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Yu CJ, Tsai SC, Liao YH, Chen CY, Wu KC. Exploring the Potential Benefits of Interventions When Addressing Simulated Altitude Hypoxia during Male Cyclist Sports: A Systematic Review. APPLIED SCIENCES 2024; 14:3091. [DOI: 10.3390/app14073091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/21/2024]
Abstract
Training in hypoxic environments enhances endurance, but the various influences of training protocols and supplementation for efficient performance are not yet clear. This systematic review explored the effects of different supplementations and interventions used to optimize the aerobic and anaerobic performance of cyclists. Data were collected from the following sources: PubMed, Google Scholar, EMBASE, WOS, Cochrane Central Register of Controlled Trials, and randomized controlled trials (RCTs). Studies that explored the effects of supplementation or intervention during cycling were selected for analysis. Five studies (67 male cyclists; mean age, 23.74–33.56 years) reported different outcomes from supplementation or intervention during the acute hypoxia of cyclists. Three studies (42 male cyclists; mean age, 25.88–36.22 years) listed the benefits of beetroot juice in preserving SpO2 (pulse oxygen saturation) and enhancing high-intensity endurance performance, effectively preventing the reduction in power output. This systematic review provided evidence that the different effects of ischemic preconditioning (IPC), sildenafil, and beetroot (BR) supplementation and intervention did not present a statistically greater benefit than for normoxia groups, but BR supplementation promoted the benefits of SpO2. Future research should evaluate the duration and higher FiO2 (simulated altitude, hypoxia) levels of hypoxia in training protocols for cyclists. This is important when determining the effectiveness of supplements or interventions in hypoxic conditions and their impact on sports performance, particularly in terms of power output.
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Affiliation(s)
- Chen-Jui Yu
- Institute of Sports Sciences, University of Taipei, Taipei City 11153, Taiwan
| | - Shiow-Chwen Tsai
- Institute of Sports Sciences, University of Taipei, Taipei City 11153, Taiwan
| | - Yi-Hung Liao
- Department of Exercise and Health Sciences, National Taipei University of Nursing and Health Sciences, Taipei City 11219, Taiwan
| | - Chung-Yu Chen
- Department of Exercise and Health Sciences, University of Taipei, Taipei City 11153, Taiwan
| | - Kuo-Cheng Wu
- Graduate Institute of Sports Training, Kinesiology, University of Taipei, Taipei City 11153, Taiwan
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2
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Rosenberg AJ, Anderson GK, McKeefer HJ, Bird J, Pentz B, Byman BRM, Jendzjowsky N, Wilson RJ, Day TA, Rickards CA. Hemorrhage at high altitude: impact of sustained hypobaric hypoxia on cerebral blood flow, tissue oxygenation, and tolerance to simulated hemorrhage in humans. Eur J Appl Physiol 2024:10.1007/s00421-024-05450-1. [PMID: 38489034 DOI: 10.1007/s00421-024-05450-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 02/22/2024] [Indexed: 03/17/2024]
Abstract
With ascent to high altitude (HA), compensatory increases in cerebral blood flow and oxygen delivery must occur to preserve cerebral metabolism and consciousness. We hypothesized that this compensation in cerebral blood flow and oxygen delivery preserves tolerance to simulated hemorrhage (via lower body negative pressure, LBNP), such that tolerance is similar during sustained exposure to HA vs. low altitude (LA). Healthy humans (4F/4 M) participated in LBNP protocols to presyncope at LA (1130 m) and 5-7 days following ascent to HA (3800 m). Internal carotid artery (ICA) blood flow, cerebral delivery of oxygen (CDO2) through the ICA, and cerebral tissue oxygen saturation (ScO2) were determined. LBNP tolerance was similar between conditions (LA: 1276 ± 304 s vs. HA: 1208 ± 306 s; P = 0.58). Overall, ICA blood flow and CDO2 were elevated at HA vs. LA (P ≤ 0.01) and decreased with LBNP under both conditions (P < 0.0001), but there was no effect of altitude on ScO2 responses (P = 0.59). Thus, sustained exposure to hypobaric hypoxia did not negatively impact tolerance to simulated hemorrhage. These data demonstrate the robustness of compensatory physiological mechanisms that preserve human cerebral blood flow and oxygen delivery during sustained hypoxia, ensuring cerebral tissue metabolism and neuronal function is maintained.
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Affiliation(s)
- Alexander J Rosenberg
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA
- Integrative Physiology Laboratory, Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, USA
- Physiology Department, Midwestern University, Downers Grove, IL, USA
| | - Garen K Anderson
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Haley J McKeefer
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | | | | | | | - Nicholas Jendzjowsky
- University of Calgary, Calgary, AB, Canada
- Institute of Respiratory Medicine & Exercise Physiology, The Lundquist Institute at UCLA Harbor Medical, Torrance, CA, USA
| | | | | | - Caroline A Rickards
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA.
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3
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Gorini Pereira F, Greenfield AM, Kuennen M, Gillum TL. Exercise induced plasma volume expansion lowers cardiovascular strain during 15-km cycling time-trial in acute normobaric hypoxia. PLoS One 2024; 19:e0297553. [PMID: 38306343 PMCID: PMC10836693 DOI: 10.1371/journal.pone.0297553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 01/09/2024] [Indexed: 02/04/2024] Open
Abstract
The purpose of our study was to assess the influence of a single high-intensity interval exercise (HIIE) bout in normoxia on plasma volume (PV) and consequent cycling performance in normobaric hypoxia (0.15 FiO2, simulating ~2,500 m). Eight males (VO2peak: 48.8 ± 3.4 mL/kg/min, 24.0 ± 1.6 years) completed a hypoxic 15 km cycling time trial (TT), followed by a crossover intervention of either HIIE (8x4 min cycling bouts at 85% of VO2peak) or CON (matched kJ production from HIIE at 50% of VO2peak). 48 hours post intervention, an identical TT was performed. Cardiovascular parameters were measured via impedance cardiography during each TT. Changes in PV was measured 24 and 48 hours post HIIE and CON. HIIE increased PV at 24 (4.1 ± 3.9%, P = 0.031) and 48 (6.7 ± 1.7, P = 0.006) hours post, while no difference was observed following the CON (1.3 ± 1.1% and 0.3 ± 2.8%). The higher PV led to an increased stroke volume (P = 0.03) and cardiac output (P = 0.02) during the hypoxic TT, while heart rate was not changed (P = 0.49). We observed no changes in time to completion (-0.63 ± 0.57 min, P = 0.054) and power output (7.37 ± 7.98 W, P = 0.078) between TTs. In the absence of environmental stress, a single bout of HIIE was an effective strategy to increase PV and reduce the cardiovascular strain during a cycling TT at moderate simulated altitude but did not impact hypoxic exercise performance. Trial registration: Clinical Trials ID: NCT05800808.
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Affiliation(s)
- Felipe Gorini Pereira
- Department of Kinesiology, California Baptist University, Riverside, CA, United States of America
- Department of Kinesiology, Indiana University, Bloomington, IN, United States of America
| | - Andrew M. Greenfield
- Department of Kinesiology, California Baptist University, Riverside, CA, United States of America
| | - Matthew Kuennen
- Department of Exercise Science, High Point University, High Point, NC, United States of America
| | - Trevor L. Gillum
- Department of Kinesiology, California Baptist University, Riverside, CA, United States of America
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Nybo L, Rønnestad B, Lundby C. High or hot-Perspectives on altitude camps and heat-acclimation training as preparation for prolonged stage races. Scand J Med Sci Sports 2024; 34:e14268. [PMID: 36350277 DOI: 10.1111/sms.14268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/19/2022] [Accepted: 10/19/2022] [Indexed: 11/11/2022]
Abstract
Adaptation to heat stress and hypoxia are relevant for athletes participating in Tour de France or similar cycling races taking place during the summertime in landscapes with varying altitude. Both to minimize detrimental performance effects associated with arterial desaturation occurring at moderate altitudes in elite athletes, respectively, reduce the risk of hyperthermia on hot days, but also as a pre-competition acclimatization strategy to boost blood volume in already highly adapted athletes. The hematological adaptations require weeks of exposure to manifest, but are attractive as an augmented hemoglobin mass may improve arterial oxygen delivery and hence benefit prolonged performances. Altitude training camps have in this context a long history in exercise physiology and are still common practice in elite cycling. However, heat-acclimation training provides an attractive alternative for some athletes either as a stand-alone approach or in combination with altitude. The present paper provides an update and practical perspectives on the potential to utilize hypoxia and heat exposure to optimize hematological adaptations. Furthermore, we will consider temporal aspects both in terms of onset and decay of the adaptations relevant for improved thermoregulatory capacity and respiratory adaptations to abate arterial desaturation during altitude exposure. From focus on involved physiological mechanisms, time course, and responsiveness in elite athletes, we will provide guidance based on our experience from practical implementation in cyclists preparing for prolonged stage races such as the Tour de France.
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Affiliation(s)
- Lars Nybo
- Department of Nutrition, Exercise and Sport, University of Copenhagen, Copenhagen, Denmark
| | - Bent Rønnestad
- Inland Norway University of Applied Sciences, Lillehammer, Norway
| | - Carsten Lundby
- Inland Norway University of Applied Sciences, Lillehammer, Norway
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Siebenmann C, Roche J, Schlittler M, Simpson LL, Stembridge M. Regulation of haemoglobin concentration at high altitude. J Physiol 2023. [PMID: 38051656 DOI: 10.1113/jp284578] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 11/21/2023] [Indexed: 12/07/2023] Open
Abstract
Lowlanders sojourning for more than 1 day at high altitude (HA) experience a reduction in plasma volume (PV) that increases haemoglobin concentration and thus restores arterial oxygen content. If the sojourn extends over weeks, an expansion of total red cell volume (RCV) occurs and contributes to the haemoconcentration. While the reduction in PV was classically attributed to an increased diuretic fluid loss, recent studies support fluid redistribution, rather than loss, as the underlying mechanism. The fluid redistribution is presumably driven by a disappearance of proteins from the circulation and the resulting reduction in oncotic pressure exerted by the plasma, although the fate of the disappearing proteins remains unclear. The RCV expansion is the result of an accelerated erythropoietic activity secondary to enhanced renal erythropoietin release, but a contribution of other mechanisms cannot be excluded. After return from HA, intravascular volumes return to normal values and the normalisation of RCV might involve selective destruction of newly formed erythrocytes, although this explanation has been strongly challenged by recent studies. In contrast to acclimatised lowlanders, native highlanders originating from the Tibetan and the Ethiopian plateaus present with a normal or only mildly elevated haemoglobin concentration. Genetic adaptations blunting the erythropoietic response to HA exposure have been proposed as an explanation for the absence of more pronounced haemoconcentration in these populations, but new evidence also supports a contribution of a larger than expected PV. The functional significance of the relatively low haemoglobin concentration in Tibetan and Ethiopian highlanders is incompletely understood and warrants further investigation.
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Affiliation(s)
| | - Johanna Roche
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy
| | - Maja Schlittler
- AO Research Institute Davos, Regenerative Orthopaedics Program, Davos, Switzerland
| | - Lydia L Simpson
- Department of Sport Science, Division of Performance Physiology and Prevention, Universität Innsbruck, Innsbruck, Austria
| | - Mike Stembridge
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
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Périard JD, Girard O, Townsend N, Bourdon P, Cocking S, Ihsan M, Lacome M, Nichols D, Travers G, Wilson MG, Piscione J, Racinais S. Hematological Adaptations Following a Training Camp in Hot and/or Hypoxic Conditions in Elite Rugby Union Players. Int J Sports Physiol Perform 2023; 18:1053-1061. [PMID: 37553108 DOI: 10.1123/ijspp.2023-0166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 06/30/2023] [Accepted: 07/08/2023] [Indexed: 08/10/2023]
Abstract
PURPOSE To investigate the effects of a training camp with heat and/or hypoxia sessions on hematological and thermoregulatory adaptations. METHODS Fifty-six elite male rugby players completed a 2-week training camp with 5 endurance and 5 repeated-sprint sessions, rugby practice, and resistance training. Players were separated into 4 groups: CAMP trained in temperate conditions at sea level, HEAT performed the endurance sessions in the heat, ALTI slept and performed the repeated sprints at altitude, and H + A was a combination of the heat and altitude groups. RESULTS Blood volume across all groups increased by 140 mL (95%CI, 42-237; P = .006) and plasma volume by 97 mL (95%CI 28-167; P = .007) following the training camp. Plasma volume was 6.3% (0.3% to 12.4%) higher in HEAT than ALTI (P = .034) and slightly higher in HEAT than H + A (5.6% [-0.3% to 11.7%]; P = .076). Changes in hemoglobin mass were not significant (P = .176), despite a ∼1.2% increase in ALTI and H + A and a ∼0.7% decrease in CAMP and HEAT. Peak rectal temperature was lower during a postcamp heat-response test in HEAT (0.3 °C [0.1-0.5]; P = .010) and H + A (0.3 °C [0.1-0.6]; P = .005). Oxygen saturation upon waking was lower in ALTI (3% [2% to 5%]; P < .001) and H + A (4% [3% to 6%]; P < .001) than CAMP and HEAT. CONCLUSION Although blood and plasma volume increased following the camp, sleeping at altitude impeded the increase when training in the heat and only marginally increased hemoglobin mass. Heat training induced adaptations commensurate with partial heat acclimation; however, combining heat training and altitude training and confinement during a training camp did not confer concomitant hematological adaptations.
