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Dorsett G, Pereira FG, Kuennen M, Waugh K, Barnard J, Bennett J, Garcia G, Gillum T. Repeated short cold-water immersions are sufficient to habituate to the cold, but do not lead to adaptations during exercise in normobaric hypoxia. Appl Physiol Nutr Metab 2024; 49:659-666. [PMID: 38301228 DOI: 10.1139/apnm-2023-0523] [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: 02/03/2024]
Abstract
We sought to assess the effects of repeated cold-water immersions (CWI) on respiratory, metabolic, and sympathoadrenal responses to graded exercise in hypoxia. Sixteen (2 female) participants (age: 21.2 ± 1.3 years; body fat: 12.3 ± 7.7%; body surface area 1.87 ± 0.16 m2, VO2peak: 48.7 ± 7.9 mL/kg/min) underwent 6 CWI in 12.0 ± 1.2 °C. Each CWI was 5 min, twice daily, separated by ≥4 h, for three consecutive days, during which metabolic data were collected. The day before and after the repeated CWI intervention, participants ran in normobaric hypoxia (FIO2 = 0.135) for 4 min at 25%, 40%, 60%, and 75% of their sea level peak oxygen consumption (VO2peak). CWI had no effect on VO2 (p > 0.05), but reduced the VE (CWI #1: 27.1 ± 17.8 versus CWI #6: 19.9 ± 12.1 L/min) (p < 0.01), VT (CWI #1: 1.3 ± 0.4 vs CWI #6: 1.1 ± 0.4 L) (p < 0.01), and VE:VO2 (CWI #1: 53.5 ± 24.1 vs CWI #6: 41.6 ± 20.5) (p < 0.01) during subsequent CWI. Further, post exercise plasma epinephrine was lower after CWI compared to before (103.3 ± 43.1; 73.4 ± 34.6 pg/mL) (p = 0.03), with no change in pre-exercising values (75.4 ± 30.7; 72.5 ± 25.9 pg/mL). While these changes were noteworthy, it is important to acknowledge there were no changes in pulmonary (VE, VT, and VE:VO2) or metabolic (VO2, SmO2, and SpO2) variables across multiple hypoxic exercise workloads following repeated CWI. CWI habituated participants to cold water, but this did not lead to adaptations during exercise in normobaric hypoxia.
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Affiliation(s)
- Geoffrey Dorsett
- Department of Kinesiology, California Baptist University, Riverside, CA, USA
| | | | - Matthew Kuennen
- Department of Exercise Science, High Point University, High Point, NC, USA
| | - Kyren Waugh
- Department of Kinesiology, California Baptist University, Riverside, CA, USA
| | - Jackson Barnard
- Department of Kinesiology, California Baptist University, Riverside, CA, USA
| | - Jonluke Bennett
- Department of Kinesiology, California Baptist University, Riverside, CA, USA
| | - Gabriel Garcia
- Department of Kinesiology, California Baptist University, Riverside, CA, USA
| | - Trevor Gillum
- Department of Kinesiology, California Baptist University, Riverside, CA, USA
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Su R, Peng P, Zhang W, Huang J, Fan J, Zhang D, He J, Ma H, Li H. Dose-effect of exercise intervention on heart rate variability of acclimatized young male lowlanders at 3,680 m. Front Physiol 2024; 15:1331693. [PMID: 38606008 PMCID: PMC11007668 DOI: 10.3389/fphys.2024.1331693] [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: 11/01/2023] [Accepted: 03/14/2024] [Indexed: 04/13/2024] Open
Abstract
This study investigated whether exercise could improve the reduced HRV in an environment of high altitude. A total of 97 young, healthy male lowlanders living at 3,680 m for >1 year were recruited. They were randomized into four groups, of which three performed-low-, moderate-, and high-intensity (LI, MI, HI) aerobic exercise for 4 weeks, respectively. The remaining was the control group (CG) receiving no intervention. For HI, compared to other groups, heart rate (p = 0.002) was significantly decreased, while standard deviation of RR intervals (p < 0.001), SD2 of Poincaré plot (p = 0.046) and the number of successive RR interval pairs that differ by > 50 ms divided by total number of RR (p = 0.032), were significantly increased after intervention. For MI, significantly increase of trigonometric interpolation in NN interval (p = 0.016) was observed after exercise. Further, a decrease in systolic blood pressure (SBP) after high-intensity exercise was found significantly associated with an increase in SD2 (r = - 0.428, p = 0.042). These results indicated that there was a dose effect of different intensities of aerobic exercise on the HRV of acclimatized lowlanders. Moderate and high-intensity aerobic exercise would change the status of the autonomic nervous system (ANS) and decrease the blood pressure of acclimatized lowlanders exposed to high altitude.
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Affiliation(s)
- Rui Su
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa, China
- School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, China
| | - Ping Peng
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa, China
| | - Wenrui Zhang
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa, China
| | - Jie Huang
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa, China
| | - Jing Fan
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa, China
| | - Delong Zhang
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, Guangzhou, China
- School of Psychology, Center for Studies of Psychological Application, and Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou, China
| | - Jiayuan He
- National Clinical Research Center for Geriatric, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- Med-X Center for Manufacturing, Sichuan University, Chengdu, Sichuan, China
| | - Hailin Ma
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa, China
| | - Hao Li
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa, China
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Richalet J, Hermand E. Modeling the oxygen transport to the myocardium at maximal exercise at high altitude. Physiol Rep 2022; 10:e15262. [PMID: 35439356 PMCID: PMC9017981 DOI: 10.14814/phy2.15262] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/22/2022] [Accepted: 03/23/2022] [Indexed: 06/14/2023] Open
Abstract
Exposure to high altitude induces a decrease in oxygen pressure and saturation in the arterial blood, which is aggravated by exercise. Heart rate (HR) at maximal exercise decreases when altitude increases in prolonged exposure to hypoxia. We developed a simple model of myocardial oxygenation in order to demonstrate that the observed blunting of maximal HR at high altitude is necessary for the maintenance of a normal myocardial oxygenation. Using data from the available scientific literature, we estimated the myocardial venous oxygen pressure and saturation at maximal exercise in two conditions: (1) with actual values of maximal HR (decreasing with altitude); (2) with sea-level values of maximal heart rate, whatever the altitude (no change in HR). We demonstrated that, in the absence of autoregulation of maximal HR, myocardial tissue oxygenation would be incompatible with life above 6200 m-7600 m, depending on the hypothesis concerning a possible increase in coronary reserve (increase in coronary blood flow at exercise). The decrease in maximal HR at high altitude could be explained by several biological mechanisms involving the autonomic nervous system and its receptors on myocytes. These experimental and clinical observations support the hypothesis that there exists an integrated system at the cellular level, which protects the myocardium from a hazardous disequilibrium between O2 supply and O2 consumption at high altitude.
