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Gatti M, Prete G, Perpetuini D, Bondi D, Verratti V, Quilici Matteucci F, Santangelo C, Annarumma S, Di Crosta A, Palumbo R, Merla A, Giaconia GC, Tommasi L, Mammarella N. The effects of real vs simulated high altitude on associative memory for emotional stimuli. Physiol Behav 2024; 287:114663. [PMID: 39128618 DOI: 10.1016/j.physbeh.2024.114663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2024] [Revised: 08/01/2024] [Accepted: 08/08/2024] [Indexed: 08/13/2024]
Abstract
INTRODUCTION This study aimed to investigate the effects of normobaric hypoxia (NH) and hypobaric hypoxia (HH) on associative memory performance for emotionally valenced stimuli. METHODS Two experiments were conducted. In Study 1, n = 18 undergraduates performed an associative memory task under three NH conditions (FiO2= 20.9 %, 15.1 %, 13.6 %) using a tent with a hypoxic generator. In Study 2, n = 20 participants were assessed in a field study at various altitudes on the Himalayan mountains, including the Pyramid Laboratory (5000 m above sea level), using functional Near-Infrared Spectroscopy (fNIRS) and behavioral assessments. RESULTS Study 1 revealed no significant differences in recognition accuracy across NH conditions. However, Study 2 showed a complex relationship between altitude and memory for emotionally valenced stimuli. At lower altitudes, participants more accurately recognized emotional stimuli compared to neutral ones, a trend that reversed at higher altitudes. Brain oxygenation varied with altitude, indicating adaptive cognitive processing, as revealed by fNIRS measurements. CONCLUSIONS These findings suggest that hypoxia affects associative memory and emotional processing in an altitude-dependent manner, highlighting adaptive cognitive mechanisms. Understanding the effects of hypobaric hypoxia on cognition and memory can help develop strategies to mitigate its impact in high-altitude and hypoxic environments.
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Affiliation(s)
- Matteo Gatti
- Department of Psychology, University "G. d'Annunzio" Chieti-Pescara, 31, Via dei Vestini, Chieti I-66013, Italy
| | - Giulia Prete
- Department of Psychology, University "G. d'Annunzio" Chieti-Pescara, 31, Via dei Vestini, Chieti I-66013, Italy
| | - David Perpetuini
- Department of Engineering and Geology, University "G. d'Annunzio" Chieti-Pescara, Pescara, Italy
| | - Danilo Bondi
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" Chieti-Pescara, Chieti, Italy
| | - Vittore Verratti
- Department of Psychology, University "G. d'Annunzio" Chieti-Pescara, 31, Via dei Vestini, Chieti I-66013, Italy.
| | | | - Carmen Santangelo
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" Chieti-Pescara, Chieti, Italy
| | - Salvatore Annarumma
- Department of Psychology, University "G. d'Annunzio" Chieti-Pescara, 31, Via dei Vestini, Chieti I-66013, Italy; Department of Biomolecular Sciences, University of Urbino, Urbino, Italy
| | - Adolfo Di Crosta
- Department of Psychology, University "G. d'Annunzio" Chieti-Pescara, 31, Via dei Vestini, Chieti I-66013, Italy
| | - Rocco Palumbo
- Department of Psychology, University "G. d'Annunzio" Chieti-Pescara, 31, Via dei Vestini, Chieti I-66013, Italy
| | - Arcangelo Merla
- Department of Engineering and Geology, University "G. d'Annunzio" Chieti-Pescara, Pescara, Italy
| | | | - Luca Tommasi
- Department of Psychology, University "G. d'Annunzio" Chieti-Pescara, 31, Via dei Vestini, Chieti I-66013, Italy
| | - Nicola Mammarella
- Department of Psychology, University "G. d'Annunzio" Chieti-Pescara, 31, Via dei Vestini, Chieti I-66013, Italy
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Orcioli-Silva D, Beretta VS, Santos PCR, Rasteiro FM, Marostegan AB, Vitório R, Gobatto CA, Manchado-Gobatto FB. Cerebral and muscle tissue oxygenation during exercise in healthy adults: A systematic review. JOURNAL OF SPORT AND HEALTH SCIENCE 2024; 13:459-471. [PMID: 38462172 PMCID: PMC11184313 DOI: 10.1016/j.jshs.2024.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 12/21/2023] [Accepted: 02/04/2024] [Indexed: 03/12/2024]
Abstract
BACKGROUND Near-infrared spectroscopy (NIRS) technology has allowed for the measurement of cerebral and skeletal muscle oxygenation simultaneously during exercise. Since this technology has been growing and is now successfully used in laboratory and sports settings, this systematic review aimed to synthesize the evidence and enhance an integrative understanding of blood flow adjustments and oxygen (O2) changes (i.e., the balance between O2 delivery and O2 consumption) within the cerebral and muscle systems during exercise. METHODS A systematic review was conducted using PubMed, Embase, Scopus, and Web of Science databases to search for relevant studies that simultaneously investigated cerebral and muscle hemodynamic changes using the near-infrared spectroscopy system during exercise. This review considered manuscripts written in English and available before February 9, 2023. Each step of screening involved evaluation by 2 independent authors, with disagreements resolved by a third author. The Joanna Briggs Institute Critical Appraisal Checklist was used to assess the methodological quality of the studies. RESULTS Twenty studies were included, of which 80% had good methodological quality, and involved 290 young or middle-aged adults. Different types of exercises were used to assess cerebral and muscle hemodynamic changes, such as cycling (n = 11), treadmill (n = 1), knee extension (n = 5), isometric contraction of biceps brachii (n = 3), and duet swim routines (n = 1). The cerebral hemodynamics analysis was focused on the frontal cortex (n = 20), while in the muscle, the analysis involved vastus lateralis (n = 18), gastrocnemius (n = 3), biceps brachii (n = 5), deltoid (n = 1), and intercostal muscle (n = 1). Overall, muscle deoxygenation increases during exercise, reaching a plateau in voluntary exhaustion, while in the brain, oxyhemoglobin concentration increases with exercise intensity, reaching a plateau or declining at the exhaustion point. CONCLUSION Muscle and cerebral oxygenation respond differently to exercise, with muscle increasing O2 utilization and cerebral tissue increasing O2 delivery during exercise. However, at the exhaustion point, both muscle and cerebral oxygenation become compromised. This is characterized by a reduction in blood flow and a decrease in O2 extraction in the muscle, while in the brain, oxygenation reaches a plateau or decline, potentially resulting in motor failure during exercise.
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Affiliation(s)
- Diego Orcioli-Silva
- Laboratory of Applied Sport Physiology (LAFAE), School of Applied Sciences (FCA), University of Campinas (UNICAMP), Limeira 13484-350, Brazil; Posture and Gait Studies Laboratory (LEPLO), Institute of Biosciences, São Paulo State University (UNESP), Rio Claro 13506-900, Brazil.
| | - Victor Spiandor Beretta
- Physical Education Department, School of Technology and Sciences, São Paulo State University (UNESP), Presidente Prudente 19060-900, Brazil
| | - Paulo Cezar Rocha Santos
- Department of Computer Science & Applied Mathematics, Weizmann Institute of Science, Rehovot 7610001, Israel; Center of Advanced Technologies in Rehabilitation, Sheba Medical Center, Ramat Gan 5265601, Israel
| | - Felipe Marroni Rasteiro
- Laboratory of Applied Sport Physiology (LAFAE), School of Applied Sciences (FCA), University of Campinas (UNICAMP), Limeira 13484-350, Brazil
| | - Anita Brum Marostegan
- Laboratory of Applied Sport Physiology (LAFAE), School of Applied Sciences (FCA), University of Campinas (UNICAMP), Limeira 13484-350, Brazil
| | - Rodrigo Vitório
- Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle upon Tyne NE1 8ST, UK
| | - Claudio Alexandre Gobatto
- Laboratory of Applied Sport Physiology (LAFAE), School of Applied Sciences (FCA), University of Campinas (UNICAMP), Limeira 13484-350, Brazil
| | - Fúlvia Barros Manchado-Gobatto
- Laboratory of Applied Sport Physiology (LAFAE), School of Applied Sciences (FCA), University of Campinas (UNICAMP), Limeira 13484-350, Brazil
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Machfer A, Bouzid MA, Fekih N, Hassen HBH, Amor HIH, Tagougui S, Chtourou H. Blunted cerebral hemodynamic responses to incremental exercise in patients with end-stage renal disease. Int Urol Nephrol 2024; 56:2411-2419. [PMID: 38441868 DOI: 10.1007/s11255-024-03991-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Accepted: 02/07/2024] [Indexed: 06/21/2024]
Abstract
PURPOSE The aims of this study were to compare cerebral hemodynamics and maximal oxygen uptake (VO2peak) in patients with end-stage renal disease (ESRD) vs. age-matched healthy controls during maximal exercise. METHODS Twelve patients with ESRD and twelve healthy adults (CTR group) performed exhaustive incremental exercise test. Throughout the exercise test, near-infrared spectroscopy allowed the investigation of changes in oxyhemoglobin (∆O2Hb), deoxyhemoglobin (∆HHb), and total hemoglobin (∆THb) in the prefrontal cortex. RESULTS Compared to CTR, VO2peak was significantly lower in ESRD group (P < 0.05). Increase in ∆THb (i.e., cerebral blood volume) was significantly blunted in ESRD (P < 0.05). ESRD patients also had impaired changes in cerebral ∆HHb and ∆O2Hb during high intensity of exercise (P < 0.05). Finally, no significant correlation was observed between VO2peak and changes in cerebral hemodynamics parameters in both groups (All P > 0.05). CONCLUSION Maximal exercise highlights subtle disorders of both hemodynamics and neuronal oxygenation in the prefrontal cortex in patients with ESRD. This may contribute to both impaired cognitive function and reduced exercise tolerance throughout the progression of the disease.
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Affiliation(s)
- Amal Machfer
- Research Laboratory: Education, Motricité, Sport et Santé, EM2S, LR19JS01, High Institute of Sport and Physical Education, University of Sfax, Sfax, Tunisia.
| | - Mohamed Amine Bouzid
- Research Laboratory: Education, Motricité, Sport et Santé, EM2S, LR19JS01, High Institute of Sport and Physical Education, University of Sfax, Sfax, Tunisia
| | - Nadia Fekih
- Research Laboratory: Education, Motricité, Sport et Santé, EM2S, LR19JS01, High Institute of Sport and Physical Education, University of Sfax, Sfax, Tunisia
| | - Hayfa Ben Haj Hassen
- Research Laboratory: Education, Motricité, Sport et Santé, EM2S, LR19JS01, High Institute of Sport and Physical Education, University of Sfax, Sfax, Tunisia
| | | | - Sèmah Tagougui
- Université de Lille, Université d'Artois, Université du Littoral Côte d'Opale, ULR 7369 - URePSSS - Unité de Recherche Pluridisciplinaire Sport, Santé, Société, Lille, France
- Montreal Clinical Research Institute (IRCM), Montreal, Canada
| | - Hamdi Chtourou
- Activité Physique, Sport et Santé, UR18JS01, Observatoire National du Sport, 1003, Tunis, Tunisia
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O'Malley CA, Norbury R, Smith SA, Fullerton CL, Mauger AR. Elevated muscle pain induced by a hypertonic saline injection reduces power output independent of physiological changes during fixed perceived effort cycling. J Appl Physiol (1985) 2024; 137:99-110. [PMID: 38813614 PMCID: PMC11389896 DOI: 10.1152/japplphysiol.00325.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 04/16/2024] [Accepted: 05/22/2024] [Indexed: 05/31/2024] Open
Abstract
Pain is a naturally occurring phenomenon that consistently inhibits exercise performance by imposing unconscious, neurophysiological alterations (e.g., corticospinal changes) as well as conscious, psychophysiological pressures (e.g., shared effort demands). Although several studies indicate that pain would elicit lower task outputs for a set intensity of perceived effort, no study has tested this. Therefore, this study investigated the impact of elevated muscle pain through a hypertonic saline injection on the power output, psychophysiological, cerebral oxygenation, and perceptual changes during fixed perceived effort exercise. Ten participants completed three visits (1 familiarization + 2 fixed perceived effort trials). Fixed perceived effort cycling corresponded to 15% above gas exchange threshold (GET) [mean rating of perceived effort (RPE) = 15 "hard"]. Before the 30-min fixed perceived effort exercise, participants received a randomized bilateral hypertonic or isotonic saline injection in the vastus lateralis. Power output, cardiorespiratory, cerebral oxygenation, and perceptual markers (e.g., affective valence) were recorded during exercise. Linear mixed-model regression assessed the condition and time effects and condition × time interactions. Significant condition effects showed that power output was significantly lower during hypertonic conditions [t107 = 208, P = 0.040, β = 4.77 W, 95% confidence interval (95% CI) [0.27 to 9.26 W]]. Meanwhile, all physiological variables (e.g., heart rate, oxygen uptake, minute ventilation) demonstrated no significant condition effects. Condition effects were observed for deoxyhemoglobin changes from baseline (t107 = -3.29, P = 0.001, β = -1.50 ΔμM, 95% CI [-2.40 to -0.61 ΔμM]) and affective valence (t127 = 6.12, P = 0.001, β = 0.93, 95% CI [0.63 to 1.23]). Results infer that pain impacts the self-regulation of fixed perceived effort exercise, as differences in power output mainly occurred when pain ratings were higher after hypertonic versus isotonic saline administration.NEW & NOTEWORTHY This study identifies that elevated muscle pain through a hypertonic saline injection causes significantly lower power output when pain is experienced but does not seem to affect exercise behavior in a residual manner. Results provide some evidence that pain operates on a psychophysiological level to alter the self-regulation of exercise behavior due to differences between conditions in cerebral deoxyhemoglobin and other perceptual parameters.
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Affiliation(s)
- Callum A O'Malley
- School of Sport and Exercise Sciences, University of Kent, Canterbury, United Kingdom
- School of Sport and Health Sciences, University of Exeter, Exeter, United Kingdom
| | - Ryan Norbury
- School of Sport and Exercise Sciences, University of Kent, Canterbury, United Kingdom
- Faculty of Sport, Technology, and Health Sciences, St Mary's University Twickenham, London, United Kingdom
| | - Samuel A Smith
- School of Sport and Exercise Sciences, University of Kent, Canterbury, United Kingdom
| | - Christopher L Fullerton
- School of Sport and Exercise Sciences, University of Kent, Canterbury, United Kingdom
- Faculty of Health Sciences and Sport, University of Stirling, Stirling, United Kingdom
| | - Alexis R Mauger
- School of Sport and Exercise Sciences, University of Kent, Canterbury, United Kingdom
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Norberto MS, Torini JVG, Firmino MS, Papoti M. Validation of Air Storage System for Hypoxia Exposure During Exercise. High Alt Med Biol 2024; 25:122-128. [PMID: 38488104 DOI: 10.1089/ham.2023.0122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2024] Open
Abstract
Norberto, Matheus S., João Victor G. Torini, Matheus S. Firmino, and Marcelo Papoti. Validation of air storage system for hypoxia exposure during exercise. High Alt Med Biol. 00:000-000, 2024.-Considering the importance of optimizing normobaric hypoxia exposure (i.e., higher delivery capacity), the current study aims to validate a hypoxic air storage system. The study has a cross-over, one-blind randomized design. The air storage is composed of a piping system that directs hypoxic air from a hypoxia generator into nylon bags. Sixteen men (age, 25.4 ± 4.8 years; height, 174.9 ± 9.4 cm; weight, 77.1 ± 17.2 kg) performed three incremental treadmill tests until exhaustion on different days. For test-retest, the subjects repeated two tests in similar hypoxia conditions (H1 and H2; fraction of inspired O2 [FIO2] = ∼0.13; reliability analysis), and one time in normoxia (FIO2 = ∼0.20; condition comparison). Subjects' performance, blood lactate concentration ([La-]), arterial oxygen saturation (SpO2), oxygen consumption (VO2), heart rate (HR), and several respiratory-derived variables were evaluated. A comparison was made between the rest, moderate intensity, and exhaustion stages. All variables were compared using the Friedman test with Durbin-Conover post hoc (p < 0.05). The hypoxia test-retest showed no statistical differences for any variable. Time analysis showed similar behavior for SpO2, HR, and cardiorespiratory variables (p < 0.01) for both conditions. The mean FIO2 at rest and during the incremental treadmill test was higher for normoxia (20.6 ± 0.2%) than for H1 (13.8 ± 0.8%) and H2 (13.7 ± 0.3%) (p < 0.001). The VO2 response was higher in normoxia than during hypoxia exposure at moderate intensity (Normoxia = 43.1 ± 8.1; H1 = 38.7 ± 5.7; H2 = 35.8 ± 8.8 ml.kg-1.min-1) and at the exhaustion stage (Normoxia = 52.7 ± 12.5; H1 = 41.9 ± 8.8; H2 = 40.5 ± 8.9 ml.kg-1.min-1) (p < 0.01). SpO2 and HR showed excellent intraclass correlation coefficient (ICC) during all moments, whereas VO2, SpO2, ratio between ventilation and CO2 production (VE/VCO2), ratio between oxygen consumption and ventilation (VE/VO2), and HR showed moderate or good ICC and coefficient of variation <9% during hypoxia test-retest exercises. Thus, the air storage system showed validity for its application and reliability in the measurements associated.
