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"Oxygen uptake kinetics"

Victor M Niemeijer, Ruud F Spee, Thijs Schoots, Pieter F F Wijn, Hareld M Kemps
The extent and speed of transient skeletal muscle deoxygenation during exercise onset in chronic heart failure (CHF) patients is related to impairments of local O2 delivery and utilization. This study examined the physiological background of submaximal exercise performance in 19 moderately impaired CHF patients (Weber class A, B, and C) compared with 19 matched healthy control (HC) subjects by measuring skeletal muscle oxygenation (SmO2) changes during cycling exercise. All subjects performed two subsequent moderate-intensity 6-minute exercise tests (bout 1 and 2) with measurements of pulmonary oxygen uptake kinetics, and SmO2 using near infrared (NIR) spatially resolved spectroscopy (SRS) at the vastus lateralis for determination of absolute oxygenation values, amplitudes, kinetics (mean response time for onset), and deoxygenation overshoot characteristics...
October 7, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Richard B Thompson, Joseph J Pagano, Kory W Mathewson, Ian Paterson, Jason R Dyck, Dalane W Kitzman, Mark J Haykowsky
The goals of the current study were to compare leg blood flow, oxygen extraction and oxygen uptake (VO2) after constant load sub-maximal unilateral knee extension (ULKE) exercise in patients with heart failure with reduced ejection fraction (HFrEF) compared to those with preserved ejection fraction (HFpEF). Previously, it has been shown that prolonged whole body VO2 recovery kinetics are directly related to disease severity and all-cause mortality in HFrEF patients. To date, no study has simultaneously measured muscle-specific blood flow and oxygen extraction post exercise recovery kinetics in HFrEF or HFpEF patients; therefore it is unknown if muscle VO2 recovery kinetics, and more specifically, the recovery kinetics of blood flow and oxygen extraction at the level of the muscle, differ between HF phenotypes...
2016: PloS One
Scott L Hummel, John Herald, Craig Alpert, Kimberlee A Gretebeck, Wendy S Champoux, Donald R Dengel, Peter V Vaitkevicius, Neil B Alexander
BACKGROUND: Submaximal oxygen uptake measures are more feasible and may better predict clinical cardiac outcomes than maximal tests in older adults with heart failure (HF). We examined relationships between maximal oxygen uptake, submaximal oxygen kinetics, functional mobility, and physical activity in older adults with HF and reduced ejection fraction. METHODS: Older adults with HF and reduced ejection fraction (n = 25, age 75 ± 7 years) were compared to 25 healthy age- and gender-matched controls...
July 2016: Journal of Geriatric Cardiology: JGC
Norio Hotta, Hisayoshi Ogata, Takaharu Kondo, Koji Ishida, Michael R Kushnick
No abstract text is available yet for this article.
May 2016: Medicine and Science in Sports and Exercise
Chad C Wiggins, Shane A Bielko, Allison J Campbell, Timothy D Mickleborough, Robert F Chapman
No abstract text is available yet for this article.
May 2016: Medicine and Science in Sports and Exercise
Greg Doncaster, Simon Marwood, John Iga, Viswanath Unnithan
PURPOSE: To examine the relationship between oxygen uptake kinetics (VO2 kinetics) and physical measures associated with soccer match play, within a group of highly trained youth soccer players. METHODS: Seventeen highly trained youth soccer players (age: 13.3 ± 0.4 year, self-assessed Tanner stage: 3 ± 1) volunteered for the study. Players initially completed an incremental treadmill protocol to exhaustion, to establish gaseous exchange threshold (GET) and VO2max (59...
September 2016: European Journal of Applied Physiology
Francois Lalonde, Maxime Caru, Daigle Chantal, Philippe Gimenez, Jonathan Tremblay, Daniel Curnier
No abstract text is available yet for this article.
May 2016: Medicine and Science in Sports and Exercise
Haruki Ishii, Nichole Seigler, Reva Crandall, Paula Rodriguez-Miguelez, Jeffrey Thomas, Caralee Forseen, Kathleen T McKie, Ryan A Harris
No abstract text is available yet for this article.