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Affiliation(s)
- Jean‐Paul Richalet
- UMR INSERM U1272 Hypoxie & PoumonUniversité Sorbonne Paris NordBobignyFrance
| | - Eric Hermand
- Université Littoral Côte d’OpaleUniversité ArtoisUniversité Lille, CHU LilleULR 7369 ‐ URePSSS‐Unité de Recherche Pluridisciplinaire Sport Santé SociétéDunkerqueFrance
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4
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Wearing OH, Nelson D, Ivy CM, Crossley DA, Scott GR. Adrenergic control of the cardiovascular system in deer mice native to high altitude. Curr Res Physiol 2022; 5:83-92. [PMID: 35169714 PMCID: PMC8829085 DOI: 10.1016/j.crphys.2022.01.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 12/23/2021] [Accepted: 01/23/2022] [Indexed: 12/26/2022] Open
Abstract
Studies of animals native to high altitude can provide valuable insight into physiological mechanisms and evolution of performance in challenging environments. We investigated how mechanisms controlling cardiovascular function may have evolved in deer mice (Peromyscus maniculatus) native to high altitude. High-altitude deer mice and low-altitude white-footed mice (P. leucopus) were bred in captivity at sea level, and first-generation lab progeny were raised to adulthood and acclimated to normoxia or hypoxia. We then used pharmacological agents to examine the capacity for adrenergic receptor stimulation to modulate heart rate (fH) and mean arterial pressure (Pmean) in anaesthetized mice, and used cardiac pressure-volume catheters to evaluate the contractility of the left ventricle. We found that highlanders had a consistently greater capacity to increase fH via pharmacological stimulation of β1-adrenergic receptors than lowlanders. Also, whereas hypoxia acclimation reduced the capacity for increasing Pmean in response to α-adrenergic stimulation in lowlanders, highlanders exhibited no plasticity in this capacity. These differences in highlanders may help augment cardiac output during locomotion or cold stress, and may preserve their capacity for α-mediated vasoconstriction to more effectively redistribute blood flow to active tissues. Highlanders did not exhibit any differences in some measures of cardiac contractility (maximum pressure derivative, dP/dtmax, or end-systolic elastance, Ees), but ejection fraction was highest in highlanders after hypoxia acclimation. Overall, our results suggest that evolved changes in sensitivity to adrenergic stimulation of cardiovascular function may help deer mice cope with the cold and hypoxic conditions at high altitude. High-altitude deer mice have evolved increased aerobic capacity in hypoxia. Cardiovascular regulation was examined in normoxia and chronic hypoxia. Highland mice had increased capacity for β1-adrenergic stimulation of heart rate. Hypoxia reduced vascular α-adrenergic sensitivity in lowland but not highland mice. Cardiac ejection fraction was elevated in highland mice in chronic hypoxia.
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Affiliation(s)
- Oliver H. Wearing
- Department of Biology, McMaster University, Hamilton, ON, Canada
- Corresponding author.
| | - Derek Nelson
- Department of Biological Sciences, University of North Texas, Denton, TX, USA
| | - Catherine M. Ivy
- Department of Biology, McMaster University, Hamilton, ON, Canada
| | - Dane A. Crossley
- Department of Biological Sciences, University of North Texas, Denton, TX, USA
| | - Graham R. Scott
- Department of Biology, McMaster University, Hamilton, ON, Canada
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Ott T, Joyce MC, Hillman AR. Effects of Acute High-Intensity Exercise With the Elevation Training Mask or Hypoxicator on Pulmonary Function, Metabolism, and Hormones. J Strength Cond Res 2021; 35:2486-2491. [PMID: 34431483 DOI: 10.1519/jsc.0000000000003175] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
ABSTRACT Ott, T, Joyce, MC, and Hillman, AR. Effects of acute high-intensity exercise with the elevation training mask or hypoxicator on pulmonary function, metabolism, and hormones. J Strength Cond Res 35(9): 2486-2491, 2021-The elevation training mask (ETM) 2.0 is an increasingly popular hands-free respiratory muscle training modality proposing to mimic altitude; however, the degree to which this occurs has been questioned. The purpose of this study was to investigate the efficacy of this modality in comparison with using a hypoxicator (HYP) during acute aerobic exercise. Eight regularly active subjects (age: 25 ± 8 years; height: 166 ± 12 cm; body mass 64 ± 10 kg; and V̇o2max: 46 ± 6 ml·kg-1·min-1) completed 3 trials, each including resting metabolic rate measurement, pulmonary function tests, and 13 sprint intervals at 90% V̇o2max using either the HYP, ETM, or control. There was no significant difference in metabolism or heart rate between conditions. Fraction of expired air in the first second was greater after exercise (p = 0.02), while oxygen saturation was lower during exercise with the HYP (p < 0.001). Human growth hormone increased with exercise, but no differences were found between conditions; however, a trend was observed for higher growth hormone after exercise in HYP vs. ETM (p = 0.08). Elevation training mask does not seem to change acute pulmonary function, metabolism, heart rate, or oxygen saturation, indicating it likely does not create a hypoxic environment or mimic altitude.
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Affiliation(s)
- Taylor Ott
- Department of Athletic Training and Exercise Science, Marywood University, Scranton, Pennsylvania
- College of Health Sciences, Department of Physical Therapy, Midwestern University, Glendale, Arizona
| | - Michael C Joyce
- Department of Athletic Training and Exercise Science, Marywood University, Scranton, Pennsylvania
- Wilkes-Barre Scranton Penguins, Wilkes-Barre, Pennsylvania
| | - Angela R Hillman
- Department of Athletic Training and Exercise Science, Marywood University, Scranton, Pennsylvania
- College of Health Sciences and Professions, School of Applied Health Sciences and Wellness, Department of Exercise Physiology, Ohio University, Athens, Ohio
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Hypoxic Exercise Exacerbates Hypoxemia and Acute Mountain Sickness in Obesity: A Case Analysis. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18179078. [PMID: 34501667 PMCID: PMC8430682 DOI: 10.3390/ijerph18179078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 08/14/2021] [Accepted: 08/23/2021] [Indexed: 12/21/2022]
Abstract
Acute mountain sickness (AMS) is a common syndrome characterized by headache, dizziness, loss of appetite, weakness, and nausea. As a major public health issue, obesity has increased in high altitude urban residents and intermittent commuters to high altitudes. The present study investigated acute hypoxic exposure and hypoxic exercise on hypoxemia severity and AMS symptoms in a physically active obese man. In this case analysis, peripheral oxygen saturation (SpO2) was used to evaluate hypoxemia, heart rate (HR) and blood pressure (BP) were used to reflect the function of autonomic nervous system (ANS), and Lake Louise scoring (LLS) was used to assess AMS. The results showed that acute hypoxic exposure led to severe hypoxemia (SpO2 = 72%) and tachycardia (HRrest = 97 bpm), and acute hypoxic exercise exacerbated severe hypoxemia (SpO2 = 59%) and ANS dysfunction (HRpeak = 167 bpm, SBP/DBP = 210/97 mmHg). At the end of the 6-h acute hypoxic exposure, the case developed severe AMS (LLS = 10) symptoms of headache, gastrointestinal distress, cyanosis, vomiting, poor appetite, and fatigue. The findings of the case study suggest that high physical activity level appears did not show a reliable protective effect against severe hypoxemia, ANS dysfunction, and severe AMS symptoms in acute hypoxia exposure and hypoxia exercise.