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Affiliation(s)
- Matheus S Norberto
- Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - João Victor G Torini
- School of Physical Education and Sports of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Matheus S Firmino
- Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
- School of Physical Education and Sports of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Marcelo Papoti
- Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
- School of Physical Education and Sports of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
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Baur DA, Baur KG, Buchanan BK, Ortiz MJ, Doody AG. Load carriage physiology in normoxia and hypoxia. Eur J Appl Physiol 2024; 124:925-943. [PMID: 37740748 PMCID: PMC10879375 DOI: 10.1007/s00421-023-05320-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 09/08/2023] [Indexed: 09/25/2023]
Abstract
PURPOSE To determine the effects of load carriage in normoxia and normobaric hypoxia on ventilatory responses, hemodynamics, tissue oxygenation, and metabolism. METHODS Healthy males (n = 12) completed 3 randomly ordered baseline graded exercise tests in the following conditions: (1) unloaded normoxic (U: FIO2 = 20.93%), (2) loaded (~ 30 kg) normoxic (LN), and (3) loaded hypoxic simulating ~ 3650 m (LH: FIO2 = ~ 13%). Thereafter, experimental exercise trials were completed in quasi-randomized order (i.e., U completed first) consisting of 3 × 10 min of walking (separated by 5 min seated rest) with stages matched with the U condition (in ascending order) for relative intensity, absolute oxygen consumption ([VO2]; 1.7 L min-1), and walking speed (1.45 ± 0.15 m s-1). RESULTS Load carriage increased perceived exertion and reduced VO2max (LN: - 7%; LH: - 32%; p < 0.05). At matched VO2, stroke volume and tidal volume were reduced and maintained with LN and LH vs. U, respectively (p < 0.05). Increases in cardiac output and minute ventilation at matched VO2 (with LH) and speed (with LN and LH), were primarily accomplished via increases in heart rate and breathing frequency (p < 0.05). Cerebral oxygenated hemoglobin (O2HHb) was increased at all intensities with LN, but deoxygenated hemoglobin and total hemoglobin were increased with LH (p < 0.05). Muscle oxygen kinetics and substrate utilization were similar between LN and U, but LH increased CHO dependence and reduced muscle O2HHb at matched speed (p < 0.05). CONCLUSION Load carriage reduces cardiorespiratory efficiency and increases physiological strain, particularly in hypoxic environments. Potential load carriage-induced alterations in cerebral blood flow may increase the risk for altitude illnesses and requires further study.
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Affiliation(s)
- Daniel A Baur
- Department of Human Performance and Wellness, Virginia Military Institute, 208 Cormack Hall, Lexington, VA, 24450, USA.
| | - Katherine G Baur
- Department of Human Performance and Wellness, Virginia Military Institute, 208 Cormack Hall, Lexington, VA, 24450, USA
| | - Beverley K Buchanan
- Department of Human Performance and Wellness, Virginia Military Institute, 208 Cormack Hall, Lexington, VA, 24450, USA
| | - Miles J Ortiz
- Department of Human Performance and Wellness, Virginia Military Institute, 208 Cormack Hall, Lexington, VA, 24450, USA
| | - Abaigeal G Doody
- Department of Human Performance and Wellness, Virginia Military Institute, 208 Cormack Hall, Lexington, VA, 24450, USA
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Bourdillon N, Subudhi AW, Fan JL, Evero O, Elliott JE, Lovering AT, Roach RC, Kayser B. AltitudeOmics: effects of 16 days acclimatization to hypobaric hypoxia on muscle oxygen extraction during incremental exercise. J Appl Physiol (1985) 2023; 135:823-832. [PMID: 37589059 PMCID: PMC10642515 DOI: 10.1152/japplphysiol.00100.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 07/11/2023] [Accepted: 08/03/2023] [Indexed: 08/18/2023] Open
Abstract
Acute altitude exposure lowers arterial oxygen content ([Formula: see text]) and cardiac output ([Formula: see text]) at peak exercise, whereas O2 extraction from blood to working muscles remains similar. Acclimatization normalizes [Formula: see text] but not peak [Formula: see text] nor peak oxygen consumption (V̇o2peak). To what extent acclimatization impacts muscle O2 extraction remains unresolved. Twenty-one sea-level residents performed an incremental cycling exercise to exhaustion near sea level (SL), in acute (ALT1) and chronic (ALT16) hypoxia (5,260 m). Arterial blood gases, gas exchange at the mouth and oxy- (O2Hb) and deoxyhemoglobin (HHb) of the vastus lateralis were recorded to assess arterial O2 content ([Formula: see text]), [Formula: see text], and V̇o2. The HHb-V̇o2 slope was taken as a surrogate for muscle O2 extraction. During moderate-intensity exercise, HHb-V̇o2 slope increased to a comparable extent at ALT1 (2.13 ± 0.94) and ALT16 (2.03 ± 0.88) compared with SL (1.27 ± 0.12), indicating increased O2 extraction. However, the HHb/[Formula: see text] ratio increased from SL to ALT1 and then tended to go back to SL values at ALT16. During high-intensity exercise, HHb-V̇o2 slope reached a break point beyond which it decreased at SL and ALT1, but not at ALT16. Increased muscle O2 extraction during submaximal exercise was associated with decreased [Formula: see text] in acute hypoxia. The significantly greater muscle O2 extraction during maximal exercise in chronic hypoxia is suggestive of an O2 reserve.NEW & NOTEWORTHY During incremental exercise muscle deoxyhemoglobin (HHb) and oxygen consumption (V̇o2) both increase linearly, and the slope of their relationship is an indirect index of local muscle O2 extraction. The latter was assessed at sea level, in acute and during chronic exposure to 5,260 m. The demonstrated presence of a muscle O2 extraction reserve during chronic exposure is coherent with previous studies indicating both limited muscle oxidative capacity and decrease in motor drive.
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Affiliation(s)
- Nicolas Bourdillon
- Institute of Sports Sciences, University of Lausanne, Lausanne, Switzerland
| | - Andrew W Subudhi
- Hybl Sports Medicine and Performance Center, Department of Human Physiology and Nutrition, University of Colorado, Colorado Springs, Colorado, United States
| | - Jui-Lin Fan
- Department of Physiology, Faculty of Medical & Health Sciences, Manaaki Manawa-The Centre for Heart Research, University of Auckland, Auckland, New Zealand
| | - Oghenero Evero
- Altitude Research Center, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - Jonathan E Elliott
- Department of Human Physiology, University of Oregon, Eugene, Oregon, United States
| | - Andrew T Lovering
- Department of Human Physiology, University of Oregon, Eugene, Oregon, United States
| | - Robert C Roach
- Altitude Research Center, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - Bengt Kayser
- Institute of Sports Sciences, University of Lausanne, Lausanne, Switzerland
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Cherouveim ED, Miliotis PG, Koskolou MD, Dipla K, Vrabas IS, Geladas ND. The Effect of Skeletal Muscle Oxygenation on Hemodynamics, Cerebral Oxygenation and Activation, and Exercise Performance during Incremental Exercise to Exhaustion in Male Cyclists. BIOLOGY 2023; 12:981. [PMID: 37508410 PMCID: PMC10376807 DOI: 10.3390/biology12070981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 06/28/2023] [Accepted: 07/06/2023] [Indexed: 07/30/2023]
Abstract
This study aimed to elucidate whether muscle blood flow restriction during maximal exercise is associated with alterations in hemodynamics, cerebral oxygenation, cerebral activation, and deterioration of exercise performance in male participants. Thirteen healthy males, cyclists (age 33 ± 2 yrs., body mass: 78.6 ± 2.5 kg, and body mass index: 25.57 ± 0.91 kg·m-1), performed a maximal incremental exercise test on a bicycle ergometer in two experimental conditions: (a) with muscle blood flow restriction through the application of thigh cuffs inflated at 120 mmHg (with cuffs, WC) and (b) without restriction (no cuffs, NC). Exercise performance significantly deteriorated with muscle blood flow restriction, as evidenced by the reductions in V˙O2max (-17 ± 2%, p < 0.001), peak power output (-28 ± 2%, p < 0.001), and time to exhaustion (-28 ± 2%, p < 0.001). Muscle oxygenated hemoglobin (Δ[O2Hb]) during exercise declined more in the NC condition (p < 0.01); however, at exhaustion, the magnitude of muscle oxygenation and muscle deoxygenation were similar between conditions (p > 0.05). At maximal effort, lower cerebral deoxygenated hemoglobin (Δ[HHb]) and cerebral total hemoglobin (Δ[THb]) were observed in WC (p < 0.001), accompanied by a lower cardiac output, heart rate, and stroke volume vs. the NC condition (p < 0.01), whereas systolic blood pressure, rating of perceived exertion, and cerebral activation (as assessed by electroencephalography (EEG) activity) were similar (p > 0.05) between conditions at task failure, despite marked differences in exercise duration, maximal aerobic power output, and V˙O2max. In conclusion, in trained cyclists, muscle blood flow restriction during an incremental cycling exercise test significantly limited exercise performance. Exercise intolerance with muscle blood flow restriction was mainly associated with attenuated cardiac responses, despite cerebral activation reaching similar maximal levels as without muscle blood flow restriction.
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Affiliation(s)
- Evgenia D Cherouveim
- Division of Sports Medicine and Biology of Exercise, School of Physical Education and Sports Science, National and Kapodistrian University of Athens, 17237 Athens, Greece
| | - Panagiotis G Miliotis
- Division of Sports Medicine and Biology of Exercise, School of Physical Education and Sports Science, National and Kapodistrian University of Athens, 17237 Athens, Greece
| | - Maria D Koskolou
- Division of Sports Medicine and Biology of Exercise, School of Physical Education and Sports Science, National and Kapodistrian University of Athens, 17237 Athens, Greece
| | - Konstantina Dipla
- Laboratory of Exercise Physiology and Biochemistry, School of Physical Education and Sports Science at Serres, Aristotle University of Thessaloniki, 62122 Serres, Greece
| | - Ioannis S Vrabas
- Laboratory of Exercise Physiology and Biochemistry, School of Physical Education and Sports Science at Serres, Aristotle University of Thessaloniki, 62122 Serres, Greece
| | - Nickos D Geladas
- Division of Sports Medicine and Biology of Exercise, School of Physical Education and Sports Science, National and Kapodistrian University of Athens, 17237 Athens, Greece
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Independent effects of acute normobaric hypoxia and hypobaric hypoxia on human physiology. Sci Rep 2022; 12:19570. [PMID: 36379983 PMCID: PMC9666440 DOI: 10.1038/s41598-022-23698-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 11/03/2022] [Indexed: 11/16/2022] Open
Abstract
The purpose of this study was to examine the effects of acute normobaric (NH, decreased FiO2) and hypobaric (HH, 4200 m ascent) hypoxia exposures compared to sea level (normobaric normoxia, NN). Tissue oxygenation, cardiovascular, and body fluid variables measured during rest and a 3-min step-test following 90-min exposures (NH, HH, NN). Muscle oxygenated hemoglobin (O2Hb) decreased, and muscle deoxygenated hemoglobin (HHb) increased environmentally independent from rest to exercise (p < 0.001). During exercise, brain O2Hb was lower at HH compared to NN (p = 0.007), trending similarly with NH (p = 0.066), but no difference between NN and NH (p = 0.158). During exercise, HR at NH (141 ± 4 beats·min-1) and HH (141 ± 3 beats·min-1) were higher than NN (127 ± 44 beats·min-1, p = 0.002), but not each other (p = 0.208). During exercise, stroke volume at HH (109.6 ± 4.1 mL·beat-1) was higher than NH (97.8 ± 3.3 mL·beat-1) and NN (99.8 ± 3.9 mL·beat-1, p ≤ 0.010) with no difference between NH and NN (p = 0.481). During exercise, cardiac output at NH (13.8 ± 0.6 L) and HH (15.5 ± 0.7 L) were higher than NN (12.6 ± 0.5 L, p ≤ 0.006) with HH also higher than NH (p = 0.001). During acute hypoxic stimuli, skeletal muscle maintains oxygenation whereas the brain does not. These differences may be mediated by environmentally specific cardiovascular compensation. Thus, caution is advised when equating NH and HH.
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10
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Alharbi AAD, Iwamoto N, Ebine N, Nakae S, Hojo T, Fukuoka Y. The Acute Effects of a Single Dose of Molecular Hydrogen Supplements on Responses to Ergogenic Adjustments during High-Intensity Intermittent Exercise in Humans. Nutrients 2022; 14:nu14193974. [PMID: 36235628 PMCID: PMC9571546 DOI: 10.3390/nu14193974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 09/19/2022] [Accepted: 09/22/2022] [Indexed: 11/23/2022] Open
Abstract
This research examined the effects of single-dose molecular hydrogen (H2) supplements on acid-base status and local muscle deoxygenation during rest, high-intensity intermittent training (HIIT) performance, and recovery. Ten healthy, trained subjects in a randomized, double-blind, crossover design received H2-rich calcium powder (HCP) (1500 mg, containing 2.544 μg of H2) or H2-depleted placebo (1500 mg) supplements 1 h pre-exercise. They performed six bouts of 7 s all-out pedaling (HIIT) at 7.5% of body weight separated by 40 s pedaling intervals, followed by a recovery period. Blood gases’ pH, PCO2, and HCO3− concentrations were measured at rest. Muscle deoxygenation (deoxy[Hb + Mb]) and tissue O2 saturation (StO2) were determined via time-resolved near-infrared spectroscopy in the vastus lateralis (VL) and rectus femoris (RF) muscles from rest to recovery. At rest, the HCP group had significantly higher PCO2 and HCO3− concentrations and a slight tendency toward acidosis. During exercise, the first HIIT bout’s peak power was significantly higher in HCP (839 ± 112 W) vs. Placebo (816 ± 108 W, p = 0.001), and HCP had a notable effect on significantly increased deoxy[Hb + Mb] concentration during HIIT exercise, despite no differences in heart rate response. The HCP group showed significantly greater O2 extraction in VL and microvascular (Hb) volume in RF during HIIT exercise. The HIIT exercise provided significantly improved blood flow and muscle reoxygenation rates in both the RF and VL during passive recovery compared to rest in all groups. The HCP supplement might exert ergogenic effects on high-intensity exercise and prove advantageous for improving anaerobic HIIT exercise performance.
