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https://www.readbyqxmd.com/read/27898641/oral-contraceptive-use-dampens-physiological-adaptations-to-sprint-interval-training
#1
Mia A Schaumberg, David G Jenkins, Xanne A K Janse de Jonge, Lynne M Emmerton, Tina L Skinner
PURPOSE: Oral contraceptive (OC) use reduces peak aerobic capacity (V˙O2peak), however, whether it also influences adaptations to training has yet to be determined. This study aimed to examine the influence of OC use on peak performance [peak power output (PPO)] and physiological adaptations [V˙O2peak and peak cardiac output (Q˙peak)] following sprint interval training (SIT) in recreationally-active women. METHODS: Women taking an OC (n=25) or experiencing natural regular menstrual cycles (MC; n=16) completed an incremental exercise test to assess V˙O2peak, PPO, and Q˙peak before, immediately after, and four weeks following 12 sessions of SIT...
November 28, 2016: Medicine and Science in Sports and Exercise
https://www.readbyqxmd.com/read/27895592/effects-of-six-months-training-on-physical-capacity-and-metaboreflex-activity-in-patients-with-multiple-sclerosis
#2
Sara Magnani, Sergio Olla, Massimiliano Pau, Girolamo Palazzolo, Filippo Tocco, Azzurra Doneddu, Maura Marcelli, Andrea Loi, Federica Corona, Francesco Corona, Giancarlo Coghe, Maria G Marrosu, Alberto Concu, Eleonora Cocco, Elisabetta Marongiu, Antonio Crisafulli
Patients with multiple sclerosis (MS) have an increased systemic vascular resistance (SVR) response during the metaboreflex. It has been hypothesized that this is the consequence of a sedentary lifestyle secondary to MS. The purpose of this study was to discover whether a 6-month training program could reverse this hemodynamic dysregulation. Patients were randomly assigned to one of the following two groups: the intervention group (MSIT, n = 11), who followed an adapted training program; and the control group (MSCTL, n = 10), who continued with their sedentary lifestyle...
2016: Frontiers in Physiology
https://www.readbyqxmd.com/read/27885445/limited-ventricular-preload-is-the-main-reason-for-reduced-stress-reserve-after-atrial-baffle-repair
#3
Andreas Eicken, Julia Michel, Alfred Hager, Daniel Tanase, Harald Kaemmerer, Julie Cleuziou, John Hess, Peter Ewert
The atrial baffle repair (ABR) significantly improved the fate of patients with transposition of the great arteries (TGA). However, these patients show impaired exercise tolerance and some present severe decline of systemic ventricular function. Intrinsic myocardial weakness, low heart rate response to exercise and diastolic filling impairment are discussed to be causative. Forty-nine long-term survivors with TGA (median age 23.7 year) after ABR were catheterized with measured oxygen consumption in four conditions (baseline, volume, atrial pacing, dobutamine) and the results were compared to 10 normal controls...
November 24, 2016: Pediatric Cardiology
https://www.readbyqxmd.com/read/27884959/cardiac-responses-to-exercise-distinguish-postural-orthostatic-tachycardia-syndrome-variants
#4
Paolo T Pianosi, Darrell R Schroeder, Philip R Fischer
We previously showed that one-third of adolescents with postural orthostatic tachycardia syndrome (POTS) have hyperkinetic circulation. In a subsequent cohort, we compare participants with POTS grouped according to cardiac output (Q˙) versus oxygen uptake (V˙O2) function, whose circulatory response to exercise lay at the lower end of this distribution. We hypothesized that such grouping determines the circulatory response to incremental-protocol, upright, cycle ergometry by whatever blend of flow and resistance adjustments best maintains normal blood pressure...
November 2016: Physiological Reports
https://www.readbyqxmd.com/read/27882604/the-dog-bone-technique-a-novel-easy-and-safe-catheter-maneuver-for-aortic-arch-and-coarctation-stenting
#5
Marinos Kantzis, Anja Lehner, Kai Thorsten Laser, Anca Racolta, Radka Vcasna, Marcus Fischer, Deniz Kececioglu, Nikolaus A Haas
BACKGROUND: Various techniques are described to facilitate stable stent implantation in aortic arch stenosis or coarctation. We describe an alternative technique, which due to its unique appearance during stent implantation, we have named "Dog Bone Technique" (DBT). TECHNIQUE: The stent/balloon assembly is placed across the stenosis, the long sheath is retrieved to uncover the distal 20-50% of the stent. The balloon is inflated with the pressure inflator just to expand slightly the stent...