May 2016: Medicine and Science in Sports and Exercise
Florent Baty, Christian Ritz, Arnoldus van Gestel, Martin Brutsche, Daniel Gerhard
BACKGROUND: The six-minute walk test (6MWT) is commonly used to quantify exercise capacity in patients with several cardio-pulmonary diseases. Oxygen uptake ([Formula: see text]O2) kinetics during 6MWT typically follow 3 distinct phases (rest, exercise, recovery) that can be modeled by nonlinear regression. Simultaneous modeling of multiple kinetics requires nonlinear mixed models methodology. To the best of our knowledge, no such curve-fitting approach has been used to analyze multiple [Formula: see text]O2 kinetics in both research and clinical practice so far...
2016: BMC Medical Research Methodology
J Koschate, U Drescher, K Baum, S Eichberg, T Schiffer, J Latsch, K Brixius, U Hoffmann
Pulmonary oxygen uptake (V˙O2) kinetics and heart rate kinetics are influenced by age and fitness. Muscular V˙O2 kinetics can be estimated from heart rate and pulmonary V˙O2. In this study the applicability of a test using pseudo-random binary sequences in combination with a model to estimate muscular V˙O2 kinetics was tested. Muscular V˙O2 kinetics were expected to be faster than pulmonary V˙O2 kinetics, slowed in aged subjects and correlated with maximum V˙O2 and heart rate kinetics. 27 elderly subjects (73±3 years; 81...
June 2016: International Journal of Sports Medicine
Peter M Christensen, Robert A Jacobs, Thomas Bonne, Daniela Flück, Jens Bangsbo, Carsten Lundby
The aim of the present study was to examine whether improvements in pulmonary oxygen uptake (V̇o2) kinetics following a short period of high-intensity training (HIT) would be associated with improved skeletal muscle mitochondrial function. Ten untrained male volunteers (age 26 ± 2 yr; mean ± SD) performed six HIT sessions (8-12 × 60 s at incremental test peak power; 271 ± 52 W) over a 2-wk period. Before and after the HIT period, V̇o2 kinetics was modeled during moderate-intensity cycling (110 ± 19 W)...
June 1, 2016: Journal of Applied Physiology
Kazuyuki Kominami, Hirotaka Nishijima, Keiko Imahashi, Toko Katsuragawa, Mitsuyo Murakami, Kazuya Yonezawa, Masatoshi Akino
We assessed the correspondence between the V-slope ventilatory threshold (VT) and the lactate threshold (LT) by using a distinctive slow submaximal ramp protocol to ensure that sufficient data points exist around the threshold. Twenty healthy young men participated. A submaximal test based on a prior maximal test (25 watt/min, medium ramp) was performed with an individual slow-ramp protocol (6-17 watt/min, slow ramp), in which the time to reach the VT workload was estimated to be 10 minutes. The LT was determined visually by detecting a rise above the resting value, without or with log-log transformation (LT1, LT2)...
September 2015: Medicine (Baltimore)
Courtney J McGowan, David B Pyne, Kevin G Thompson, Ben Rattray
It is widely accepted that warming-up prior to exercise is vital for the attainment of optimum performance. Both passive and active warm-up can evoke temperature, metabolic, neural and psychology-related effects, including increased anaerobic metabolism, elevated oxygen uptake kinetics and post-activation potentiation. Passive warm-up can increase body temperature without depleting energy substrate stores, as occurs during the physical activity associated with active warm-up. While the use of passive warm-up alone is not commonplace, the idea of utilizing passive warming techniques to maintain elevated core and muscle temperature throughout the transition phase (the period between completion of the warm-up and the start of the event) is gaining in popularity...
November 2015: Sports Medicine
T Yamagishi, J Babraj
AIM: This study aimed to determine effects of recovery intensity (passive, 20, 30 and 40%V̇ O2peak) on oxygen uptake kinetics, performance and blood lactate accumulation during repeated sprints. METHODS: 7 moderately-trained male participants (V̇ O2peak: 48.1 ± 5.1 ml·kg-1·min-1) performed 4 x 30-s repeated Wingate tests on 4 separate occasions. RESULTS: Recovery of V̇ O2 between sprints was prolonged with recovery intensity (time required to reach 50% V̇ O2peak: Passive: 50 ± 9; 20%: 81 ± 17; 30%: 130 ± 43; 40%: 188 ± 62 sec, P<0...
