT0...
April 25, 2017: Respiratory Care
https://www.readbyqxmd.com/read/28435685/quantification-and-physiological-significance-of-the-rightward-shift-of-the-v-slope-during-incremental-cardiopulmonary-exercise-testing
#13
Hirotaka Nishijima, Kazuo Kondo, Kazuya Yonezawa, Hiroki Hashimoto, Masayuki Sakurai
BACKGROUND: Ventilatory anaerobic threshold (VAT) is frequently used as a measure of exercise tolerance, with the V-slope method being the standard; however, this needs to be visually determined. Over the years, we have observed that the V-slope itself often appears to shift rightward before the appearance of the VAT (RtShift: rightward shift of V-slope). This phenomenon has long been known to occur during the first 1-2 min of steady-state exercise and disappears thereafter; it is attributed to CO2 storage, presumably in active muscle...
2017: BMC Sports Science, Medicine and Rehabilitation
https://www.readbyqxmd.com/read/28399379/physiology-of-arousal-in-osa-and-potential-impacts-for-sedative-treatment
#14
Amy S Jordan, Fergal J O'Donoghue, Jennifer M Cori, John Trinder
Treatment options for patients with obstructive sleep apnea (OSA) intolerant of continuous positive airway pressure (CPAP) are limited. Thus, new therapies are sought. Recently, there has been interest in using sedatives to delay arousal from sleep, allowing upper airway dilator muscle recruitment sufficient to re-open the airway while maintaining sleep. In this review the rationale for sedative use and prior sedative studies in OSA are presented, along with a description of six factors that may determine sedative treatment success...
April 11, 2017: American Journal of Respiratory and Critical Care Medicine
https://www.readbyqxmd.com/read/28389695/effects-of-low-temperature-on-breathing-pattern-and-ventilatory-responses-during-hibernation-in-the-golden-mantled-ground-squirrel
#15
Cheryl L Webb, William K Milsom
During entrance into hibernation in golden-mantled ground squirrels (Callospermophilus lateralis), ventilation decreases as metabolic rate and body temperature fall. Two patterns of respiration occur during deep hibernation. At 7 °C body temperature (T b ), a breathing pattern characterized by episodes of multiple breaths (20.6 ± 1.9 breaths/episode) separated by long apneas or nonventilatory periods (T nvp ) (mean = 11.1 ± 1.2 min) occurs, while at 4 °C T b , a pattern in which breaths are evenly distributed and separated by a relatively short T nvp (0...
April 7, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28389601/anterior-cerebral-blood-velocity-and-end-tidal-co2-responses-to-exercise-differ-in-children-and-adults
#16
Lindsay A Ellis, Philip N Ainslie, Victoria A Armstrong, Laura Emily Morris, Ryan Gerard Simair, Nathan R Sletten, Christine M Tallon, Ali Mary McManus
Little is known about the response of the cerebrovasculature to acute exercise in children and how these responses might differ with adults. Therefore, we compared changes in middle cerebral artery blood velocity (MCAVmean), partial pressure of end-tidal carbon dioxide (PETCO2), blood pressure and ventilation (VE) in response to incremental exercise between children and adults. Thirteen children [aged 9±1 (SD) y] and 13 sex-matched adults [aged 25±4 y] completed a maximal exercise test during which MCAVmean, PETCO2 and VE were measured continuously...
April 7, 2017: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/28388274/six-minute-stepper-test-to-set-pulmonary-rehabilitation-intensity-in-patients-with-copd-a-retrospective-study
#17
Tristan Bonnevie, Francis-Edouard Gravier, Marie Leboullenger, Clément Médrinal, Catherine Viacroze, Antoine Cuvelier, Jean-François Muir, Catherine Tardif, David Debeaumont
Pulmonary rehabilitation (PR) improves outcomes in patients with chronic obstructive pulmonary disease (COPD). Optimal assessment includes cardiopulmonary exercise testing (CPET), but consultations are limited. Field tests could be used to individualize PR instead of CPET. The six-minute stepper test (6MST) is easy to set up and its sensitivity and reproducibility have previously been reported in patients with COPD. The aim of this study was to develop a prediction equation to set intensity in patients attending PR, based on the 6MST...
April 7, 2017: COPD
https://www.readbyqxmd.com/read/28386984/ventilatory-and-behavioural-responses-of-the-marbled-sole-pseudopleuronectes-yokohamae-to-progressive-hypoxia
#18
H Nishizawa, Y Kono, N Arai, J Shoji, H Mitamura
This study identified ventilatory and behavioural responses in the marbled sole Pseudopleuronectes yokohamae under experimentally induced progressive decreases in dissolved oxygen (DO) levels. Ventilation frequency showed an increase with decreasing DO levels from normoxia to 2·75 mg O2  l(-1) , followed by a decrease in ventilation frequency at decreased DO levels from 2·00 to 0·75 mg O2 l(-1) . At DO levels below 2·00 mg l(-1) , behaviours at the bottom were suppressed, whereas avoidance behaviours increased...
April 7, 2017: Journal of Fish Biology
https://www.readbyqxmd.com/read/28384329/oxygen-uptake-efficiency-slope-as-a-useful-measure-of-cardiorespiratory-fitness-in-morbidly-obese-women
#19
Tatiana Onofre, Nicole Oliver, Renata Carlos, Amanda Felismino, Renata Cristina Corte, Eliane Silva, Selma Bruno
Cardiopulmonary assessment through oxygen uptake efficiency slope (OUES) data has shown encouraging results, revealing that we can obtain important clinical information about functional status. Until now, the use of OUES has not been established as a measure of cardiorespiratory capacity in an obese adult population, only in cardiac and pulmonary diseases or pediatric patients. The aim of this study was to characterize submaximal and maximal levels of OUES in a sample of morbidly obese women and analyze its relationship with traditional measures of cardiorespiratory fitness, anthropometry and pulmonary function...
2017: PloS One
https://www.readbyqxmd.com/read/28382813/oxygen-uptake-and-body-composition-after-aquatic-physical-training-in-women-with-fibromyalgia-a-randomized-controlled-trial
#20
Carolina P Andrade, Antonio R Zamunér, Meire Forti, Thalita F França, Nayara Y Tamburús, Ester Silva
BACKGROUND: Aquatic physical training (APT) has been strongly recommended to improve symptoms in fibromyalgia syndrome (FMS). However, its effects on body composition and whether lean body mass (LBM) directly influences the aerobic functional capacity of this population are still not clear. AIM: To investigate whether APT can help improve body composition and increase the aerobic functional capacity in women with FMS, and whether oxygen consumption (VO2) related to LBM can better quantify the functional capacity of this population...
April 4, 2017: European Journal of Physical and Rehabilitation Medicine
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