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Richalet JP. [Adaption to chronic hypoxaemia by populations living at high altitude]. Rev Mal Respir 2021; 38:395-403. [PMID: 33541755 DOI: 10.1016/j.rmr.2020.11.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 10/13/2020] [Indexed: 12/14/2022]
Abstract
Permanent life at high altitude induces important physiological stresses linked to the exposure to chronic hypoxia. Various strategies have been adopted by diverse populations living in the Andes, Tibet or East Africa. The main mechanism is an increase in red blood cell production, more marked in Andeans than in Tibetans or Ethiopians. Other changes are observed in the cardiovascular or respiratory systems, as well as in the utero-placental circulation. Sometimes, a de-adaptation process to hypoxia develops, when erythrocytosis becomes excessive and leads to haematological, vascular and cerebral complications (Monge's disease or chronic mountain sickness). Pulmonary hypertension may also appear. Therapeutic options are available but not sufficiently used. Genetic studies have recently been undertaken to try to better understand the evolution of the human genome in populations living in various high altitude regions of the world, as well as the genetic risk factors for chronic diseases. A new model has appeared, intermittent chronic hypoxia, due to the development of economic activities (mainly mining) in desert regions of the Altiplano.
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Affiliation(s)
- J-P Richalet
- Laboratoire « Hypoxie & Poumon », UMR Inserm U1272, Université Sorbonne Paris Nord 13, 74, rue Marcel-Cachin, 93017 Bobigny cedex, France.
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Vagal Threshold Determination during Incremental Stepwise Exercise in Normoxia and Normobaric Hypoxia. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17207579. [PMID: 33086469 PMCID: PMC7590016 DOI: 10.3390/ijerph17207579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 10/01/2020] [Accepted: 10/14/2020] [Indexed: 11/20/2022]
Abstract
This study focuses on the determination of the vagal threshold (Tva) during exercise with increasing intensity in normoxia and normobaric hypoxia. The experimental protocol was performed by 28 healthy men aged 20 to 30 years. It included three stages of exercise on a bicycle ergometer with a fraction of inspired oxygen (FiO2) 20.9% (normoxia), 17.3% (simulated altitude ~1500 m), and 15.3% (~2500 m) at intensity associated with 20% to 70% of the maximal heart rate reserve (MHRR) set in normoxia. Tva level in normoxia was determined at exercise intensity corresponding with (M ± SD) 45.0 ± 5.6% of MHRR. Power output at Tva (POth), representing threshold exercise intensity, decreased with increasing degree of hypoxia (normoxia: 114 ± 29 W; FiO2 = 17.3%: 110 ± 27 W; FiO2 = 15.3%: 96 ± 32 W). Significant changes in POth were observed with FiO2 = 15.3% compared to normoxia (p = 0.007) and FiO2 = 17.3% (p = 0.001). Consequentially, normoxic %MHRR adjusted for hypoxia with FiO2 = 15.3% was reduced to 39.9 ± 5.5%. Considering the convenient altitude for exercise in hypoxia, POth did not differ excessively between normoxic conditions and the simulated altitude of ~1500 m, while more substantial decline of POth occurred at the simulated altitude of ~2500 m compared to the other two conditions.
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Fornasiero A, Savoldelli A, Stella F, Callovini A, Bortolan L, Zignoli A, Low DA, Mourot L, Schena F, Pellegrini B. Shortening Work-Rest Durations Reduces Physiological and Perceptual Load During Uphill Walking in Simulated Cold High-Altitude Conditions. High Alt Med Biol 2020; 21:249-257. [PMID: 32412801 DOI: 10.1089/ham.2019.0136] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Fornasiero, Alessandro, Aldo Savoldelli, Federico Stella, Alexa Callovini, Lorenzo Bortolan, Andrea Zignoli, David A. Low, Laurent Mourot, Federico Schena, and Barbara Pellegrini. Shortening work-rest durations reduces physiological and perceptual load during uphill walking in simulated cold high-altitude conditions. High Alt Med Biol. 21:249-257, 2020. Background: We investigated the effects of two different work-rest durations on the physiological and perceptual responses to a simulated mountain hike in a cold hypoxic environment. Materials and Methods: Twelve healthy nonacclimatized active men (age 31.3 ± 5.3 years, body mass index 22.4 ± 1.5 kg/m2) completed a 80-minute work-matched intermittent exercise on a motorized treadmill (25% incline, fixed self-selected speed), in a simulated mountain environment (-25°C, FiO2 = 11%, ≈5000 m a.s.l.), wearing extreme cold weather gear, once with short (20 × 3 minutes walking with 1 minute rest; SHORT) and once with long (10 × 6 minutes walking with 2 minutes rest; LONG) work-rest durations. Heart rate (HR), pulse oxygen saturation (SpO2), rate of perceived exertion (RPE), and thermal sensation (TS) were assessed throughout the exercise protocols. Cardiac autonomic modulation was assessed before (PRE) and after exercise (POST) in supine position, as well as during standing resting periods by means of HR recovery (HRR) assessment. Results: SpO2 and TS were similar (p > 0.05) in SHORT and LONG protocols. HR and RPE were increased, and HRR reduced during LONG compared to SHORT (p < 0.05). Parasympathetic activity indices were reduced at POST after both protocols (p < 0.05), but to a lesser extent after SHORT (p < 0.05). Conclusions: Reduced work-rest durations are associated with improved perceptual responses and less perturbation of cardiac autonomic balance, compared to longer work-rest durations. Shorter exercise periods from more frequent breaks during hikes at high altitude may represent a valid strategy to limit the impact of exercise under extreme environmental conditions.
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Affiliation(s)
- Alessandro Fornasiero
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Aldo Savoldelli
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Federico Stella
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, Rovereto, Italy
| | - Alexa Callovini
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, Rovereto, Italy
| | - Lorenzo Bortolan
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Andrea Zignoli
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, Rovereto, Italy.,Department of Industrial Engineering, University of Trento, Trento, Italy
| | - David A Low
- Research Institute for Sport and Exercise Sciences (RISES), Liverpool John Moores University, Liverpool, United Kingdom
| | - Laurent Mourot
- Laboratory of Prognostic Markers and Regulatory Factors of Cardiovascular Diseases and Exercise Performance, Health, Innovation Platform (EA 3920), University of Bourgogne Franche-Comté, Besançon, France.,Tomsk Polytechnic University, Tomsk, Russia
| | - Federico Schena
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Barbara Pellegrini
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
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Girard O, Brocherie F, Millet GP. Effects of Altitude/Hypoxia on Single- and Multiple-Sprint Performance: A Comprehensive Review. Sports Med 2018; 47:1931-1949. [PMID: 28451905 DOI: 10.1007/s40279-017-0733-z] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Many sport competitions, typically involving the completion of single- (e.g. track-and-field or track cycling events) and multiple-sprint exercises (e.g. team and racquet sports, cycling races), are staged at terrestrial altitudes ranging from 1000 to 2500 m. Our aim was to comprehensively review the current knowledge on the responses to either acute or chronic altitude exposure relevant to single and multiple sprints. Performance of a single sprint is generally not negatively affected by acute exposure to simulated altitude (i.e. normobaric hypoxia) because an enhanced anaerobic energy release compensates for the reduced aerobic adenosine triphosphate production. Conversely, the reduction in air density in terrestrial altitude (i.e. hypobaric hypoxia) leads to an improved sprinting performance when aerodynamic drag is a limiting factor. With the repetition of maximal efforts, however, repeated-sprint ability is more altered (i.e. with earlier and larger performance decrements) at high altitudes (>3000-3600 m or inspired fraction of oxygen <14.4-13.3%) compared with either normoxia or low-to-moderate altitudes (<3000 m or inspired fraction of oxygen >14.4%). Traditionally, altitude training camps involve chronic exposure to low-to-moderate terrestrial altitudes (<3000 m or inspired fraction of oxygen >14.4%) for inducing haematological adaptations. However, beneficial effects on sprint performance after such altitude interventions are still debated. Recently, innovative 'live low-train high' methods, in isolation or in combination with hypoxic residence, have emerged with the belief that up-regulated non-haematological peripheral adaptations may further improve performance of multiple sprints compared with similar normoxic interventions.
