scholarly journals Effects of genetic factors on high altitude training performance

2021 ◽  
Vol 5 (1) ◽  
pp. 2
Author(s):  
Havva Eda Cicavoğlu ◽  
Cansel Kaya ◽  
Mesut Cerit
Keyword(s):  
High Altitude ◽  
Hypoxia Inducible Factor ◽  
Circulatory System ◽  
Endurance Performance ◽  
Superior Performance ◽  
Metabolic Efficiency ◽  
Altitude Training ◽  
Monitoring And Control ◽  
Hypoxic Conditions ◽  
And Performance

High altitude is considered to be 1800-6000 meters. With the decrease of atmospheric pressure at this altitude, adequate oxygenation cannot be achieved in the tissues and hypoxia develops in the circulatory system. Athletes aim to provide superior performance by training in hypoxic conditions. Varying adaptations in hypobaric hypoxia environments by geographically separated populations represent well-trained specimens that may be relevant to endurance performance. While inhabitants of the Andes show higher levels of hemoglobin and saturation than Tibetans at similar altitude, Ethiopian climbers maintain oxygen delivery despite the hemoglobin levels and saturation typical in sea level ranges. It can also be predicted a significant relationship between the angiotensin converting enzyme (ACE) genotype, which affects metabolic efficiency and performance in hypoxic environments (high altitude). One of the genes that develop at high altitude and occur in response to hypoxia is the hypoxia inducible factor 1 alpha (HIF-1α) gene encoded by the hypoxia inducible factor (HIF-1A) gene. The vascular endothelial growth factor (VEGF-A) gene, which is another gene with angiogenetic factor produced in response to hypoxia, is revealed by the transcription of the HIF-1 alpha gene. Genetic heritage, environmental factors, and the character of exercise loads applied within the framework of lifestyle, neuromuscular development, balanced nutrition, and cultural differences that trigger athletic success may reveal individual changes or differences. Considering all these variables, monitoring and control of performance improvement and athletic achievement graph may become more predictable.

scholarly journals Physiological aspects of altitude training and the use of altitude simulators

2005 ◽  
Vol 133 (5-6) ◽  
pp. 307-311
Author(s):  
Goran Rankovic ◽  
Dragan Radovanovic
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Training Stimulus ◽  
Endurance Athletes ◽  
Altitude Training ◽  
Moderate Altitude ◽  
Improve Performance ◽  
Hypoxic Conditions ◽  
Training Programmes ◽  
Training Modalities

Altitude training in various forms is widely practiced by athletes and coaches in an attempt to improve sea level endurance. Training at high altitude may improve performance at sea level through altitude acclimatization, which improves oxygen transport and/or utilization, or through hypoxia, which intensifies the training stimulus. This basic physiological aspect allows three training modalities: live high and train high (classic high-altitude training), live low and train high (training through hypoxia), and live high and train low (the new trend). In an effort to reduce the financial and logistical challenges of traveling to high-altitude training sites, scientists and manufactures have developed artificial high-altitude environments, which simulate the hypoxic conditions of moderate altitude (2000-3000 meters). Endurance athletes from many sports have recently started using nitrogen environments, or hypoxic rooms and tents as part of their altitude training programmes. The results of controlled studies on these modalities of high-altitude training, their practical approach, and ethics are summarized.

Adaptation of iron requirement to hypoxic conditions at high altitude

2015 ◽  
Vol 119 (12) ◽  
pp. 1432-1440 ◽  
Author(s):  
Max Gassmann ◽  
Martina U. Muckenthaler
Keyword(s):  
High Altitude ◽  
Iron Homeostasis ◽  
Oxygen Carrier ◽  
Hypoxia Inducible Factor ◽  
Iron Availability ◽  
Iron Release ◽  
Erythroid Precursor ◽  
Enhanced Absorption ◽  
Hypoxic Conditions ◽  
Gene Expression Control