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Affiliation(s)
- Julien D Périard
- Research Institute for Sport and Exercise, University of Canberra, Canberra, ACT,Australia
- Department of Research and Scientific Support, Aspetar Orthopedic and Sports Medicine Hospital, Doha,Qatar
| | - Olivier Girard
- Department of Research and Scientific Support, Aspetar Orthopedic and Sports Medicine Hospital, Doha,Qatar
- School of Human Sciences (Exercise and Sport Science), University of Western Australia, Crawley, WA,Australia
| | - Nathan Townsend
- Department of Research and Scientific Support, Aspetar Orthopedic and Sports Medicine Hospital, Doha,Qatar
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha,Qatar
| | - Pitre Bourdon
- Department of Sport Science, ASPIRE, Academy for Sports Excellence, Doha,Qatar
- Alliance for Research in Exercise, Nutrition and Activity (ARENA), University of South Australia, Adelaide, SA,Australia
| | - Scott Cocking
- Department of Research and Scientific Support, Aspetar Orthopedic and Sports Medicine Hospital, Doha,Qatar
- Department of Sport Science, ASPIRE, Academy for Sports Excellence, Doha,Qatar
| | - Mohammed Ihsan
- Department of Research and Scientific Support, Aspetar Orthopedic and Sports Medicine Hospital, Doha,Qatar
| | - Mathieu Lacome
- Department of Research, Sport Laboratory, Expertise and Performance, French Institute of Sports (INSEP), Paris,France
- Department of Performance and Analytics, Parma Calcio, Parma,Italy
| | - David Nichols
- Department of Research and Scientific Support, Aspetar Orthopedic and Sports Medicine Hospital, Doha,Qatar
| | - Gavin Travers
- Department of Research and Scientific Support, Aspetar Orthopedic and Sports Medicine Hospital, Doha,Qatar
- Space Medicine Team, European Astronaut Center, Köln,Germany
| | - Mathew G Wilson
- Department of Research and Scientific Support, Aspetar Orthopedic and Sports Medicine Hospital, Doha,Qatar
- Institute of Sport, Exercise and Health, University College London, London,United Kingdom
| | - Julien Piscione
- Department of Research, Sport Laboratory, Expertise and Performance, French Institute of Sports (INSEP), Paris,France
| | - Sebastien Racinais
- Department of Research and Scientific Support, Aspetar Orthopedic and Sports Medicine Hospital, Doha,Qatar
- Department of Research, Sport Laboratory, Expertise and Performance, French Institute of Sports (INSEP), Paris,France
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7
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Mairbäurl H, Kilian S, Seide S, Muckenthaler MU, Gassmann M, Benedict RK. The Increase in Hemoglobin Concentration With Altitude Differs Between World Regions and Is Less in Children Than in Adults. Hemasphere 2023; 7:e854. [PMID: 37038466 PMCID: PMC10082317 DOI: 10.1097/hs9.0000000000000854] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 01/28/2023] [Indexed: 04/12/2023] Open
Abstract
To compensate for decreased oxygen partial pressure, high-altitude residents increase hemoglobin concentrations [Hb]. The elevation varies between world regions, posing problems in defining cutoff values for anemia or polycythemia. The currently used altitude adjustments (World Health Organization [WHO]), however, do not account for regional differences. Data from The Demographic and Health Survey (DHS) Program were analyzed from 32 countries harboring >4% of residents at altitudes above 1000 m. [Hb]-increase, (ΔHb/km altitude) was calculated by linear regression analysis. Tables show 95% reference intervals (RIs) for different altitude ranges, world regions, and age groups. The prevalence of anemia and polycythemia was calculated using regressions in comparison to WHO adjustments. The most pronounced Δ[Hb]/km was found in East Africans and South Americans while [Hb] increased least in South/South-East Asia. In African regions and Middle East, [Hb] was decreased in some altitude regions showing inconsistent changes in different age groups. Of note, in all regions, the Δ[Hb]/km was lower in children than in adults, and in the Middle East, it was even negative. Overall, the Δ[Hb]/km from our analysis differed from the region-independent adjustments currently suggested by the WHO resulting in a lower anemia prevalence at very high altitudes. The distinct patterns of Δ[Hb] with altitude in residents from different world regions imply that one single, region-independent correction factor for altitude is not be applicable for diagnosing abnormal [Hb]. Therefore, we provide regression coefficients and reference-tables that are specific for world regions and altitude ranges to improve diagnosing abnormal [Hb].
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Affiliation(s)
- Heimo Mairbäurl
- Translational Pneumology, University Hospital Heidelberg, Germany
- Translational Lung Research Center Heidelberg (TLRC), Member of the German Center for Lung Research, Heidelberg, Germany
| | - Samuel Kilian
- Institute of Medical Biometry and Informatics (IMBI), University of Heidelberg, Germany
| | - Svenja Seide
- Institute of Medical Biometry and Informatics (IMBI), University of Heidelberg, Germany
| | - Martina U. Muckenthaler
- Translational Lung Research Center Heidelberg (TLRC), Member of the German Center for Lung Research, Heidelberg, Germany
- Pediatric Oncology, Hematology & Immunology, University Hospital Heidelberg, Germany
| | - Max Gassmann
- Institute of Veterinary Physiology, Vetsuisse Faculty, and Zurich Center for Integrative Human Physiology (ZIHP), University of Zürich, Switzerland
- Universidad Peruana Cayetano Heredia (UPCH), Lima, Peru
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Burtscher J, Mallet RT, Pialoux V, Millet GP, Burtscher M. Adaptive Responses to Hypoxia and/or Hyperoxia in Humans. Antioxid Redox Signal 2022; 37:887-912. [PMID: 35102747 DOI: 10.1089/ars.2021.0280] [Citation(s) in RCA: 52] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Significance: Oxygen is indispensable for aerobic life, but its utilization exposes cells and tissues to oxidative stress; thus, tight regulation of cellular, tissue, and systemic oxygen concentrations is crucial. Here, we review the current understanding of how the human organism (mal-)adapts to low (hypoxia) and high (hyperoxia) oxygen levels and how these adaptations may be harnessed as therapeutic or performance enhancing strategies at the systemic level. Recent Advances: Hyperbaric oxygen therapy is already a cornerstone of modern medicine, and the application of mild hypoxia, that is, hypoxia conditioning (HC), to strengthen the resilience of organs or the whole body to severe hypoxic insults is an important preparation for high-altitude sojourns or to protect the cardiovascular system from hypoxic/ischemic damage. Many other applications of adaptations to hypo- and/or hyperoxia are only just emerging. HC-sometimes in combination with hyperoxic interventions-is gaining traction for the treatment of chronic diseases, including numerous neurological disorders, and for performance enhancement. Critical Issues: The dose- and intensity-dependent effects of varying oxygen concentrations render hypoxia- and/or hyperoxia-based interventions potentially highly beneficial, yet hazardous, although the risks versus benefits are as yet ill-defined. Future Directions: The field of low and high oxygen conditioning is expanding rapidly, and novel applications are increasingly recognized, for example, the modulation of aging processes, mood disorders, or metabolic diseases. To advance hypoxia/hyperoxia conditioning to clinical applications, more research on the effects of the intensity, duration, and frequency of altered oxygen concentrations, as well as on individual vulnerabilities to such interventions, is paramount. Antioxid. Redox Signal. 37, 887-912.
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Affiliation(s)
- Johannes Burtscher
- Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland.,Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Robert T Mallet
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Vincent Pialoux
- Inter-University Laboratory of Human Movement Biology EA7424, University Claude Bernard Lyon 1, University of Lyon, Lyon, France
| | - Grégoire P Millet
- Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland.,Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
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9
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Skattebo Ø, Hallén J. Individual variations in pre‐altitude hemoglobin mass influence hemoglobin mass responses to repeated altitude sojourns. Scand J Med Sci Sports 2022; 32:1493-1501. [DOI: 10.1111/sms.14218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 07/22/2022] [Accepted: 07/28/2022] [Indexed: 11/29/2022]
Affiliation(s)
- Øyvind Skattebo
- Department of Physical Performance Norwegian School of Sport Sciences Oslo Norway
| | - Jostein Hallén
- Department of Physical Performance Norwegian School of Sport Sciences Oslo Norway
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10
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Saugy JJ, Schmoutz T, Botrè F. Altitude and Erythropoietin: Comparative Evaluation of Their Impact on Key Parameters of the Athlete Biological Passport: A Review. Front Sports Act Living 2022; 4:864532. [PMID: 35847455 PMCID: PMC9282833 DOI: 10.3389/fspor.2022.864532] [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: 01/28/2022] [Accepted: 05/30/2022] [Indexed: 11/13/2022] Open
Abstract
The hematological module of the Athlete's Biological Passport (ABP) identifies doping methods and/or substances used to increase the blood's capacity to transport or deliver oxygen to the tissues. Recombinant human erythropoietin (rhEPOs) are doping substances known to boost the production of red blood cells and might have an effect on the blood biomarkers of the ABP. However, hypoxic exposure influences these biomarkers similarly to rhEPOs. This analogous impact complicates the ABP profiles' interpretation by antidoping experts. The present study aimed to collect and identify, through a literature search, the physiological effects on ABP blood biomarkers induced by these external factors. A total of 43 studies were selected for this review. A positive correlation (R2 = 0.605, r = 0.778, p < 0.001) was identified between the hypoxic dose and the increase in hemoglobin concentration (HGB) percentage. In addition, the change in the reticulocyte percentage (RET%) has been identified as one of the most sensitive parameters to rhEPO use. The mean effects of rhEPO on blood parameters were greater than those induced by hypoxic exposure (1.7 times higher for HGB and RET% and 4 times higher for hemoglobin mass). However, rhEPO micro-doses have shown effects that are hardly distinguishable from those identified after hypoxic exposure. The results of the literature search allowed to identify temporal and quantitative evolution of blood parameters in connection with different hypoxic exposure doses, as well as different rhEPOs doses. This might be considered to provide justified and well-documented interpretations of physiological changes in blood parameters of the Athlete Biological Passport.