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Affiliation(s)
- Olivier Girard
- Aspetar Orthopaedic and Sports Medicine Hospital, Athlete Health and Performance Research Centre, Doha, Qatar.
- ISSUL, Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland.
| | - Franck Brocherie
- Laboratory Sport, Expertise and Performance (EA 7370), Research Department, French Institute of Sport (INSEP), Paris, France
- ISSUL, Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Grégoire P Millet
- ISSUL, Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
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Gonzalez NC, Kuwahira I. Systemic Oxygen Transport with Rest, Exercise, and Hypoxia: A Comparison of Humans, Rats, and Mice. Compr Physiol 2018; 8:1537-1573. [PMID: 30215861 DOI: 10.1002/cphy.c170051] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The objective of this article is to compare and contrast the known characteristics of the systemic O2 transport of humans, rats, and mice at rest and during exercise in normoxia and hypoxia. This analysis should help understand when rodent O2 transport findings can-and cannot-be applied to human responses to similar conditions. The O2 -transport system was analyzed as composed of four linked conductances: ventilation, alveolo-capillary diffusion, circulatory convection, and tissue capillary-cell diffusion. While the mechanisms of O2 transport are similar in the three species, the quantitative differences are naturally large. There are abundant data on total O2 consumption and on ventilatory and pulmonary diffusive conductances under resting conditions in the three species; however, there is much less available information on pulmonary gas exchange, circulatory O2 convection, and tissue O2 diffusion in mice. The scarcity of data largely derives from the difficulty of obtaining blood samples in these small animals and highlights the need for additional research in this area. In spite of the large quantitative differences in absolute and mass-specific O2 flux, available evidence indicates that resting alveolar and arterial and venous blood PO2 values under normoxia are similar in the three species. Additionally, at least in rats, alveolar and arterial blood PO2 under hypoxia and exercise remain closer to the resting values than those observed in humans. This is achieved by a greater ventilatory response, coupled with a closer value of arterial to alveolar PO2 , suggesting a greater efficacy of gas exchange in the rats. © 2018 American Physiological Society. Compr Physiol 8:1537-1573, 2018.
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Affiliation(s)
- Norberto C Gonzalez
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Ichiro Kuwahira
- Department of Pulmonary Medicine, Tokai University School of Medicine, Tokai University Tokyo Hospital, Tokyo, Japan
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12
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Fornasiero A, Savoldelli A, Skafidas S, Stella F, Bortolan L, Boccia G, Zignoli A, Schena F, Mourot L, Pellegrini B. Delayed parasympathetic reactivation and sympathetic withdrawal following maximal cardiopulmonary exercise testing (CPET) in hypoxia. Eur J Appl Physiol 2018; 118:2189-2201. [PMID: 30051338 DOI: 10.1007/s00421-018-3945-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 07/13/2018] [Indexed: 12/14/2022]
Abstract
PURPOSE This study investigated the effects of acute hypoxic exposure on post-exercise cardiac autonomic modulation following maximal cardiopulmonary exercise testing (CPET). METHODS Thirteen healthy men performed CPET and recovery in normoxia (N) and normobaric hypoxia (H) (FiO2 = 13.4%, ≈ 3500 m). Post-exercise cardiac autonomic modulation was assessed during recovery (300 s) through the analysis of fast-phase and slow-phase heart rate recovery (HRR) and heart rate variability (HRV) indices. RESULTS Both short-term, T30 (mean difference (MD) 60.0 s, 95% CI 18.2-101.8, p = 0.009, ES 1.01), and long-term, HRRt (MD 21.7 s, 95% CI 4.1-39.3, p = 0.020, ES 0.64), time constants of HRR were higher in H. Fast-phase (30 and 60 s) and slow-phase (300 s) HRR indices were reduced in H either when expressed in bpm or in percentage of HRpeak (p < 0.05). Chronotropic reserve recovery was lower in H than in N at 30 s (MD - 3.77%, 95% CI - 7.06 to - 0.49, p = 0.028, ES - 0.80) and at 60 s (MD - 7.23%, 95% CI - 11.45 to - 3.01, p = 0.003, ES - 0.81), but not at 300 s (p = 0.436). Concurrently, Ln-RMSSD was reduced in H at 60 and 90 s (p < 0.01) but not at other time points during recovery (p > 0.05). CONCLUSIONS Affected fast-phase, slow-phase HRR and HRV indices suggested delayed parasympathetic reactivation and sympathetic withdrawal after maximal exercise in hypoxia. However, a similar cardiac autonomic recovery was re-established within 5 min after exercise cessation. These findings have several implications in cardiac autonomic recovery interpretation and in HR assessment in response to high-intensity hypoxic exercise.
