1
|
Xie J, Xie S, Zhong Z, Dong H, Huang P, Zhou S, Tian H, Zhang J, Wu Y, Li P. Hypoxic preacclimatization combining intermittent hypoxia exposure with physical exercise significantly promotes the tolerance to acute hypoxia. Front Physiol 2024; 15:1367642. [PMID: 38633296 PMCID: PMC11021865 DOI: 10.3389/fphys.2024.1367642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 03/19/2024] [Indexed: 04/19/2024] Open
Abstract
Background: Both hypoxia exposure and physical exercise before ascending have been proved to promote high altitude acclimatization, whether the combination of these two methods can bring about a better effect remains uncertain. Therefore, we designed this study to evaluate the effect of hypoxic preacclimatization combining intermittent hypoxia exposure (IHE) and physical exercise on the tolerance to acute hypoxia and screen the optimal preacclimatization scheme among the lowlanders. Methods: A total of 120 Han Chinese young men were enrolled and randomly assigned into four groups, including the control group and three experimental groups with hypoxic preacclimatization of 5-day rest, 5-day exercise, and 3-day exercise in a hypobaric chamber, respectively. Main physical parameters for hypoxia acclimatization, AMS incidence, physical and mental capacity were measured for each participant in the hypobaric chamber simulated to the altitude of 4500 m in the effect evaluation stage. The effect was compared between different schemes. Results: During the effect evaluation stage, SpO2 of the 5-day rest group and 5-day exercise group was significantly higher than that of the control group (p = 0.001 and p = 0.006, respectively). The participants with 5-day rest had significantly lower HR than the controls (p = 0.018). No significant differences of AMS incidence were found among the four groups, while the proportion of AMS headache symptom (moderate and severe vs. mild) was significantly lower in the 3-day exercise group than that in the control group (p = 0.002). The 5-day exercise group had significantly higher VO2max, than the other three groups (p = 0.033, p < 0.001, and p = 0.023, respectively). The 5-day exercise group also had significantly higher digital symbol and pursuit aiming test scores, while shorter color selection reaction time than the control group (p = 0.005, p = 0.005, and p = 0.004, respectively). Conclusion: Hypoxic preacclimatization combining IHE with physical exercise appears to be efficient in promoting the tolerance to acute hypoxia. Hypoxia duration and physical exercise of moderate intensity are helpful for improvement of SpO2 and HR, relief of AMS headache symptoms, and enhancement of mental and physical operation capacity.
Collapse
Affiliation(s)
- Jiaxin Xie
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Shenwei Xie
- Department of Health Management, The 953rd Hospital of PLA, Shigatse, China
| | - Zhifeng Zhong
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Huaping Dong
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Pei Huang
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Simin Zhou
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Huaijun Tian
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Jijian Zhang
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Yu Wu
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| | - Peng Li
- Department of High Altitude Operational Medicine, College of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, China
| |
Collapse
|
2
|
Richalet JP, Hermand E, Lhuissier FJ. Cardiovascular physiology and pathophysiology at high altitude. Nat Rev Cardiol 2024; 21:75-88. [PMID: 37783743 DOI: 10.1038/s41569-023-00924-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/16/2023] [Indexed: 10/04/2023]
Abstract
Oxygen is vital for cellular metabolism; therefore, the hypoxic conditions encountered at high altitude affect all physiological functions. Acute hypoxia activates the adrenergic system and induces tachycardia, whereas hypoxic pulmonary vasoconstriction increases pulmonary artery pressure. After a few days of exposure to low oxygen concentrations, the autonomic nervous system adapts and tachycardia decreases, thereby protecting the myocardium against high energy consumption. Permanent exposure to high altitude induces erythropoiesis, which if excessive can be deleterious and lead to chronic mountain sickness, often associated with pulmonary hypertension and heart failure. Genetic factors might account for the variable prevalence of chronic mountain sickness, depending on the population and geographical region. Cardiovascular adaptations to hypoxia provide a remarkable model of the regulation of oxygen availability at the cellular and systemic levels. Rapid exposure to high altitude can have adverse effects in patients with cardiovascular diseases. However, intermittent, moderate hypoxia might be useful in the management of some cardiovascular disorders, such as coronary heart disease and heart failure. The aim of this Review is to help physicians to understand the cardiovascular responses to hypoxia and to outline some recommendations that they can give to patients with cardiovascular disease who wish to travel to high-altitude destinations.