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Affiliation(s)
- Jonas J. Saugy
- Institute of Sport Sciences, University of Lausanne (ISSUL), Lausanne, Switzerland
- Research and Expertise in anti-Doping Sciences (REDs), University of Lausanne, Lausanne, Switzerland
- *Correspondence: Jonas J. Saugy
| | - Tania Schmoutz
- Institute of Sport Sciences, University of Lausanne (ISSUL), Lausanne, Switzerland
| | - Francesco Botrè
- Institute of Sport Sciences, University of Lausanne (ISSUL), Lausanne, Switzerland
- Research and Expertise in anti-Doping Sciences (REDs), University of Lausanne, Lausanne, Switzerland
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11
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Ruggiero L, Harrison SWD, Rice CL, McNeil CJ. Neuromuscular fatigability at high altitude: Lowlanders with acute and chronic exposure, and native highlanders. Acta Physiol (Oxf) 2022; 234:e13788. [PMID: 35007386 PMCID: PMC9286620 DOI: 10.1111/apha.13788] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 01/04/2022] [Accepted: 01/05/2022] [Indexed: 01/18/2023]
Abstract
Ascent to high altitude is accompanied by a reduction in partial pressure of inspired oxygen, which leads to interconnected adjustments within the neuromuscular system. This review describes the unique challenge that such an environment poses to neuromuscular fatigability (peripheral, central and supraspinal) for individuals who normally reside near to sea level (SL) (<1000 m; ie, lowlanders) and for native highlanders, who represent the manifestation of high altitude-related heritable adaptations across millennia. Firstly, the effect of acute exposure to high altitude-related hypoxia on neuromuscular fatigability will be examined. Under these conditions, both supraspinal and peripheral fatigability are increased compared with SL. The specific mechanisms contributing to impaired performance are dependent on the exercise paradigm and amount of muscle mass involved. Next, the effect of chronic exposure to high altitude (ie, acclimatization of ~7-28 days) will be considered. With acclimatization, supraspinal fatigability is restored to SL values, regardless of the amount of muscle mass involved, whereas peripheral fatigability remains greater than SL except when exercise involves a small amount of muscle mass (eg, knee extensors). Indeed, when whole-body exercise is involved, peripheral fatigability is not different to acute high-altitude exposure, due to competing positive (haematological and muscle metabolic) and negative (respiratory-mediated) effects of acclimatization on neuromuscular performance. In the final section, we consider evolutionary adaptations of native highlanders (primarily Himalayans of Tibet and Nepal) that may account for their superior performance at altitude and lesser degree of neuromuscular fatigability compared with acclimatized lowlanders, for both single-joint and whole-body exercise.
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Affiliation(s)
- Luca Ruggiero
- Laboratory of Physiomechanics of Locomotion Department of Pathophysiology and Transplantation University of Milan Milan Italy
| | - Scott W. D. Harrison
- School of Kinesiology Faculty of Health Sciences The University of Western Ontario London Ontario Canada
| | - Charles L. Rice
- School of Kinesiology Faculty of Health Sciences The University of Western Ontario London Ontario Canada
- Department of Anatomy and Cell Biology Schulich School of Medicine and Dentistry The University of Western Ontario London Ontario Canada
| | - Chris J. McNeil
- Centre for Heart, Lung & Vascular Health School of Health and Exercise Sciences University of British Columbia Kelowna British Columbia Canada
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12
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Treml B, Wallner B, Blank C, Fries D, Schobersberger W. The Influence of Environmental Hypoxia on Hemostasis—A Systematic Review. Front Cardiovasc Med 2022; 9:813550. [PMID: 35252392 PMCID: PMC8894865 DOI: 10.3389/fcvm.2022.813550] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 01/24/2022] [Indexed: 12/26/2022] Open
Abstract
Humans have been ascending to high altitudes for centuries, with a growing number of professional- and leisure-related sojourns occurring in this millennium. A multitude of scientific reports on hemostatic disorders at high altitude suggest that hypoxia is an independent risk factor. However, no systematic analysis of the influence of environmental hypoxia on coagulation, fibrinolysis and platelet function has been performed. To fill this gap, we performed a systematic literature review, including only the data of healthy persons obtained during altitude exposure (<60 days). The results were stratified by the degree of hypoxia and sub-categorized into active and passive ascents and sojourns. Twenty-one studies including 501 participants were included in the final analysis. Since only one study provided relevant data, no conclusions regarding moderate altitudes (1,500–2,500 m) could be drawn. At high altitude (2,500–5,400 m), only small pathophysiological changes were seen, with a possible impact of increasing exercise loads. Elevated thrombin generation seems to be balanced by decreased platelet activation. Viscoelastic methods do not support increased thrombogenicity, with fibrinolysis being unaffected by high altitude. At extreme altitude (5,400–8,850 m), the limited data showed activation of coagulation in parallel with stimulation of fibrinolysis. Furthermore, multiple confounding variables at altitude, like training status, exercise load, fluid status and mental stress, prevent definitive conclusions being drawn on the impact of hypoxia on hemostasis. Thus, we cannot support the hypothesis that hypoxia triggers hypercoagulability and increases the risk of thromboembolic disorders, at least in healthy sojourners.
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Affiliation(s)
- Benedikt Treml
- General and Surgical Intensive Care Medicine, Department of Anesthesiology and Critical Care Medicine, Medical University Innsbruck, Innsbruck, Austria
| | - Bernd Wallner
- Department of Anesthesiology and Critical Care Medicine, Medical University Innsbruck, Innsbruck, Austria
- *Correspondence: Bernd Wallner
| | - Cornelia Blank
- Institute for Sports Medicine, Alpine Medicine and Health Tourism, Private University for Health Sciences, Medical Informatics and Technology UMIT, Hall i.T. and Tirol Kliniken GmbH, University Hospital Innsbruck, Innsbruck, Austria
| | - Dietmar Fries
- General and Surgical Intensive Care Medicine, Department of Anesthesiology and Critical Care Medicine, Medical University Innsbruck, Innsbruck, Austria
| | - Wolfgang Schobersberger
- Institute for Sports Medicine, Alpine Medicine and Health Tourism, Private University for Health Sciences, Medical Informatics and Technology UMIT, Hall i.T. and Tirol Kliniken GmbH, University Hospital Innsbruck, Innsbruck, Austria
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13
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Koivisto-Mørk AE, Svendsen IS, Skattebo Ø, Hallén J, Paulsen G. Impact of baseline serum ferritin and supplemental iron on altitude-induced hemoglobin mass response in elite athletes. Scand J Med Sci Sports 2021; 31:1764-1773. [PMID: 33908091 DOI: 10.1111/sms.13982] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 03/26/2021] [Accepted: 04/16/2021] [Indexed: 01/05/2023]
Abstract
The present study explored the impact of pre-altitude serum (s)-ferritin and iron supplementation on changes in hemoglobin mass (ΔHbmass) following altitude training. Measures of Hbmass and s-ferritin from 107 altitude sojourns (9-28 days at 1800-2500 m) with world-class endurance athletes (males n = 41, females n = 25) were analyzed together with iron supplementation and self-reported illness. Altitude sojourns with a hypoxic dose [median (range)] of 1169 (912) km·h increased Hbmass (mean ± SD) 36 ± 38 g (3.7 ± 3.7%, p < 0.001) and decreased s-ferritin -11 (190) µg·L-1 (p = 0.001). Iron supplements [27 (191) mg·day-1 ] were used at 45 sojourns (42%), while only 11 sojourns (10%) were commenced with s-ferritin <35 µg/L. Hbmass increased by 4.6 ± 3.7%, 3.4 ± 3.3%, 4.2 ± 4.3%, and 2.9 ± 3.4% with pre-altitude s-ferritin ≤35 µg·L-1 , 36-50 µg·L-1 , 51-100 µg·L-1 , and >100 µg·L-1 , respectively, with no group difference (p = 0.400). Hbmass increased by 4.1 ± 3.9%, 3.0 ± 3.0% and 3.7 ± 4.7% without, ≤50 mg·day-1 or >50 mg·day-1 supplemental iron, respectively (p = 0.399). Linear mixed model analysis revealed no interaction between pre-altitude s-ferritin and iron supplementation on ΔHbmass (p = 0.906). However, each 100 km·h increase in hypoxic dose augmented ΔHbmass by an additional 0.4% (95% CI: 0.1-0.7%; p = 0.012), while each 1 g·kg-1 higher pre-altitude Hbmass reduced ΔHbmass by -1% (-1.6 to -0.5; p < 0.001), and illness lowered ΔHbmass by -5.7% (-8.3 to -3.1%; p < 0.001). In conclusion, pre-altitude s-ferritin or iron supplementation were not related to the altitude-induced increase in Hbmass (3.7%) in world-class endurance athletes with clinically normal iron stores.
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Affiliation(s)
- Anu Elisa Koivisto-Mørk
- Norwegian Olympic Sports Centre, Norwegian Olympic and Paralympic Committee and Confederation of Sports, Oslo, Norway
| | - Ida Siobhan Svendsen
- Norwegian Olympic Sports Centre, Norwegian Olympic and Paralympic Committee and Confederation of Sports, Oslo, Norway
| | - Øyvind Skattebo
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - Jostein Hallén
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - Gøran Paulsen
- Norwegian Olympic Sports Centre, Norwegian Olympic and Paralympic Committee and Confederation of Sports, Oslo, Norway.,Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
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14
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Schlittler M, Gatterer H, Turner R, Regli IB, Woyke S, Strapazzon G, Rasmussen P, Kob M, Mueller T, Goetze JP, Maillard M, van Hall G, Feraille E, Siebenmann C. Regulation of plasma volume in male lowlanders during 4 days of exposure to hypobaric hypoxia equivalent to 3500 m altitude. J Physiol 2020; 599:1083-1096. [PMID: 33124686 PMCID: PMC7894546 DOI: 10.1113/jp280601] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 10/27/2020] [Indexed: 12/16/2022] Open
Abstract
Key points Acclimatization to hypoxia leads to a reduction in plasma volume (PV) that restores arterial O2 content. Findings from studies investigating the mechanisms underlying this PV contraction have been controversial, possibly as experimental conditions were inadequately controlled. We examined the mechanisms underlying the PV contraction evoked by 4 days of exposure to hypobaric hypoxia (HH) in 11 healthy lowlanders, while strictly controlling water intake, diet, temperature and physical activity. Exposure to HH‐induced an ∼10% PV contraction that was accompanied by a reduction in total circulating protein mass, whereas diuretic fluid loss and total body water remained unchanged. Our data support an oncotically driven fluid redistribution from the intra‐ to the extravascular space, rather than fluid loss, as the mechanism underlying HH‐induced PV contraction.
Abstract Extended hypoxic exposure reduces plasma volume (PV). The mechanisms underlying this effect are controversial, possibly as previous studies have been confounded by inconsistent experimental conditions. Here, we investigated the effect of hypobaric hypoxia (HH) on PV in a cross‐over study that strictly controlled for diet, water intake, physical activity and temperature. Eleven males completed two 4‐day sojourns in a hypobaric chamber, one in normoxia (NX) and one in HH equivalent to 3500 m altitude. PV, urine output, volume‐regulating hormones and plasma protein concentration were determined daily. Total body water (TBW) was determined at the end of both sojourns by deuterium dilution. Although PV was 8.1 ± 5.8% lower in HH than in NX after 24 h and remained ∼10% lower thereafter (all P < 0.002), no differences were detected in TBW (P = 0.17) or in 24 h urine volumes (all P > 0.23). Plasma renin activity and circulating aldosterone were suppressed in HH during the first half of the sojourn (all P < 0.05) but thereafter similar to NX, whereas no differences were detected for copeptin between sojourns (all P > 0.05). Markers for atrial natriuretic peptide were higher in HH than NX after 30 min (P = 0.001) but lower during the last 2 days (P < 0.001). While plasma protein concentration was similar between sojourns, total circulating protein mass (TCP) was reduced in HH at the same time points as PV (all P < 0.03). Despite transient hormonal changes favouring increased diuresis, HH did not enhance urine output. Instead, the maintained TBW and reduced TCP support an oncotically driven fluid redistribution into the extravascular compartment as the mechanism underlying PV contraction. Acclimatization to hypoxia leads to a reduction in plasma volume (PV) that restores arterial O2 content. Findings from studies investigating the mechanisms underlying this PV contraction have been controversial, possibly as experimental conditions were inadequately controlled. We examined the mechanisms underlying the PV contraction evoked by 4 days of exposure to hypobaric hypoxia (HH) in 11 healthy lowlanders, while strictly controlling water intake, diet, temperature and physical activity. Exposure to HH‐induced an ∼10% PV contraction that was accompanied by a reduction in total circulating protein mass, whereas diuretic fluid loss and total body water remained unchanged. Our data support an oncotically driven fluid redistribution from the intra‐ to the extravascular space, rather than fluid loss, as the mechanism underlying HH‐induced PV contraction.