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Affiliation(s)
- Alessandro Fornasiero
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, via Matteo del Ben, 5/b, 38068, Rovereto, Italy. .,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
| | - Aldo Savoldelli
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, via Matteo del Ben, 5/b, 38068, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Spyros Skafidas
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, via Matteo del Ben, 5/b, 38068, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Federico Stella
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, via Matteo del Ben, 5/b, 38068, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Lorenzo Bortolan
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, via Matteo del Ben, 5/b, 38068, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Gennaro Boccia
- NeuroMuscularFunction Research Group, Department of Medical Sciences, School of Exercise and Sport Sciences, University of Turin, Turin, Italy
| | - Andrea Zignoli
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, via Matteo del Ben, 5/b, 38068, Rovereto, Italy
| | - Federico Schena
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, via Matteo del Ben, 5/b, 38068, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Laurent Mourot
- Laboratory of Prognostic Markers and Regulatory Factors of Cardiovascular Diseases and Exercise Performance, Health, Innovation Platform (EA 3920), University of Bourgogne Franche-Comté, Besançon, France.,Tomsk Polytechnic University, Tomsk, Russia
| | - Barbara Pellegrini
- CeRiSM, Sport Mountain and Health Research Centre, University of Verona, via Matteo del Ben, 5/b, 38068, Rovereto, Italy.,Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
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13
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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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14
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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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15
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Flaherty G, O'Connor R, Johnston N. Altitude training for elite endurance athletes: A review for the travel medicine practitioner. Travel Med Infect Dis 2016; 14:200-11. [PMID: 27040934 DOI: 10.1016/j.tmaid.2016.03.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 03/22/2016] [Accepted: 03/23/2016] [Indexed: 11/30/2022]
Abstract
High altitude training is regarded as an integral component of modern athletic preparation, especially for endurance sports such as middle and long distance running. It has rapidly achieved popularity among elite endurance athletes and their coaches. Increased hypoxic stress at altitude facilitates key physiological adaptations within the athlete, which in turn may lead to improvements in sea-level athletic performance. Despite much research in this area to date, the exact mechanisms which underlie such improvements remain to be fully elucidated. This review describes the current understanding of physiological adaptation to high altitude training and its implications for athletic performance. It also discusses the rationale and main effects of different training models currently employed to maximise performance. Athletes who travel to altitude for training purposes are at risk of suffering the detrimental effects of altitude. Altitude illness, weight loss, immune suppression and sleep disturbance may serve to limit athletic performance. This review provides an overview of potential problems which an athlete may experience at altitude, and offers specific training recommendations so that these detrimental effects are minimised.
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Affiliation(s)
- Gerard Flaherty
- School of Medicine, National University of Ireland, Galway, Ireland; School of Medicine, International Medical University, Kuala Lumpur, Malaysia.
| | - Rory O'Connor
- School of Biomedical Science, National University of Ireland, Galway, Ireland.
| | - Niall Johnston
- School of Medicine, National University of Ireland, Galway, Ireland.
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16
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García-Flores LA, Medina S, Cejuela R, Martínez-Sanz JM, Oger C, Galano JM, Durand T, Casas-Pina T, Martínez-Hernández P, Ferreres F, Gil-Izquierdo Á. Assessment of oxidative stress biomarkers – neuroprostanes and dihomo-isoprostanes – in the urine of elite triathletes after two weeks of moderate-altitude training. Free Radic Res 2016; 50:485-94. [DOI: 10.3109/10715762.2015.1111514] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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17
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Richalet JP. Physiological and Clinical Implications of Adrenergic Pathways at High Altitude. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 903:343-56. [DOI: 10.1007/978-1-4899-7678-9_23] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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18
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Richalet JP, Lhuissier FJ. Aging, Tolerance to High Altitude, and Cardiorespiratory Response to Hypoxia. High Alt Med Biol 2015; 16:117-24. [DOI: 10.1089/ham.2015.0030] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Jean-Paul Richalet
- Université Paris 13, Sorbonne Paris Cité, “Hypoxie et Poumon,” Bobigny, France
- AP-HP, Hôpital Avicenne, Service de Physiologie, Explorations Fonctionnelles et Médecine du Sport, Bobigny, France
| | - François J. Lhuissier
- Université Paris 13, Sorbonne Paris Cité, “Hypoxie et Poumon,” Bobigny, France
- AP-HP, Hôpital Avicenne, Service de Physiologie, Explorations Fonctionnelles et Médecine du Sport, Bobigny, France
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19
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Kriemler S, Radtke T, Bürgi F, Lambrecht J, Zehnder M, Brunner-La Rocca HP. Short-term cardiorespiratory adaptation to high altitude in children compared with adults. Scand J Med Sci Sports 2015; 26:147-55. [PMID: 25648726 DOI: 10.1111/sms.12422] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2014] [Indexed: 11/25/2022]
Abstract
As short-term cardiorespiratory adaptation to high altitude (HA) exposure has not yet been studied in children, we assessed acute mountain sickness (AMS), hypoxic ventilatory response (HVR) at rest and maximal exercise capacity (CPET) at low altitude (LA) and HA in pre-pubertal children and their fathers. Twenty father-child pairs (11 ± 1 years and 44 ± 4 years) were tested at LA (450 m) and HA (3450 m) at days 1, 2, and 3 after fast ascent (HA1/2/3). HVR was measured at rest and CPET was performed on a cycle ergometer. AMS severity was mild to moderate with no differences between generations. HVR was higher in children than adults at LA and increased at HA similarly in both groups. Peak oxygen uptake (VO2 peak) relative to body weight was similar in children and adults at LA and decreased significantly by 20% in both groups at HA; maximal heart rate did not change at HA in children while it decreased by 16% in adults (P < 0.001). Changes in HVR and VO2 peak from LA to HA were correlated among the biological child-father pairs. In conclusion, cardiorespiratory adaptation to altitude seems to be at least partly hereditary. Even though children and their fathers lose similar fractions of aerobic capacity going to high altitude, the mechanisms might be different.
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Affiliation(s)
- S Kriemler
- Epidemiology, Biostatistics and Prevention Institute, University of Zürich, Zurich, Switzerland
| | - T Radtke
- Epidemiology, Biostatistics and Prevention Institute, University of Zürich, Zurich, Switzerland
| | - F Bürgi
- Epidemiology, Biostatistics and Prevention Institute, University of Zürich, Zurich, Switzerland
| | - J Lambrecht
- Department of Preventive Cardiology and Sports Medicine, University Clinic for Cardiology, Inselspital, University Hospital, Berne, Switzerland
| | - M Zehnder
- Department of Clinical Research, University and Inselspital Berne, Berne, Switzerland
| | - H P Brunner-La Rocca
- Medical University Center Maastricht, Cardiology, University of Maastricht, Maastricht, The Netherlands
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20
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Coustet B, Lhuissier FJ, Vincent R, Richalet JP. Electrocardiographic changes during exercise in acute hypoxia and susceptibility to severe high-altitude illnesses. Circulation 2015; 131:786-94. [PMID: 25561515 DOI: 10.1161/circulationaha.114.013144] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The goals of this study were to compare ECG at moderate exercise in normoxia and hypoxia at the same heart rate, to provide evidence of independent predictors of hypoxia-induced ECG changes, and to evaluate ECG risk factors of severe high-altitude illness. METHODS AND RESULTS A total of 456 subjects performed a 20-minute hypoxia exercise test with continuous recording of ECG and physiological measurements before a sojourn above 4000 m. Hypoxia did not induce any conduction disorder, arrhythmias, or change in QRS axis. The amplitude of the P wave in V1 was lower in hypoxia than in normoxia. The amplitudes of the R, S, and T waves and the Sokolow index decreased in hypoxia. Under hypoxia, the amplitude of the ST segment decreased in II and V6 and increased in V1, the ST slope rose in V5 and V6, and the J point was lower in II, V5, and V6. Multivariate regression of hypoxic/normoxic ratios of electrophysiological parameters and clinical characteristics showed a correlation between the decrease in Sokolow index and T-wave amplitude in V5 with desaturation at exercise. Trained status and low body mass index were associated with a smaller decrease in T-wave amplitude in V5 and V6. Comparison of ECG between subjects suffering or not suffering from severe high-altitude illness failed to show any difference. CONCLUSIONS During a hypoxia exercise test, a dose-dependent hypoxia-induced decrease in the amplitude of the P/QRS/T waves was observed. No standard ECG characteristic predicted the risk of developing severe high-altitude illness. Further studies are required to clarify the cause of these electric changes and their potential predictive role in cardiac events.