Collapse
Affiliation(s)
- Jean-Paul Richalet
- Hypoxie et Poumon, Université Sorbonne Paris Nord, INSERM U1272, Paris, France.
| | - Eric Hermand
- Unité de Recherche Pluridisciplinaire Sport Santé Société, ULR 7369-URePSSS, Université Littoral Côte d'Opale, Université Artois, Université Lille, CHU Lille, Dunkirk, France
| | | |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Effects of Acute Moderate Hypoxia versus Normoxia on Metabolic and Cardiac Function and Skeletal Muscle Oxygenation during Endurance Exercise at the Same Heart Rate Level. Metabolites 2022; 12:metabo12100975. [PMID: 36295877 PMCID: PMC9609186 DOI: 10.3390/metabo12100975] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 10/11/2022] [Accepted: 10/13/2022] [Indexed: 01/24/2023] Open
Abstract
This study aimed to investigate the effects of acute moderate hypoxia (HYP), compared with those of normoxia (NORM), during endurance exercise with the same HR level on metabolic function, skeletal muscle oxygenation, and cardiac function. Twelve healthy men (aged 25.1 ± 2.3 years) completed 30 min of endurance exercise using a cycle ergometer with the same HR level (136.5 ± 1.5 bpm) corresponding to 70% maximal heart rate (HRmax) under NORM (760 mmHg) and HYP (526 mmHg, simulated 3000 m altitude) after a 30 min exposure in the respective environments on different days, in random order. Exercise load, rating of perceived exertion (RPE), metabolic function (saturation of percutaneous oxygen; SpO2, minute ventilation; oxygen uptake; VO2, carbon dioxide excretion; respiratory exchange ratio; RER, and oxygen pulse), skeletal muscle oxygen profiles (oxyhemoglobin, oxhb, deoxyhemoglobin, dxhb, total hemoglobin, and tissue oxygenation index; StO2), and cardiac function (heart rate, stroke volume, cardiac output, end-diastolic volume, end-systolic volume, and ejection fraction) were measured during endurance exercise. HYP showed a lower exercise load with the same RPE during exercise than did NORM. In addition, HYP showed a lower SpO2, VO2, oxygen pulse, oxhb, and StO2, and a higher RER and dxhb during exercise than NORM. We found that HYP showed lower exercise load and VO2 at the same RPE than NORM and also confirmed a higher anaerobic metabolism and oxygen inflow into skeletal muscle tissue due to the limitation of oxygen delivery capacity.
Collapse
|
5
|
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] [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.
Collapse
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
- *Correspondence: Erich Hohenauer,
| | - 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
| |
Collapse
|
6
|
Herberg U, Knies R, Müller N, Breuer J. Altitude exposure in pediatric pulmonary hypertension-are we ready for (flight) recommendations? Cardiovasc Diagn Ther 2021; 11:1122-1136. [PMID: 34527538 DOI: 10.21037/cdt-20-494] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 08/27/2020] [Indexed: 11/06/2022]
Abstract
Patients with congenital heart disease are surviving further into adulthood and want to participate in multiple activities. This includes exposure to high altitude by air travel or recreational activities, such as hiking and skiing. However, at an altitude of about 2,500 m, the barometric environmental pressure is reduced and the partial pressure of inspired oxygen drops from 21% to 15% (hypobaric hypoxia). In physiologic response to high-altitude-related hypoxia, pulmonary vasoconstriction is induced within minutes of exposure followed by compensatory hyperventilation and increased cardiac output. Even in healthy children and adults, desaturation can be profound and lead to a significant rise in pulmonary pressure and resistance. Individuals with already increased pulmonary pressure may be placed at risk during high-altitude exposure, as compensatory mechanisms may be limited. Little is known about the physiological response and risk of developing clinically relevant events on altitude exposure in pediatric pulmonary hypertension (PAH). Current guidelines are, in the absence of clinical studies, mainly based on expert opinion. Today, healthcare professionals are increasingly faced with the question, how best to assess and advise on the safety of individuals with PAH planning air travel or an excursion to mountain areas. To fill the gap, this article summarises the current clinical knowledge on moderate to high altitude exposure in patients with different forms of pediatric PAH.