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Affiliation(s)
| | - Noriaki Iwamoto
- Graduate School of Health and Sports Science, Doshisha University, Kyoto 610-0396, Japan
| | - Naoyuki Ebine
- Graduate School of Health and Sports Science, Doshisha University, Kyoto 610-0396, Japan
| | - Satoshi Nakae
- Human Augmentation Research Center, National Institute of Advanced Industrial Science and Technology, Kashiwa II Campus, The University of Tokyo, Chiba 277-0882, Japan
| | - Tatsuya Hojo
- Graduate School of Health and Sports Science, Doshisha University, Kyoto 610-0396, Japan
| | - Yoshiyuki Fukuoka
- Graduate School of Health and Sports Science, Doshisha University, Kyoto 610-0396, Japan
- Correspondence: ; Tel.: +81-774-65-7530; Fax: +81-774-65-6029
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11
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Hohenauer E, Freitag L, Herten M, Siallagan J, Pollock E, Taube W, Clijsen R. The Methodological Quality of Studies Investigating the Acute Effects of Exercise During Hypoxia Over the Past 40 years: A Systematic Review. Front Physiol 2022; 13:919359. [PMID: 35784889 PMCID: PMC9243659 DOI: 10.3389/fphys.2022.919359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 05/09/2022] [Indexed: 11/25/2022] Open
Abstract
Exercise under hypoxia and the physiological impact compared to normoxia or hypoxia has gained attention in the last decades. However, methodological quality assessment of articles in this area is lacking in the literature. Therefore, this article aimed to evaluate the methodologic quality of trials studying exercise under hypoxia. An electronic search was conducted until December 2021. The search was conducted in PubMed, CENTRAL, and PEDro using the PICO model. (P) Participants had to be healthy, (I) exercise under normobaric or hypobaric hypoxia had to be (C) compared to exercise in normoxia or hypoxia on (O) any physiological outcome. The 11-item PEDro scale was used to assess the methodological quality (internal validity) of the studies. A linear regression model was used to evaluate the evolution of trials in this area, using the total PEDro score of the rated trials. A total of n = 81 studies met the inclusion criteria and were processed in this study. With a mean score of 5.1 ± 0.9 between the years 1982 and 2021, the mean methodological quality can be described as "fair." Only one study reached the highest score of 8/10, and n = 2 studies reached the lowest observed value of 3/10. The linear regression showed an increase of the PEDro score of 0.1 points per decade. A positive and small tendency toward increased methodologic quality was observed. The current results demonstrate that a positive and small tendency can be seen for the increase in the methodological quality in the field of exercise science under hypoxia. A "good" methodological quality, reaching a PEDro score of 6 points can be expected in the year 2063, using a linear regression model analysis. To accelerate this process, future research should ensure that methodological quality criteria are already included during the planning phase of a study.
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Affiliation(s)
- Erich Hohenauer
- Rehabilitation and Exercise Science Laboratory (RES Lab), Department of Business Economics, Health and Social Care, University of Applied Sciences and Arts of Southern Switzerland, Landquart, Switzerland
- International University of Applied Sciences THIM, Landquart, Switzerland
- Department of Neurosciences and Movement Science, University of Fribourg, Fribourg, Switzerland
- Department of Movement and Sport Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Livia Freitag
- Rehabilitation and Exercise Science Laboratory (RES Lab), Department of Business Economics, Health and Social Care, University of Applied Sciences and Arts of Southern Switzerland, Landquart, Switzerland
| | - Miriam Herten
- Rehabilitation and Exercise Science Laboratory (RES Lab), Department of Business Economics, Health and Social Care, University of Applied Sciences and Arts of Southern Switzerland, Landquart, Switzerland
| | - Julia Siallagan
- Rehabilitation and Exercise Science Laboratory (RES Lab), Department of Business Economics, Health and Social Care, University of Applied Sciences and Arts of Southern Switzerland, Landquart, Switzerland
| | - Elke Pollock
- Department of Physiotherapy, Zurich University of Applied Sciences, Zurich, Switzerland
| | - Wolfgang Taube
- Department of Neurosciences and Movement Science, University of Fribourg, Fribourg, Switzerland
| | - Ron Clijsen
- Rehabilitation and Exercise Science Laboratory (RES Lab), Department of Business Economics, Health and Social Care, University of Applied Sciences and Arts of Southern Switzerland, Landquart, Switzerland
- International University of Applied Sciences THIM, Landquart, Switzerland
- Department of Movement and Sport Sciences, Vrije Universiteit Brussel, Brussels, Belgium
- Department of Health, Bern University of Applied Sciences, Berne, Switzerland
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12
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Abstract
Ischemic heart disease and stroke are the number 1 and number 2 causes of death worldwide, respectively. A lifelong commitment to exercise reduces the risk of these adverse events and is also associated with several cardiometabolic improvements, including reductions in blood pressure, cholesterol, and inflammatory markers, as well as improved glucose control. Routine exercise also reduces the risk of developing comorbidities that increase the risk of cardiovascular or cerebrovascular disease. While the benefits of a lifelong commitment to exercise are well documented, there is a complex interaction between exercise and stroke risk, such that the risk of ischemic or hemorrhagic stroke may increase acutely during or immediately following exercise. In this article, we discuss the physiological responses to different types of exercise, as well as the determinants of resting and exertional cerebrovascular perfusion, and explore the complex interaction between atrial fibrillation, exercise, and stroke risk. Finally, we highlight the increased risk of stroke during different types of exercise, as well as factors that may alleviate this risk.
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Affiliation(s)
- Justin A Edward
- Department of Medicine-Cardiology, University of Colorado Anschutz Medical Campus, Aurora. (J.A.E., W.K.C.)
| | - William K Cornwell
- Department of Medicine-Cardiology, University of Colorado Anschutz Medical Campus, Aurora. (J.A.E., W.K.C.).,Clinical Translational Research Center, University of Colorado Anschutz Medical Campus, Aurora. (W.K.C.)
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13
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Ruggiero L, Harrison SWD, Rice CL, McNeil CJ. Neuromuscular fatigability at high altitude: Lowlanders with acute and chronic exposure, and native highlanders. Acta Physiol (Oxf) 2022; 234:e13788. [PMID: 35007386 PMCID: PMC9286620 DOI: 10.1111/apha.13788] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 01/04/2022] [Accepted: 01/05/2022] [Indexed: 01/18/2023]
Abstract
Ascent to high altitude is accompanied by a reduction in partial pressure of inspired oxygen, which leads to interconnected adjustments within the neuromuscular system. This review describes the unique challenge that such an environment poses to neuromuscular fatigability (peripheral, central and supraspinal) for individuals who normally reside near to sea level (SL) (<1000 m; ie, lowlanders) and for native highlanders, who represent the manifestation of high altitude-related heritable adaptations across millennia. Firstly, the effect of acute exposure to high altitude-related hypoxia on neuromuscular fatigability will be examined. Under these conditions, both supraspinal and peripheral fatigability are increased compared with SL. The specific mechanisms contributing to impaired performance are dependent on the exercise paradigm and amount of muscle mass involved. Next, the effect of chronic exposure to high altitude (ie, acclimatization of ~7-28 days) will be considered. With acclimatization, supraspinal fatigability is restored to SL values, regardless of the amount of muscle mass involved, whereas peripheral fatigability remains greater than SL except when exercise involves a small amount of muscle mass (eg, knee extensors). Indeed, when whole-body exercise is involved, peripheral fatigability is not different to acute high-altitude exposure, due to competing positive (haematological and muscle metabolic) and negative (respiratory-mediated) effects of acclimatization on neuromuscular performance. In the final section, we consider evolutionary adaptations of native highlanders (primarily Himalayans of Tibet and Nepal) that may account for their superior performance at altitude and lesser degree of neuromuscular fatigability compared with acclimatized lowlanders, for both single-joint and whole-body exercise.
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Affiliation(s)
- Luca Ruggiero
- Laboratory of Physiomechanics of LocomotionDepartment of Pathophysiology and TransplantationUniversity of MilanMilanItaly
| | - Scott W. D. Harrison
- School of KinesiologyFaculty of Health SciencesThe University of Western OntarioLondonOntarioCanada
| | - Charles L. Rice
- School of KinesiologyFaculty of Health SciencesThe University of Western OntarioLondonOntarioCanada
- Department of Anatomy and Cell BiologySchulich School of Medicine and DentistryThe University of Western OntarioLondonOntarioCanada
| | - Chris J. McNeil
- Centre for Heart, Lung & Vascular HealthSchool of Health and Exercise SciencesUniversity of British ColumbiaKelownaBritish ColumbiaCanada
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14
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Travers G, Kippelen P, Trangmar SJ, González-Alonso J. Physiological Function during Exercise and Environmental Stress in Humans-An Integrative View of Body Systems and Homeostasis. Cells 2022; 11:383. [PMID: 35159193 PMCID: PMC8833916 DOI: 10.3390/cells11030383] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 11/26/2022] Open
Abstract
Claude Bernard's milieu intérieur (internal environment) and the associated concept of homeostasis are fundamental to the understanding of the physiological responses to exercise and environmental stress. Maintenance of cellular homeostasis is thought to happen during exercise through the precise matching of cellular energetic demand and supply, and the production and clearance of metabolic by-products. The mind-boggling number of molecular and cellular pathways and the host of tissues and organ systems involved in the processes sustaining locomotion, however, necessitate an integrative examination of the body's physiological systems. This integrative approach can be used to identify whether function and cellular homeostasis are maintained or compromised during exercise. In this review, we discuss the responses of the human brain, the lungs, the heart, and the skeletal muscles to the varying physiological demands of exercise and environmental stress. Multiple alterations in physiological function and differential homeostatic adjustments occur when people undertake strenuous exercise with and without thermal stress. These adjustments can include: hyperthermia; hyperventilation; cardiovascular strain with restrictions in brain, muscle, skin and visceral organs blood flow; greater reliance on muscle glycogen and cellular metabolism; alterations in neural activity; and, in some conditions, compromised muscle metabolism and aerobic capacity. Oxygen supply to the human brain is also blunted during intense exercise, but global cerebral metabolism and central neural drive are preserved or enhanced. In contrast to the strain seen during severe exercise and environmental stress, a steady state is maintained when humans exercise at intensities and in environmental conditions that require a small fraction of the functional capacity. The impact of exercise and environmental stress upon whole-body functions and homeostasis therefore depends on the functional needs and differs across organ systems.
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Affiliation(s)
- Gavin Travers
- The European Astronaut Centre, The European Space Agency, Linder Höhe, 51147 Cologne, Germany;
| | - Pascale Kippelen
- Centre for Human Performance, Exercise and Rehabilitation, Brunel University London, Uxbridge UB8 3PH, UK;
- Division of Sport, Health and Exercise Sciences, Department of Life Sciences, Brunel University London, Uxbridge UB8 3PH, UK
| | - Steven J. Trangmar
- School of Life and Health Sciences, University of Roehampton, London SW15 4JD, UK;
| | - José González-Alonso
- Centre for Human Performance, Exercise and Rehabilitation, Brunel University London, Uxbridge UB8 3PH, UK;
- Division of Sport, Health and Exercise Sciences, Department of Life Sciences, Brunel University London, Uxbridge UB8 3PH, UK
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15
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Tari B, Shirzad M, Behboodpour N, Belfry GR, Heath M. Exercise intensity-specific changes to cerebral blood velocity do not modulate a postexercise executive function benefit. Neuropsychologia 2021; 161:108018. [PMID: 34487738 DOI: 10.1016/j.neuropsychologia.2021.108018] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 08/30/2021] [Accepted: 09/02/2021] [Indexed: 12/20/2022]
Abstract
Executive function is transiently improved (i.e., <60-min) following a single bout of aerobic exercise. A candidate mechanism for this improvement is an exercise-mediated increase in cerebral blood flow (CBF). Further, it has been proposed that an increase in CBF across the continuum of increasing exercise intensities improves the magnitude of a postexercise executive function benefit (i.e., drive theory); however, this proposal has not been empirically tested. Here, participants completed four experimental sessions: a V̇O2peak test to determine cardiorespiratory fitness and estimated lactate threshold (LT), followed by separate 10-min sessions of light- (i.e., 25 W), moderate- (i.e., 80% estimated LT), and heavy-intensity (i.e., 15% of the difference between LT and V̇O2peak) aerobic exercise. An estimate of CBF during exercise was achieved via transcranial Doppler ultrasound and near-infrared spectroscopy to quantify blood velocity (BV) through the middle cerebral artery and deoxygenated hemoglobin (HHb), respectively. Executive function was assessed before and after each session via the executive-mediated antisaccade task (i.e., saccade mirror-symmetrical to a target). Results demonstrated that BV increased in relation to increasing exercise intensity, whereas HHb decreased by a comparable magnitude independent of intensity. In terms of executive function, null hypothesis and equivalence tests indicated a comparable magnitude postexercise reduction in antisaccade reaction time across exercise intensities. Accordingly, the magnitude of CBF change during exercise does not impact the magnitude of a postexercise executive function benefit.
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Affiliation(s)
- Benjamin Tari
- School of Kinesiology, Faculty of Health Sciences, University of Western Ontario, 1151 Richmond St, London, ON, N6A 3K7, Canada
| | - Mustafa Shirzad
- School of Kinesiology, Faculty of Health Sciences, University of Western Ontario, 1151 Richmond St, London, ON, N6A 3K7, Canada
| | - Nikan Behboodpour
- School of Kinesiology, Faculty of Health Sciences, University of Western Ontario, 1151 Richmond St, London, ON, N6A 3K7, Canada
| | - Glen R Belfry
- School of Kinesiology, Faculty of Health Sciences, University of Western Ontario, 1151 Richmond St, London, ON, N6A 3K7, Canada; Canadian Centre for Activity and Aging, University of Western Ontario, 1201 Western Rd, London, ON, N6G 1H1, Canada
| | - Matthew Heath
- School of Kinesiology, Faculty of Health Sciences, University of Western Ontario, 1151 Richmond St, London, ON, N6A 3K7, Canada; Canadian Centre for Activity and Aging, University of Western Ontario, 1201 Western Rd, London, ON, N6G 1H1, Canada; Graduate Program in Neuroscience, University of Western Ontario, 1151 Richmond St, London, ON, N6A 3K7, Canada.
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16
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Fan JL, Wu TY, Lovering AT, Nan L, Bang WL, Kayser B. Differential Brain and Muscle Tissue Oxygenation Responses to Exercise in Tibetans Compared to Han Chinese. Front Physiol 2021; 12:617954. [PMID: 33716766 PMCID: PMC7943468 DOI: 10.3389/fphys.2021.617954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 01/18/2021] [Indexed: 11/13/2022] Open
Abstract
The Tibetans’ better aerobic exercise capacity at altitude remains ill-understood. We tested the hypothesis that Tibetans display better muscle and brain tissue oxygenation during exercise in hypoxia. Using near-infrared spectrometry (NIRS) to provide indices of tissue oxygenation, we measured oxy- and deoxy-hemoglobin ([O2Hb] and [HHb], respectively) responses of the vastus lateralis muscle and the right prefrontal cortex in ten Han Chinese and ten Tibetans during incremental cycling to exhaustion in a pressure-regulated chamber at simulated sea-level (air at 1 atm: normobaric normoxia) and 5,000 m (air at 0.5 atm: hypobaric hypoxia). Hypoxia reduced aerobic capacity by ∼22% in both groups (d = 0.8, p < 0.001 vs. normoxia), while Tibetans consistently outperformed their Han Chinese counterpart by ∼32% in normoxia and hypoxia (d = 1.0, p = 0.008). We found cerebral [O2Hb] was higher in Tibetans at normoxic maximal effort compared Han (p = 0.001), while muscle [O2Hb] was not different (p = 0.240). Hypoxic exercise lowered muscle [O2Hb] in Tibetans by a greater extent than in Han (interaction effect: p < 0.001 vs. normoxic exercise). Muscle [O2Hb] was lower in Tibetans when compared to Han during hypoxic exercise (d = 0.9, p = 0.003), but not during normoxic exercise (d = 0.4, p = 0.240). Muscle [HHb] was not different between the two groups during normoxic and hypoxic exercise (p = 0.778). Compared to Han, our findings revealed a higher brain tissue oxygenation in Tibetans during maximal exercise in normoxia, but lower muscle tissue oxygenation during exercise in hypoxia. This would suggest that the Tibetans privileged oxygenation of the brain at the expense of that of the muscle.