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Affiliation(s)
- Baptiste Coustet
- From the Université Paris 13, Sorbonne Paris Cité, Laboratoire "Hypoxie et Poumon," EA2363 and Assistance Publique-Hôpitaux de Paris, Hôpital Avicenne, Service de Physiologie, Explorations Fonctionnelles et Médecine du Sport, Bobigny, France
| | - François J Lhuissier
- From the Université Paris 13, Sorbonne Paris Cité, Laboratoire "Hypoxie et Poumon," EA2363 and Assistance Publique-Hôpitaux de Paris, Hôpital Avicenne, Service de Physiologie, Explorations Fonctionnelles et Médecine du Sport, Bobigny, France
| | - Renaud Vincent
- From the Université Paris 13, Sorbonne Paris Cité, Laboratoire "Hypoxie et Poumon," EA2363 and Assistance Publique-Hôpitaux de Paris, Hôpital Avicenne, Service de Physiologie, Explorations Fonctionnelles et Médecine du Sport, Bobigny, France
| | - Jean-Paul Richalet
- From the Université Paris 13, Sorbonne Paris Cité, Laboratoire "Hypoxie et Poumon," EA2363 and Assistance Publique-Hôpitaux de Paris, Hôpital Avicenne, Service de Physiologie, Explorations Fonctionnelles et Médecine du Sport, Bobigny, France.
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Le Meur Y, Louis J, Aubry A, Guéneron J, Pichon A, Schaal K, Corcuff JB, Hatem SN, Isnard R, Hausswirth C. Maximal exercise limitation in functionally overreached triathletes: role of cardiac adrenergic stimulation. J Appl Physiol (1985) 2014; 117:214-22. [DOI: 10.1152/japplphysiol.00191.2014] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Functional overreaching (F-OR) induced by heavy load endurance training programs has been associated with reduced heart rate values both at rest and during exercise. Because this phenomenon may reflect an impairment of cardiac response, this research was conducted to test this hypothesis. Thirty-five experienced male triathletes were tested (11 control and 24 overload subjects) before overloading (Pre), immediately after overloading (Mid), and after a 2-wk taper period (Post). Physiological responses were assessed during an incremental cycling protocol to volitional exhaustion, including catecholamines release, oxygen uptake (V̇o2), arteriovenous O2 difference, cardiac output (Q̇), and systolic (SBP) and diastolic blood pressure (DBP). Twelve subjects of the overload group developed signs of F-OR at Mid (decreased performance with concomitant high perceived fatigue), while 12 others did not [acute fatigue group (AF)]. V̇o2max was reduced only in F-OR subjects at Mid. Lower Q̇ and SBP values with greater arteriovenous O2 difference were reported in F-OR subjects at all exercising intensities, while no significant change was observed in the control and AF groups. A concomitant decrease in epinephrine excretion was reported only in the F-OR group. All values returned to baseline at Post. Following an overload endurance training program leading to F-OR, the cardiac response to exhaustive exercise is transiently impaired, possibly due to reduced epinephrine excretion. This finding is likely to explain the complex process of underperformance syndrome experienced by F-OR endurance athletes during heavy load programs.
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Affiliation(s)
- Yann Le Meur
- Laboratory of Sport, Expertise and Performance, Research Department, French National Institute of Sport, Expertise and Performance, (INSEP) Paris, France
| | - Julien Louis
- Laboratory of Sport, Expertise and Performance, Research Department, French National Institute of Sport, Expertise and Performance, (INSEP) Paris, France
| | - Anaël Aubry
- Laboratory of Sport, Expertise and Performance, Research Department, French National Institute of Sport, Expertise and Performance, (INSEP) Paris, France
| | - Jacques Guéneron
- Medical Department, French National Institute of Sport, Expertise and Performance, Paris, France
| | - Aurélien Pichon
- Laboratory of Functional and Cellular Responses to Hypoxia, University Paris 13 North, Sorbonne Paris City, Bobigny, France
| | - Karine Schaal
- Laboratory of Sport, Expertise and Performance, Research Department, French National Institute of Sport, Expertise and Performance, (INSEP) Paris, France
- Sports Performance Laboratory, Sports Medicine Program, University of California, Davis, Sacramento, California
| | - Jean-Benoît Corcuff
- Department of Nuclear Medicine, Centre Hospitalier Universitaire Bordeaux, Bordeaux, France
| | - Stéphane N. Hatem
- Department of Cardiology, Pitié-Salpêtrière Hospital, Assistance Publique-Hôpitaux de Paris, Faculté de Médecine Pierre et Marie Curie, Paris, France; and
- University Paris 6, Paris, France; Institute of Cardiometabolism and Nutrition (ICAN), Paris, France
| | - Richard Isnard
- Department of Cardiology, Pitié-Salpêtrière Hospital, Assistance Publique-Hôpitaux de Paris, Faculté de Médecine Pierre et Marie Curie, Paris, France; and
- University Paris 6, Paris, France; Institute of Cardiometabolism and Nutrition (ICAN), Paris, France
| | - Christophe Hausswirth
- Laboratory of Sport, Expertise and Performance, Research Department, French National Institute of Sport, Expertise and Performance, (INSEP) Paris, France
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Le Meur Y, Pichon A, Schaal K, Schmitt L, Louis J, Gueneron J, Vidal PP, Hausswirth C. Evidence of parasympathetic hyperactivity in functionally overreached athletes. Med Sci Sports Exerc 2014; 45:2061-71. [PMID: 24136138 DOI: 10.1249/mss.0b013e3182980125] [Citation(s) in RCA: 133] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE We analyzed HR variability (HRV) to detect alterations in autonomic function that may be associated with functional overreaching (F-OR) in endurance athletes. METHODS Twenty-one trained male triathletes were randomly assigned to either intensified training (n = 13) or normal training (n = 8) groups during 5 wk. HRV measures were taken daily during a 1-wk moderate training (baseline), a 3-wk overload training, and a 1-wk taper. RESULTS All the subjects of the intensified training group demonstrated a decrease in maximal incremental running test performance at the end of the overload period (-9.0% ± 2.1% of baseline value) followed by a performance supercompensation after the taper and were therefore diagnosed as F-OR. According to a qualitative statistical analysis method, a likely to very likely negative effect of F-OR on HR was observed at rest in supine and standing positions, using isolated seventh-day values and weekly average values, respectively. When considering the values obtained once per week, no clear effect of F-OR on HRV parameters was found. In contrast, the weekly mean of each HRV parameter showed a larger change in indices of parasympathetic tone in the F-OR group than the control group in supine position (with a 96%/4%/0% chance to demonstrate a positive/trivial/negative effect on Ln RMSSD after the overload period; 77%/22%/1% on LnHF) and standing position [98%/1%/1% on Ln RMSSD; 99%/0%/1% on LnHF; 95%/1%/4% on Ln(LF + HF)]. During the taper, theses responses were reversed. CONCLUSIONS Using daily HRV recordings averaged over each week, this study detected a progressive increase in the parasympathetic modulation of HR in endurance athletes led to F-OR. It also revealed that due to a wide day-to-day variability, isolated, once per week HRV recordings may not detect training-induced autonomic modulations in F-OR athletes.