Collapse
Affiliation(s)
- Ulrike Herberg
- Department of Pediatric Cardiology, University Hospital Bonn, Bonn, Germany
| | - Ralf Knies
- Department of Pediatric Cardiology, University Hospital Bonn, Bonn, Germany
| | - Nicole Müller
- Department of Pediatric Cardiology, University Hospital Bonn, Bonn, Germany
| | - Johannes Breuer
- Department of Pediatric Cardiology, University Hospital Bonn, Bonn, Germany
| |
Collapse
|
7
|
Forrer A, Scheiwiller PM, Mademilov M, Lichtblau M, Sheraliev U, Marazhapov NH, Saxer S, Bader P, Appenzeller P, Aydaralieva S, Muratbekova A, Sooronbaev TM, Ulrich S, Bloch KE, Furian M. Exercise Performance in Central Asian Highlanders: A Cross-Sectional Study. High Alt Med Biol 2021; 22:386-394. [PMID: 34432548 DOI: 10.1089/ham.2020.0211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Forrer, Aglaia, Philipp M. Scheiwiller, Maamed Mademilov, Mona Lichtblau, Ulan Sheraliev, Nuriddin H. Marazhapov, Stéphanie Saxer, Patrick Bader, Paula Appenzeller, Shoira Aydaralieva, Aybermet Muratbekova, Talant M. Sooronbaev, Silvia Ulrich, Konrad E. Bloch, and Michael Furian. Exercise performance in central Asian highlanders: A cross-sectional study. High Alt Med Biol. 00:000-000, 2021. Introduction: Life-long exposure to hypobaric hypoxia induces physiologic adaptations in highlanders that may modify exercise performance; however, reference data for altitude populations are scant. Methods: Life-long residents of the Tien Shan mountain range, 2,500 - 3,500 m, Kyrgyzstan, free of cardiopulmonary disease, underwent cardiopulmonary cycle exercise tests with a progressive ramp protocol to exhaustion at 3,250 m. ECG, breath-by-breath pulmonary gas exchange, and oxygen saturation by pulse oximetry (SpO2) were measured. Results: Among 81 highlanders, age (mean ± SD) 48 ± 10 years, 46% women, SpO2 at rest was 88% ± 2%, peak oxygen uptake (V'O2peak) was 21.6 ± 5.9 mL/kg/min (76% ± 15% predicted for a low-altitude reference population); peak work rate (Wpeak) was 117 ± 37 W (77% ± 17% predicted), SpO2 at peak was 84% ± 5%, heart rate reserve (220 - age - maximal heart rate) was 28 ± 17/min, ventilatory reserve (maximal voluntary ventilation - maximal minute ventilation) was 68 ± 32 l/min, and respiratory exchange ratio was 1.03 ± 0.09. Peak BORG-CR10 dyspnea and leg fatigue scores were 5.1 ± 2.0 and 6.3 ± 2.1. In multivariable linear regression analyses, age and sex were robust determinants of Wpeak, V'O2peak, and metabolic equivalent (MET) at peak, whereas body mass index, resting systolic blood pressure, and mean pulmonary artery pressure were not. Conclusions: The current study shows that V'O2peak and Wpeak of highlanders studied at 3,250 m, near their altitude of residence, were reduced by about one quarter compared with mean predicted values for lowlanders. The provided prediction models for V'O2peak, Wpeak, and METs in central Asian highlanders might be valuable for comparisons with other high altitude populations.
Collapse
Affiliation(s)
- Aglaia Forrer
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland.,Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Philipp M Scheiwiller
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland.,Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Maamed Mademilov
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic.,Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Mona Lichtblau
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland.,Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Ulan Sheraliev
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic.,Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Nuriddin H Marazhapov
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic.,Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Stéphanie Saxer
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland.,Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Patrick Bader
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland.,Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Paula Appenzeller
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland.,Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Shoira Aydaralieva
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic.,Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Aybermet Muratbekova
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic.,Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Talant M Sooronbaev
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic.,Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Silvia Ulrich
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland.,Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Konrad E Bloch
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland.,Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| | - Michael Furian
- Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland.,Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland, and Bishkek, Kyrgyz Republic
| |
Collapse
|
8
|
Mallet RT, Burtscher J, Richalet JP, Millet GP, Burtscher M. Impact of High Altitude on Cardiovascular Health: Current Perspectives. Vasc Health Risk Manag 2021; 17:317-335. [PMID: 34135590 PMCID: PMC8197622 DOI: 10.2147/vhrm.s294121] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 05/12/2021] [Indexed: 12/12/2022] Open
Abstract
Globally, about 400 million people reside at terrestrial altitudes above 1500 m, and more than 100 million lowlanders visit mountainous areas above 2500 m annually. The interactions between the low barometric pressure and partial pressure of O2, climate, individual genetic, lifestyle and socio-economic factors, as well as adaptation and acclimatization processes at high elevations are extremely complex. It is challenging to decipher the effects of these myriad factors on the cardiovascular health in high altitude residents, and even more so in those ascending to high altitudes with or without preexisting diseases. This review aims to interpret epidemiological observations in high-altitude populations; present and discuss cardiovascular responses to acute and subacute high-altitude exposure in general and more specifically in people with preexisting cardiovascular diseases; the relations between cardiovascular pathologies and neurodegenerative diseases at altitude; the effects of high-altitude exercise; and the putative cardioprotective mechanisms of hypobaric hypoxia.