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Affiliation(s)
- Jui-Lin Fan
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Tian Yi Wu
- Research Center for High Altitude Medicine, Tibet University Medical College, Lhasa, China.,National Key Laboratory of High Altitude Medicine, Xining, China
| | - Andrew T Lovering
- Department of Human Physiology, University of Oregon, Eugene, OR, United States
| | - Liya Nan
- National Key Laboratory of High Altitude Medicine, Xining, China
| | - Wang Liang Bang
- National Key Laboratory of High Altitude Medicine, Xining, China
| | - Bengt Kayser
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
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17
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Ashley JD, Shelley JH, Sun J, Song J, Trent JA, Ambrosio LD, Larson DJ, Larson RD, Yabluchanskiy A, Kellawan JM. Cerebrovascular responses to graded exercise in young healthy males and females. Physiol Rep 2020; 8:e14622. [PMID: 33112497 PMCID: PMC7592493 DOI: 10.14814/phy2.14622] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 10/04/2020] [Indexed: 01/06/2023] Open
Abstract
Although systemic sex-specific differences in cardiovascular responses to exercise are well established, the comparison of sex-specific cerebrovascular responses to exercise has gone under-investigated especially, during high intensity exercise. Therefore, our purpose was to compare cerebrovascular responses in males and females throughout a graded exercise test (GXT). Twenty-six participants (13 Females and 13 Males, 24 ± 4 yrs.) completed a GXT on a recumbent cycle ergometer consisting of 3-min stages. Each sex completed 50W, 75W, 100W stages. Thereafter, power output increased 30W/stage for females and 40W/stage for males until participants were unable to maintain 60-80 RPM. The final stage completed by the participant was considered maximum workload(Wmax ). Respiratory gases (End-tidal CO2 , EtCO2 ), middle cerebral artery blood velocity (MCAv), heart rate (HR), non-invasive mean arterial pressure (MAP), cardiac output (CO), and stroke volume (SV) were continuously recorded on a breath-by-breath or beat-by-beat basis. Cerebral perfusion pressure, CPP = MAP (0. 7,355 distance from heart-level to doppler probe) and cerebral vascular conductance index, CVCi = MCAv/CPP 100mmHg were calculated. The change from baseline (Δ) in MCAv was similar between the sexes during the GXT (p = .091, ωp2 = 0.05). However, ΔCPP (p < .001, ωp2 = 0.25) was greater in males at intensities ≥ 80% Wmax and ΔCVCi (p = .005, ωp2 = 0.15) was greater in females at 100% Wmax . Δ End-tidal CO2 (ΔEtCO2 ) was not different between the sexes during exercise (p = .606, ωp2 = -0.03). These data suggest there are sex-specific differences in cerebrovascular control, and these differences may only be identifiable at high and severe intensity exercise.
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Affiliation(s)
- John D. Ashley
- Department of Health and Exercise ScienceHuman Circulation Research LaboratoryUniversity of OklahomaNormanOKUSA
| | - Joe H. Shelley
- Department of Health and Exercise ScienceHuman Circulation Research LaboratoryUniversity of OklahomaNormanOKUSA
| | - Jongjoo Sun
- Department of Health and Exercise ScienceHuman Circulation Research LaboratoryUniversity of OklahomaNormanOKUSA
| | - Jiwon Song
- Department of Health and Exercise ScienceHuman Circulation Research LaboratoryUniversity of OklahomaNormanOKUSA
| | - Jacob A. Trent
- Department of Health and Exercise ScienceHuman Circulation Research LaboratoryUniversity of OklahomaNormanOKUSA
| | - Luis D. Ambrosio
- Department of Health and Exercise ScienceHuman Circulation Research LaboratoryUniversity of OklahomaNormanOKUSA
| | - Daniel J. Larson
- Department of Health and Exercise Science, Sport, Health, and Exercise Data Analytics LaboratoryUniversity of OklahomaNormanOKUSA
| | - Rebecca D. Larson
- Department of Health and Exercise ScienceBody Composition and Physical Performance Research LaboratoryUniversity of OklahomaNormanOKUSA
| | - Andriy Yabluchanskiy
- Oklahoma Center for GeroscienceDepartment of Biochemistry and Molecular BiologyUniversity of Oklahoma Health Sciences CenterOklahoma CityOKUSA
| | - J. Mikhail Kellawan
- Department of Health and Exercise ScienceHuman Circulation Research LaboratoryUniversity of OklahomaNormanOKUSA
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18
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Triantafyllou GA, Dipla K, Triantafyllou A, Gkaliagkousi E, Douma S. Measurement and Changes in Cerebral Oxygenation and Blood Flow at Rest and During Exercise in Normotensive and Hypertensive Individuals. Curr Hypertens Rep 2020; 22:71. [PMID: 32852614 DOI: 10.1007/s11906-020-01075-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
PURPOSE OF REVIEW Summarize the methods used for measurement of cerebral blood flow and oxygenation; describe the effects of hypertension on cerebral blood flow and oxygenation. RECENT FINDINGS Information regarding the effects of hypertension on cerebrovascular circulation during exercise is very limited, despite a plethora of methods to help with its assessment. In normotensive individuals performing incremental exercise testing, total blood flow to the brain increases. In contrast, the few studies performed in hypertensive patients suggest a smaller increase in cerebral blood flow, despite higher blood pressure levels. Endothelial dysfunction and increased vasoconstrictor concentration, as well as large vessel atherosclerosis and decreased small vessel number, have been proposed as the underlying mechanisms. Hypertension may adversely impact oxygen and blood delivery to the brain, both at rest and during exercise. Future studies should utilize the newer, noninvasive techniques to better characterize the interplay between the brain and exercise in hypertension.
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Affiliation(s)
- Georgios A Triantafyllou
- 3rd Department of Internal Medicine, Papageorgiou Hospital, Aristotle University of Thessaloniki, Ring Road Nea Eukarpia, 56403, Thessaloniki, Greece.,Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh Medical Center, 3459 Fifth Avenue, Pittsburgh, PA, 15213, USA
| | - Konstantina Dipla
- Exercise Physiology and Biochemistry Laboratory, Department of Sports Science at Serres, Aristotle University of Thessaloniki, Agios Ioannis, 62122, Serres, Greece
| | - Areti Triantafyllou
- 3rd Department of Internal Medicine, Papageorgiou Hospital, Aristotle University of Thessaloniki, Ring Road Nea Eukarpia, 56403, Thessaloniki, Greece.
| | - Eugenia Gkaliagkousi
- 3rd Department of Internal Medicine, Papageorgiou Hospital, Aristotle University of Thessaloniki, Ring Road Nea Eukarpia, 56403, Thessaloniki, Greece
| | - Stella Douma
- 3rd Department of Internal Medicine, Papageorgiou Hospital, Aristotle University of Thessaloniki, Ring Road Nea Eukarpia, 56403, Thessaloniki, Greece
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19
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Manferdelli G, Marzorati M, Easton C, Porcelli S. Changes in prefrontal cerebral oxygenation and microvascular blood volume in hypoxia and possible association with acute mountain sickness. Exp Physiol 2020; 106:76-85. [DOI: 10.1113/ep088515] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 07/24/2020] [Indexed: 01/30/2023]
Affiliation(s)
- Giorgio Manferdelli
- Institute of Biomedical Technologies National Research Council Segrate Italy
- School of Health and Exercise Sciences University of the West of Scotland Paisley UK
| | - Mauro Marzorati
- Institute of Biomedical Technologies National Research Council Segrate Italy
| | - Chris Easton
- School of Health and Exercise Sciences University of the West of Scotland Paisley UK
| | - Simone Porcelli
- Institute of Biomedical Technologies National Research Council Segrate Italy
- Department of Molecular Physiology University of Pavia Pavia Italy
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20
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New Directions in Exercise Prescription: Is There a Role for Brain-Derived Parameters Obtained by Functional Near-Infrared Spectroscopy? Brain Sci 2020; 10:brainsci10060342. [PMID: 32503207 PMCID: PMC7348779 DOI: 10.3390/brainsci10060342] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 05/25/2020] [Accepted: 05/29/2020] [Indexed: 02/06/2023] Open
Abstract
In the literature, it is well established that regular physical exercise is a powerful strategy to promote brain health and to improve cognitive performance. However, exact knowledge about which exercise prescription would be optimal in the setting of exercise–cognition science is lacking. While there is a strong theoretical rationale for using indicators of internal load (e.g., heart rate) in exercise prescription, the most suitable parameters have yet to be determined. In this perspective article, we discuss the role of brain-derived parameters (e.g., brain activity) as valuable indicators of internal load which can be beneficial for individualizing the exercise prescription in exercise–cognition research. Therefore, we focus on the application of functional near-infrared spectroscopy (fNIRS), since this neuroimaging modality provides specific advantages, making it well suited for monitoring cortical hemodynamics as a proxy of brain activity during physical exercise.
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Marillier M, Rupp T, Bouzat P, Walther G, Baillieul S, Millet GY, Robach P, Verges S. Cerebral haemodynamics and oxygenation during whole‐body exercise over 5 days at high altitude. Exp Physiol 2020; 106:65-75. [DOI: 10.1113/ep088354] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 01/27/2020] [Indexed: 11/08/2022]
Affiliation(s)
- Mathieu Marillier
- HP2 Laboratory INSERM Grenoble Alpes University CHU Grenoble Alpes Grenoble France
| | - Thomas Rupp
- HP2 Laboratory INSERM Grenoble Alpes University CHU Grenoble Alpes Grenoble France
- Inter‐University Laboratory of Human Movement Sciences EA 7424 University Savoie Mont Blanc Chambery France
| | - Pierre Bouzat
- Grenoble Institute of Neurosciences INSERM U836 Grenoble Alpes University Grenoble France
| | | | - Sébastien Baillieul
- HP2 Laboratory INSERM Grenoble Alpes University CHU Grenoble Alpes Grenoble France
| | - Guillaume Y. Millet
- HP2 Laboratory INSERM Grenoble Alpes University CHU Grenoble Alpes Grenoble France
- Univ Lyon UJM‐Saint‐Etienne Laboratoire Interuniversitaire de Biologie de la Motricité EA 7424 F‐42023 Saint‐Etienne France
| | - Paul Robach
- HP2 Laboratory INSERM Grenoble Alpes University CHU Grenoble Alpes Grenoble France
- Ecole Nationale des Sports de Montagne site de l'Ecole Nationale de Ski et d'Alpinisme Chamonix France
| | - Samuel Verges
- HP2 Laboratory INSERM Grenoble Alpes University CHU Grenoble Alpes Grenoble France
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Bourdillon N, Yazdani S, Vesin JM, Subudhi AW, Lovering AT, Roach RC, Kayser B. AltitudeOmics: Spontaneous Baroreflex Sensitivity During Acclimatization to 5,260 m: A Comparison of Methods. Front Physiol 2020; 10:1505. [PMID: 31920710 PMCID: PMC6914841 DOI: 10.3389/fphys.2019.01505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 11/28/2019] [Indexed: 11/13/2022] Open
Abstract
Introduction Baroreflex sensitivity (BRS) is essential to ensure rapid adjustment to variations in blood pressure (BP). Spontaneous baroreflex function can be assessed using continuous recordings of blood pressure. The goal of this study was to compare four methods for BRS quantification [the sequence, Bernardi's (BER), frequency and transfer function methods] to identify the most consistent method across an extreme range of conditions: rest and exercise, in normoxia, hypoxia, hypocapnia, and hypercapnia. Methods Using intra-radial artery BP in young healthy participants, BRS was calculated and compared using the four methods in normoxia, acute and chronic hypoxia (terrestrial altitude of 5,260 m) in hypocapnia (hyperventilation), hypercapnia (rebreathing) and during ramp exercise to exhaustion. Results The sequence and BER methods for BRS estimation showed good agreement during the resting and exercise protocols, whilst the ultra- and very-low frequency bands of the frequency and transfer function methods were more discrepant. Removing respiratory frequency from the blood pressure traces affected primarily the sequence and BER methods and occasionally the frequency and transfer function methods. Discussion/Conclusion The sequence and BER methods contained more respiratory related information than the frequency and transfer function methods, indicating that the former two methods predominantly rely on respiratory effects of BRS. BER method is recommended because it is the easiest to compute and even though it tends to overestimate BRS compared to the sequence method, it is consistent with the other methods, whilst its interquartile range is the smallest.
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Affiliation(s)
- Nicolas Bourdillon
- Institue of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Sasan Yazdani
- Applied Signal Processing Group, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Jean-Marc Vesin
- Applied Signal Processing Group, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Andrew W Subudhi
- Altitude Research Center, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States.,Human Physiology and Nutrition, University of Colorado Colorado Springs, Colorado Springs, CO, United States
| | - Andrew T Lovering
- Department of Human Physiology, University of Oregon, Eugene, OR, United States
| | - Robert C Roach
- Altitude Research Center, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Bengt Kayser
- Institue of Sport Sciences, University of Lausanne, Lausanne, Switzerland
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Azevedo RDA, Béjar Saona JE, Inglis EC, Iannetta D, Murias JM. The effect of the fraction of inspired oxygen on the NIRS-derived deoxygenated hemoglobin "breakpoint" during ramp-incremental test. Am J Physiol Regul Integr Comp Physiol 2019; 318:R399-R409. [PMID: 31850819 DOI: 10.1152/ajpregu.00291.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
During ramp-incremental (RI) exercise to exhaustion, the near-infrared spectroscopy-derived deoxygenated hemoglobin ([HHb]) signal in the vastus lateralis muscle shows a linear increase up to a point at which a plateau-like response is manifested ([HHb]bp). This study investigated if 1) the [HHb]bp is affected by different fractions of inspired O2 (FIO2) [hypoxia (16%; HYPO); normoxia (21%; NORM); hyperoxia (30%; HYPER)]; and 2) an abrupt change to hyperoxic-inspired gas just before the occurrence of the [HHb]bp (HYPERSWITCH) would affect the [HHb] plateau-like response. Ten physically active male participants reported to the laboratory on four separate occasions to perform an RI test to exhaustion in NORM, HYPO, and HYPER and an RI test to exhaustion with an abrupt increase in FIO2 (30%; HYPERSWITCH) 15 W before the power output (PO) associated with [HHb]bp in normoxia. PO, [HHb], tissue O2 (StO2), and pulse O2 saturation (SpO2) were recorded continuously. Peak PO was significantly lower in HYPO (290 ± 21 W) and higher in HYPER (321 ± 22 W) and HYPERSWITCH (320 ± 19 W) compared with NORM (311 ± 18 W). The PO associated with [HHb]bp was not different between NORM and HYPER (246 ± 23 vs. 247 ± 24 W), but it was lower in HYPO (198 ± 31 W) than NORM and HYPER. The PO associated with the [HHb]bp in HYPERSWITCH (240 ± 23) was not different compared with NORM. HYPER and HYPERSWITCH resulted in greater StO2 and SpO2 compared with NORM. These results suggest that the [HHb]bp response is not dependent of O2 driving pressure and that other physiological mechanisms might determine its occurrence.