September 11, 2015: Journal of Sports Medicine and Physical Fitness
Melitta A McNarry, Danielle Lambrick, Nicole Westrupp, James Faulkner
The pulmonary oxygen uptake response is deleteriously influenced by obesity in prepubertal children, as evidenced by a slower phase II response. To date, no studies have investigated the ability of an exercise intervention to ameliorate this. The objective of the study was to investigate the influence of a 6-week, high-intensity, games-orientated intervention on the oxygen uptake kinetic response of prepubertal obese and normal-weight children during heavy-intensity exercise. Thirteen normal-weight and 15 obese children participated in a twice-weekly exercise intervention involving repeated bouts of 6-min high-intensity, games-orientated exercises followed by 2 min of recovery...
October 2015: Applied Physiology, Nutrition, and Metabolism, Physiologie Appliquée, Nutrition et Métabolisme
Anthony J Barron, Niti M Dhutia, Sven Gläser, Beate Koch, Ralf Ewert, Anne Obst, Marcus Dörr, Henry Völzke, Darrel P Francis, Roland Wensel
BACKGROUND: Cardiopulmonary exercise testing allows for assessment of cardiac and respiratory limitation, but is often affected by patient effort. Indices of oxygen kinetics, including the oxygen uptake efficiency slope (OUES), oxygen uptake-work-rate slope (VO2-WR slope) and the heart rate-oxygen uptake slope (HR-VO2 slope) are relatively effort independent but may be affected by patient characteristics. The objective of this study is to identify the impact of factors, such as age, gender, body size, respiratory function, smoking and beta-blockade on these parameters, as well as generate predictive equations...
June 2015: IJC Metabolic & Endocrine
Kelly de Jesus, Ana Sousa, Karla de Jesus, João Ribeiro, Leandro Machado, Ferran Rodríguez, Kari Keskinen, João Paulo Vilas-Boas, Ricardo J Fernandes
Swimming and training are carried out with wide variability in distances and intensities. However, oxygen uptake kinetics for the intensities seen in swimming has not been reported. The purpose of this study was to assess and compare the oxygen uptake kinetics throughout low-moderate to severe intensities during incremental swimming exercise. We hypothesized that the oxygen uptake kinetic parameters would be affected by swimming intensity. Twenty male trained swimmers completed an incremental protocol of seven 200-m crawl swims to exhaustion (0...
September 2015: Applied Physiology, Nutrition, and Metabolism, Physiologie Appliquée, Nutrition et Métabolisme
Catherine Kiely, Joel Rocha, Eamonn O'Connor, Donal O'Shea, Simon Green, Mikel Egaña
We investigated if the magnitude of the Type 2 diabetes (T2D)-induced impairments in peak oxygen uptake (V̇O2) and V̇O2 kinetics was affected by menopausal status. Twenty-two women with T2D (8 premenopausal, 14 postmenopausal), and 22 nondiabetic (ND) women (11 premenopausal, 11 postmenopausal) matched by age (range = 30-59 yr) were recruited. Participants completed four bouts of constant-load cycling at 80% of their ventilatory threshold for the determination of V̇O2 kinetics. Cardiac output (CO) (inert gas rebreathing) was recorded at rest and at 30 s and 240 s during two additional bouts...
October 15, 2015: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology
Azmy Faisal, Zaid Zoumot, Pallav L Shah, J Alberto Neder, Michael I Polkey, Nicholas S Hopkinson
BACKGROUND: The impact of bronchoscopic lung volume reduction (BLVR) on physiologic responses to exercise in patients with advanced emphysema remains incompletely understood. We hypothesized that effective BLVR (e-BLVR), defined as a reduction in residual volume > 350 mL, would improve cardiovascular responses to exercise and accelerate oxygen uptake (Vo₂) kinetics. METHODS: Thirty-one patients (FEV1, 36% ± 9% predicted; residual volume, 219% ± 57% predicted) underwent a constant intensity exercise test at 70% peak work rate to the limit of tolerance before and after treatment bronchoscopy (n = 24) or sham bronchoscopy (n = 7)...
February 2016: Chest
Neil Armstrong, Alan R Barker, Alison M McManus
AIM: To provide an evidence-based review of muscle metabolism changes with sex-, age- and maturation with reference to the development of youth sport performance. METHODS: A narrative review of data from both invasive and non-invasive studies, from 1970 to 2015, founded on personal databases supported with computer searches of PubMed and Google Scholar. RESULTS: Youth sport performance is underpinned by sex-, age- and maturation-related changes in muscle metabolism...
July 2015: British Journal of Sports Medicine
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