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Affiliation(s)
- Maja Schlittler
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy
| | - Hannes Gatterer
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy
| | - Rachel Turner
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy
| | - Ivo B Regli
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy.,Department of Anesthesia and Intensive Care Medicine, 'F. Tappeiner' Hospital, Merano, Italy
| | - Simon Woyke
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy.,Department of Anaesthesiology and Intensive Care Medicine, Medical University of Innsbruck, Austria
| | - Giacomo Strapazzon
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy
| | | | - Michael Kob
- Division of Clinical Nutrition, Bolzano Regional Hospital, Bolzano, Italy
| | - Thomas Mueller
- Department of Clinical Pathology, Hospital of Bolzano, Bolzano, Italy
| | - Jens P Goetze
- Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Marc Maillard
- Service of Nephrology, University Hospital of Lausanne, Lausanne, Switzerland
| | - Gerrit van Hall
- Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Clinical Metabolomics Core Facility, Rigshospitalet, University of Copenhagen, Denmark
| | - Eric Feraille
- National Center of Competence in Research Kidney Control of Homeostasis (Kidney.CH), Zurich, Switzerland.,Department of Cellular Physiology and Metabolism, University of Geneva University Medical Center, Geneva, Switzerland
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15
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Mairbäurl H, Gassmann M, Muckenthaler MU. Geographical ancestry affects normal hemoglobin values in high-altitude residents. J Appl Physiol (1985) 2020; 129:1451-1459. [PMID: 33002380 DOI: 10.1152/japplphysiol.00025.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Increasing the hemoglobin (Hb) concentration is a major mechanism adjusting arterial oxygen content to decreased oxygen partial pressure of inspired air at high altitude. Approximately 5% of the world's population living at altitudes higher than 1,500 m shows this adaptive mechanism. Notably, there is a wide variation in the extent of increase in Hb concentration among different populations. This short review summarizes available information on Hb concentrations of high-altitude residents living at comparable altitudes (3,500-4,500 m) in different regions of the world. An increased Hb concentration is found in all high-altitude populations. The highest mean Hb concentration was found in adult male Andean residents and in Han Chinese living at high altitude, whereas it was lowest in Ethiopians, Tibetans, and Sherpas. A lower plasma volume in Andean high-altitude natives may offer a partial explanation. Indeed, male Andean high-altitude natives have a lower plasma volume than Tibetans and Ethiopians. Moreover, Hb values were lower in adult, nonpregnant females than in males; differences between populations of different ancestry were less pronounced. Various genetic polymorphisms were detected in high-altitude residents thought to favor life in a hypoxic environment, some of which correlate with the relatively low Hb concentration in the Tibetans and Ethiopians, whereas differences in angiotensin-converting enzyme allele distribution may be related to elevated Hb in the Andeans. Taken together, these results indicate different sensitivity of oxygen dependent control of erythropoiesis or plasma volume among populations of different geographical ancestry, offering explanations for differences in the Hb concentration at high altitude.
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Affiliation(s)
- Heimo Mairbäurl
- Departmment of Translational Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,Translational Lung Research Center Heidelberg, Member of the German Center for Lung Research, Heidelberg, Germany
| | - Max Gassmann
- Vetsuisse Faculty, Institute of Veterinary Physiology, University of Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.,Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Martina U Muckenthaler
- Translational Lung Research Center Heidelberg, Member of the German Center for Lung Research, Heidelberg, Germany.,Departmment of Pediatric Hematology, Oncology and Immunology, University Hospital Heidelberg, Heidelberg, Germany.,Molecular Medicine Partnership Unit, University of Heidelberg, Heidelberg, Germany.,German Centre for Cardiovascular Research, Partner Site Heidelberg/Mannheim, Germany
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16
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Oberholzer L, Bonne TC, Breenfeldt Andersen A, Bejder J, Højgaard Christensen R, Baastrup Nordsborg N, Lundby C. Reproducibility of the CO rebreathing technique with a lower CO dose and a shorter rebreathing duration at sea level and at 2320 m of altitude. Scandinavian Journal of Clinical and Laboratory Investigation 2020; 80:590-599. [PMID: 32955368 DOI: 10.1080/00365513.2020.1818282] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Total hemoglobin mass (Hbmass) is routinely assessed in studies by the carbon monoxide (CO) rebreathing. Its clinical application is often hindered due to the consequent rise in carboxyhemoglobin (%HbCO) and the concern of CO toxicity. We tested the reproducibility of the CO rebreathing with a CO dose of 0.5 mL/kg body mass (CO0.5) compared to 1.5 mL/kg (CO1.5) and when shortening the CO rebreathing protocol. Therefore, CO rebreathing was performed 1×/day in eight healthy individuals on four consecutive days. On each day, either CO0.5 (CO0.5-1 and CO0.5-2) or CO1.5 (CO1.5-1 and CO1.5-2) was administered. Venous blood samples to determine %HbCO and quantify Hbmass were obtained prior to, and at 6 (T6), 8 (T8) and 10 min (T10) of CO rebreathing. This protocol was tested at sea level and at 2320 m to investigate the altitude-related measurement error. At sea level, the mean difference (95% limits of agreement) in Hbmass between CO0.5-1 and CO0.5-2 was 26 g (-26; 79 g) and between CO1.5-1 and CO1.5-2, it was 17 g (-18; 52 g). The respective typical error (TE) corresponded to 2.4% (CO0.5) and 1.5% (CO1.5), while it was 6.5% and 3.0% at 2320 m. With CO0.5, shortening the CO rebreathing resulted in a TE for Hbmass of 4.4% (T8 vs. T10) and 14.1% (T6 vs T10) and with CO1.5, TE was 1.6% and 5.8%. In conclusion, the CO dose and rebreathing time for the CO rebreathing procedure can be decreased at the cost of a measurement error ranging from 1.5-14.1%.
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Affiliation(s)
- Laura Oberholzer
- Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Christian Bonne
- Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Jacob Bejder
- Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | | | - Carsten Lundby
- Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,Innland University of Applied Sciences, Lillehammer, Norway
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17
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Athanasiadou I, Christian Voss S, El Saftawy W, Al-Maadheed M, Valsami G, Georgakopoulos C. Hyperhydration using different hydration agents does not affect the haematological markers of the athlete biological passport in euhydrated volunteers. J Sports Sci 2020; 38:1924-1932. [DOI: 10.1080/02640414.2020.1763772] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Ioanna Athanasiadou
- Anti-Doping Lab Qatar, Doha, Qatar
- Laboratory of Biopharmaceutics & Pharmacokinetics, Department of Pharmacy, School of Health Sciences, National & Kapodistrian University of Athens, Athens, Greece
| | | | | | | | - Georgia Valsami
- Laboratory of Biopharmaceutics & Pharmacokinetics, Department of Pharmacy, School of Health Sciences, National & Kapodistrian University of Athens, Athens, Greece
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18
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Luo X, Feng L, Bai X, Zhu J, Zhao G, Wu M, Yan Z. Continuous changes in biological levels of complete blood count in a high altitude area of China. SAGE Open Med 2020; 8:2050312120931334. [PMID: 32587693 PMCID: PMC7294479 DOI: 10.1177/2050312120931334] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 05/11/2020] [Indexed: 11/17/2022] Open
Abstract
Objectives We aimed to establish a new reference interval of blood cell parameters by classifying and counting blood Cells of 16- to 85-year-old healthy volunteers and observing continuous changes with age. Methods We analyzed the blood cell parameters of 42,678 cases (men, 24,406; women, 18,272), and compared the blood cell parameters of men and women in different age groups using an independent samples t-test. Using limits of 2.5%-97.5%, a 90% confidence interval was used to develop new reference intervals. Results Counts of blood cell parameters, including white blood Cells, neutrophils, lymphocytes, monocytes, eosinophils, basophils, red blood Cells, hemoglobin, hematocrit, distribution width of red blood Cells and platelets, were found to differ between men and women in different age groups. These parameters were used to establish a new reference interval of blood Cells. Conclusion The blood cell parameters of both men and women changed with increasing age. The reference interval that we established will provide more accurate basic evidence for clinical diagnosis and treatment of diseases.
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Affiliation(s)
- Xuan Luo
- Department of Laboratory, People's Hospital of Yuxi City, Yuxi, P.R. China
| | - Lei Feng
- Department of Laboratory, People's Hospital of Yuxi City, Yuxi, P.R. China
| | - XueJing Bai
- Department of Laboratory, People's Hospital of Yuxi City, Yuxi, P.R. China
| | - JiangXian Zhu
- Department of Laboratory, People's Hospital of Yuxi City, Yuxi, P.R. China
| | - GuanCheng Zhao
- Department of Laboratory, People's Hospital of Yuxi City, Yuxi, P.R. China
| | - MengNa Wu
- Department of Laboratory, People's Hospital of Yuxi City, Yuxi, P.R. China
| | - ZeFeng Yan
- Department of Laboratory, People's Hospital of Yuxi City, Yuxi, P.R. China
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19
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MILLET GRÉGOIREP, BROCHERIE FRANCK. Hypoxic Training Is Beneficial in Elite Athletes. Med Sci Sports Exerc 2020; 52:515-518. [DOI: 10.1249/mss.0000000000002142] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Hematological status and endurance performance predictors after low altitude training supported by normobaric hypoxia: a double-blind, placebo controlled study. Biol Sport 2020; 36:341-349. [PMID: 31938005 PMCID: PMC6945048 DOI: 10.5114/biolsport.2019.88760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 07/04/2019] [Accepted: 09/25/2019] [Indexed: 11/20/2022] Open
Abstract
The benefits of altitude/hypoxic training for sea level performance are still under debate. This study examined the effects of low altitude training supported by normobaric hypoxia on hematological status and endurance performance predictors in elite female cyclists. Twenty-two female cyclists trained for 3 weeks at low altitude (<1100 m) and 2 weeks near sea level. During the first 3 weeks, 15 subjects stayed in hypoxic rooms simulating an altitude of 2200 m (+NH group, n = 8) or 1000 m (placebo group, n = 7), and 7 (control group) stayed in regular rooms. Significant increases in total hemoglobin mass (tHb-mass: p = 0.008, p = 0.025), power at 4 mmol·l-1 lactate (PAT4: p = 0.004, p = 0.005) (in absolute and relative values, respectively) and maximal power (PF: p = 0.034) (in absolute values) were observed. However, these effects were not associated with normobaric hypoxia. Changes in tHb-mass were not associated with initial concentrations of ferritin or transferrin receptor, whereas changes in relative tHb-mass (r = -0.53, p = 0.012), PF (r = -0.53, p = 0.01) and PAT4 (r = -0.65, p = 0.001) were inversely correlated with initial values. Changes in tHb-mass and PAT4 were positively correlated (r = 0.50, p = 0.017; r = 0.47, p = 0.028). Regardless of normobaric hypoxia application, low altitude training followed by sea-level training might improve hematological status in elite female cyclists, especially with relatively low initial values of tHb-mass, which could translate into enhanced endurance performance.
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21
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Mairbäurl H. Kinetics of Changes in Hemoglobin After Ascent to and Return from High Altitude. ACTA ACUST UNITED AC 2019. [DOI: 10.1007/s42978-019-00044-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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22
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Mikkelsen CJ, Junge N, Piil JF, Morris NB, Oberholzer L, Siebenmann C, Lundby C, Nybo L. Prolonged Heat Acclimation and Aerobic Performance in Endurance Trained Athletes. Front Physiol 2019; 10:1372. [PMID: 31749712 PMCID: PMC6843002 DOI: 10.3389/fphys.2019.01372] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Accepted: 10/16/2019] [Indexed: 11/17/2022] Open
Abstract
Heat acclimation (HA) involves physiological adaptations that directly promote exercise performance in hot environments. However, for endurance-athletes it is unclear if adaptations also improve aerobic capacity and performance in cool conditions, partly because previous randomized controlled trial (RCT) studies have been restricted to short intervention periods. Prolonged HA was therefore deployed in the present RCT study including 21 cyclists [38 ± 2 years, 184 ± 1 cm, 80.4 ± 1.7 kg, and maximal oxygen uptake (VO2max) of 58.1 ± 1.2 mL/min/kg; mean ± SE] allocated to either 5½ weeks of training in the heat [HEAT (n = 12)] or cool control [CON (n = 9)]. Training registration, familiarization to test procedures, determination of VO2max, blood volume and 15 km time trial (TT) performance were assessed in cool conditions (14°C) during a 2-week lead-in period, as well as immediately pre and post the intervention. Participants were instructed to maintain total training volume and complete habitual high intensity intervals in normal settings; but HEAT substituted part of cool training with 28 ± 2 sessions in the heat (1 h at 60% VO2max in 40°C; eliciting core temperatures above 39°C in all sessions), while CON completed all training in cool conditions. Acclimation for HEAT was verified by lower sweat sodium [Na+], reduced steady-state heart rate and improved submaximal exercise endurance in the heat. However, when tested in cool conditions both peak power output and VO2max remained unchanged for HEAT (pre 60.0 ± 1.5 vs. 59.8 ± 1.3 mL O2/min/kg). TT performance tested in 14°C was improved for HEAT and average power output increased from 298 ± 6 to 315 ± 6 W (P < 0.05), but a similar improvement was observed for CON (from 294 ± 11 to 311 ± 10 W). Based on the present findings, we conclude that training in the heat was not superior compared to normal (control) training for improving aerobic power or TT performance in cool conditions.