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Affiliation(s)
| | | | | | - Danilo Iannetta
- Faculty of Kinesiology, University of Calgary, Calgary, Canada
| | - Juan M Murias
- Faculty of Kinesiology, University of Calgary, Calgary, Canada
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Caen K, Vermeire K, Pogliaghi S, Moerman A, Niemeijer V, Bourgois JG, Boone J. Aerobic Interval Training Impacts Muscle and Brain Oxygenation Responses to Incremental Exercise. Front Physiol 2019; 10:1195. [PMID: 31616312 PMCID: PMC6764183 DOI: 10.3389/fphys.2019.01195] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 09/03/2019] [Indexed: 11/18/2022] Open
Abstract
The purpose of the present study was to assess the effects of aerobic interval training on muscle and brain oxygenation to incremental ramp exercise. Eleven physically active subjects performed a 6-week interval training period, proceeded and followed by an incremental ramp exercise to exhaustion (25 W min–1). Throughout the tests pulmonary gas exchange and muscle (Vastus Lateralis) and brain (prefrontal cortex) oxygenation [concentration of deoxygenated and oxygenated hemoglobin, HHb and O2Hb, and tissue oxygenation index (TOI)] were continuously recorded. Following the training intervention V.O2peak had increased with 7.8 ± 5.0% (P < 0.001). The slope of the decrease in muscle TOI had decreased (P = 0.017) 16.6 ± 6.4% and the amplitude of muscle HHb and totHb had increased (P < 0.001) 40.4 ± 15.8 and 125.3 ± 43.1%, respectively. The amplitude of brain O2Hb and totHb had increased (P < 0.05) 40.1 ± 18.7 and 26.8 ± 13.6%, respectively. The training intervention shifted breakpoints in muscle HHb, totHb and TOI, and brain O2Hb, HHb, totHb and TOI to a higher absolute work rate and V.O2 (P < 0.05). The relative (in %) change in V.O2peak was significantly correlated to relative (in %) change slope of muscle TOI (r = 0.69, P = 0.011) and amplitude of muscle HHb (r = 0.72, P = 0.003) and totHb (r = 0.52, P = 0.021), but not to changes in brain oxygenation. These results indicate that interval training affects both muscle and brain oxygenation, coinciding with an increase in aerobic fitness (i.e., V.O2peak). The relation between the change in V.O2peak and muscle but not brain oxygenation suggests that brain oxygenation per se is not a primary factor limiting exercise tolerance during incremental exercise.
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Affiliation(s)
- Kevin Caen
- Department of Movement and Sports Sciences, Ghent University, Ghent, Belgium
| | - Kobe Vermeire
- Department of Movement and Sports Sciences, Ghent University, Ghent, Belgium
| | - Silvia Pogliaghi
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Annelies Moerman
- Department of Anesthesiology, Ghent University Hospital, Ghent, Belgium
| | - Victor Niemeijer
- Department of Sports Medicine, Elkerliek Hospital, Helmond, Netherlands
| | | | - Jan Boone
- Department of Movement and Sports Sciences, Ghent University, Ghent, Belgium
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Raberin A, Meric H, Mucci P, Lopez Ayerbe J, Durand F. Muscle and cerebral oxygenation during exercise in athletes with exercise-induced hypoxemia: A comparison between sea level and acute moderate hypoxia. Eur J Sport Sci 2019; 20:803-812. [PMID: 31526237 DOI: 10.1080/17461391.2019.1669717] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The objective of the present study was to evaluate the influence of exercise-induced hypoxemia (EIH) on muscle and cerebral oxygenation responses during maximal exercise in normoxia and in acute moderate hypoxia (fraction of inspired oxygen: 15.3%, 2400 m). EIH was defined as a drop in hemoglobin saturation of at least 4% for at least three consecutive minutes during maximal exercise at sea level. Twenty-five athletes performed incremental treadmill tests to assess maximal oxygen consumption (VO2max) in normoxia and in hypoxia. Oxygenation of the vastus lateralis muscle and the left prefrontal cortex of the brain was monitored using near-infrared spectroscopy. During the normoxic test, 15 athletes exhibited EIH; they displayed a larger change in muscle levels of oxyhemoglobin (ΔO2Hb) (p = 0.04) and a greater change in cerebral levels of deoxyhemoglobin (ΔHHb) (p = 0.02) than athletes without EIH (NEIH group). During the hypoxic test, muscle ΔO2Hb was lower in the EIH group than in the NEIH group (p = 0.03). At VO2max, hypoxia was associated with a smaller cerebral ΔO2Hb in both groups, and a greater cerebral ΔHHb compared to normoxia in the NEIH group only (p = 0.02). No intergroup differences in changes in muscle oxygenation were observed. The severity of O2 arterial desaturation was negatively correlated with changes in total muscle hemoglobin in normoxia (r = -0.48, p = 0.01), and positively correlated with the cerebral ΔHHb in normoxia (r = 0.45, p = 0.02). The occurrence of EIH at sea level was associated with specific muscle and cerebral oxygenation responses to exercise under both normoxia and moderate hypoxia.
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Affiliation(s)
- Antoine Raberin
- LEPSA, EA 4604, Université de Perpignan Via Domitia, Font Romeu, France
| | - Henri Meric
- LEPSA, EA 4604, Université de Perpignan Via Domitia, Font Romeu, France
| | - Patrick Mucci
- Univ. Lille, Univ. Artois, Univ. Littoral Côte d'Opale, EA 7369 - URePSSS - Unité de Recherche Pluridisciplinaire Sport Santé Société, Lille, France
| | | | - Fabienne Durand
- LEPSA, EA 4604, Université de Perpignan Via Domitia, Font Romeu, France
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Vandekerckhove K, Coomans I, Moerman A, Panzer J, De Groote K, De Wilde H, Bove T, François K, De Wolf D, Boone J. Differences in cerebral and muscle oxygenation patterns during exercise in children with univentricular heart after Fontan operation compared to healthy peers. Int J Cardiol 2019; 290:86-92. [PMID: 31133431 DOI: 10.1016/j.ijcard.2019.05.040] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 04/02/2019] [Accepted: 05/17/2019] [Indexed: 11/30/2022]
Abstract
BACKGROUND We assess whether the lower exercise tolerance in children with univentricular heart (UVH) after Fontan operation is associated with altered peripheral muscular and cerebral tissue oxygenation. METHODS 18 children with UVH and 20 healthy subjects performed an incremental ramp exercise test. Changes in the cerebral and muscular pattern of oxygenated (O2Hb) and deoxygenated hemoglobin (HHb) and local tissue oxygenation (TOI) were analyzed by means of Near Infrared Spectroscopy (NIRS). Correlations between arterial saturation during exercise and tissue oxygenation were evaluated. RESULTS In UVH, maximal oxygen consumption (VO2peak/kg, 28.9 ± 7.9 vs. 46.3 ± 11.9 ml/min/kg, P < 0.001), heart rate (HRpeak, 168 ± 13 vs. 193 ± 12 bpm, P < 0.001) and load (Ppeak, 73 ± 19 vs. 133 ± 68 W, P < 0.001) were lower, VE/VCO2 slope was higher (34.5 ± 5.9 vs. 27.1 ± 3.9, P < 0.001). A faster and steeper course up to the same level of HHb and absent increase in O2Hb was seen at cerebral level in UVH; tissue oxygenation index (TOI) demonstrated a steady decrease from the start of exercise. At the muscular level, HHb curve has a similar pattern compared to controls, with an early cessation. O2Hb has a similar pattern, but with early discontinuation at a higher O2Hb-level. Muscular TOI has the same course throughout exercise, starting from a lower level. Lower arterial saturation and higher age correlated with lower VO2peak; higher amplitude of muscular TOI and lower amplitude cerebral TOI correlated with higher VO2peak. CONCLUSION Children after Fontan procedure have different oxygenation mechanisms at muscular and cerebral level. This reflects a different balance between O2 supply to O2 demand which might contribute to the reduced exercise tolerance in this patient population.
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Affiliation(s)
| | - Ilse Coomans
- Department of Pediatric Cardiology, Ghent University Hospital, Ghent, Belgium
| | - Annelies Moerman
- Department of Anesthesiology, Ghent University Hospital, Ghent, Belgium
| | - Joseph Panzer
- Department of Pediatric Cardiology, Ghent University Hospital, Ghent, Belgium
| | - Katya De Groote
- Department of Pediatric Cardiology, Ghent University Hospital, Ghent, Belgium
| | - Hans De Wilde
- Department of Pediatric Cardiology, Ghent University Hospital, Ghent, Belgium
| | - Thierry Bove
- Department of Cardiac Surgery, Ghent University Hospital, Ghent, Belgium
| | - Katrien François
- Department of Cardiac Surgery, Ghent University Hospital, Ghent, Belgium
| | - Daniel De Wolf
- Department of Pediatric Cardiology, Ghent University Hospital, Ghent, Belgium
| | - Jan Boone
- Department of Movement and Sports Sciences, Ghent University, Ghent, Belgium
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Kriel Y, Askew CD, Solomon C. Sprint interval exercise versus continuous moderate intensity exercise: acute effects on tissue oxygenation, blood pressure and enjoyment in 18-30 year old inactive men. PeerJ 2019; 7:e7077. [PMID: 31211019 PMCID: PMC6557258 DOI: 10.7717/peerj.7077] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 05/04/2019] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Sprint interval training (SIT) can be as effective, or more effective, than continuous moderate intensity exercise (CMIE) for improving a primary risk factor for cardiometabolic disease, low cardiorespiratory fitness (CRF). However, there has been no direct comparison in inactive individuals, of the acute effects of a session of SIT with a work-matched session of CMIE on local oxygen utilisation, which is a primary stimulus for increasing CRF. Furthermore, post-exercise blood pressure (BP) and enjoyment, if symptomatic and low, respectively, have implications for safety and adherence to exercise and have not been compared between these specific conditions. It was hypothesised that in young inactive men, local oxygen utilisation would be higher, while post-exercise BP and enjoyment would be lower for SIT, when compared to CMIE. METHODS A total of 11 inactive men (mean ± SD; age 23 ± 4 years) completed a maximal ramp-incremental exercise test followed by two experiment conditions: (1) SIT and (2) work-matched CMIE on a cycle ergometer on separate days. Deoxygenated haemoglobin (∆HHb) in the pre-frontal cortex (FH), gastrocnemius (GN), left vastus lateralis (LVL) and the right vastus lateralis (RVL) muscles, systemic oxygen utilisation (VO2), systolic (SBP) and diastolic (DBP) blood pressure and physical activity enjoyment scale (PACES) were measured during the experiment conditions. RESULTS During SIT, compared to CMIE, ∆HHb in FH (p = 0.016) and GN (p = 0.001) was higher, while PACES (p = 0.032) and DBP (p = 0.043) were lower. No differences in SBP and ∆HHb in LVL and RVL were found between conditions. CONCLUSIONS In young inactive men, higher levels of physiological stress occurred during SIT, which potentially contributed to lower levels of post-exercise DBP and enjoyment, when compared to CMIE.
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Affiliation(s)
- Yuri Kriel
- School of Health and Sports Sciences, University of the Sunshine Coast, Sippy Downs, Australia
| | - Christopher D. Askew
- School of Health and Sports Sciences, University of the Sunshine Coast, Sippy Downs, Australia
| | - Colin Solomon
- School of Health and Sports Sciences, University of the Sunshine Coast, Sippy Downs, Australia
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Holanda MA, Alves-de-Almeida M, Lima JW, Taunay TC, Gondim FA, P.R.Cavalcanti R, Mont’Alverne FJ, Sousa NDS, Oliveira MF, Pereira ED. Short-term effects of non-invasive ventilation on cerebral blood flow and cognitive function in COPD. Respir Physiol Neurobiol 2018; 258:53-59. [DOI: 10.1016/j.resp.2018.05.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 05/23/2018] [Accepted: 05/28/2018] [Indexed: 11/17/2022]
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Williams KA, Bell K, Jacobs RA, Subudhi AW. Supplemental Oxygen Does Not Influence Self-selected Work Rate at Moderate Altitude. Med Sci Sports Exerc 2018; 51:575-581. [PMID: 30299413 DOI: 10.1249/mss.0000000000001801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
INTRODUCTION It is well known that supplemental oxygen can increase aerobic power output during high-intensity and/or maximal efforts at moderate altitude, yet the effects on self-selected work rate during lower-intensity, submaximal exercise are unknown. We reasoned that if the degree of arterial oxygen saturation (SaO2) influences teleoanticipatory regulation of power output, supplemental oxygen given at moderate altitude would increase average power output during exercise performed at self-selected work rates corresponding to RPE 9 (very light) and 13 (somewhat hard). METHODS Twenty-three subjects (17 males, 6 females) completed one familiarization [fraction of inspired O2 (FIO2) = 0.209] and two blinded, experimental trials (FIO2 = 0.209 and FIO2 = 0.267). In each trial, subjects self-regulated their work rate on a cycle ergometer to maintain RPE 9 for 5 min and RPE 13 for 10 min, before performing an incremental step test to exhaustion (25 W·min). Oxygen consumption (V˙O2) and SaO2 via pulse oximetry (SpO2) were continuously monitored. Subjects were asked to guess the experimental condition after each stage of the protocol. RESULTS Supplemental oxygen increased SpO2 throughout exercise (~4%; P < 0.001) and was associated with greater peak power output (4% ± 4%; P < 0.001) and V˙O2 (5% ± 10%; P = 0.010) during the incremental test, but did not increase average power output selected during exercise at RPE 9 (P = 0.235) or 13 (P = 0.992). Subjects were unable to perceive the difference in FIO2 at any stage (P > 0.14). CONCLUSIONS Small increases in inspired oxygen concentration at moderate altitude are imperceptible and do not appear to influence selection of submaximal work rates at RPE ≤ 13.
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Affiliation(s)
- Kirsten A Williams
- University of Colorado Colorado Springs, Department of Biology, Colorado Springs, CO
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Ferguson SAH, Eves ND, Roy BD, Hodges GJ, Cheung SS. Effects of mild whole body hypothermia on self-paced exercise performance. J Appl Physiol (1985) 2018; 125:479-485. [PMID: 29672229 DOI: 10.1152/japplphysiol.01134.2017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study examined self-paced, high-intensity exercise during mild hypothermia and whether hyperoxia might offset any potential impairment. Twelve trained males each completed 15-km time trials in three environmental conditions: Neutral (23°C, [Formula: see text] 0.21), Cold (0°C, [Formula: see text] 0.21), and Cold+Hyper (0°C, [Formula: see text] 0.40). Cold and Cold+Hyper trials occurred after a 0.5°C drop in rectal temperature. Rectal temperature was higher ( P ≤ 0.016) throughout Neutral compared with Cold and Cold+Hyper; Cold had a higher ( P ≤ 0.035) rectal temperature than Cold+Hyper from 2.5 to 7.5 km, and hyperoxia did not alter thermal sensation or comfort. Oxyhemoglobin saturation decreased from ~98% to ~94% with Neutral and Cold, but was maintained at ~99% in Cold+Hyper ( P < 0.01). Cerebral tissue oxygenation index (TOI) was higher in Neutral than in Cold throughout the time trial (TT) ( P ≤ 0.001), whereas Cold+Hyper were unchanged ( P ≥ 0.567) from Neutral by 2.5 km. Muscle TOI was maintained in Cold+Hyper compared with Neutral and was higher ( P ≤ 0.046) than Cold throughout the entire TT. Power output during Cold (246 ± 41 W) was lower than Neutral (260 ± 38 W) at all 2.5-km intervals ( P ≤ 0.012) except at 12.5 km. Power output during Cold+Hyper (256 ± 42 W) was unchanged ( P ≥ 0.161) from Neutral throughout the TT, and was higher than Cold from 7.5 km onward. Average cadence was higher in Neutral (93 ± 8 rpm) than in either Cold or Cold+Hyper (Cold: 89 ± 7 and Cold+Hyper: 90 ± 8 rpm, P = 0.031). In conclusion, mild hypothermia reduced self-paced exercise performance; hyperoxia during mild hypothermia restored performance to thermoneutral levels, likely due to maintenance of oxygen availability rather than any thermogenic benefit. NEW & NOTEWORTHY We examined self-paced, high-intensity exercise with 0.5°C rectal temperature decreases in a 0°C ambient environment, along with whether hyperoxia could offset any potential impairment. During a 15-km time trial, power output was lower with hypothermia than with thermoneutral. However, with hypothermia, hyperoxia of [Formula: see text] = 0.40 restored power output despite there being no thermophysiological improvement. Hypothermia impairs exercise performance, whereas hyperoxia likely restored performance due to maintenance of oxygen availability rather than any thermogenic benefit.