Collapse
Affiliation(s)
- Robert T Mallet
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Johannes Burtscher
- Department of Biomedical Sciences, University of Lausanne, Lausanne, CH-1015, Switzerland
- Institute of Sport Sciences, University of Lausanne, Lausanne, CH-1015, Switzerland
| | - Jean-Paul Richalet
- Laboratoire Hypoxie & Poumon, UMR Inserm U1272, Université Sorbonne Paris Nord 13, Bobigny Cedex, F-93017, France
| | - Gregoire P Millet
- Department of Biomedical Sciences, University of Lausanne, Lausanne, CH-1015, Switzerland
- Institute of Sport Sciences, University of Lausanne, Lausanne, CH-1015, Switzerland
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, A-6020, Austria
- Austrian Society for Alpine and High-Altitude Medicine, Mieming, Austria
| |
Collapse
|
9
|
Modelling the relationships between arterial oxygen saturation, exercise intensity and the level of aerobic performance in acute hypoxia. Eur J Appl Physiol 2021; 121:1993-2003. [PMID: 33782716 DOI: 10.1007/s00421-021-04667-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 03/16/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE The aim of this study was to establish a model to estimate the level of arterial oxygen saturation (SpO2) and help determine the appropriate hypoxic dose in humans exercising in acute hypoxia. METHODS SpO2 values were collected in seven untrained (UTS) and seven endurance-trained male subjects (ETS) who performed six cycle incremental and maximal tests at sea level and at simulated altitudes of 1000, 1500, 2500, 3500 and 4500 m. Oxygen uptake was continuously measured and maximal oxygen uptake ([Formula: see text]) was determined in each subject and at each altitude. Intensity was expressed as percentage of [Formula: see text]. RESULTS There were strong non-linear relationships between altitude and SpO2 at low, moderate and high intensity both in ETS and UTS (r = 0.97, p < 0.001). SpO2 was significantly correlated to exercise intensity at sea level and at all simulated altitudes in ETS but only from 2500 m in UTS. There were inverse correlations between SpO2 and sea-level [Formula: see text] at all altitudes, which were stronger from 2500 m and with the increase in exercise intensity. The three-variable model we established predicts (p < 0.001) the SpO2 level of individuals exercising in acute hypoxia based on their sea-level [Formula: see text], the intensity of exercise and the altitude level. CONCLUSION The model demonstrates that the drop of SpO2 during exercise in acute hypoxia is larger with the increase in both sea-level [Formula: see text] and exercise intensity. The model also highlights that the pivotal altitude from which the fall in SpO2 is exacerbated is between 2000 and 2500 m, depending on both sea-level [Formula: see text] and exercise intensity.
Collapse
|
10
|
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.
Collapse
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
| |
Collapse
|
11
|
Ulrich S, Schneider SR, Bloch KE. Effect of hypoxia and hyperoxia on exercise performance in healthy individuals and in patients with pulmonary hypertension: a systematic review. J Appl Physiol (1985) 2017; 123:1657-1670. [PMID: 28775065 DOI: 10.1152/japplphysiol.00186.2017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Exercise performance is determined by oxygen supply to working muscles and vital organs. In healthy individuals, exercise performance is limited in the hypoxic environment at altitude, when oxygen delivery is diminished due to the reduced alveolar and arterial oxygen partial pressures. In patients with pulmonary hypertension (PH), exercise performance is already reduced near sea level due to impairments of the pulmonary circulation and gas exchange, and, presumably, these limitations are more pronounced at altitude. In studies performed near sea level in healthy subjects, as well as in patients with PH, maximal performance during progressive ramp exercise and endurance of submaximal constant-load exercise were substantially enhanced by breathing oxygen-enriched air. Both in healthy individuals and in PH patients, these improvements were mediated by a better arterial, muscular, and cerebral oxygenation, along with a reduced sympathetic excitation, as suggested by the reduced heart rate and alveolar ventilation at submaximal isoloads, and an improved pulmonary gas exchange efficiency, especially in patients with PH. In summary, in healthy individuals and in patients with PH, alterations in the inspiratory Po2 by exposure to hypobaric hypoxia or normobaric hyperoxia reduce or enhance exercise performance, respectively, by modifying oxygen delivery to the muscles and the brain, by effects on cardiovascular and respiratory control, and by alterations in pulmonary gas exchange. The understanding of these physiological mechanisms helps in counselling individuals planning altitude or air travel and prescribing oxygen therapy to patients with PH.
Collapse
Affiliation(s)
- Silvia Ulrich
- Pulmonary Division and Center for Human Integrative Physiology, University of Zurich , Zurich , Switzerland
| | - Simon R Schneider
- Pulmonary Division and Center for Human Integrative Physiology, University of Zurich , Zurich , Switzerland
| | - Konrad E Bloch
- Pulmonary Division and Center for Human Integrative Physiology, University of Zurich , Zurich , Switzerland
| |
Collapse
|
12
|
Park HY, Nam SS. Application of "living high-training low" enhances cardiac function and skeletal muscle oxygenation during submaximal exercises in athletes. J Exerc Nutrition Biochem 2017; 21:13-20. [PMID: 28712261 PMCID: PMC5508055 DOI: 10.20463/jenb.2017.0064] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 02/28/2017] [Accepted: 03/17/2017] [Indexed: 12/03/2022] Open
Abstract
PURPOSE The aim of this study was to determine the efficiency of the application of living high-training low (LHTL) on cardiac function and skeletal muscle oxygenation during submaximal exercises compared with that of living low-training low (LLTL) in athletes. METHODS Male middle- and long-distance runners (n = 20) were randomly assigned into the LLTL group (n = 10, living at 1000-m altitude and training at 700-1330-m altitude) and the LHTL group (n = 10, living at simulated 3000-m altitude and training at 700-1330-m altitude). Their cardiac function and skeletal muscle oxygenation during submaximal exercises at sea level before and after training at each environmental condition were evaluated. RESULTS There was a significant interaction only in the stroke volume (SV); however, the heart rate (HR), end-diastolic volume (EDV), and end-systolic volume (ESV) showed significant main effects within time; HR and SV significantly increased during training in the LHTL group compared with those in the LLTL group. EDV also significantly increased during training in both groups; however, the LHTL group had a higher increase than the LLTL group. ESV significantly increased during training in the LLTL group. There was no significant difference in the ejection fraction and cardiac output. The skeletal muscle oxygen profiles had no significant differences but improved in the LHTL group compared with those in the LLTL group. CONCLUSION LHTL can yield favorable effects on cardiac function by improving the HR, SV, EDV, and ESV during submaximal exercises compared with LLTL in athletes.