November 24, 2016: Journal of Interventional Cardiology
https://www.readbyqxmd.com/read/27853886/home-based-isometric-exercise-training-induced-reductions-resting-blood-pressure
#6
Jonathan D Wiles, Natalie Goldring, Damian Coleman
PURPOSE: Isometric exercise training (IET) reduces resting blood pressure (BP). Most previous protocols impose exercise barriers which undermine its effectiveness as a potential physical therapy for altering BP. An inexpensive, home-based programme would promote IET as a valuable tool in the fight against hypertension. The aims of this study were: (a) to investigate whether home-based wall squat training could successfully reduce resting BP and (b) to explore the physiological variables that might mediate a change in resting BP...
November 16, 2016: European Journal of Applied Physiology
https://www.readbyqxmd.com/read/27852718/high-intensity-interval-training-versus-moderate-intensity-steady-state-training-in-uk-cardiac-rehabilitation-programmes-hiit-or-miss-uk-study-protocol-for-a-multicentre-randomised-controlled-trial-and-economic-evaluation
#7
Gordon McGregor, Simon Nichols, Thomas Hamborg, Lucy Bryning, Rhiannon Tudor-Edwards, David Markland, Jenny Mercer, Stefan Birkett, Stuart Ennis, Richard Powell, Brian Begg, Mark J Haykowsky, Prithwish Banerjee, Lee Ingle, Rob Shave, Karianne Backx
INTRODUCTION: Current international guidelines for cardiac rehabilitation (CR) advocate moderate-intensity exercise training (MISS, moderate-intensity steady state). This recommendation predates significant advances in medical therapy for coronary heart disease (CHD) and may not be the most appropriate strategy for the 'modern' patient with CHD. High-intensity interval training (HIIT) appears to be a safe and effective alternative, resulting in greater improvements in peak oxygen uptake (VO2 peak)...
November 16, 2016: BMJ Open
https://www.readbyqxmd.com/read/27843548/assessment-of-proximal-pulmonary-arterial-stiffness-using-magnetic-resonance-imaging-effects-of-technique-age-and-exercise
#8
Jonathan R Weir-McCall, Anu Kamalasanan, Deidre B Cassidy, Allan D Struthers, Brian J Lipworth, J Graeme Houston
INTRODUCTION: To compare the reproducibility of pulmonary pulse wave velocity (PWV) techniques, and the effects of age and exercise on these. METHODS: 10 young healthy volunteers (YHV) and 20 older healthy volunteers (OHV) with no cardiac or lung condition were recruited. High temporal resolution phase contrast sequences were performed through the main pulmonary arteries (MPAs), right pulmonary arteries (RPAs) and left pulmonary arteries (LPAs), while high spatial resolution sequences were obtained through the MPA...
2016: BMJ Open Respiratory Research
https://www.readbyqxmd.com/read/27834447/physical-capacity-in-lvad-patients-hemodynamic-principles-diagnostic-tools-and-training-control
#9
Nils Reiss, Thomas Schmidt, Anke Workowski, Detlev Willemsen, Jan D Schmitto, Axel Haverich, Birna Bjarnason-Wehrens
Over time left ventricular assist devices (LVAD) have become an alternative to heart transplantation because of enormous technical development and miniaturization. Most patients present a significant improvement in clinical conditions and exercise capacity. Nevertheless, exercise tolerance remains markedly limited even after LVAD implantation compared to a control group. The complex physiological and hemodynamic changes in LVAD patients, both at rest and during exercise, are not yet understood, or at least not completely...
November 11, 2016: International Journal of Artificial Organs
https://www.readbyqxmd.com/read/27824602/exercise-pulmonary-haemodynamics-predict-outcome-in-patients-with-systemic-sclerosis
#10
Adriana Stamm, Stéphanie Saxer, Mona Lichtblau, Elisabeth D Hasler, Suzana Jordan, Lars C Huber, Konrad E Bloch, Oliver Distler, Silvia Ulrich
The aim of the present study was to investigate the prognostic value of exercise haemodynamics measured during right heart catheterisation (RHC) in patients with systemic sclerosis (SSc) referred for evaluation of pulmonary hypertension.SSc patients undergoing RHC at rest and during maximal supine incremental cycle exercise were grouped into resting precapillary pulmonary hypertension (PHrest) (mean pulmonary artery pressure (mPAP) ≥25 mmHg, pulmonary artery wedge pressure <15 mmHg), exercise-induced pulmonary hypertension (PHex) (mPAP ≥30 mmHg and mPAP/cardiac output >3 mmHg·L(-1)·min(-1) at maximal exercise), and without pulmonary hypertension (PHnone)...