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Affiliation(s)
- Steven A H Ferguson
- Department of Kinesiology, Brock University , St. Catharines, Ontario , Canada
| | - Neil D Eves
- Centre for Heart, Lung and Vascular Health, University of British Columbia , Kelowna, British Columbia , Canada
| | - Brian D Roy
- Department of Kinesiology, Brock University , St. Catharines, Ontario , Canada
| | - Gary J Hodges
- Department of Kinesiology, Brock University , St. Catharines, Ontario , Canada
| | - Stephen S Cheung
- Department of Kinesiology, Brock University , St. Catharines, Ontario , Canada
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Mourot L. Limitation of Maximal Heart Rate in Hypoxia: Mechanisms and Clinical Importance. Front Physiol 2018; 9:972. [PMID: 30083108 PMCID: PMC6064954 DOI: 10.3389/fphys.2018.00972] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 07/02/2018] [Indexed: 12/17/2022] Open
Abstract
The use of exercise intervention in hypoxia has grown in popularity amongst patients, with encouraging results compared to similar intervention in normoxia. The prescription of exercise for patients largely rely on heart rate recordings (percentage of maximal heart rate (HRmax) or heart rate reserve). It is known that HRmax decreases with high altitude and the duration of the stay (acclimatization). At an altitude typically chosen for training (2,000-3,500 m) conflicting results have been found. Whether or not this decrease exists or not is of importance since the results of previous studies assessing hypoxic training based on HR may be biased due to improper intensity. By pooling the results of 86 studies, this literature review emphasizes that HRmax decreases progressively with increasing hypoxia. The dose–response is roughly linear and starts at a low altitude, but with large inter-study variabilities. Sex or age does not seem to be a major contributor in the HRmax decline with altitude. Rather, it seems that the greater the reduction in arterial oxygen saturation, the greater the reduction in HRmax, due to an over activity of the parasympathetic nervous system. Only a few studies reported HRmax at sea/low level and altitude with patients. Altogether, due to very different experimental design, it is difficult to draw firm conclusions in these different clinical categories of people. Hence, forthcoming studies in specific groups of patients are required to properly evaluate (1) the HRmax change during acute hypoxia and the contributing factors, and (2) the physiological and clinical effects of exercise training in hypoxia with adequate prescription of exercise training intensity if based on heart rate.
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Affiliation(s)
- Laurent Mourot
- EA 3920 Prognostic Markers and Regulatory Factors of Cardiovascular Diseases and Exercise Performance, Health, Innovation Platform, University of Franche-Comté, Besançon, France.,Tomsk Polytechnic University, Tomsk, Russia
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Bourdillon N, Yazdani S, Subudhi AW, Lovering AT, Roach RC, Vesin JM, Kayser B. AltitudeOmics: Baroreflex Sensitivity During Acclimatization to 5,260 m. Front Physiol 2018; 9:767. [PMID: 29977210 PMCID: PMC6021743 DOI: 10.3389/fphys.2018.00767] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 05/31/2018] [Indexed: 11/13/2022] Open
Abstract
Introduction: Baroreflex sensitivity (BRS) is essential to ensure rapid adjustment to variations in blood pressure (BP). Little is known concerning the adaptive responses of BRS during acclimatization to high altitude at rest and during exercise. Methods: Twenty-one healthy sea-level residents were tested near sea level (SL, 130 m), the 1st (ALT1) and 16th day (ALT16) at 5,260 m using radial artery catheterization. BRS was calculated using the sequence method (direct interpretation of causal link between BP and heartrate). At rest, subjects breathed a hyperoxic mixture (250 mmHg O2, end tidal) to isolate the preponderance of CO2 chemoreceptors. End-tidal CO2 varied from 20 to 50 mmHg to assess peripheral chemoreflex. Rebreathing provoked incremental increase in CO2, increasing BP to assess baroreflex. During incremental cycling exercise to exhaustion, subjects breathed room air. Results: Resting BRS decreased in ALT1 which was exacerbated in ALT16. This decrease in ALT1 was reversible upon additional inspired CO2, but not in ALT16. BRS decrease during exercise was greater and occurred at lower workloads in ALT1 compared to SL. At ALT16, this decrease returned toward SL values. Discussion/Conclusion: This study is the first to report attenuated BRS in acute hypoxia, exacerbated in chronic hypoxia. In ALT1, hypocapnia triggered BRS reduction whilst in ALT16 resetting of chemoreceptor triggered BRS reduction. The exercise BRS resetting was impaired in ALT1 but normalized in ALT16. These BRS decreases indicate decreased control of BP and may explain deteriorations of cardiovascular status during exposure to high altitude.
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Affiliation(s)
- Nicolas Bourdillon
- Institute of Sports Sciences of the University of Lausanne, Lausanne, Switzerland
| | - Sasan Yazdani
- Applied Signal Processing Group, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Andrew W Subudhi
- Department of Biology, University of Colorado, Colorado Springs, CO, United States.,Altitude Research Center, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Andrew T Lovering
- Department of Human Physiology, University of Oregon, Eugene, OR, United States
| | - Robert C Roach
- Altitude Research Center, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Jean-Marc Vesin
- Applied Signal Processing Group, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Bengt Kayser
- Institute of Sports Sciences of the University of Lausanne, Lausanne, Switzerland
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Abstract
Hyperoxia results from the inhalation of mixtures of gas containing higher partial pressures of oxygen (O2) than normal air at sea level. Exercise in hyperoxia affects the cardiorespiratory, neural and hormonal systems, as well as energy metabolism in humans. In contrast to short-term exposure to hypoxia (i.e. a reduced partial pressure of oxygen), acute hyperoxia may enhance endurance and sprint interval performance by accelerating recovery processes. This narrative literature review, covering 89 studies published between 1975 and 2016, identifies the acute ergogenic effects and health concerns associated with hyperoxia during exercise; however, long-term adaptation to hyperoxia and exercise remain inconclusive. The complexity of the biological responses to hyperoxia, as well as the variations in (1) experimental designs (e.g. exercise intensity and modality, level of oxygen, number of participants), (2) muscles involved (arms and legs) and (3) training status of the participants may account for the discrepancies.
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Evaluating the methods used for measuring cerebral blood flow at rest and during exercise in humans. Eur J Appl Physiol 2018; 118:1527-1538. [DOI: 10.1007/s00421-018-3887-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 05/09/2018] [Indexed: 10/16/2022]
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Furian M, Hartmann SE, Latshang TD, Flueck D, Murer C, Scheiwiller PM, Osmonov B, Ulrich S, Kohler M, Poulin MJ, Bloch KE. Exercise Performance of Lowlanders with COPD at 2,590 m: Data from a Randomized Trial. Respiration 2018; 95:422-432. [PMID: 29502125 DOI: 10.1159/000486450] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 12/20/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Effects of hypobaric hypoxia at altitude on exercise performance of lowlanders with chronic obstructive pulmonary disease (COPD) have not been studied in detail. OBJECTIVES To quantify changes in exercise performance and associated physiologic responses in lowlanders with COPD travelling to moderate altitude. METHODS A total of 31 COPD patients with a median age (quartiles) of 66 years (59; 69) and FEV1 of 56% predicted (49; 69) living below 800 m performed a constant-load bicycle exercise to exhaustion at 60% of the maximal work rate at 490 m (Zurich) and at an identical work rate at 2,590 m (Davos) in randomized order. Pulmonary gas exchange, pulse oximetry (SpO2), cerebral tissue oxygenation (CTO; near-infrared spectroscopy), and middle cerebral artery peak blood flow velocity (MCAv) by Doppler ultrasound during 30 s at end exercise were compared between altitudes. RESULTS With ascent from 490 to 2,590 m, the median endurance time (quartiles) was reduced from 500 s (256; 795) to 205 s (139; 297) by a median (95% CI) of 303 s (150-420) (p < 0.001). End exercise SpO2 decreased from 92% (89; 94) to 81% (77; 84) and CTO from 62% (56; 66) to 55% (50; 60); end exercise minute ventilation increased from 40.6 L/min (35.5; 47.8) to 47.2 L/min (39.6; 58.7) (p < 0.05; all comparisons 2,590 vs. 490 m). MCAv increased similarly from rest to end exercise at 490 m (+25% [17; 36]) and at 2,590 m (+21% [14; 30]). However, the ratio of MCAv increase to SpO2 drop during exercise decreased from +6%/% (3; 12) at 490 m to +3%/% (2; 5) at 2,590 m (p < 0.05). CONCLUSIONS In lowlanders with COPD travelling to 2,590 m, exercise endurance is reduced by more than half compared to 490 m in association with reductions in systemic and cerebral oxygen availability.
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Affiliation(s)
- Michael Furian
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland.,Institute of Human Movement Sciences and Sport, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Sara E Hartmann
- Department of Physiology and Pharmacology and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Tsogyal D Latshang
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Deborah Flueck
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Christian Murer
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | | | - Batyr Osmonov
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyzstan
| | - Silvia Ulrich
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Malcolm Kohler
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Marc J Poulin
- Department of Physiology and Pharmacology and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Konrad E Bloch
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
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Brugniaux JV, Coombs GB, Barak OF, Dujic Z, Sekhon MS, Ainslie PN. Highs and lows of hyperoxia: physiological, performance, and clinical aspects. Am J Physiol Regul Integr Comp Physiol 2018; 315:R1-R27. [PMID: 29488785 DOI: 10.1152/ajpregu.00165.2017] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Molecular oxygen (O2) is a vital element in human survival and plays a major role in a diverse range of biological and physiological processes. Although normobaric hyperoxia can increase arterial oxygen content ([Formula: see text]), it also causes vasoconstriction and hence reduces O2 delivery in various vascular beds, including the heart, skeletal muscle, and brain. Thus, a seemingly paradoxical situation exists in which the administration of oxygen may place tissues at increased risk of hypoxic stress. Nevertheless, with various degrees of effectiveness, and not without consequences, supplemental oxygen is used clinically in an attempt to correct tissue hypoxia (e.g., brain ischemia, traumatic brain injury, carbon monoxide poisoning, etc.) and chronic hypoxemia (e.g., severe COPD, etc.) and to help with wound healing, necrosis, or reperfusion injuries (e.g., compromised grafts). Hyperoxia has also been used liberally by athletes in a belief that it offers performance-enhancing benefits; such benefits also extend to hypoxemic patients both at rest and during rehabilitation. This review aims to provide a comprehensive overview of the effects of hyperoxia in humans from the "bench to bedside." The first section will focus on the basic physiological principles of partial pressure of arterial O2, [Formula: see text], and barometric pressure and how these changes lead to variation in regional O2 delivery. This review provides an overview of the evidence for and against the use of hyperoxia as an aid to enhance physical performance. The final section addresses pathophysiological concepts, clinical studies, and implications for therapy. The potential of O2 toxicity and future research directions are also considered.
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Affiliation(s)
| | - Geoff B Coombs
- Centre for Heart, Lung, and Vascular Health, University of British Columbia , Kelowna, British Columbia , Canada
| | - Otto F Barak
- Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia.,Faculty of Sport and Physical Education, University of Novi Sad, Novi Sad, Serbia
| | - Zeljko Dujic
- Department of Integrative Physiology, School of Medicine, University of Split , Split , Croatia
| | - Mypinder S Sekhon
- Centre for Heart, Lung, and Vascular Health, University of British Columbia , Kelowna, British Columbia , Canada.,Division of Critical Care Medicine, Department of Medicine, Vancouver General Hospital, University of British Columbia , Vancouver, British Columbia , Canada
| | - Philip N Ainslie
- Centre for Heart, Lung, and Vascular Health, University of British Columbia , Kelowna, British Columbia , Canada
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Smale BA, Northey JM, Smee DJ, Versey NG, Rattray B. Compression garments and cerebral blood flow: Influence on cognitive and exercise performance. Eur J Sport Sci 2017; 18:315-322. [PMID: 29239696 DOI: 10.1080/17461391.2017.1413139] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This study aimed to describe the effect of compression garments on middle cerebral artery blood flow velocity (MCAv) in relation to cognitive and exercise performance whilst cycling. In a randomised-controlled-cross-over design, 15 well-trained male cyclists were recruited to participate in three identical trials wearing loose fitting shorts (control), low-grade, or medium-grade compression garments. The protocol involved four 8 min increments of cycling at 30%, 50%, 70%, and 85% maximal power output and a 4 km time-trial. Participants undertook a cognitive Stroop task at baseline and at the midpoint of each increment. MCAv was monitored with Transcranial Doppler Ultrasonography. Mean arterial pressure (MAP) and partial pressure of end-tidal CO2 (PetCO2) were measured throughout. MCAv, MAP, PetCO2, and reaction time of the complex Stroop task were influenced by exercise intensity, but not compression garments. Compression garments significantly affected cognitive accuracy in the complex Stroop task such that low-grade compression appeared to enhance cognitive accuracy in comparison to the control condition at the highest intensity (p = .010). Time-trial performance did not differ between the control (338.0 ± 17.3 s), low-grade (338.7 ± 18.7 s), or medium-grade (342.2 ± 19.3 s) conditions (p = .114). Compression garments did not affect MCAv during exercise or time-trial performance, but compression may be beneficial for improved cognitive accuracy during high-intensity exercise. Further research is required to elucidate the potential impact on cognitive performance.
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Affiliation(s)
- Brittany A Smale
- a Discipline of Sport and Exercise Science, Faculty of Health , University of Canberra , Canberra , Australia.,b The University of Canberra Research Institute for Sport and Exercise (UCRISE) , Canberra , Australia
| | - Joseph M Northey
- a Discipline of Sport and Exercise Science, Faculty of Health , University of Canberra , Canberra , Australia.,b The University of Canberra Research Institute for Sport and Exercise (UCRISE) , Canberra , Australia
| | - Disa J Smee
- a Discipline of Sport and Exercise Science, Faculty of Health , University of Canberra , Canberra , Australia
| | - Nathan G Versey
- c Physiology , Australian Institute of Sport , Canberra , Australia
| | - Ben Rattray
- a Discipline of Sport and Exercise Science, Faculty of Health , University of Canberra , Canberra , Australia.,b The University of Canberra Research Institute for Sport and Exercise (UCRISE) , Canberra , Australia
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38
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Smith KJ, Ainslie PN. Regulation of cerebral blood flow and metabolism during exercise. Exp Physiol 2017; 102:1356-1371. [PMID: 28786150 DOI: 10.1113/ep086249] [Citation(s) in RCA: 194] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Accepted: 07/31/2017] [Indexed: 12/18/2022]
Abstract
NEW FINDINGS What is the topic of this review? The manuscript collectively combines the experimental observations from >100 publications focusing on the regulation of cerebral blood flow and metabolism during exercise from 1945 to the present day. What advances does it highlight? This article highlights the importance of traditional and historical assessments of cerebral blood flow and metabolism during exercise, as well as traditional and new insights into the complex factors involved in the integrative regulation of brain blood flow and metabolism during exercise. The overarching theme is the importance of quantifying cerebral blood flow and metabolism during exercise using techniques that consider multiple volumetric cerebral haemodynamics (i.e. velocity, diameter, shear and flow). Cerebral function in humans is crucially dependent upon continuous oxygen delivery, metabolic nutrients and active regulation of cerebral blood flow (CBF). As a consequence, cerebrovascular function is precisely titrated by multiple physiological mechanisms, characterized by complex integration, synergism and protective redundancy. At rest, adequate CBF is regulated through reflexive responses in the following order of regulatory importance: fluctuating arterial blood gases (in particularly, partial pressure of carbon dioxide), cerebral metabolism, arterial blood pressure, neurogenic activity and cardiac output. Unfortunately, the magnitude that these integrative and synergistic relationships contribute to governing the CBF during exercise remains unclear. Despite some evidence indicating that CBF regulation during exercise is dependent on the changes of blood pressure, neurogenic activity and cardiac output, their role as a primary governor of the CBF response to exercise remains controversial. In contrast, the balance between the partial pressure of carbon dioxide and cerebral metabolism continues to gain empirical support as the primary contributor to the intensity-dependent changes in CBF observed during submaximal, moderate and maximal exercise. The goal of this review is to summarize the fundamental physiology and mechanisms involved in regulation of CBF and metabolism during exercise. The clinical implications of a better understanding of CBF during exercise and new research directions are also outlined.