Collapse
Affiliation(s)
- Hun-Young Park
- Physical Activity and Performance Institute, Konkuk University, SeoulRepublic of Korea
- Department of Sports Medicine, Kyung Hee University, YonginRepublic of Korea
| | - Sang-Seok Nam
- Department of Sports Medicine, Kyung Hee University, YonginRepublic of Korea
| |
Collapse
|
13
|
Moon HW, Sunoo S, Park HY, Lee DJ, Nam SS. Effects of various acute hypoxic conditions on metabolic parameters and cardiac function during exercise and recovery. SPRINGERPLUS 2016; 5:1294. [PMID: 27547668 PMCID: PMC4977266 DOI: 10.1186/s40064-016-2952-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 07/29/2016] [Indexed: 01/08/2023]
Abstract
Purpose Evaluation of metabolic parameters and cardiac function is important to determine the decrease in aerobic exercise capacity under hypoxic conditions. However, the variations in metabolic parameters and cardiac function and the reasons for the decrease in aerobic exercise capacity under hypoxic conditions have not been clearly explained. The purpose of this study was to compare the responses between sea level and various acute normobaric hypoxic conditions on metabolic parameters and cardiac function during exercise and recovery in order to evaluate aerobic exercise capacity. Methods Ten healthy male participants (21.3 ± 3.06 y) performed submaximal bicycle exercise (116.7 ± 20.1 W and 60 rpm) at sea level (20.9 % O2) and under various normobaric hypoxic conditions (16.5 % O2, 14.5 % O2, 12.8 % O2, and 11.2 % O2) in a random order. Metabolic parameters (arterial oxygen saturation; SPO2, oxygen consumption; VO2, blood lactate level) and cardiac function (heart rate; HR, stroke volume; SV, end-systolic volume; ESV, end-diastolic volume; EDV, ejection fraction; EF, cardiac output; CO) were measured at rest, during exercise (30 min), and recovery (30 min). We compared the responses on metabolic parameters and cardiac function between the different oxygen partial pressure conditions during exercise and recovery. Results The various acute normobaric hypoxic conditions did not affect VO2 and SV during exercise and recovery. SPO2 decreased (p < .05) and blood lactate level increased (p < .05) as the oxygen partial pressure decreased. HR, EF, CO increased (p < .05) and EDV, ESV decreased (p < .05) at oxygen partial pressures of 14.5 % O2 and below compared with 20.9 and 16.5 % O2 during exercise and recovery. Conclusion A decrease in the oxygen partial pressure to 14.5 % O2 and below might be associated with significant changes in metabolic parameters and cardiac function during exercise and recovery. These changes are an acute compensation response to reduced aerobic exercise capacity by decreased oxygen delivering and utilizing capacities under hypoxic conditions.