December 2016: European Respiratory Journal: Official Journal of the European Society for Clinical Respiratory Physiology
https://www.readbyqxmd.com/read/27804106/the-role-of-transient-receptor-potential-vanilloid-2-channel-in-cardiac-aging
#11
Shannon Jones, Adrien Mann, Mariah C Worley, Logan Fulford, David Hall, Rajiv Karani, Min Jiang, Nathan Robbins, Jack Rubinstein, Sheryl E Koch
BACKGROUND: The aging heart is characterized by cellular and molecular changes leading to a decline in physiologic function and cardiac remodeling, specifically the development of myocyte hypertrophy and fibrosis. Transient receptor potential vanilloid 2 (TRPV2), a stretch-mediated channel and regulator of calcium homeostasis, plays a key role in the function and structure of the heart. TRPV2 also plays an important role in the adaptive and maladaptive compensatory mechanisms of the heart in response to pathologic and exercise-induced stress...
November 1, 2016: Aging Clinical and Experimental Research
https://www.readbyqxmd.com/read/27799391/exercise-ageing-and-the-lung
#12
Michael A Roman, Harry B Rossiter, Richard Casaburi
This review provides a pulmonary-focused description of the age-associated changes in the integrative physiology of exercise, including how declining lung function plays a role in promoting multimorbidity in the elderly through limitation of physical function. We outline the ageing of physiological systems supporting endurance activity: 1) coupling of muscle metabolism to mechanical power output; 2) gas transport between muscle capillary and mitochondria; 3) matching of muscle blood flow to its requirement; 4) oxygen and carbon dioxide carrying capacity of the blood; 5) cardiac output; 6) pulmonary vascular function; 7) pulmonary oxygen transport; 8) control of ventilation; and 9) pulmonary mechanics and respiratory muscle function...
November 2016: European Respiratory Journal: Official Journal of the European Society for Clinical Respiratory Physiology
https://www.readbyqxmd.com/read/27787335/cardiovascular-drift-during-training-for-fitness-in-metabolic-syndrome-patients
#13
Felix Morales-Palomo, Miguel Ramirez-Jimenez, Juan Fernando Ortega, Jesus Garcia Pallares, Ricardo Mora-Rodriguez
PURPOSE: The health benefits of a training program are largely influenced by the exercise dose and intensity. We sought to determine if during a training bout of continuous vs. interval exercise the workload needs to be reduced to maintain the prescribed target heart rate. METHODS: Fourteen obese (31±4 kg·m) middle-age (57±8 y) individuals with metabolic syndrome, underwent two exercise training bouts matched by energy expenditure (i.e., 70±5 min of continuous exercise; CE or 45 min of interval exercise; HIIT)...
October 27, 2016: Medicine and Science in Sports and Exercise
https://www.readbyqxmd.com/read/27785335/single-session-of-sprint-interval-training-elicits-similar-cardiac-output-but-lower-oxygen-uptake-versus-ramp-exercise-to-exhaustion-in-men-and-women
#14
Trevor Horn, Garret Roverud, Kandice Sutzko, Melissa Browne, Cristina Parra, Todd A Astorino
Sprint interval training (SIT) elicits comparable long-term adaptations versus continuous exercise training (CEX) including increased maximal oxygen uptake (VO2max) and fat utilization. However, there is limited research examining acute hemodynamic responses to SIT. The aim of this study was to examine hemodynamic responses to low-volume SIT. Active men (n=6, VO2max = 39.8 ± 1.7 mL/kg/min) and women (n=7, VO2max = 37.3 ± 5.7 mL/kg/min) performed a ramp-based VO2max test (RAMP) to determine workload for the SIT session...
2016: International Journal of Physiology, Pathophysiology and Pharmacology
https://www.readbyqxmd.com/read/27784687/dietary-nitrate-supplementation-and-exercise-tolerance-in-patients-with-heart-failure-with-reduced-ejection-fraction
#15
Daniel M Hirai, Joel T Zelt, Joshua H Jones, Luiza G Castanhas, Robert F Bentley, Wendy Earle, Patti Staples, Michael E Tschakovsky, John McCans, Denis E O'Donnell, J Alberto Neder
Endothelial dysfunction and reduced nitric oxide (NO) signaling are key abnormalities leading to skeletal muscle oxygen delivery-utilization mismatch and poor physical capacity in patients with heart failure with reduced ejection fraction (HFrEF). Oral inorganic nitrate supplementation provides an exogenous source of NO that may enhance locomotor muscle function and oxygenation with consequent improvement in exercise tolerance in HFrEF. Thirteen patients (left ventricular ejection fraction ≤40%) were enrolled in a double-blind, randomized crossover study to receive concentrated nitrate-rich (nitrate) or nitrate-depleted (placebo) beetroot juice for 9 days...