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Affiliation(s)
- Yann Le Meur
- 1Laboratory of Sport, Expertise and Performance, National Institute of Sport, Expertise and Performance, Paris, FRANCE; 2Laboratory of Functional and Cellular Responses to Hypoxia, University Paris 13 North, Bobigny, FRANCE; 3Sports Medicine Program, Sports Performance Laboratory, University of California, Davis, Sacramento, CA; 4French National Ski Center, Prémanon, FRANCE; 5National Institute of Sport, Expertise and Performance, Medical Department, Paris, FRANCE; and 6CESeM, CNRS, University Paris Descartes, Paris, FRANCE
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Afshari A, Safari M, Oshvandi K, Soltanian AR. The Effect of the Open and Closed System Suctions on Cardiopulmonary Parameters: Time and Costs in Patients Under Mechanical Ventilation. Nurs Midwifery Stud 2014. [DOI: 10.17795/nmsjournal14097] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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24
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The Effect of the Open and Closed System Suctions on Cardiopulmonary Parameters: Time and Costs in Patients Under Mechanical Ventilation. Nurs Midwifery Stud 2014. [DOI: 10.5812/nms.14097] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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The effect of the open and closed system suctions on cardiopulmonary parameters: time and costs in patients under mechanical ventilation. Nurs Midwifery Stud 2014; 3:e14097. [PMID: 25414899 PMCID: PMC4228526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 11/25/2013] [Accepted: 11/27/2013] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND One of the measures to keep the airway open is suctioning of endotracheal tube in patients under ventilation. This procedure can be accompanied with some complications. Selection of appropriate method of suctioning can prevent incidence of acute complications. OBJECTIVES This study aimed to compare the effects of the open and closed system suctioning methods on blood pressure, mean arterial pressure, heart rate, percentage of arterial oxygen saturation, time, and costs in patients under mechanical ventilation. PATIENTS AND METHODS This clinical trial study was conducted on 40 patients in ICU. Patients' blood pressure, heart rate, arterial oxygen saturation, related costs, and length of suctioning procedure were measured and recorded immediately before and one, five, ten, and fifteen minutes after suctioning. Data were analyzed using paired t test and repeated measure analysis of variance. RESULTS No significant differences were observed between the two suctioning methods in terms of mean systolic blood pressure (P = 0.075), diastolic blood pressure (P = 0.405), and mean arterial pressure (P = 0.257) in the five consecutive measurements. However, significant changes were observed in heart rate (P = 0.025) and percentage of arterial oxygen saturation (P < 0.001). The mean lengths of time in open and closed suctioning methods were 5.59 ± 0.211 and 4.34 ± 0.039 seconds, respectively (P < 0.001). The cost of the closed system was lower than the open method for the patients who were admitted to ICU for longer than two days. CONCLUSIONS Closed suction caused fewer disturbances in patients' hemodynamic condition, took shorter time, and is more economical. Therefore, this method can replace open suction method in caring of severely critically ill patients.
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Recommendations for resuscitation after ascent to high altitude and in aircrafts. Int J Cardiol 2013; 167:1703-11. [DOI: 10.1016/j.ijcard.2012.11.077] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2012] [Accepted: 11/11/2012] [Indexed: 12/31/2022]
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Le Meur Y, Hausswirth C, Natta F, Couturier A, Bignet F, Vidal PP. A multidisciplinary approach to overreaching detection in endurance trained athletes. J Appl Physiol (1985) 2012. [PMID: 23195630 DOI: 10.1152/japplphysiol.01254.2012] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In sport, high training load required to reach peak performance pushes human adaptation to their limits. In that process, athletes may experience general fatigue, impaired performance, and may be identified as overreached (OR). When this state lasts for several months, an overtraining syndrome is diagnosed (OT). Until now, no variable per se can detect OR, a requirement to prevent the transition from OR to OT. It encouraged us to further investigate OR using a multivariate approach, including physiological, biomechanical, cognitive, and perceptive monitoring. Twenty-four highly trained triathletes were separated into an overload group and a normo-trained group (NT) during 3 wk of training. Given the decrement of their running performance, 11 triathletes were diagnosed as OR after this period. A discriminant analysis showed that the changes of eight parameters measured during a maximal incremental test could explain 98.2% of the OR state (lactatemia, heart rate, biomechanical parameters and effort perception). Variations in heart rate and lactatemia were the two most discriminating factors. When the multifactorial analysis was restricted to these variables, the classification score reached 89.5%. Catecholamines and creatine kinase concentrations at rest did not change significantly in both groups. Running pattern was preserved and cognitive performance decrement was observed only at exhaustion in OR subjects. This study showed that monitoring various variables is required to prevent the transition between NT and OR. It emphasized that an OR index, which combines heart rate and blood lactate concentration changes after a strenuous training period, could be helpful to routinely detect OR.
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Affiliation(s)
- Yann Le Meur
- National Institute of Sport, Expertise and Performance (INSEP), Research Department, Paris, France
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Effects of a high-carbohydrate versus high-protein meal on acute responses to hypoxia at rest and exercise. Eur J Appl Physiol 2012; 113:691-702. [DOI: 10.1007/s00421-012-2472-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Accepted: 07/28/2012] [Indexed: 12/21/2022]
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Abstract
A stay at high altitude exposes an individual to various environmental changes (cold, exercise, isolation) but the most stressful for the body is hypoxia. However, the cardiovascular system yields some efficient mechanisms of acclimatization to oxygen lack. Hypoxia activates the adrenergic system and induces a tachycardia that decreases during a prolonged stay at altitude. The desensitization of the adrenergic system leads to a decrease in maximal heart rate and a protection of the myocardium against an energy disequilibrium that could be potentially harmful for the heart. Hypoxia induces a peripheral vasodilation and a pulmonary vasoconstriction, leading to few changes in systemic blood pressure and an increase in pulmonary blood pressure (PHT) that can contribute to a high altitude pulmonary edema. Advice to a cardiac patient who plans to go to high altitude should take into account that all diseases aggravated by increased adrenergic activity or associated with a PHT or a hypoxemia (right-to-left shunt) will be aggravated at high altitude. As altitude increases, a patient with a coronary disease will present an ischemic threshold for a lower power output during an EKG exercise test. The only test allowing predicting the tolerance to high altitude is the hypoxia exercise test realized at 30% of maxVO(2)and at an equivalent altitude of 4,800m.
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Affiliation(s)
- Jean-Paul Richalet
- AP-HP, hôpital Avicenne, service de physiologie, explorations fonctionnelles et médecine du sport, Bobigny cedex, 93009 France.