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Affiliation(s)
- Kurt J Smith
- Cardiovascular Research Group, School of Sports Science, Exercise and Health, University of Western Australia, Crawley, WA, Australia.,Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, BC, Canada
| | - Philip N Ainslie
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, BC, Canada
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Santos-Concejero J, Billaut F, Grobler L, Oliván J, Noakes TD, Tucker R. Brain oxygenation declines in elite Kenyan runners during a maximal interval training session. Eur J Appl Physiol 2017; 117:1017-1024. [PMID: 28321639 DOI: 10.1007/s00421-017-3590-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 03/13/2017] [Indexed: 11/29/2022]
Abstract
PURPOSE The purpose of this study was to characterise the cerebral oxygenation (Cox) response during a high-intensity interval training session in Kenyan runners, and to examine any relationship with running performance. METHODS 15 Kenyan runners completed a 5-km time trial (TT) and a Fatigue Training Test on a treadmill (repeated running bouts of 1-km at a pace 5% faster than their mean 5-km TT pace with a 30-s recovery until exhaustion). Changes in Cox were monitored via near-infrared spectroscopy through concentration changes in oxy- and deoxy-haemoglobin (Δ[O2Hb] and Δ[HHb]), tissue oxygenation index (TOI), and total hemoglobin index (nTHI). RESULTS The number of 1-km repetitions achieved by the participants was 5.5 ± 1.2 repetitions at a mean pace of 20.5 ± 0.7 km h-1. Δ[O2Hb] measured at the end of each running repetition declined progressively over the course of the trial (p = 0.01, ES = 4.59). Δ[HHb] increased during each running bout until the end of the Fatigue Training Test (p < 0.001; ES = 6.0). TOI decreased significantly from the beginning of the test (p = 0.013, ES = 1.83), whereas nTHI remained stable (ES = 0.08). The Cox decline in the Fatigue Training Test was negatively correlated with the speed at which the test was completed (p = 0.017; r = -0.61), suggesting that the best performers were able to defend their Cox better than those of lower running ability. CONCLUSIONS In conclusion, this study suggests that elite Kenyan runners cannot defend cerebral oxygenation when forced to exercise to their physiological limits. This emphasises the critical importance of pacing in their racing success.
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Affiliation(s)
- Jordan Santos-Concejero
- Department of Physical Education and Sport, Faculty of Physical Activity and Sport Sciences, University of the Basque Country UPV/EHU, Portal de Lasarte 71, 01007, Vitoria-Gasteiz, Spain. .,UCT/MRC Research Unit for Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Cape Town, South Africa.
| | - F Billaut
- Department of Kinesiology, University Laval, Quebec, Canada
| | - L Grobler
- Department of Sport Science, University of Stellenbosch, Stellenbosch, South Africa
| | - J Oliván
- Department of Physiology, European University of Madrid, Madrid, Spain
| | - T D Noakes
- UCT/MRC Research Unit for Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Cape Town, South Africa
| | - R Tucker
- UCT/MRC Research Unit for Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Cape Town, South Africa.,School of Medicine, University of the Free State, Bloemfontein, South Africa
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40
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Ulrich S, Hasler ED, Müller-Mottet S, Keusch S, Furian M, Latshang TD, Schneider S, Saxer S, Bloch KE. Mechanisms of Improved Exercise Performance under Hyperoxia. Respiration 2017; 93:90-98. [PMID: 28068656 DOI: 10.1159/000453620] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 11/18/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The impact of hyperoxia on exercise limitation is still incompletely understood. OBJECTIVES We investigated to which extent breathing hyperoxia enhances the exercise performance of healthy subjects and which physiologic mechanisms are involved. METHODS A total of 32 healthy volunteers (43 ± 15 years, 12 women) performed 4 bicycle exercise tests to exhaustion with ramp and constant-load protocols (at 75% of the maximal workload [Wmax] on FiO2 0.21) on separate occasions while breathing ambient (FiO2 0.21) or oxygen-enriched air (FiO2 0.50) in a random, blinded order. Workload, endurance, gas exchange, pulse oximetry (SpO2), and cerebral (CTO) and quadriceps muscle tissue oxygenation (QMTO) were measured. RESULTS During the final 15 s of ramp exercising with FiO2 0.50, Wmax (mean ± SD 270 ± 80 W), SpO2 (99 ± 1%), and CTO (67 ± 9%) were higher and the Borg CR10 Scale dyspnea score was lower (4.8 ± 2.2) than the corresponding values with FiO2 0.21 (Wmax 257 ± 76 W, SpO2 96 ± 3%, CTO 61 ± 9%, and Borg CR10 Scale dyspnea score 5.7 ± 2.6, p < 0.05, all comparisons). In constant-load exercising with FiO2 0.50, endurance was longer than with FiO2 0.21 (16 min 22 s ± 7 min 39 s vs. 10 min 47 s ± 5 min 58 s). With FiO2 0.50, SpO2 (99 ± 0%) and QMTO (69 ± 8%) were higher than the corresponding isotime values to end-exercise with FiO2 0.21 (SpO2 96 ± 4%, QMTO 66 ± 9%), while minute ventilation was lower in hyperoxia (82 ± 18 vs. 93 ± 23 L/min, p < 0.05, all comparisons). CONCLUSION In healthy subjects, hyperoxia increased maximal power output and endurance. It improved arterial, cerebral, and muscle tissue oxygenation, while minute ventilation and dyspnea perception were reduced. The findings suggest that hyperoxia enhanced cycling performance through a more efficient pulmonary gas exchange and a greater availability of oxygen to muscles and the brain (cerebral motor and sensory neurons).
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Affiliation(s)
- Silvia Ulrich
- Pulmonary Clinic, University Hospital Zurich, Zurich, Switzerland
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41
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Buzza G, Lovell GP, Askew CD, Kerhervé H, Solomon C. The Effect of Short and Long Term Endurance Training on Systemic, and Muscle and Prefrontal Cortex Tissue Oxygen Utilisation in 40 - 60 Year Old Women. PLoS One 2016; 11:e0165433. [PMID: 27832088 PMCID: PMC5104477 DOI: 10.1371/journal.pone.0165433] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 10/11/2016] [Indexed: 01/02/2023] Open
Abstract
Purpose Aerobic endurance training (ET) increases systemic and peripheral oxygen utilisation over time, the adaptation pattern not being linear. However, the timing and mechanisms of changes in oxygen utilisation, associated with training beyond one year are not known. This study tested the hypothesis that in women aged 40–60 years performing the same current training load; systemic O2 utilisation (VO2) and tissue deoxyhaemoglobin (HHb) in the Vastus Lateralis (VL) and Gastrocnemius (GAST) would be higher in long term trained (LTT; > 5 yr) compared to a short term trained (STT; 6–24 months) participants during ramp incremental (RI) cycling, but similar during square-wave constant load (SWCL) cycling performed at the same relative intensity (below ventilatory turn point [VTP]); and that pre-frontal cortex (PFC) HHb would be similar between participant groups in both exercise conditions. Methods Thirteen STT and 13 LTT participants performed RI and SWCL conditions on separate days. VO2, and VL, GAST, and PFC HHb were measured simultaneously. Results VO2peak was higher in LTT compared to STT, and VO2 was higher in LTT at each relative intensities of 25%, 80% and 90% of VTP in SWCL. HHb in the VL was significantly higher in LTT compared to STT at peak exercise (4.54 ± 3.82 vs 1.55 ± 2.33 μM), and at 25% (0.99 ± 1.43 vs 0.04 ± 0.96 μM), 80% (3.19 ± 2.93 vs 1.14 ± 1.82 μM) and 90% (4.62 ± 3.12 vs 2.07 ± 2.49 μM) of VTP in SWCL. Conclusions The additional (12.9 ± 9.3) years of ET in LTT, resulted in higher VO2, and HHb in the VL at peak exercise, and sub—VTP exercise. These results indicate that in women 40–60 years old, systemic and muscle O2 utilisation continues to improve with ET beyond two years.
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Affiliation(s)
- Gavin Buzza
- School of Health and Sport Sciences, University of the Sunshine Coast, Sippy Downs, Australia
- * E-mail:
| | - Geoff P. Lovell
- School of Social Sciences, University of the Sunshine Coast, Sippy Downs, Australia
| | - Christopher D. Askew
- School of Health and Sport Sciences, University of the Sunshine Coast, Sippy Downs, Australia
| | - Hugo Kerhervé
- School of Health and Sport Sciences, University of the Sunshine Coast, Sippy Downs, Australia
| | - Colin Solomon
- School of Health and Sport Sciences, University of the Sunshine Coast, Sippy Downs, Australia
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Kriel Y, Kerhervé HA, Askew CD, Solomon C. The Effect of Active versus Passive Recovery Periods during High Intensity Intermittent Exercise on Local Tissue Oxygenation in 18 - 30 Year Old Sedentary Men. PLoS One 2016; 11:e0163733. [PMID: 27677081 PMCID: PMC5038964 DOI: 10.1371/journal.pone.0163733] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 09/13/2016] [Indexed: 12/29/2022] Open
Abstract
PURPOSE High intensity interval training (HIIT) has been proposed as a time-efficient format of exercise to reduce the chronic disease burden associated with sedentary behaviour. Changes in oxygen utilisation at the local tissue level during an acute session of HIIT could be the primary stimulus for the health benefits associated with this format of exercise. The recovery periods of HIIT effect the physiological responses that occur during the session. It was hypothesised that in sedentary individuals, local and systemic oxygen utilisation would be higher during HIIT interspersed with active recovery periods, when compared to passive recovery periods. METHODS Twelve sedentary males (mean ± SD; age 23 ± 3 yr) completed three conditions on a cycle ergometer: 1) HIIT with passive recovery periods between four bouts (HIITPASS) 2) HIIT with active recovery periods between four bouts (HIITACT) 3) HIITACT with four HIIT bouts replaced with passive periods (REC). Deoxygenated haemoglobin (HHb) in the vastus lateralis (VL) and gastrocnemius (GN) muscles and the pre-frontal cortex (FH), oxygen consumption (VO2), power output and heart rate (HR) were measured continuously during the three conditions. RESULTS There was a significant increase in HHb at VL during bouts 2 (p = 0.017), 3 (p = 0.035) and 4 (p = 0.035) in HIITACT, compared to HIITPASS. Mean power output was significantly lower in HIITACT, compared to HIITPASS (p < 0.001). There was a significant main effect for site in both HIITPASS (p = 0.029) and HIITACT (p = 0.005). There were no significant differences in VO2 and HR between HIITPASS and HIITACT. CONCLUSIONS The increase in HHb at VL and the lower mean power output during HIITACT could indicate that a higher level of deoxygenation contributes to decreased mechanical power in sedentary participants. The significant differences in HHb between sites indicates the specificity of oxygen utilisation.
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Affiliation(s)
- Yuri Kriel
- School of Health and Sports Sciences, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | - Hugo A. Kerhervé
- School of Health and Sports Sciences, University of the Sunshine Coast, Sippy Downs, QLD, Australia
- Laboratoire Interuniversitaire de Biologie de la Motricité, Université Savoie Mont Blanc, Le Bourget du Lac, France
| | - Christopher D. Askew
- School of Health and Sports Sciences, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | - Colin Solomon
- School of Health and Sports Sciences, University of the Sunshine Coast, Sippy Downs, QLD, Australia
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Boone J, Vandekerckhove K, Coomans I, Prieur F, Bourgois JG. An integrated view on the oxygenation responses to incremental exercise at the brain, the locomotor and respiratory muscles. Eur J Appl Physiol 2016; 116:2085-2102. [PMID: 27613650 DOI: 10.1007/s00421-016-3468-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 08/31/2016] [Indexed: 12/26/2022]
Abstract
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. These breakpoints were located in a narrow intensity range between 75 and 90 % of the maximal [Formula: see text] and were closely related to traditionally determined thresholds in pulmonary gas exchange (respiratory compensation point), blood lactate measurements (maximal lactate steady state), and critical power. Therefore, it has been assumed that these breakpoints in the oxygenation patterns at different sites in the body might be equivalent and could, therefore, be used interchangeably. In the present review the typical oxygenation responses (at locomotor and respiratory muscle level, and cerebral level) are described and a possible framework is provided showing the physiological events that might link the breakpoints at different body sites with the thresholds determined from pulmonary gas exchange and blood lactate measurements. However, despite a possible physiological association, several arguments prevent the current practical application of these breakpoints measured at a single site as markers of exercise intensity making it highly questionable whether measurements of the oxygenation response at one single site can be used as a reflection of whole-body responses to different exercise intensities.
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Affiliation(s)
- Jan Boone
- Department of Movement and Sport Sciences, Ghent University, Watersportlaan 2, 9000, Ghent, Belgium.