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Affiliation(s)
- C. Jacob Mikkelsen
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Nicklas Junge
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Jacob F. Piil
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Nathan B. Morris
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Laura Oberholzer
- Centre for Physical Activity Research, Copenhagen University Hospital, Copenhagen, Denmark
| | - Christoph Siebenmann
- Centre for Physical Activity Research, Copenhagen University Hospital, Copenhagen, Denmark
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy
| | - Carsten Lundby
- Centre for Physical Activity Research, Copenhagen University Hospital, Copenhagen, Denmark
- Innland Norway University of Applied Sciences, Lillehammer, Norway
| | - Lars Nybo
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
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23
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Akunov A, Sydykov A, Toktash T, Doolotova A, Sarybaev A. Hemoglobin Changes After Long-Term Intermittent Work at High Altitude. Front Physiol 2018; 9:1552. [PMID: 30443224 PMCID: PMC6221958 DOI: 10.3389/fphys.2018.01552] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 10/16/2018] [Indexed: 12/11/2022] Open
Abstract
Chronic high altitude hypoxia leads to an increase in red cell numbers and hemoglobin concentration. However, the effects of long-term intermittent hypoxia on hemoglobin concentration have not fully been studied. The aim of this study was to evaluate hemoglobin levels in workers commuting between an elevation of 3,800 m (2-week working shift) and lowland below 1,700 m (2 weeks of holiday). A total of 266 healthy males, aged from 20 to 69 years (mean age 45.9 ± 0.6 years), were included into this study. The duration of intermittent high altitude exposure ranged from 0 to 21 years. Any cardiac or pulmonary disorder was excluded during annual check-ups including clinical examination, clinical lab work (blood cell count, urine analysis, and biochemistry), ECG, echocardiography, and pulmonary function tests. The mean hemoglobin level in workers was 16.2 ± 0.11 g/dL. Univariate linear regression revealed an association of the hemoglobin levels with the years of exposure. Hemoglobin levels increased 0.068 g/dL [95% CI: 0.037 to 0.099, p < 0.001] for every year of intermittent high altitude exposure. Further, after adjusting for other confounding variables (age, living at low or moderate altitude, body mass index, and occupation) using multivariable regression analysis, the magnitude of hemoglobin level changes decreased, but remained statistically significant: 0.046 g/dL [95% CI: 0.005 to 0.086, p < 0.05]. Besides that, a weak linear relationship between hemoglobin levels and body mass index was revealed, which was independent of the years of exposure to high altitude (0.065 g/dL [95% CI: 0.006 to 0.124, p < 0.05]). We concluded that hemoglobin levels have a linear relationship with the exposure years spent in intermittent hypoxia and body mass index.
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Affiliation(s)
- Almaz Akunov
- Department of Mountain and Sleep Medicine and Pulmonary Hypertension, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyzstan.,Kyrgyz Indian Mountain Biomedical Research Center, Bishkek, Kyrgyzstan
| | - Akylbek Sydykov
- Department of Mountain and Sleep Medicine and Pulmonary Hypertension, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyzstan.,Excellence Cluster Cardio-Pulmonary System, Universities of Giessen and Marburg Lung Center, Member of the German Center for Lung Research (DZL), Justus Liebig University Giessen, Giessen, Germany
| | - Turgun Toktash
- Medical Department, Kumtor Gold Company, Bishkek, Kyrgyzstan
| | - Anara Doolotova
- Medical Department, Kumtor Gold Company, Bishkek, Kyrgyzstan
| | - Akpay Sarybaev
- Department of Mountain and Sleep Medicine and Pulmonary Hypertension, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyzstan.,Kyrgyz Indian Mountain Biomedical Research Center, Bishkek, Kyrgyzstan
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24
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Impact of Energy Availability, Health, and Sex on Hemoglobin-Mass Responses Following Live-High-Train-High Altitude Training in Elite Female and Male Distance Athletes. Int J Sports Physiol Perform 2018; 13:1090-1096. [PMID: 29431548 DOI: 10.1123/ijspp.2017-0547] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
PURPOSE The authors investigated the effects of sex, energy availability (EA), and health status on the change in hemoglobin mass (ΔHbmass) in elite endurance athletes over ∼3-4 wk of live-high-train-high altitude training in Flagstaff, AZ (2135 m; n = 27 women; n = 21 men; 27% 2016 Olympians). METHODS Precamp and postcamp Hbmass (optimized carbon monoxide rebreathing method) and iron status were measured, EA was estimated via food and training logs, and a Low Energy Availability in Females Questionnaire (LEAFQ) and a general injury/illness questionnaire were completed. Hypoxic exposure (h) was calculated with low (<500 h), moderate (500-600 h), and high (>600 h) groupings. RESULTS Absolute and relative percentage ΔHbmass was significantly greater in women (6.2% [4.0%], P < .001) than men (3.2% [3.3%], P = .008). %ΔHbmass showed a dose-response with hypoxic exposure (3.1% [3.8%] vs 4.9% [3.8%] vs 6.8% [3.7%], P = .013). Hbmasspre was significantly higher in eumenorrheic vs amenorrheic women (12.2 [1.0] vs 11.3 [0.5] g/kg, P = .004). Although statistically underpowered, %ΔHbmass was significantly less in sick (n = 4, -0.5% [0.4%]) vs healthy (n = 44, 5.4% [3.8%], P < .001) athletes. There were no significant correlations between self-reported iron intake, sex hormones, or EA on Hbmass outcomes. However, there was a trend for a negative correlation between LEAFQ score and %ΔHbmass (r = -.353, P = .07). CONCLUSIONS The findings confirm the importance of baseline Hbmass and exposure to hypoxia on increases in Hbmass during altitude training, while emphasizing the importance of athlete health and indices of EA on an optimal baseline Hbmass and hematological response to hypoxia.
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25
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Turner G, Fudge BW, Pringle JSM, Maxwell NS, Richardson AJ. Altitude training in endurance running: perceptions of elite athletes and support staff. J Sports Sci 2018; 37:163-172. [PMID: 29932816 DOI: 10.1080/02640414.2018.1488383] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
This study sought to establish perceptions of elite endurance athletes on the role and worth of altitude training. Elite British endurance runners were surveyed to identify the altitude and hypoxic training methods utilised, along with reasons for use, and any situational, cultural and behaviour factors influencing these. Prior to the 2012 Olympics Games, 39 athletes and 20 support staff (coaches/practitioners) completed an internet-based survey to establish differences between current practices and the accepted "best-practice". Almost all of the athletes (98%) and support staff (95%) surveyed had utilised altitude and hypoxic training, or had advised it to athletes. 75% of athletes believed altitude and hypoxia to be a "very important" factor in their training regime, with 50% of support staff believing the same. Athletes and support staff were in agreement of the methods of altitude training utilised (i.e. 'hypoxic dose' and strategy), with camps lasting 3-4 weeks at 1,500-2,500 m being the most popular. Athletes and support staff are utilising altitude and hypoxic training methods in a manner agreeing with research-based suggestions. The survey identified a number of specific challenges and priorities, which could provide scope to optimise future altitude training methods for endurance performance in these elite groups.
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Affiliation(s)
- Gareth Turner
- a Centre for Sport and Exercise Science and Medicine (SESAME) , University of Brighton , Eastbourne , UK.,c EIS Performance Centre , Loughborough University , Loughborough , UK
| | - Barry W Fudge
- b National Performance Centre , Loughborough University , Loughborough , UK
| | - Jamie S M Pringle
- c EIS Performance Centre , Loughborough University , Loughborough , UK
| | - Neil S Maxwell
- a Centre for Sport and Exercise Science and Medicine (SESAME) , University of Brighton , Eastbourne , UK
| | - Alan J Richardson
- a Centre for Sport and Exercise Science and Medicine (SESAME) , University of Brighton , Eastbourne , UK
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26
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Burtscher M, Gatterer H, Burtscher J, Mairbäurl H. Extreme Terrestrial Environments: Life in Thermal Stress and Hypoxia. A Narrative Review. Front Physiol 2018; 9:572. [PMID: 29867589 PMCID: PMC5964295 DOI: 10.3389/fphys.2018.00572] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 04/30/2018] [Indexed: 12/22/2022] Open
Abstract
Living, working and exercising in extreme terrestrial environments are challenging tasks even for healthy humans of the modern new age. The issue is not just survival in remote environments but rather the achievement of optimal performance in everyday life, occupation, and sports. Various adaptive biological processes can take place to cope with the specific stressors of extreme terrestrial environments like cold, heat, and hypoxia (high altitude). This review provides an overview of the physiological and morphological aspects of adaptive responses in these environmental stressors at the level of organs, tissues, and cells. Furthermore, adjustments existing in native people living in such extreme conditions on the earth as well as acute adaptive responses in newcomers are discussed. These insights into general adaptability of humans are complemented by outcomes of specific acclimatization/acclimation studies adding important information how to cope appropriately with extreme environmental temperatures and hypoxia.
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Affiliation(s)
- Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria.,Austrian Society for Alpine and Mountain Medicine, Innsbruck, Austria
| | - Hannes Gatterer
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria.,Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy
| | - Johannes Burtscher
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Heimo Mairbäurl
- Medical Clinic VII, Sports Medicine, University Hospital Heidelberg, Heidelberg, Germany.,German Center for Lung Research (DZL/TLRC-H), Heidelberg, Germany
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27
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Mairbäurl H. Neocytolysis: How to Get Rid of the Extra Erythrocytes Formed by Stress Erythropoiesis Upon Descent From High Altitude. Front Physiol 2018; 9:345. [PMID: 29674976 PMCID: PMC5896414 DOI: 10.3389/fphys.2018.00345] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 03/20/2018] [Indexed: 01/18/2023] Open
Abstract
Neocytolysis is the selective destruction of those erythrocytes that had been formed during stress-erythropoiesis in hypoxia in order to increase the oxygen transport capacity of blood. Neocytolysis likely aims at decreasing this excess amount of erythrocytes and hemoglobin (Hb) when it is not required anymore and to decrease blood viscosity. Neocytolysis seems to occur upon descent from high altitude. Similar processes seem to occur in microgravity, and are also discussed to mediate the replacement of erythrocytes containing fetal hemoglobin (HbF) with those having adult hemoglobin (HbA) after birth. This review will focus on hypoxia at high altitude. Hemoglobin concentration and total hemoglobin in blood increase by 20-50% depending on the altitude (i.e., the degree of hypoxia) and the duration of the sojourn. Upon return to normoxia hemoglobin concentration, hematocrit, and reticulocyte counts decrease faster than expected from inhibition of stress-erythropoiesis and normal erythrocyte destruction rates. In parallel, an increase in haptoglobin, bilirubin, and ferritin is observed, which serve as indirect markers of hemolysis and hemoglobin-breakdown. At the same time markers of progressing erythrocyte senescence appear even on reticulocytes. Unexpectedly, reticulocytes from hypoxic mice show decreased levels of the hypoxia-inducible factor HIF-1α and decreased activity of the BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3), which results in elevated mitochondrial activity in these cells. Furthermore, hypoxia increases the expression of miR-21, which inhibits the expression of catalase and thus decreases one of the most important mechanisms protecting against oxygen free radicals in erythrocytes. This unleashes a series of events which likely explain neocytolysis, because upon re-oxygenation systemic and mitochondrial oxygen radical formation increases and causes the selective destruction of those erythrocytes having impaired anti-oxidant capacity.