Adequate acclimatization time to enable adjustment to hypoxic conditions is one of the most important aspects for mountaineers ascending to high altitude. Accordingly, most reviews emphasize mechanisms that cope with reduced oxygen supply. However, during sojourns to high altitude adjustment to elevated iron demand is equally critical. Thus in this review we focus on the interaction between oxygen and iron homeostasis. We review the role of iron 1) in the oxygen sensing process and erythropoietin (Epo) synthesis, 2) in gene expression control mediated by the hypoxia-inducible factor-2 (HIF-2), and 3) as an oxygen carrier in hemoglobin, myoglobin, and cytochromes. The blood hormone Epo that is abundantly expressed by the kidney under hypoxic conditions stimulates erythropoiesis in the bone marrow, a process requiring high iron levels. To ensure that sufficient iron is provided, Epo-controlled erythroferrone that is expressed in erythroid precursor cells acts in the liver to reduce expression of the iron hormone hepcidin. Consequently, suppression of hepcidin allows for elevated iron release from storage organs and enhanced absorption of dietary iron by enterocytes. As recently observed in sojourners at high altitude, however, iron uptake may be hampered by reduced appetite and gastrointestinal bleeding. Reduced iron availability, as observed in a hypoxic mountaineer, enhances hypoxia-induced pulmonary hypertension and may contribute to other hypoxia-related diseases. Overall, adequate systemic iron availability is an important prerequisite to adjust to high-altitude hypoxia and may have additional implications for disease-related hypoxic conditions.

scholarly journals Is Hypoxic/Altitude Training an Important Topic in the Field of Hypoxia?

2021 ◽  
Author(s):  
Grégoire P. Millet ◽  
Martin Burtscher ◽  
Johannes Burtscher
Keyword(s):  
Biological Sciences ◽  
Molecular Mechanisms ◽  
Performance Enhancement ◽  
Hypoxia Inducible Factor ◽  
Altitude Training ◽  
Systemic Hypoxia ◽  
Biomedical Journals ◽  
And Performance ◽  
Number Of Citations ◽  
Hif Pathway

AbstractHypoxia is an essential topic in medical or biological sciences. The main aims of the present study were to examine the most important medical articles (i.e., the top 100 most cited) on hypoxia. We examine how the Nobel-prize awarded hypoxia inducible factor (HIF)-pathway discovery in the early 1990s has changed the thematic composition of this body of literature, with a special emphasis on the studies linking hypoxia and cancer. We searched Pubmed for articles with the terms #Hypox, #Altitude, or #Mountain in the title that have been published in biomedical journals and ranked the articles on their number of citations in Web of Science. A second search was performed in all journals for articles related to hypoxia and cancer. Strikingly, only 12 of the top-100 most-cited articles on hypoxia and only 3 articles of the top-100 articles related to cancer were published before 1995. Moreover, only 5 articles from prior 1995 reached 1000 citations, while 27 articles published in 1995 or later were cited more than 1000 times, most of them on the HIF-1 pathway. Eighty percent of the top-100 articles were related to the HIF pathway, while there were no articles on the application of hypoxia either for therapeutic use (i.e., hypoxic conditioning in patients) or for performance enhancement (i.e., altitude training in athletes). In conclusion, the early-1990s discovery of the HIF pathway and of its molecular regulation has shifted the focus of hypoxia research towards molecular mechanisms and consequences of tissue hypoxia, most notably in cancer. The importance of studies focusing on clinical and performance applications of systemic hypoxia is relatively lower.

Iron Requirement in Hypoxic Conditions

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. SCI-44-SCI-44
Author(s):  
Max Gassmann
Keyword(s):  
High Altitude ◽  
Iron Homeostasis ◽  
Conflicts Of Interest ◽  
Hypoxia Inducible Factor ◽  
Iron Release ◽  
Erythroid Precursor ◽  
Enhanced Absorption ◽  
Hypoxic Conditions ◽  
Gene Expression Control ◽  
Storage Organs

While highlanders in the Andes and Himalayas are well adapted to live at high altitude, adequate acclimatization time to slowly adjust to hypoxic conditions is among the most important aspects for ascending mountaineers. Accordingly, most reports emphasize on mechanisms that cope with reduced oxygenation. Notably, during a journey to high altitude coverage of the elevated iron demand is equally critical. Thus, it's crucial to focus on the crosstalk between oxygen and iron homeostasis. I will discuss the role of iron in the oxygen sensing process and erythropoietin (Epo) synthesis as well as in gene expression control mediated by the hypoxia-inducible factor-2 (HIF-2). The blood hormone Epo that is abundantly expressed by the kidney under hypoxic conditions stimulates erythropoiesis in the bone marrow, a process that requires high quantities of iron. To ensure that sufficient iron is provided, hypoxia-induced soluble factors - such as the novel Epo-controlled erythroferrone that is expressed in erythroid precursor cells - reach the liver where they reduce expression of the iron hormone hepcidin. In turn, suppression of hepcidin allows both, elevated iron release from storage organs and enhanced absorption of dietary iron by enterocytes. As recently observed in sojourners at high altitude, however, iron uptake may be hampered by reduced appetite and gastrointestinal bleeding. Overall, adequate systemic iron availability is an important prerequisite to adjust not only to high-altitude induced hypoxia but to treat disease-related hypoxic conditions. Disclosures No relevant conflicts of interest to declare.