Collapse
Affiliation(s)
- Hwang-Woon Moon
- Department of Sports and Outdoors, Eulji University, Yangji-dong, Sujeong-gu, Seongnam-si, Gyeonggi-do 461-713 Republic of Korea
| | - Sub Sunoo
- Department of Sports Medicine, Kyunghee University, 1732, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 17104 Republic of Korea
| | - Hun-Young Park
- Performance Activity and Performance Institute, Konkuk University, Hwayang-dong, Gwangjin-gu, Seoul, 143-701 Republic of Korea
| | - Dong-Jun Lee
- Department of Physical Education, MyongJi University, Yongin Campus, Nam-dong, Cheoin-gu, Yongin-si, Gyeonggi-do 449-728 Republic of Korea
| | - Sang-Seok Nam
- Department of Sports Medicine, Kyunghee University, 1732, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 17104 Republic of Korea
| |
Collapse
|
14
|
Vieira SS, Lemes B, de T C de Carvalho P, N de Lima R, S Bocalini D, A S Junior J, Arsa G, A Casarin C, L Andrade E, J Serra A. Does Stroke Volume Increase During an Incremental Exercise? A Systematic Review. Open Cardiovasc Med J 2016; 10:57-63. [PMID: 27347221 PMCID: PMC4896996 DOI: 10.2174/1874192401610010057] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Revised: 09/20/2015] [Accepted: 10/22/2015] [Indexed: 11/22/2022] Open
Abstract
INTRODUCTION Cardiac output increases during incremental-load exercise to meet metabolic skeletal muscle demand. This response requires a fast adjustment in heart rate and stroke volume. The heart rate is well known to increase linearly with exercise load; however, data for stroke volume during incremental-load exercise are unclear. Our objectives were to (a) review studies that have investigated stroke volume on incremental load exercise and (b) summarize the findings for stroke volume, primarily at maximal-exercise load. METHODS A comprehensive review of the Cochrane Library's, Embase, Medline, SportDiscus, PubMed, and Web of Sci-ence databases was carried out for the years 1985 to the present. The search was performed between February and June 2014 to find studies evaluating changes in stroke volume during incremental-load exercise. Controlled and uncontrolled trials were evaluated for a quality score. RESULTS The stroke volume data in maximal-exercise load are inconsistent. There is evidence to hypothesis that stroke volume increases during maximal-exercise load, but other lines of evidence indicate that stroke volume reaches a plateau under these circumstances, or even decreases. CONCLUSION The stroke volume are unclear, include contradictory evidence. Additional studies with standardized reporting for subjects (e.g., age, gender, physical fitness, and body position), exercise test protocols, and left ventricular function are required to clarify the characteristics of stroke volume during incremental maximal-exercise load.
Collapse
Affiliation(s)
- Stella S Vieira
- Universidade Federal de São Paulo, Laboratório de Fisiologia e Fisiopatologia Cardíaca, São Paulo, SP, Brazil
| | - Brunno Lemes
- Universidade Federal de São Paulo, Laboratório de Fisiologia e Fisiopatologia Cardíaca, São Paulo, SP, Brazil
| | - Paulo de T C de Carvalho
- Universidade Nove de Julho, Programa de Pós-Graduação em Biofotônica Aplicada a Ciências da Saúde, São Paulo, SP, Brazil
| | - Rafael N de Lima
- Universidade Nove de Julho, Programa de Pós-Graduação em Biofotônica Aplicada a Ciências da Saúde, São Paulo, SP, Brazil
| | - Danilo S Bocalini
- Laboratorio de Fisiologia Transacional dos Programas de Pos Graduacao em Educacao Fisica e Ciências do En-velhecimento, São Paulo, SP, Brasil
| | - José A S Junior
- Universidade Nove de Julho, Programa de Pós-Graduação em Medicina, São Paulo, SP, Brazil
| | - Gisela Arsa
- Universidade Federal do Mato Grosso, Programa de Mestrado em Educação Física, Cuiabá, MT, Brazil
| | - Cezar A Casarin
- Universidade Nove de Julho, Programa de Pós-Graduação em Biofotônica Aplicada a Ciências da Saúde, São Paulo, SP, Brazil
| | - Erinaldo L Andrade
- Laboratorio de Fisiologia Transacional dos Programas de Pos Graduacao em Educacao Fisica e Ciências do En-velhecimento, São Paulo, SP, Brasil
| | - Andrey J Serra
- Universidade Nove de Julho, Programa de Pós-Graduação em Biofotônica Aplicada a Ciências da Saúde, São Paulo, SP, Brazil
| |
Collapse
|
15
|
Bian SZ, Jin J, Zhang JH, Li QN, Yu J, Yu SY, Chen JF, Yu XJ, Qin J, Huang L. Principal Component Analysis and Risk Factors for Acute Mountain Sickness upon Acute Exposure at 3700 m. PLoS One 2015; 10:e0142375. [PMID: 26554385 PMCID: PMC4640520 DOI: 10.1371/journal.pone.0142375] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 10/21/2015] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVE We aimed to describe the heterogeneity in the clinical presentation of acute mountain sickness (AMS) and to identify its primary risk factors. METHODS The participants (n = 163) received case report form questionnaires, and their heart rate (HR), oxygen saturation (SpO2), echocardiographic and transcranial Doppler variables, ability to perform mental and physical work, mood and psychological factors were assessed within 18 to 22 hours after arriving at 3700 m from sea level (500 m) by plane. First, we examined the differences in all variables between the AMS-positive and the AMS-negative groups. Second, an adjusted regression analysis was performed after correlation and principal component analyses. RESULTS The AMS patients had a higher diastolic vertebral artery velocity (Vd; p = 0.018), a higher HR (p = 0.006) and a lower SpO2. The AMS subjects also experienced poorer sleep quality, as quantified using the Athens Insomnia Scale (AIS). Moreover, the AMS population exhibited more negative mood states, including anxiety, depression, hostility, fatigue and confusion. Five principal components focused on diverse aspects were also found to be significant. Additionally, more advanced age (p = 0.007), a higher HR (p = 0.034), a higher Vd (p = 0.014), a higher AIS score (p = 0.030), a decreased pursuit aiming capacity (p = 0.035) and decreased vigor (p = 0.015) were risk factors for AMS. CONCLUSIONS Mood states play critical roles in the development of AMS. Furthermore, an elevated HR and Vd, advanced age, elevated AIS sores, insufficient vigor and decreased mental work capacity are independent risk factors for AMS.