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Affiliation(s)
- Heimo Mairbäurl
- Medical Clinic VII, Sports Medicine, Translational Lung Research Center, German Center for Lung Research, University Hospital Heidelberg, Heidelberg, Germany
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Lee MK, Han KD, Lee JH, Sohn SY, Jeong JS, Kim MK, Baek KH, Song KH, Kwon HS. High hemoglobin levels are associated with decreased risk of diabetic retinopathy in Korean type 2 diabetes. Sci Rep 2018; 8:5538. [PMID: 29615813 PMCID: PMC5882879 DOI: 10.1038/s41598-018-23905-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 03/02/2018] [Indexed: 02/07/2023] Open
Abstract
Anemia is an independent risk factor for the development of diabetic retinopathy (DR) in patients with type 2 diabetes mellitus (DM). Hemoglobin levels may also be associated with DR. We investigated the association between hemoglobin levels and DR risk. This cross-sectional, population-based study utilized data from 2,123 type 2 DM patients aged ≥30 years who participated in the Korea National Health and Nutrition Examination Survey from 2008 to 2012. Participants underwent an ophthalmic examination, including fundus photographs. A multiple logistic regression analysis was performed to evaluate the relationship between hemoglobin levels and DR risk. The mean hemoglobin levels in patients with and without DR were 13.76 ± 0.12 and 14.33 ± 0.05 g/dL, respectively, with anemia observed in 16.2 (2.4)% and 7.8 (0.8)%, respectively. A 19% decrease in DR risk was found with a 1.0-g/dL increase in hemoglobin level. DR risk exhibited a decreasing trend with increasing hemoglobin levels (P for trend <0.0001). The adjusted odds ratio of DR was significantly lower in the highest hemoglobin quartile. Our findings indicate that high hemoglobin levels are significantly related to a decreased DR risk in Korean type 2 diabetes.
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Affiliation(s)
- Min-Kyung Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Myongji hospital, Gyeonggi-do, Republic of Korea
| | - Kyung-Do Han
- Department of Medical Statistics, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Jae-Hyuk Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Myongji hospital, Gyeonggi-do, Republic of Korea
| | - Seo-Young Sohn
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Myongji hospital, Gyeonggi-do, Republic of Korea
| | - Jee-Sun Jeong
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Mee-Kyoung Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Ki-Hyun Baek
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Ki-Ho Song
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Hyuk-Sang Kwon
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
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Bejder J, Nordsborg NB. Specificity of “Live High-Train Low” Altitude Training on Exercise Performance. Exerc Sport Sci Rev 2018; 46:129-136. [DOI: 10.1249/jes.0000000000000144] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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30
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Twomey R, Wrightson J, Fletcher H, Avraam S, Ross E, Dekerle J. Exercise-induced Fatigue in Severe Hypoxia after an Intermittent Hypoxic Protocol. Med Sci Sports Exerc 2018; 49:2422-2432. [PMID: 28708702 DOI: 10.1249/mss.0000000000001371] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
PURPOSE Exercise-induced central fatigue is alleviated after acclimatization to high altitude. The adaptations underpinning this effect may also be induced with brief, repeated exposures to severe hypoxia. The purpose of this study was to determine whether (i) exercise tolerance in severe hypoxia would be improved after an intermittent hypoxic (IH) protocol and (ii) exercise-induced central fatigue would be alleviated after an IH protocol. METHODS Nineteen recreationally active men were randomized into two groups who completed ten 2-h exposures in severe hypoxia (IH: partial pressure of inspired O2 82 mm Hg; n = 11) or normoxia (control; n = 8). Seven sessions involved cycling for 30 min at 25% peak power (W˙peak) in IH and at a matched heart rate in normoxia. Participants performed baseline constant-power cycling to task failure in severe hypoxia (TTF-Pre). After the intervention, the cycling trial was repeated (TTF-Post). Before and after exercise, responses to transcranial magnetic stimulation and supramaximal femoral nerve stimulation were obtained to assess central and peripheral contributions to neuromuscular fatigue. RESULTS From pre- to postexercise in TTF-Pre, maximal voluntary contraction (MVC), cortical voluntary activation (VATMS), and potentiated twitch force (Qtw,pot) decreased in both groups (all P < 0.05). After IH, TTF-Post was improved (535 ± 213 s vs 713 ± 271 s, P < 0.05) and an additional isotime trial was performed. After the IH intervention only, the reduction in MVC and VATMS was attenuated at isotime (P < 0.05). No differences were observed in the control group. CONCLUSIONS Whole-body exercise tolerance in severe hypoxia was prolonged after a protocol of IH. This may be related to an alleviation of the central contribution to neuromuscular fatigue.
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Affiliation(s)
- Rosie Twomey
- 1Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB, CANADA; 2Centre for Sport and Exercise Science and Medicine, University of Brighton, Eastbourne, UNITED KINGDOM; and 3English Institute of Sport, Bisham Abbey National Sports Centre, Marlow, UNITED KINGDOM
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31
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Wang X, Wei W, Yuan F, Li S, Lin J, Zhang J. Regional cerebral blood flow in natives at high altitude: An arterial spin labeled MRI study. J Magn Reson Imaging 2018; 48:708-717. [PMID: 29493838 DOI: 10.1002/jmri.25996] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Accepted: 02/13/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND It is known that a neurologic sequence occurs at high altitudes (HA); hence, cerebral blood flow (CBF) might vary by altitude. PURPOSE To use arterial spin labeled (ASL) MRI to evaluate absolute CBF differences between subjects who live at HA and lowlands. STUDY TYPE Cohort prospective trial. POPULATION In all, 64 HA Tibetans, 19 lowland Tibetans, and 25 lowland Han subjects. FIELD STRENGTH/SEQUENCE CBF was measured with the pulsed ASL sequence at 3T. ASSESSMENT CBF was correlated with abode altitude in HA Tibetans; CBF differences among HA Tibetans, lowland Tibetans, and lowland Han subjects was assessed. STATISTICAL TESTS Pearson correlation assessed the correlation. Independent t-tests analyzed group differences. RESULTS In HA Tibetans, CBF decreased with altitude in the bilateral anterior and posterior cingulate gyri, fusiform gyrus, cerebellar tonsil and cortices, and thalamus as well as left middle and inferior temporal gyri and right insula (P < 0.05); HA Tibetans (vs. lowland Tibetans) had lower CBF in the left hemisphere (precuneus, anterior cingulate gyrus, fusiform gyrus, and lingual gyrus) and right hemisphere (superior parietal lobule, precuneus, posterior cingulate gyrus, and cerebellar tonsil), while they had higher CBF in the left inferior parietal lobule, lentiform nucleus, and inferior frontal gyrus (P < 0.05). The overlapping regions, in which CBF in HA Tibetans correlated with altitude and decreased (vs. lowland Tibetans), were selected for region of interest analysis, and the results showed lower CBF in HA Tibetans than lowland Han subjects (P < 0.05). DATA CONCLUSION HA adaptation in Tibetans is associated with a decrease of regional CBF. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 4 J. Magn. Reson. Imaging 2018.
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Affiliation(s)
- Xiaochuan Wang
- Department of Neurology, Affiliated Hospital of Hangzhou Normal University, Hangzhou, China
| | - Wenping Wei
- MRI Center, First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Fengjuan Yuan
- Institute of Brain Diseases and Cognition, Medical College of Xiamen University, Xiamen, China
| | - Shanhua Li
- Institute of Brain Diseases and Cognition, Medical College of Xiamen University, Xiamen, China
| | - Jianzhong Lin
- Magnetic Resonance Center, Zhongshan Hospital Xiamen University, Xiamen, China
| | - Jiaxing Zhang
- Institute of Brain Diseases and Cognition, Medical College of Xiamen University, Xiamen, China
- Institute for Brain Research and Rehabilitation, South China Normal University, Guangzhou, China
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Sotiridis A, Debevec T, Mekjavić IB. Letter to the Editor: Combined effects of hypoxia and heat: importance of hypoxic dose. Am J Physiol Regul Integr Comp Physiol 2018; 314:R228-R229. [PMID: 29388459 DOI: 10.1152/ajpregu.00347.2017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Alexandros Sotiridis
- Department of Automation, Biocybernetics and Robotics, "Jozef Stefan" Institute , Ljubljana , Slovenia
| | - Tadej Debevec
- Department of Automation, Biocybernetics and Robotics, "Jozef Stefan" Institute , Ljubljana , Slovenia
| | - Igor B Mekjavić
- Department of Automation, Biocybernetics and Robotics, "Jozef Stefan" Institute , Ljubljana , Slovenia.,Department of Biomedical Physiology and Kinesiology, Simon Fraser University, British Columbia, Canada
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33
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Millet GP, Chapman RF, Girard O, Brocherie F. Is live high -train low altitude training relevant for elite athletes? Flawed analysis from inaccurate data. Br J Sports Med 2017; 53:923-925. [PMID: 29247024 DOI: 10.1136/bjsports-2017-098083] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/09/2017] [Indexed: 11/04/2022]
Affiliation(s)
- Gregoire P Millet
- Institute of Sport Sciences, Faculty of Biology and Medicine, ISSUL, University of Lausanne, Lausanne, Switzerland
| | - Robert F Chapman
- Department of Kinesiology, HH Morris Human Performance Laboratory, Indiana University, Bloomington, Indiana, USA
| | - Olivier Girard
- Aspetar Orthopaedic and Sports Medicine Hospital, Athlete Health and Performance Research Centre, Doha, Qatar
| | - Franck Brocherie
- Research Department, Laboratory Sport, Expertise and Performance, French Institute of Sport (INSEP), Paris, France
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Siebenmann C, Keiser S, Robach P, Lundby C. CORP: The assessment of total hemoglobin mass by carbon monoxide rebreathing. J Appl Physiol (1985) 2017; 123:645-654. [DOI: 10.1152/japplphysiol.00185.2017] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 06/14/2017] [Accepted: 06/26/2017] [Indexed: 11/22/2022] Open
Abstract
In this Cores of Reproducibility in Physiology (CORP) article, we present the theory and practical aspects of the carbon monoxide (CO) rebreathing method for the determination of total hemoglobin mass in humans. With CO rebreathing, a small quantity of CO is diluted in O2and rebreathed for a specified time period, during which most of the CO is absorbed and bound to circulating hemoglobin. The dilution principle then allows calculation of the total number of circulating hemoglobin molecules based on the number of absorbed CO molecules and the resulting changes in the fraction of carboxyhemoglobin in blood. Total hemoglobin mass is derived by multiplication with the molar weight of hemoglobin. CO rebreathing has been used for >100 yr and has undergone steady improvement so that today excellent values in terms of accuracy and precision can be achieved if the methodological precautions are carefully followed.
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Affiliation(s)
- Christoph Siebenmann
- The Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Stefanie Keiser
- Center for Integrative Human Physiology, Institute of Physiology, University of Zürich, Zürich, Switzerland; and
| | - Paul Robach
- National School for Mountain Sports, Site of the National School for Skiing and Mountaineering (ENSA), Chamonix, France
| | - Carsten Lundby
- The Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
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35
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Siebenmann C, Robach P, Lundby C. Regulation of blood volume in lowlanders exposed to high altitude. J Appl Physiol (1985) 2017; 123:957-966. [PMID: 28572493 DOI: 10.1152/japplphysiol.00118.2017] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 05/18/2017] [Accepted: 05/31/2017] [Indexed: 12/21/2022] Open
Abstract
Humans ascending to high altitude (HA) experience a reduction in arterial oxyhemoglobin saturation and, as a result, arterial O2 content ([Formula: see text]). As HA exposure extends, this reduction in [Formula: see text] is counteracted by an increase in arterial hemoglobin concentration. Initially, hemoconcentration is exclusively related to a reduction in plasma volume (PV), whereas after several weeks a progressive expansion in total red blood cell volume (RCV) contributes, although often to a modest extent. Since the decrease in PV is more rapid and usually more pronounced than the expansion in RCV, at least during the first weeks of exposure, a reduction in circulating blood volume is common at HA. Although the regulation of hematological responses to HA has been investigated for decades, it remains incompletely understood. This is not only related to the large number of mechanisms that could be involved and the complexity of their interplay but also to the difficulty of conducting comprehensive experiments in the often secluded HA environment. In this review, we present our understanding of the kinetics, the mechanisms and the physiological relevance of the HA-induced reduction in PV and expansion in RCV.