scholarly journals Whole-Genome Sequencing Identifies the Egl Nine Homologue 3 (egln3/phd3) and Protein Phosphatase 1 Regulatory Inhibitor Subunit 2 (PPP1R2P1) Associated with High-Altitude Polycythemia in Tibetans at High Altitude

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Luobu Gesang ◽  
Lamu Gusang ◽  
Ciren Dawa ◽  
Gawa Gesang ◽  
Kang Li
Keyword(s):  
High Altitude ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Protein Phosphatase ◽  
Hypoxia Inducible Factor ◽  
Protein Phosphatase 1 ◽  
Whole Genome ◽  
Single Nucleotide Variants ◽  
Single Nucleotide ◽  
Hypoxic Conditions

Background. The hypoxic conditions at high altitudes are great threats to survival, causing pressure for adaptation. More and more high-altitude denizens are not adapted with the condition known as high-altitude polycythemia (HAPC) that featured excessive erythrocytosis. As a high-altitude sickness, the etiology of HAPC is still unclear. Methods. In this study, we reported the whole-genome sequencing-based study of 10 native Tibetans with HAPC and 10 control subjects followed by genotyping of selected 21 variants from discovered single nucleotide variants (SNVs) in an independent cohort (232 cases and 266 controls). Results. We discovered the egl nine homologue 3 (egln3/phd3) (14q13.1, rs1346902, P=1.91×10−5) and PPP1R2P1 (Protein Phosphatase 1 Regulatory Inhibitor Subunit 2) gene (6p21.32, rs521539, P=0.012). Our results indicated an unbiased framework to identify etiological mechanisms of HAPC and showed that egln3/phd3 and PPP1R2P1 may be associated with the susceptibility to HAPC. Egln3/phd3b is associated with hypoxia-inducible factor subunit α (HIFα). Protein Phosphatase 1 Regulatory Inhibitor is associated with reactive oxygen species (ROS) and oxidative stress. Conclusions. Our genome sequencing conducted in Tibetan HAPC patients identified egln3/phd3 and PPP1R2P1 associated with HAPC.

scholarly journals The Influence of High-Altitude Acclimatization on Ventilatory and Blood Oxygen Saturation Responses During Normoxic and Hypoxic Testing

2016 ◽  
Vol 50 (1) ◽  
pp. 125-133 ◽  
Author(s):  
Anton Ušaj ◽  
Stojan Burnik
Keyword(s):  
Oxygen Saturation ◽  
High Altitude ◽  
Ventilatory Threshold ◽  
Body Height ◽  
Endurance Performance ◽  
Cycle Ergometer ◽  
Blood Oxygen ◽  
Blood Oxygen Saturation ◽  
Hypoxic Conditions ◽  
High Altitude Acclimatization

AbstractWe investigated how acclimatization effects achieved during a high-altitude alpinist expedition influence endurance performance, ventilation (${\dot V_E}$) and blood oxygen saturation (SaO2) in normoxic (NOR) and hypoxic conditions (HYP). An incremental testing protocol on a cycle ergometer was used to determine the power output corresponding to the Lactate (PLT) and Ventilatory Threshold (PVT) in NOR and HYP (FiO2=0.13) as indirect characteristics of endurance performance in both conditions. Furthermore, changes in ${\dot V_E}$, SaO2, blood pH and Pco2 were measured at a similar absolute exercise intensity of 180 W in NOR and HYP conditions. Seven experienced alpinists (mean ± SD: age: 50 ± 6 yrs; body mass: 76 ± 5 kg; body height: 175 ± 8 cm) volunteered to participate in this study after they had reached the summit of Gasherbrum II and Ama Dablam. They had therefore experienced the limitations of their acclimatization. Individual differences of PLT between values reached after and before the expedition (∆PLT) correlated (r = 0.98, p = 0.01) with differences of SaO2 (∆SaO2) in HYP, and differences of PVT (∆PVT) correlated (r = -0.83, p = 0.02) with differences of ${\dot V_E}\left( {\Delta {{\dot V}_E}} \right)$ in HYP. The results suggest that the acclimatization may not have an equivocal and simple influence on the performance in hypoxia: enhanced blood oxygen saturation may be accompanied by increased endurance only, when the increase exceeded 2-3%, but enhanced ventilation, when increased more than 10 l/min in HYP, could detrimentally influence endurance.

scholarly journals High-Altitude Adaptation: Mechanistic Insights from Integrated Genomics and Physiology