Collapse
Affiliation(s)
- Shi-Zhu Bian
- Institute of Cardiovascular Diseases of PLA; Xinqiao Hospital, Third Military Medical University, Chongqing, China
- Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Jun Jin
- Institute of Cardiovascular Diseases of PLA; Xinqiao Hospital, Third Military Medical University, Chongqing, China
- Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Ji-Hang Zhang
- Institute of Cardiovascular Diseases of PLA; Xinqiao Hospital, Third Military Medical University, Chongqing, China
- Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Qian-Ning Li
- Department of Neurology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Jie Yu
- Institute of Cardiovascular Diseases of PLA; Xinqiao Hospital, Third Military Medical University, Chongqing, China
- Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Shi-Yong Yu
- Institute of Cardiovascular Diseases of PLA; Xinqiao Hospital, Third Military Medical University, Chongqing, China
- Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Jian-Fei Chen
- Institute of Cardiovascular Diseases of PLA; Xinqiao Hospital, Third Military Medical University, Chongqing, China
- Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Xue-Jun Yu
- Institute of Cardiovascular Diseases of PLA; Xinqiao Hospital, Third Military Medical University, Chongqing, China
- Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Jun Qin
- Institute of Cardiovascular Diseases of PLA; Xinqiao Hospital, Third Military Medical University, Chongqing, China
- Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Lan Huang
- Institute of Cardiovascular Diseases of PLA; Xinqiao Hospital, Third Military Medical University, Chongqing, China
- Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| |
Collapse
|
16
|
Schiffer TA, Ekblom B, Lundberg JO, Weitzberg E, Larsen FJ. Dynamic regulation of metabolic efficiency explains tolerance to acute hypoxia in humans. FASEB J 2014; 28:4303-11. [DOI: 10.1096/fj.14-251710] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Tomas A. Schiffer
- Department of Physiology and PharmacologyKarolinska InstitutetStockholmSweden
| | - Björn Ekblom
- Åstrand Laboratory of Work PhysiologySwedish School of Sports and Health SciencesStockholmSweden
| | - Jon O. Lundberg
- Department of Physiology and PharmacologyKarolinska InstitutetStockholmSweden
| | - Eddie Weitzberg
- Department of Physiology and PharmacologyKarolinska InstitutetStockholmSweden
| | - Filip J. Larsen
- Department of Physiology and PharmacologyKarolinska InstitutetStockholmSweden
| |
Collapse
|
17
|
Moore CM, Swain DP, Ringleb SI, Morrison S. The Effects of Acute Hypoxia and Exercise on Marksmanship. Med Sci Sports Exerc 2014; 46:795-801. [DOI: 10.1249/mss.0000000000000148] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
18
|
Lara B, Salinero JJ, Del Coso J. Altitude is Positively Correlated to Race Time during the Marathon. High Alt Med Biol 2014; 15:64-9. [DOI: 10.1089/ham.2013.1060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Beatriz Lara
- Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain
| | - Juan José Salinero
- Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain
| | - Juan Del Coso
- Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain
| |
Collapse
|
19
|
Adami A, Fagoni N, Ferretti G. The Q˙-V˙O2 diagram: an analytical interpretation of oxygen transport in arterial blood during exercise in humans. Respir Physiol Neurobiol 2014; 193:55-61. [PMID: 24440436 DOI: 10.1016/j.resp.2014.01.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 01/07/2014] [Accepted: 01/08/2014] [Indexed: 10/25/2022]
Abstract
A new analysis of the relationship between cardiac output (Q˙) and oxygen consumption V˙O2 is presented (Q˙-V˙O2 diagram). Data from different sources in the literature have been used for validation in three conditions: exercise and rest in normoxia, and exercise in hypoxia. The effects of changes in arterial oxygen concentration CaO2 on Q˙ are discussed, as well as the effects of predominant sympathetic or vagal stimulation. Differences appear depending on whether CaO2 is varied by means of changes in blood haemoglobin concentration or changes in arterial oxygen saturation. The present Q˙-V˙O2 diagram allows comprehensive description of oxygen transport in exercising humans; it expands applicability of the historical Q˙-V˙O2 relationship to include CaO2 variations; it opens new pathways for understanding underlying mechanisms; it allows computation of Q˙ from CaO2 and V˙O2 measurements, when Q˙ cannot be measured.