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Richalet JP, Letournel M, Souberbielle JC. Effects of high-altitude hypoxia on the hormonal response to hypothalamic factors. Am J Physiol Regul Integr Comp Physiol 2010; 299:R1685-92. [PMID: 20926759 DOI: 10.1152/ajpregu.00484.2010] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Acute and chronic exposure to high altitude induces various physiological changes, including activation or inhibition of various hormonal systems. In response to activation processes, a desensitization of several pathways has been described, especially in the adrenergic system. In the present study, we aimed to assess whether the hypophyseal hormones are also subjected to a hypoxia-induced decrease in their response to hypothalamic factors. Basal levels of hormones and the responses of TSH, thyroid hormones, prolactin, sex hormones, and growth hormone to the injection of TRH, gonadotropin-releasing hormone, and growth hormone-releasing hormone (GHRH) were studied in eight men in normoxia and on prolonged exposure (3-4 days) to an altitude of 4,350 m. Thyroid hormones were elevated at altitude (+16 to +21%), while TSH levels were unchanged, and follicle-stimulating hormone and prolactin decreased, while leutinizing hormone was unchanged. Norepinephrine and cortisol levels were elevated, while no change was observed in levels of epinephrine, dopamine, growth hormone (GH), IGF-1, and IGFBP-3. The mean response to hypothalamic factors was similar in both altitudes for all studied hormones, although total T4 was lower in hypoxia during 45 to 60 min after injection. The effect of hypoxia on the hypophyseal response to hypothalamic factors was similar among subjects, except for the GH response to GHRH administration. We conclude that prolonged exposure to high-altitude hypoxia induces contrasted changes in hormonal levels, but the hypophyseal response to hypothalamic factors does not appear to be blunted.
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Affiliation(s)
- Jean-Paul Richalet
- Université Paris 13, Unité de Formation et de Recherche Santé Médecine Biologie Humaine, Laboratoire Réponses Cellulaires et Fonctionnelles à l'Hypoxie, Bobigny, France.
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Higgins JP, Tuttle T, Higgins JA. Altitude and the heart: is going high safe for your cardiac patient? Am Heart J 2010; 159:25-32. [PMID: 20102863 DOI: 10.1016/j.ahj.2009.10.028] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Accepted: 10/21/2009] [Indexed: 11/24/2022]
Abstract
Our aging population combined with the ease of travel and the interest in high altitude recreation pursuits exposes more patients to the acute physiologic effects of high altitude and lower oxygen availability. Acute exposure to high altitude is associated with significant alterations to the cardiovascular system. These may be important in patients with underlying cardiovascular disease who are not able to compensate to such physiologic changes. Exacerbating factors pertinent to patients with cardiovascular disease include acute hypoxia, increased myocardial work, increased epinephrine release, and increased pulmonary artery pressures. This review summarizes the physiology and clinical evidence regarding acute altitude exposure on the cardiopulmonary system with practical recommendations to address the question: "Is it safe for me to ski in the Rockies or climb Mt. Kilimanjaro?"
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Abstract
Aerobic exercise capacity decreases with exposure to hypoxia. This article focuses on the effects of hypoxia on nervous system function and the potential consequences for the exercising human. Emphasis is put on somatosensory muscle afferents due to their crucial role in the reflex inhibition of muscle activation and in cardiorespiratory reflex control during exercise. We review the evidence of hypoxia influences on muscle afferents and discuss important consequences for exercise performance. Efferent (motor) nerves are less affected at altitude and are thought to stay fairly functional even in severe levels of arterial hypoxemia. Altitude also alters autonomic nervous system functions, which are thought to play an important role in the regulation of cardiac output and ventilation. Finally, the consequences of hypoxia-induced cortical adaptations and dysfunctions are evaluated in terms of neurotransmitter turnover, brain electrical activity, and cortical excitability. Even though the cessation of exercise or the reduction of exercise intensity, when reaching maximum performance, implies reduced motor recruitment by the nervous system, the mechanisms that lead to the de-recruitment of active muscle are still not well understood. In moderate hypoxia, muscle afferents appear to play an important role, whereas in severe hypoxia brain oxygenation may play a more important role.
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Affiliation(s)
- Markus Amann
- University of Zürich , Institute of Physiology, and ETH Zürich, Exercise Physiology, Zürich, Switzerland.
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Marcora SM. Commentaries on Viewpoint: Evidence that reduced skeletal muscle recruitment explains the lactate paradox during exercise at high altitude. J Appl Physiol (1985) 2009; 106:743-4. [DOI: 10.1152/japplphysiol.zdg-8397-vpcomm.2008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Bibliography. Current world literature. Systemic lupus erythematosus and Sjögren's syndrome. Curr Opin Rheumatol 2008; 20:631-2. [PMID: 18698190 DOI: 10.1097/bor.0b013e3283110091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Frappell PB, León-Velarde F, Rivera-Ch M. Oxygen transport at high altitude--an integrated perspective. Introduction. Respir Physiol Neurobiol 2007; 158:115-20. [PMID: 17889816 DOI: 10.1016/j.resp.2007.08.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2007] [Accepted: 08/13/2007] [Indexed: 10/22/2022]
Affiliation(s)
- Peter B Frappell
- Adaptational and Evolutionary Respiratory Physiology Laboratory, Department of Zoology, La Trobe University, Melbourne, Victoria, Australia.
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Mollard P, Woorons X, Letournel M, Lamberto C, Favret F, Pichon A, Beaudry M, Richalet JP. Determinant factors of the decrease in aerobic performance in moderate acute hypoxia in women endurance athletes. Respir Physiol Neurobiol 2007; 159:178-86. [PMID: 17766196 DOI: 10.1016/j.resp.2007.06.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2007] [Revised: 06/23/2007] [Accepted: 06/23/2007] [Indexed: 11/28/2022]
Abstract
The purpose of this study was to evaluate the limiting factors of maximal aerobic performance in endurance trained (TW) and sedentary (UW) women. Subjects performed four incremental tests on a cycle ergometer at sea level and in normobaric hypoxia corresponding to 1000, 2500 and 4500 m. Maximal oxygen uptake decrement (Delta VO2 max) was larger in TW at each altitude. Maximal heart rate and ventilation decreased at 4500 m in TW. Maximal cardiac output remained unchanged. In both groups, arterialized oxygen saturation (Sa'O2 max) decreased at and above 2500 m and maximal O2 transport (QaO2 max) decreased from 1000 m. At 4500 m, there was no more difference in QaO2 max between TW and UW. Mixed venous O2 pressure (PvO2 max) was lower and O2 extraction (O2ERmax) greater in TW at each altitude. The primary determinant factor of VO2 max decrement in moderate acute hypoxia in trained and untrained women is a reduced maximal O2 transport that cannot be compensate by tissue O2 extraction.
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Affiliation(s)
- Pascal Mollard
- Université Paris 13, Laboratoire Réponses cellulaires et fonctionnelles à l'hypoxie, EA2363, ARPE, 74 rue Marcel Cachin, 93017 Bobigny Cedex, France.
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