- Center of Sports Medicine, Ghent University Hospital, Ghent, Belgium.
| | | | - Ilse Coomans
- Department of Pediatric Cardiology, Ghent University Hospital, Ghent, Belgium
| | - Fabrice Prieur
- CIAMS, Univ Paris-Sud, Université Paris Saclay, 91405, Orsay Cedex, France
- CIAMS Université d'Orléans, 45067, Orléans, France
| | - Jan G Bourgois
- Department of Movement and Sport Sciences, Ghent University, Watersportlaan 2, 9000, Ghent, Belgium
- Center of Sports Medicine, Ghent University Hospital, Ghent, Belgium
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Lefferts WK, Babcock MC, Tiss MJ, Ives SJ, White CN, Brutsaert TD, Heffernan KS. Effect of hypoxia on cerebrovascular and cognitive function during moderate intensity exercise. Physiol Behav 2016; 165:108-18. [PMID: 27402021 DOI: 10.1016/j.physbeh.2016.07.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 07/03/2016] [Accepted: 07/07/2016] [Indexed: 12/25/2022]
Abstract
Exercise in hypoxia places added demands on the brain and cerebrovasculature that can impact cognitive function. The purpose of this study was to investigate the effect of acute hypoxia on cerebrovascular hemodynamics, markers of neuro-steroidal modulation and brain-blood barrier (BBB) integrity, and cognition during exercise. Thirty healthy participants (21±4yrs., BMI 24.0±2.6kg∙m(-2); 15 men) were randomized to both a≈2.5h normoxic (FiO2 20.0%) and hypoxic (FiO2 12.5%) condition on two separate days. After 1.25h, participants underwent 10min of exercise-alone (cycling at 55% HRmax) and 15min of exercise+cognitive testing. Prefrontal cortex (PFC) tissue oxygenation and middle cerebral artery (MCA) mean blood velocity (MnV) were measured using near-infrared spectroscopy and transcranial Doppler respectively at rest, during exercise-alone, and during exercise+cognitive testing. Salivary levels of dehydroepiandosterone [DHEA], DHEA-sulfate [DHEAS]) and neuron specific enolase (NSE) were measured pre and post exercise. Cognition was assessed using standard metrics of accuracy and reaction time (RT), and advanced metrics from drift-diffusion modeling across memory recognition, N-Back and Flanker tasks. MCA MnV increased from rest to exercise (p<0.01) and was unchanged with addition of cognitive testing during exercise in both normoxia and hypoxia. PFC oxygenation increased during exercise (p<0.05) and was further increased with addition of cognitive challenge in normoxia but decreased during exercise in hypoxia (p<0.05) with further reductions occurring with addition of cognitive tasks (p<0.05). DHEA and NSE increased and decreased post-exercise, respectively, in both normoxia and hypoxia (p<0.01). Accuracy on cognitive tasks was similar in normoxia compared to hypoxia, while RT was slower in hypoxia vs normoxia across memory recognition (p<0.01) and Flanker tasks (p=0.04). Drift-diffusion modeling suggested changes in memory RT were due to increases in caution (p<0.01). Overall cognitive performance is maintained during exercise in hypoxia concomitant with slower RT in select cognitive tasks and reduced oxygenation in the PFC. These changes were accompanied by slight increases in neuro-steroidal modulation but appear independent of changes in NSE, a biomarker of BBB integrity. Maintained accuracy and select increases in RT during hypoxic exercise may be related behavioral changes in caution.
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Pires FO, Dos Anjos CAS, Covolan RJM, Pinheiro FA, St Clair Gibson A, Noakes TD, Magalhães FH, Ugrinowitsch C. Cerebral Regulation in Different Maximal Aerobic Exercise Modes. Front Physiol 2016; 7:253. [PMID: 27458381 PMCID: PMC4932816 DOI: 10.3389/fphys.2016.00253] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 06/10/2016] [Indexed: 11/23/2022] Open
Abstract
We investigated cerebral responses, simultaneously with peripheral and ratings of perceived exertion (RPE) responses, during different VO2MAX-matched aerobic exercise modes. Nine cyclists (VO2MAX of 57.5 ± 6.2 ml·kg−1·min−1) performed a maximal, controlled-pace incremental test (MIT) and a self-paced 4 km time trial (TT4km). Measures of cerebral (COX) and muscular (MOX) oxygenation were assessed throughout the exercises by changes in oxy- (O2Hb) and deoxy-hemoglobin (HHb) concentrations over the prefrontal cortex (PFC) and vastus lateralis (VL) muscle, respectively. Primary motor cortex (PMC) electroencephalography (EEG), VL, and rectus femoris EMG were also assessed throughout the trials, together with power output and cardiopulmonary responses. The RPE was obtained at regular intervals. Similar motor output (EMG and power output) occurred from 70% of the duration in MIT and TT4km, despite the greater motor output, muscle deoxygenation (↓ MOX) and cardiopulmonary responses in TT4km before that point. Regarding cerebral responses, there was a lower COX (↓ O2Hb concentrations in PFC) at 20, 30, 40, 50 and 60%, but greater at 100% of the TT4km duration when compared to MIT. The alpha wave EEG in PMC remained constant throughout the exercise modes, with greater values in TT4km. The RPE was maximal at the endpoint in both exercises, but it increased slower in TT4km than in MIT. Results showed that similar motor output and effort tolerance were attained at the closing stages of different VO2MAX-matched aerobic exercises, although the different disturbance until that point. Regardless of different COX responses during most of the exercises duration, activation in PMC was preserved throughout the exercises, suggesting that these responses may be part of a centrally-coordinated exercise regulation.
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Affiliation(s)
- Flávio O Pires
- Exercise Psychophysiology Research Group, School of Arts, Sciences, and Humanities, University of São PauloSão Paulo, Brazil; Department of Sport, School of Physical Education and Sport, University of São PauloSão Paulo, Brazil
| | - Carlos A S Dos Anjos
- Neurophysics Group, Gleb Wataghin Physics Institute, University of Campinas Campinas, Brazil
| | - Roberto J M Covolan
- Neurophysics Group, Gleb Wataghin Physics Institute, University of Campinas Campinas, Brazil
| | - Fabiano A Pinheiro
- Exercise Psychophysiology Research Group, School of Arts, Sciences, and Humanities, University of São PauloSão Paulo, Brazil; Department of Sport, School of Physical Education and Sport, University of São PauloSão Paulo, Brazil
| | | | - Timothy D Noakes
- Department of Human Biology, Sports Science Institute of South Africa, University of Cape Town Cape Town, South Africa
| | - Fernando H Magalhães
- Exercise Psychophysiology Research Group, School of Arts, Sciences, and Humanities, University of São Paulo São Paulo, Brazil
| | - Carlos Ugrinowitsch
- Department of Sport, School of Physical Education and Sport, University of São Paulo São Paulo, Brazil
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Keramidas ME, Kölegård R, Mekjavic IB, Eiken O. PlanHab: hypoxia exaggerates the bed-rest-induced reduction in peak oxygen uptake during upright cycle ergometry. Am J Physiol Heart Circ Physiol 2016; 311:H453-64. [PMID: 27342877 DOI: 10.1152/ajpheart.00304.2016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 06/20/2016] [Indexed: 11/22/2022]
Abstract
The study examined the effects of hypoxia and horizontal bed rest, separately and in combination, on peak oxygen uptake (V̇o2 peak) during upright cycle ergometry. Ten male lowlanders underwent three 21-day confinement periods in a counterbalanced order: 1) normoxic bed rest [NBR; partial pressure of inspired O2 (PiO2 ) = 133.1 ± 0.3 mmHg]; 2) hypoxic bed rest (HBR; PiO2 = 90.0 ± 0.4 mmHg), and 3) hypoxic ambulation (HAMB; PiO2 = 90.0 ± 0.4 mmHg). Before and after each confinement, subjects performed two incremental-load trials to exhaustion, while inspiring either room air (AIR), or a hypoxic gas (HYPO; PiO2 = 90.0 ± 0.4 mmHg). Changes in regional oxygenation of the vastus lateralis muscle and the frontal cerebral cortex were monitored with near-infrared spectroscopy. Cardiac output (CO) was recorded using a bioimpedance method. The AIR V̇o2 peak was decreased by both HBR (∼13.5%; P ≤ 0.001) and NBR (∼8.6%; P ≤ 0.001), with greater drop after HBR (P = 0.01). The HYPO V̇o2 peak was also reduced by HBR (-9.7%; P ≤ 0.001) and NBR (-6.1%; P ≤ 0.001). Peak CO was lower after both bed-rest interventions, and especially after HBR (HBR: ∼13%, NBR: ∼7%; P ≤ 0.05). Exercise-induced alterations in muscle and cerebral oxygenation were blunted in a similar manner after both bed-rest confinements. No changes were observed in HAMB. Hence, the bed-rest-induced decrease in V̇o2 peak was exaggerated by hypoxia, most likely due to a reduction in convective O2 transport, as indicated by the lower peak values of CO.
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Affiliation(s)
- Michail E Keramidas
- Department of Environmental Physiology, Swedish Aerospace Physiology Center, School of Technology and Health, Royal Institute of Technology, Stockholm, Sweden;
| | - Roger Kölegård
- Department of Environmental Physiology, Swedish Aerospace Physiology Center, School of Technology and Health, Royal Institute of Technology, Stockholm, Sweden
| | - Igor B Mekjavic
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia; and Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Ola Eiken
- Department of Environmental Physiology, Swedish Aerospace Physiology Center, School of Technology and Health, Royal Institute of Technology, Stockholm, Sweden
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Fan JL, Kayser B. Fatigue and Exhaustion in Hypoxia: The Role of Cerebral Oxygenation. High Alt Med Biol 2016; 17:72-84. [DOI: 10.1089/ham.2016.0034] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Affiliation(s)
- Jui-Lin Fan
- Centre for Translational Physiology, University of Otago, Wellington, New Zealand
- Department of Surgery & Anaesthesia, University of Otago, Wellington, New Zealand
| | - Bengt Kayser
- Institute of Sports Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
- Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
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Tellez HF, Morrison SA, Neyt X, Mairesse O, Piacentini MF, Macdonald-Nethercott E, Pangerc A, Dolenc-Groselj L, Eiken O, Pattyn N, Mekjavic IB, Meeusen R. Exercise during Short-Term and Long-Term Continuous Exposure to Hypoxia Exacerbates Sleep-Related Periodic Breathing. Sleep 2016; 39:773-83. [PMID: 26951389 PMCID: PMC4791611 DOI: 10.5665/sleep.5626] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 11/21/2015] [Indexed: 12/21/2022] Open
Abstract
STUDY OBJECTIVES Exposure to hypoxia elevates chemosensitivity, which can lead to periodic breathing. Exercise impacts gas exchange, altering chemosensitivity; however, interactions between sleep, exercise and chronic hypoxic exposure have not been examined. This study investigated whether exercise exacerbates sleep-related periodic breathing in hypoxia. METHODS Two experimental phases. Short-Term Phase: a laboratory controlled, group-design study in which 16 active, healthy men (age: 25 ± 3 y, height: 1.79 ± 0.06 m, mass: 74 ± 8 kg) were confined to a normobaric hypoxic environment (FIO2 = 0.139 ± 0.003, 4,000 m) for 10 days, after random assignment to a sedentary (control, CON) or cycle-exercise group (EX). Long-Term Phase: conducted at the Concordia Antarctic Research Station (3,800 m equivalent at the Equator) where 14 men (age: 36 ± 9 y, height: 1.77 ± 0.09 m, mass: 75 ± 10 kg) lived for 12-14 months, continuously confined. Participants were stratified post hoc based on self-reported physical activity levels. We quantified apnea-hypopnea index (AHI) and physical activity variables. RESULTS Short-Term Phase: mean AHI scores were significantly elevated in the EX group compared to CON (Night1 = CON: 39 ± 51, EX: 91 ± 59; Night10 = CON: 32 ± 32, EX: 92 ± 48; P = 0.046). Long-Term Phase: AHI was correlated to mean exercise time (R(2) = 0.4857; P = 0.008) and the coefficient of variation in night oxyhemoglobin saturation (SpO2; R(2) = 0.3062; P = 0.049). CONCLUSIONS Data indicate that exercise (physical activity) per se affects night SpO2 concentrations and AHI after a minimum of two bouts of moderate-intensity hypoxic exercise, while habitual physical activity in hypobaric hypoxic confinement affects breathing during sleep, up to 13+ months' duration.
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Affiliation(s)
- Helio Fernandez Tellez
- Vrije Universiteit Brussels, Human Physiology & Sports Medicine Department, Brussels, Belgium
- Royal Military Academy of Brussels, VIPER Research Unit, Brussels, Belgium
| | - Shawnda A. Morrison
- Department of Automation, Biocybernetics, and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
- Institute of Clinical Neurophysiology, University Clinical Centre, Ljubljana, Slovenia
| | - Xavier Neyt
- Royal Military Academy of Brussels, VIPER Research Unit, Brussels, Belgium
- Royal Military Academy Brussels, CISS, Brussels, Belgium
| | - Olivier Mairesse
- Vrije Universiteit Brussels, Human Physiology & Sports Medicine Department, Brussels, Belgium
- Sleep Laboratory & Unit for Chronobiology-Brugmann University Hospital Free University of Brussels (U.L.B./V.U.B), Brussels, Belgium
| | - Maria Francesca Piacentini
- Vrije Universiteit Brussels, Human Physiology & Sports Medicine Department, Brussels, Belgium
- Department of Movement, Human and Health Sciences, University of Rome Foro Italico, Rome, Italy
| | - Eoin Macdonald-Nethercott
- JF Intensive Care Unit, Addenbrooke's Hospital, Cambridge, United Kingdom
- Institut polaire français Paul-Emile Victor, Technopôle Brest-Iroise, Plouzané, France
| | - Andrej Pangerc
- Institute of Clinical Neurophysiology, University Clinical Centre, Ljubljana, Slovenia
| | - Leja Dolenc-Groselj
- Institute of Clinical Neurophysiology, University Clinical Centre, Ljubljana, Slovenia
| | - Ola Eiken
- Department of Environmental Physiology, Swedish Aerospace Physiology Centre, Royal Institute of Technology, Stockholm, Sweden
| | - Nathalie Pattyn
- Vrije Universiteit Brussels, Human Physiology & Sports Medicine Department, Brussels, Belgium
- Royal Military Academy of Brussels, VIPER Research Unit, Brussels, Belgium
- Experimental and Applied Psychology Department, Brussels, Belgium
| | - Igor B. Mekjavic
- Department of Automation, Biocybernetics, and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Romain Meeusen
- Vrije Universiteit Brussels, Human Physiology & Sports Medicine Department, Brussels, Belgium
- School of Public Health, Tropical Medicine and Health Sciences, James Cook University, Townsville City, Queensland, Australia
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49
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Exercise Intolerance in Heart Failure: Did We Forget the Brain? Can J Cardiol 2016; 32:475-84. [DOI: 10.1016/j.cjca.2015.12.021] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 12/21/2015] [Accepted: 12/21/2015] [Indexed: 01/15/2023] Open
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50
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Kume D, Akahoshi S, Yamagata T, Wakimoto T, Nagao N. Does voluntary hypoventilation during exercise impact EMG activity? SPRINGERPLUS 2016; 5:149. [PMID: 27026846 PMCID: PMC4766162 DOI: 10.1186/s40064-016-1845-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 02/15/2016] [Indexed: 11/17/2022]
Abstract
It has been reported that exercise under hypoxic conditions induces reduced muscle oxygenation, which could be related to enhanced activity on electromyography (EMG). Although it has been demonstrated that exercise under conditions of voluntary hypoventilation (VH) evokes muscle deoxygenation, it is unclear whether VH during exercise impacts EMG. Seven men performed bicycle exercise for 5 min at 65 % of peak oxygen uptake with normal breathing (NB) and VH. Muscle oxygenation; concentration changes in oxyhemoglobin (Oxy-Hb), deoxyhemoglobin (Deoxy-Hb) and total hemoglobin (Total-Hb); and surface EMG in the vastus lateralis muscle were simultaneously measured. In the VH condition, Oxy-Hb was significantly lower and Deoxy-Hb was significantly higher compared to those in the NB condition (P < 0.05 for both), whereas there was no significant difference in Total-Hb between the two conditions. We observed significantly higher values (P < 0.05) on integrated EMG during exercise under VH conditions compared to those under NB conditions. This study suggests that VH during exercise augments EMG activity.
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Affiliation(s)
- Daisuke Kume
- Department of Integrated Arts and Science, National Institute of Technology, Okinawa College, 905, Henoko, Nago, Okinawa 905-2192 Japan
| | - Shogo Akahoshi
- Department of Health and Sports Science, Kawasaki University of Medical Welfare, 288, Matsushima, Kurashiki, Okayama 701-0193 Japan
| | - Takashi Yamagata
- Department of Clothing, Japan Women's University, 2-8-1, Mejirodai, Bunkyoku, Tokyo 112-8681 Japan
| | - Toshihiro Wakimoto
- Department of Health and Sports Science, Kawasaki University of Medical Welfare, 288, Matsushima, Kurashiki, Okayama 701-0193 Japan
| | - Noriki Nagao
- Department of Nursing, Hyogo University, 2301, Hiraokachoshinzaike, Kakogawa, Hyogo 675-0195 Japan
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