2021 ◽  
Author(s):  
Jay F Storz
Keyword(s):  
High Altitude ◽  
Hypoxia Inducible Factor ◽  
Feedback Regulation ◽  
Genomic Analyses ◽  
Manipulative Experiments ◽  
Altitude Adaptation ◽  
Mechanisms Of Adaptation ◽  
Physiological Pathways ◽  
Underlying Mechanisms ◽  
Integrated Genomics

AbstractPopulation genomic analyses of high-altitude humans and other vertebrates have identified numerous candidate genes for hypoxia adaptation, and the physiological pathways implicated by such analyses suggest testable hypotheses about underlying mechanisms. Studies of highland natives that integrate genomic data with experimental measures of physiological performance capacities and subordinate traits are revealing associations between genotypes (e.g., hypoxia-inducible factor gene variants) and hypoxia-responsive phenotypes. The subsequent search for causal mechanisms is complicated by the fact that observed genotypic associations with hypoxia-induced phenotypes may reflect second-order consequences of selection-mediated changes in other (unmeasured) traits that are coupled with the focal trait via feedback regulation. Manipulative experiments to decipher circuits of feedback control and patterns of phenotypic integration can help identify causal relationships that underlie observed genotype–phenotype associations. Such experiments are critical for correct inferences about phenotypic targets of selection and mechanisms of adaptation.

Effect of altitude conditions on combustion and performance of a turbocharged direct-injection diesel engine

2021 ◽  
pp. 095440702110262
Author(s):  
Zhentao Liu ◽  
Jinlong Liu
Keyword(s):  
Diesel Engine ◽  
High Altitude ◽  
Diesel Engines ◽  
Direct Injection ◽  
Pressure Rise ◽  
Ambient Conditions ◽  
Allowable Limit ◽  
Spray Formation ◽  
Direct Injection Diesel Engine ◽  
And Performance

Market globalization necessitates the development of heavy duty diesel engines that can operate at altitudes up to 5000 m without significant performance deterioration. But the current scenario is that existing studies on high altitude effects are still not sufficient or detailed enough to take effective measures. This study applied a single cylinder direct injection diesel engine with simulated boosting pressure to investigate the performance degradation at high altitude, with the aim of adding more knowledge to the literature. Such a research engine was conducted at constant speed and injection strategy but different ambient conditions from sea level to 5000 m in altitude. The results indicated the effects of altitude on engine combustion and performance can be summarized as two aspects. First comes the extended ignition delay at high altitude, which would raise the rate of pressure rise to a point that can exceed the maximum allowable limit and therefore shorten the engine lifespan. The other disadvantage of high-altitude operation is the reduced excess air ratio and gas density inside cylinder. Worsened spray formation and mixture preparation, together with insufficient and late oxidation, would result in reduced engine efficiency, increased emissions, and power loss. The combustion and performance deteriorations were noticeable when the engine was operated above 4000 m in altitude. All these findings support the need for further fundamental investigations of in-cylinder activities of diesel engines working at plateau regions.

scholarly journals Nutrition for Older Athletes: Focus on Sex-Differences

Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1409
Author(s):  
Barbara Strasser ◽  
Dominik Pesta ◽  
Jörn Rittweger ◽  
Johannes Burtscher ◽  
Martin Burtscher
Keyword(s):  
Sex Differences ◽  
Exercise Training ◽  
Role Model ◽  
Healthy Aging ◽  
Endurance Performance ◽  
Metabolic Efficiency ◽  
Older Athletes ◽  
Age Related ◽  
Masters Athletes ◽  
Physical Capacities

Regular physical exercise and a healthy diet are major determinants of a healthy lifespan. Although aging is associated with declining endurance performance and muscle function, these components can favorably be modified by regular physical activity and especially by exercise training at all ages in both sexes. In addition, age-related changes in body composition and metabolism, which affect even highly trained masters athletes, can in part be compensated for by higher exercise metabolic efficiency in active individuals. Accordingly, masters athletes are often considered as a role model for healthy aging and their physical capacities are an impressive example of what is possible in aging individuals. In the present review, we first discuss physiological changes, performance and trainability of older athletes with a focus on sex differences. Second, we describe the most important hormonal alterations occurring during aging pertaining regulation of appetite, glucose homeostasis and energy expenditure and the modulatory role of exercise training. The third part highlights nutritional aspects that may support health and physical performance for older athletes. Key nutrition-related concerns include the need for adequate energy and protein intake for preventing low bone and muscle mass and a higher demand for specific nutrients (e.g., vitamin D and probiotics) that may reduce the infection burden in masters athletes. Fourth, we present important research findings on the association between exercise, nutrition and the microbiota, which represents a rapidly developing field in sports nutrition.

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