Collapse
Affiliation(s)
- Alessandra Adami
- Département de Neurosciences Fondamentales, Université de Genève, 1 Rue Michel Servet, CH-1211 Genève 4, Switzerland
| | - Nazzareno Fagoni
- Dipartimento di Scienze Cliniche e Sperimentali, Università di Brescia, Viale Europa 11, I-25123 Brescia, Italy
| | - Guido Ferretti
- Département de Neurosciences Fondamentales, Université de Genève, 1 Rue Michel Servet, CH-1211 Genève 4, Switzerland; Dipartimento di Scienze Cliniche e Sperimentali, Università di Brescia, Viale Europa 11, I-25123 Brescia, Italy.
| |
Collapse
|
20
|
Boos CJ, Hodkinson PD, Mellor A, Green NP, Bradley D, Greaves K, Woods DR. The Effects of Prolonged Acute Hypobaric Hypoxia on Novel Measures of Biventricular Performance. Echocardiography 2013; 30:534-41. [DOI: 10.1111/echo.12088] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Affiliation(s)
| | | | - Adrian Mellor
- Consultant Anaesthetist; James Cook University Hospital; Middlesborough; United Kingdom
| | - Nick P. Green
- RAF Centre of Aviation Medicine; RAF Henlow; Beds; United Kingdom
| | - Daniel Bradley
- Cardiovascular Division; GE Healthcare; Herts; United Kingdom
| | | | | |
Collapse
|
21
|
Billat VL, Petot H, Landrain M, Meilland R, Koralsztein JP, Mille-Hamard L. Cardiac output and performance during a marathon race in middle-aged recreational runners. ScientificWorldJournal 2012; 2012:810859. [PMID: 22645458 PMCID: PMC3356747 DOI: 10.1100/2012/810859] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Accepted: 12/28/2011] [Indexed: 11/26/2022] Open
Abstract
PURPOSE Despite the increasing popularity of marathon running, there are no data on the responses of stroke volume (SV) and cardiac output (CO) to exercise in this context. We sought to establish whether marathon performance is associated with the ability to sustain high fractional use of maximal SV and CO (i.e, cardiac endurance) and/or CO, per meter (i.e., cardiac cost). METHODS We measured the SV, heart rate (HR), CO, and running speed of 14 recreational runners in an incremental, maximal laboratory test and then during a real marathon race (mean performance: 3 hr 30 min ± 45 min). RESULTS Our data revealed that HR, SV and CO were all in a high but submaximal steady state during the marathon (87.0 ± 1.6%, 77.2 ± 2.6%, and 68.7 ± 2.8% of maximal values, respectively). Marathon performance was inversely correlated with an upward drift in the CO/speed ratio (mL of CO × m(-1)) (r = -0.65, P < 0.01) and positively correlated with the runner's ability to complete the race at a high percentage of the speed at maximal SV (r = 0.83, P < 0.0002). CONCLUSION Our results showed that marathon performance is inversely correlated with cardiac cost and positively correlated with cardiac endurance. The CO response could be a benchmark for race performance in recreational marathon runners.
Collapse
Affiliation(s)
- Véronique L Billat
- UBIAE, U902 INSERM, University of Evry-Val-D'Essonne, 91025 Evry, France.
| | | | | | | | | | | |
Collapse
|
22
|
Taylor BJ, Kjaergaard J, Snyder EM, Olson TP, Johnson BD. Pulmonary capillary recruitment in response to hypoxia in healthy humans: a possible role for hypoxic pulmonary venoconstriction? Respir Physiol Neurobiol 2011; 177:98-107. [PMID: 21513822 PMCID: PMC3103649 DOI: 10.1016/j.resp.2011.04.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2010] [Revised: 04/06/2011] [Accepted: 04/07/2011] [Indexed: 10/18/2022]
Abstract
We examined mechanisms by which hypoxia may elicit pulmonary capillary recruitment in humans. On separate occasions, twenty-five healthy adults underwent exposure to intravenous saline infusion (30 ml/kg ∼ 15 min) or 17-h normobaric hypoxia ( [FIO2 = 12.5%). Cardiac output (Q) and pulmonary capillary blood volume (Vc) were measured before and after saline infusion and hypoxic-exposure by a rebreathing method. Pulmonary artery systolic pressure (sPpa) and left ventricular (LV) diastolic function were assessed before and after hypoxic-exposure via echocardiography. Saline infusion increased Q and Vc (P < 0.05) with no change in Vc/Q (P = 0.97). Hypoxic-exposure increased Vc (P < 0.01) despite no change in Q (P = 0.25), increased sPpa (P < 0.01), and impaired LV relaxation. Multiple regression suggested that ∼ 37% of the hypoxia-mediated increase in Vc was attributable to alterations in Q, sPpa and LV diastolic function. In conclusion, hypoxia-induced pulmonary capillary recruitment in humans is only partly accounted for by changes in Q, sPpa and LV diastolic function. We speculate that hypoxic pulmonary venoconstriction may play a role in such recruitment.
Collapse
Affiliation(s)
- Bryan J Taylor
- Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic & Foundation, Rochester, MN 55902, USA.
| | | | | | | | | |
Collapse
|