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Affiliation(s)
- Christoph Siebenmann
- The Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark; and
| | - Paul Robach
- National School for Mountain Sports, Site of the National School for Skiing and Mountaineering (ENSA), Chamonix, France
| | - Carsten Lundby
- The Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark; and
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Flück D, Morris LE, Niroula S, Tallon CM, Sherpa KT, Stembridge M, Ainslie PN, McManus AM. UBC-Nepal expedition: markedly lower cerebral blood flow in high-altitude Sherpa children compared with children residing at sea level. J Appl Physiol (1985) 2017; 123:1003-1010. [PMID: 28572497 DOI: 10.1152/japplphysiol.00292.2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 05/28/2017] [Accepted: 05/30/2017] [Indexed: 12/12/2022] Open
Abstract
Developmental cerebral hemodynamic adaptations to chronic high-altitude exposure, such as in the Sherpa population, are largely unknown. To examine hemodynamic adaptations in the developing human brain, we assessed common carotid (CCA), internal carotid (ICA), and vertebral artery (VA) flow and middle cerebral artery (MCA) velocity in 25 (9.6 ± 1.0 yr old, 129 ± 9 cm, 27 ± 8 kg, 14 girls) Sherpa children (3,800 m, Nepal) and 25 (9.9 ± 0.7 yr old, 143 ± 7 cm, 34 ± 6 kg, 14 girls) age-matched sea level children (344 m, Canada) during supine rest. Resting gas exchange, blood pressure, oxygen saturation and heart rate were assessed. Despite comparable age, height and weight were lower (both P < 0.01) in Sherpa compared with sea level children. Mean arterial pressure, heart rate, and ventilation were similar, whereas oxygen saturation (95 ± 2 vs. 99 ± 1%, P < 0.01) and end-tidal Pco2 (24 ± 3 vs. 36 ± 3 Torr, P < 0.01) were lower in Sherpa children. Global cerebral blood flow was ∼30% lower in Sherpa compared with sea level children. This was reflected in a lower ICA flow (283 ± 108 vs. 333 ± 56 ml/min, P = 0.05), VA flow (78 ± 26 vs. 118 ± 35 ml/min, P < 0.05), and MCA velocity (72 ± 14 vs. 88 ± 14 cm/s, P < 0.01). CCA flow was similar between Sherpa and sea level children (425 ± 92 vs. 441 ± 81 ml/min, P = 0.52). Scaling flow and oxygen uptake for differences in vessel diameter and body size, respectively, led to the same findings. A lower cerebral blood flow in Sherpa children may reflect specific cerebral hemodynamic adaptations to chronic hypoxia.NEW & NOTEWORTHY Cerebral blood flow is lower in Sherpa children compared with children residing at sea level; this may reflect a cerebral hemodynamic pattern, potentially due to adaptation to a hypoxic environment.
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Affiliation(s)
- Daniela Flück
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Science, University of British Columbia, Kelowna, British Columbia, Canada;
| | - Laura E Morris
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Science, University of British Columbia, Kelowna, British Columbia, Canada
| | - Shailesh Niroula
- Institute of Medicine, Tribhuvan University, Kirtipur, Nepal.,Khunde Hospital, Khunde, Nepal; and
| | - Christine M Tallon
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Science, University of British Columbia, Kelowna, British Columbia, Canada
| | | | - Mike Stembridge
- Cardiff School of Sport, Cardiff Metropolitan University, Cardiff, United Kingdom
| | - Philip N Ainslie
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Science, University of British Columbia, Kelowna, British Columbia, Canada
| | - Ali M McManus
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Science, University of British Columbia, Kelowna, British Columbia, Canada
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Keramidas ME, Mekjavic IB, Eiken O. LunHab: interactive effects of a 10 day sustained exposure to hypoxia and bedrest on aerobic exercise capacity in male lowlanders. Exp Physiol 2017; 102:694-710. [DOI: 10.1113/ep086167] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 03/20/2017] [Indexed: 11/08/2022]
Affiliation(s)
- Michail E. Keramidas
- 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
- Department of Biomedical Physiology and Kinesiology; Simon Fraser University; Burnaby BC 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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Endurance, aerobic high-intensity, and repeated sprint cycling performance is unaffected by normobaric “Live High-Train Low”: a double-blind placebo-controlled cross-over study. Eur J Appl Physiol 2017; 117:979-988. [DOI: 10.1007/s00421-017-3586-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Accepted: 03/08/2017] [Indexed: 10/19/2022]
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Beidleman BA, Staab JE, Muza SR, Sawka MN. Quantitative model of hematologic and plasma volume responses after ascent and acclimation to moderate to high altitudes. Am J Physiol Regul Integr Comp Physiol 2016; 312:R265-R272. [PMID: 28039191 DOI: 10.1152/ajpregu.00225.2016] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 12/22/2016] [Accepted: 12/24/2016] [Indexed: 11/22/2022]
Abstract
Despite decades of research, the magnitude and time course of hematologic and plasma volume (PV) changes following rapid ascent and acclimation to various altitudes are not precisely described. To develop a quantitative model, we utilized a comprehensive database and general linear mixed models to analyze 1,055 hemoglobin ([Hb]) and hematocrit (Hct) measurements collected at sea level and repeated time points at various altitudes in 393 unacclimatized men (n = 270) and women (n = 123) who spent between 2 h and 7 days at 2,500-4,500 m under well-controlled and standardized experimental conditions. The PV change (ΔPV) was calculated from [Hb] and Hct measurements during a time period when erythrocyte volume is stable. The results are 1) ΔPV decreases rapidly (~6%) after the 1st day at 2,500 m and [Hb] and Hct values increase by 0.5 g/dl and 1.5 points, respectively; 2) ΔPV decreases an additional 1%, and [Hb] and Hct increase an additional 0.1 g/dl and 0.2 points every 500-m increase in elevation above 2,500 m after the 1st day; 3) ΔPV continues to decrease over time at altitude, but the magnitude of this decrease and subsequent increase in [Hb] and Hct levels is dependent on elevation and sex; and 4) individuals with high initial levels of [Hb] and Hct and older individuals hemoconcentrate less at higher elevations. This study provides the first quantitative delineation of ΔPV and hematological responses during the first week of exposure over a wide range of altitudes and demonstrates that absolute altitude and time at altitude, as well as initial hematologic status, sex, and age impact the response.
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Affiliation(s)
- Beth A Beidleman
- Thermal and Mountain Medicine Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts; and
| | - Janet E Staab
- Thermal and Mountain Medicine Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts; and
| | - Stephen R Muza
- Thermal and Mountain Medicine Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts; and
| | - Michael N Sawka
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia
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Saugy JJ, Rupp T, Faiss R, Lamon A, Bourdillon N, Millet GP. Cycling Time Trial Is More Altered in Hypobaric than Normobaric Hypoxia. Med Sci Sports Exerc 2016; 48:680-8. [PMID: 26559447 DOI: 10.1249/mss.0000000000000810] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE Slight physiological differences between acute exposure in normobaric hypoxia (NH) and hypobaric hypoxia (HH) have been reported. Taken together, these differences suggest different physiological responses to hypoxic exposure to a simulated altitude (NH) versus a terrestrial altitude (HH). For this purpose, in the present study, we aimed to directly compare the time-trial performance after acute hypoxia exposure (26 h, 3450 min) by the same subjects under three different conditions: NH, HH, and normobaric normoxia (NN). Based on all of the preceding studies examining the differences among these hypoxic conditions, we hypothesized greater performance impairment in HH than in NH. METHODS The experimental design consisted of three sessions: NN (Sion: FiO2, 20.93), NH (Sion, hypoxic room: FiO2, 13.6%; barometric pressure, 716 mm Hg), and HH (Jungfraujoch: FiO2, 20.93; barometric pressure, 481 mm Hg). The performance was evaluated at the end of each session with a cycle time trial of 250 kJ. RESULTS The mean time trial duration in NN was significantly shorter than under the two hypoxic conditions (P < 0.001). In addition, the mean duration in NH was significantly shorter than that in HH (P < 0.01). The mean pulse oxygen saturation during the time trial was significantly lower for HH than for NH (P < 0.05), and it was significantly higher in NN than for the two other sessions (P < 0.001). CONCLUSION As previously suggested, HH seems to be a more stressful stimulus, and NH and HH should not be used interchangeability when endurance performance is the main objective. The principal factor in this performance difference between hypoxic conditions seemed to be the lower peripheral oxygen saturation in HH at rest, as well as during exercise.
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Affiliation(s)
- Jonas J Saugy
- 1ISSUL, Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, SWITZERLAND; 2Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, SWITZERLAND; 3Exercise Physiology Laboratory, Savoie Mont Blanc University, Chambery, FRANCE
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Montero D, Lundby C. Red cell volume response to exercise training: Association with aging. Scand J Med Sci Sports 2016; 27:674-683. [DOI: 10.1111/sms.12798] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/18/2016] [Indexed: 12/13/2022]
Affiliation(s)
- D. Montero
- Zurich Center for Integrative Human Physiology (ZIHP); Institute of Physiology; University of Zurich; Zurich Switzerland
| | - C. Lundby
- Zurich Center for Integrative Human Physiology (ZIHP); Institute of Physiology; University of Zurich; Zurich Switzerland
- Food, Nutrition & Sport Science; Gothenburg University; Gothenburg Sweden
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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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Siebenmann C, Cathomen A, Hug M, Keiser S, Lundby AK, Hilty MP, Goetze JP, Rasmussen P, Lundby C. Hemoglobin mass and intravascular volume kinetics during and after exposure to 3,454-m altitude. J Appl Physiol (1985) 2015; 119:1194-201. [DOI: 10.1152/japplphysiol.01121.2014] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 02/25/2015] [Indexed: 01/14/2023] Open
Abstract
High altitude (HA) exposure facilitates a rapid contraction of plasma volume (PV) and a slower occurring expansion of hemoglobin mass (Hbmass). The kinetics of the Hbmass expansion has never been examined by multiple repeated measurements, and this was our primary study aim. The second aim was to investigate the mechanisms mediating the PV contraction. Nine healthy, normally trained sea-level (SL) residents (8 males, 1 female) sojourned for 28 days at 3,454 m. Hbmass was measured and PV was estimated by carbon monoxide rebreathing at SL, on every 4th day at HA, and 1 and 2 wk upon return to SL. Four weeks at HA increased Hbmass by 5.26% (range 2.5-11.1%; P < 0.001). The individual Hbmass increases commenced with up to 12 days of delay and reached a maximal rate of 4.04 ± 1.02 g/day after 14.9 ± 5.2 days. The probability for Hbmass to plateau increased steeply after 20–24 days. Upon return to SL Hbmass decayed by −2.46 ± 2.3 g/day, reaching values similar to baseline after 2 wk. PV, aldosterone concentration, and renin activity were reduced at HA ( P < 0.001) while the total circulating protein mass remained unaffected. In summary, the Hbmass response to HA exposure followed a sigmoidal pattern with a delayed onset and a plateau after ∼3 wk. The decay rate of Hbmass upon descent to SL did not indicate major changes in the rate of erythrolysis. Moreover, our data support that PV contraction at HA is regulated by the renin-angiotensin-aldosterone axis and not by changes in oncotic pressure.