October 26, 2016: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology
https://www.readbyqxmd.com/read/27779551/does-exercise-ventilatory-inefficiency-predict-poor-outcome-in-heart-failure-patients-with-copd
#16
Maria Clara Alencar, Flavio F Arbex, Aline Souza, Adriana Mazzuco, Priscila A Sperandio, Alcides Rocha, Daniel M Hirai, Frederico Mancuso, Danilo C Berton, Audrey Borghi-Silva, Dirceu Almeida, Denis E OʼDonnel, J Alberto Neder
PURPOSE: To investigate whether the opposite effects of heart failure (HF) and chronic obstructive pulmonary disease (COPD) on exercise ventilatory inefficiency (minute ventilation [(Equation is included in full-text article.)E]-carbon dioxide output [(Equation is included in full-text article.)CO2] relationship) would negatively impact its prognostic relevance. METHODS: After treatment optimization and an incremental cardiopulmonary exercise test, 30 male patients with HF-COPD (forced expiratory volume in 1 second [FEV1] = 57% ± 17% predicted, ejection fraction = 35% ± 6%) were prospectively followed up during 412 ± 261 days for major cardiac events...
November 2016: Journal of Cardiopulmonary Rehabilitation and Prevention
https://www.readbyqxmd.com/read/27769997/exaggerated-coronary-vasoconstriction-limits-muscle-metaboreflex-induced-increases-in-ventricular-performance-in-hypertension
#17
Marty D Spranger, Jasdeep Kaur, Javier A Sala-Mercado, Abhinav C Krishnan, Rania Abu-Hamdah, Alberto Alvarez, Tiago M Machado, Robert A Augustyniak, Donal S O'Leary
Increases in myocardial oxygen consumption during exercise mainly occur via increases in coronary blood flow (CBF) as cardiac oxygen extraction is high even at rest. However, sympathetic coronary constrictor tone can limit increases in CBF. Increased sympathetic nerve activity (SNA) during exercise is, in part, a function of muscle metaboreflex activation (MMA). As SNA is heightened even at rest in subjects with hypertension (HTN), we tested whether HTN causes exaggerated coronary vasoconstriction during mild treadmill exercise with MMA (elicited by reducing hindlimb blood flow by ~60%) thereby limiting increases in CBF and ventricular performance...
October 21, 2016: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/27768947/effects-of-crude-oil-on-in-situ-cardiac-function-in-young-adult-mahi-mahi-coryphaena-hippurus
#18
Derek Nelson, Rachael M Heuer, Georgina K Cox, John D Stieglitz, Ronald Hoenig, Edward M Mager, Daniel D Benetti, Martin Grosell, Dane A Crossley
Exposure to polycyclic aromatic hydrocarbons (PAH) negatively impacts exercise performance in fish species but the physiological modifications that result in this phenotype are poorly understood. Prior studies have shown that embryonic and juvenile mahi-mahi (Coryphaeus hippurus) exposed to PAH exhibit morphological abnormalities, altered cardiac development and reduced swimming performance. It has been suggested that cardiovascular function inhibited by PAH exposure accounts for the compromised exercise performance in fish species...
October 14, 2016: Aquatic Toxicology
https://www.readbyqxmd.com/read/27767984/the-optimum-hematocrit
#19
Walter H Reinhart
The hematocrit (Hct) determines the oxygen carrying capacity of blood, but also increases blood viscosity and thus flow resistance. From this dual role the concept of an optimum Hct for tissue oxygenation has been derived. Viscometric studies using the ratio Hct/blood viscosity at high shear rate showed an optimum Hct of 50-60% for red blood cell (RBC) suspensions in plasma. For the perfusion of an artificial microvascular network with 5-70μm channels the optimum Hct was 60-70% for high driving pressures. With lower shear rates or driving pressures the optimum Hct shifted towards lower values...
October 21, 2016: Clinical Hemorheology and Microcirculation
https://www.readbyqxmd.com/read/27765846/non-invasive-assessment-of-cardiac-output-by-brachial-cuff-technique-comparison-to-the-open-circuit-acetylene-washin-method
#20
Pavol Sajgalik, Vaclav Kremen, Alex R Carlson, Vratislav Fabian, Chul-Ho Kim, Courtney M Wheatley, Vaclav Gerla, John A Schirger, Thomas P Olson, Bruce D Johnson
Cardiac output (CO) assessment as a basic hemodynamic parameter has been of interest in exercise physiology, cardiology and anesthesiology. Non-invasive techniques available are technically challenging, and thus difficult to use outside of the clinical or laboratory setting. We propose a novel method of non-invasive CO assessment using a single upper arm cuff. The method uses the arterial pressure pulse wave signal acquired from the brachial artery during 20 second intervals of suprasystolic occlusion. This method was evaluated on a cohort of 12 healthy individuals (age of 27...
October 20, 2016: Journal of Applied Physiology
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