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Affiliation(s)
- C. Siebenmann
- Center for Integrative Human Physiology, Institute of Physiology, University of Zürich, Zürich, Switzerland
- Department of Environmental Physiology, School of Technology and Health, Royal Institute of Technology, Solna, Sweden
| | - A. Cathomen
- Institute of Human Movement Sciences and Sport, ETH Zürich, Zürich, Switzerland
| | - M. Hug
- Center for Integrative Human Physiology, Institute of Physiology, University of Zürich, Zürich, Switzerland
| | - S. Keiser
- Center for Integrative Human Physiology, Institute of Physiology, University of Zürich, Zürich, Switzerland
| | - A. K. Lundby
- Center for Integrative Human Physiology, Institute of Physiology, University of Zürich, Zürich, Switzerland
| | - M. P. Hilty
- Intensive Care Unit, University Hospital of Zürich, Zürich, Switzerland
| | - J. P. Goetze
- Department of Clinical Biochemistry, Copenhagen, and Aarhus University, Aarhus, Denmark
| | | | - C. Lundby
- Center for Integrative Human Physiology, Institute of Physiology, University of Zürich, Zürich, Switzerland
- Food and Nutrition and Sport Science, Gothenburg University, Gothenburg, Sweden
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Yan Y, Shi Y, Wang C, Guo P, Wang J, Zhang CY, Zhang C. Influence of a high-altitude hypoxic environment on human plasma microRNA profiles. Sci Rep 2015; 5:15156. [PMID: 26468998 PMCID: PMC4606833 DOI: 10.1038/srep15156] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 09/16/2015] [Indexed: 11/09/2022] Open
Abstract
Circulating microRNAs (miRNAs) are promising disease biomarkers. However, the influence of high-altitude hypoxic environments on plasma miRNA profiles remains unknown. This study included a total of 509 plasma samples from 278 native Tibetans and 80 newly arrived migrant Han Chinese (Tibet Han) residing at 3560 m and 151 Han Chinese residing at 8.9 m (Nanjing Han). The levels of 754 miRNAs were initially determined using a TaqMan Low Density Array (TLDA) in two pooled samples from 50 Tibet Han and 50 Nanjing Han individuals. Some markedly altered miRNAs in Tibet Han were subsequently measured in all 509 plasma samples by individual qRT-PCR. Compared with the Nanjing Han, 172 miRNAs were differentially expressed in the Tibet Han (105 upregulated and 67 downregulated). The correlation coefficient for the two groups was 0.72. Several upregulated miRNAs were randomly selected for analysis by qRT-PCR, and the results were consistent with those identified by TLDA. These miRNAs were also significantly increased in the Tibetans compared with the Nanjing Han. Furthermore, these altered miRNAs showed strong positive correlations with red blood cell counts and hemoglobin values. These data are the first to provide clear evidence that a high-altitude hypoxic environment significantly affects human plasma miRNA profiles.
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Affiliation(s)
- Yan Yan
- Department of Clinical Laboratory, Jinling Hospital, State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University School of Medicine, Nanjing University, Nanjing 210002, China.,Jiangsu Engineering Research Center for microRNA Biology and Biotechnology, Advance Research Institute of Life Sciences, Nanjing University, Nanjing, China
| | - Yonghui Shi
- Department of Clinical Laboratory, Jinling Hospital, State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University School of Medicine, Nanjing University, Nanjing 210002, China
| | - Cheng Wang
- Department of Clinical Laboratory, Jinling Hospital, State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University School of Medicine, Nanjing University, Nanjing 210002, China.,Jiangsu Engineering Research Center for microRNA Biology and Biotechnology, Advance Research Institute of Life Sciences, Nanjing University, Nanjing, China
| | - Pengtao Guo
- Department of Clinical Laboratory, the Forty-First Hospital of PLA, Nêdong, China
| | - Junjun Wang
- Department of Clinical Laboratory, Jinling Hospital, State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University School of Medicine, Nanjing University, Nanjing 210002, China
| | - Chen-Yu Zhang
- Jiangsu Engineering Research Center for microRNA Biology and Biotechnology, Advance Research Institute of Life Sciences, Nanjing University, Nanjing, China
| | - Chunni Zhang
- Department of Clinical Laboratory, Jinling Hospital, State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University School of Medicine, Nanjing University, Nanjing 210002, China.,Jiangsu Engineering Research Center for microRNA Biology and Biotechnology, Advance Research Institute of Life Sciences, Nanjing University, Nanjing, China
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Govus AD, Garvican-Lewis LA, Abbiss CR, Peeling P, Gore CJ. Pre-Altitude Serum Ferritin Levels and Daily Oral Iron Supplement Dose Mediate Iron Parameter and Hemoglobin Mass Responses to Altitude Exposure. PLoS One 2015; 10:e0135120. [PMID: 26263553 PMCID: PMC4532405 DOI: 10.1371/journal.pone.0135120] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 07/17/2015] [Indexed: 11/18/2022] Open
Abstract
PURPOSE To investigate the influence of daily oral iron supplementation on changes in hemoglobin mass (Hbmass) and iron parameters after 2-4 weeks of moderate altitude exposure. METHODS Hematological data collected from 178 athletes (98 males, 80 females) exposed to moderate altitude (1,350-3,000 m) were analysed using linear regression to determine how altitude exposure combined with oral iron supplementation influenced Hbmass, total iron incorporation (TII) and blood iron parameters [ferritin and transferrin saturation (TSAT)]. RESULTS Altitude exposure (mean ± s: 21 ± 3 days) increased Hbmass by 1.1% [-0.4, 2.6], 3.3% [1.7, 4.8], and 4.0% [2.0, 6.1] from pre-altitude levels in athletes who ingested nil, 105 mg and 210 mg respectively, of oral iron supplement daily. Serum ferritin levels decreased by -33.2% [-46.9, -15.9] and 13.8% [-32.2, 9.7] from pre-altitude levels in athletes who supplemented with nil and 105 mg of oral iron supplement daily, but increased by 36.8% [1.3, 84.8] in athletes supplemented with 210 mg of oral iron daily. Finally, athletes who ingested either 105 mg or 210 mg of oral iron supplement daily had a greater TII compared with non-supplemented athletes (0 versus 105 mg: effect size (d) = -1.88 [-2.56, -1.17]; 0 versus 210 mg: effect size (d) = -2.87 [-3.88, -1.66]). CONCLUSION Oral iron supplementation during 2-4 weeks of moderate altitude exposure may enhance Hbmass production and assist the maintenance of iron balance in some athletes with low pre-altitude iron stores.
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Affiliation(s)
- Andrew D. Govus
- Centre for Exercise and Sports Science Research, School of Exercise and Health Science, Edith Cowan University, Joondalup, WA, Australia
- * E-mail:
| | - Laura A. Garvican-Lewis
- Department of Physiology, Australian Institute of Sport, Bruce, ACT, Australia
- Research Institute for Sport and Exercise, University of Canberra, Bruce, ACT, Australia
| | - Chris R. Abbiss
- Centre for Exercise and Sports Science Research, School of Exercise and Health Science, Edith Cowan University, Joondalup, WA, Australia
| | - Peter Peeling
- School of Sport Science, Exercise & Health, University of Western Australia, Crawley, WA, Australia
| | - Christopher J. Gore
- Department of Physiology, Australian Institute of Sport, Bruce, ACT, Australia
- Exercise Physiology Laboratory, Flinders University, Bedford Park, SA, Australia
- Research Institute for Sport and Exercise, University of Canberra, Bruce, ACT, Australia
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Lundby C, Robach P. Performance Enhancement: What Are the Physiological Limits? Physiology (Bethesda) 2015; 30:282-92. [DOI: 10.1152/physiol.00052.2014] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Our objective is to highlight some key physiological determinants of endurance exercise performance and to discuss how these can be further improved. V̇o2max remains remarkably stable throughout an athletic career. By contrast, exercise economy, lactate threshold, and critical power may be improved in world-class athletes by specific exercise training regimes and/or with more years of training.
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Affiliation(s)
- C. Lundby
- Zürich Center for Integrative Human Physiology, Institute of Physiology, University of Zürich, Zürich, Switzerland
- Food & Nutrition & Sport Science, Gothenburg University, Gothenburg, Sweden; and
| | - P. Robach
- Ecole Nationale des Sports de Montagne, Site de l'Ecole Nationale de Ski et d'Alpinisme, Chamonix, France
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Holliss BA, Burden RJ, Jones AM, Pedlar CR. Eight weeks of intermittent hypoxic training improves submaximal physiological variables in highly trained runners. J Strength Cond Res 2015; 28:2195-203. [PMID: 24513622 DOI: 10.1519/jsc.0000000000000406] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
It is unclear whether intermittent hypoxic training (IHT) results in improvements in physiological variables associated with endurance running. Twelve highly trained runners (VO2peak 70.0 ± 3.5 ml·kg-1·min-1) performed incremental treadmill tests to exhaustion in normobaric normoxia and hypoxia (16.0% FIO2) to assess submaximal and maximal physiological variables and the limit of tolerance (T-Lim). Participants then completed 8 weeks of moderate to heavy intensity normoxic training (control [CONT]) or IHT (twice weekly 40 minutes runs, in combination with habitual training), in a single blinded manner, before repeating the treadmill tests. Submaximal heart rate decreased significantly more after IHT (-5 ± 5 b·min-1; p = 0.001) than after CONT ( -1 ± 5 b·min-1; p = 0.021). Changes in submaximal V[Combining Dot Above]O2 were significantly different between groups (p ≤ 0.05); decreasing in the IHT group in hypoxia (-2.6 ± 1.7 ml·kg-1·min-1; p = 0.001) and increasing in the CONT group in normoxia (+1.1 ± 2.1 ml·kg-1·min-1; p = 0.012). There were no VO2peak changes within either group, and while T-Lim improved post-IHT in hypoxia (p = 0.031), there were no significant differences between groups. Intermittent hypoxic training resulted in a degree of enhanced cardiovascular fitness that was evident during submaximal, but not maximal intensity exercise. These results suggest that moderate to heavy intensity IHT provides a mean of improving the capacity for submaximal exercise and may be useful for pre-acclimatization for subsequent exercise in hypoxia, but additional research is required to establish its efficacy for athletic performance at sea level.
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Affiliation(s)
- Ben A Holliss
- 1College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom; 2British Swimming National Centre, Sports Training Village, University of Bath, Bath, United Kingdom; and 3Centre for Health, Applied Sport and Exercise Science, St. Mary's University College, Twickenham, United Kingdom
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Ryan BJ, Wachsmuth NB, Schmidt WF, Byrnes WC, Julian CG, Lovering AT, Subudhi AW, Roach RC. AltitudeOmics: rapid hemoglobin mass alterations with early acclimatization to and de-acclimatization from 5260 m in healthy humans. PLoS One 2014; 9:e108788. [PMID: 25271637 PMCID: PMC4182755 DOI: 10.1371/journal.pone.0108788] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 08/26/2014] [Indexed: 01/09/2023] Open
Abstract
It is classically thought that increases in hemoglobin mass (Hbmass) take several weeks to develop upon ascent to high altitude and are lost gradually following descent. However, the early time course of these erythropoietic adaptations has not been thoroughly investigated and data are lacking at elevations greater than 5000 m, where the hypoxic stimulus is dramatically increased. As part of the AltitudeOmics project, we examined Hbmass in healthy men and women at sea level (SL) and 5260 m following 1, 7, and 16 days of high altitude exposure (ALT1/ALT7/ALT16). Subjects were also studied upon return to 5260 m following descent to 1525 m for either 7 or 21 days. Compared to SL, absolute Hbmass was not different at ALT1 but increased by 3.7±5.8% (mean ± SD; n = 20; p<0.01) at ALT7 and 7.6±6.6% (n = 21; p<0.001) at ALT16. Following descent to 1525 m, Hbmass was reduced compared to ALT16 (−6.0±3.7%; n = 20; p = 0.001) and not different compared to SL, with no difference in the loss in Hbmass between groups that descended for 7 (−6.3±3.0%; n = 13) versus 21 days (−5.7±5.0; n = 7). The loss in Hbmass following 7 days at 1525 m was correlated with an increase in serum ferritin (r = −0.64; n = 13; p<0.05), suggesting increased red blood cell destruction. Our novel findings demonstrate that Hbmass increases within 7 days of ascent to 5260 m but that the altitude-induced Hbmass adaptation is lost within 7 days of descent to 1525 m. The rapid time course of these adaptations contrasts with the classical dogma, suggesting the need to further examine mechanisms responsible for Hbmass adaptations in response to severe hypoxia.
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Affiliation(s)
- Benjamin J. Ryan
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado, United States of America
- * E-mail:
| | - Nadine B. Wachsmuth
- Department of Sports Medicine/Sports Physiology, University of Bayreuth, Bayreuth, Germany
| | - Walter F. Schmidt
- Department of Sports Medicine/Sports Physiology, University of Bayreuth, Bayreuth, Germany
| | - William C. Byrnes
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado, United States of America
| | - Colleen G. Julian
- Altitude Research Center, Department of Emergency Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Andrew T. Lovering
- Department of Human Physiology, University of Oregon, Eugene, Oregon, United States of America
| | - Andrew W. Subudhi
- Altitude Research Center, Department of Emergency Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, Colorado, United States of America
| | - Robert C. Roach
- Altitude Research Center, Department of Emergency Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
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Jacobs RA. Con: Live high-train low does not improve sea-level performance beyond that achieved with the equivalent living and training at sea level. High Alt Med Biol 2014; 14:328-30. [PMID: 24377336 DOI: 10.1089/ham.2013.1040] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Robert A Jacobs
- 1 Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich , Zurich, Switzerland
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