• Aeronautical Physiology and High Altitude Training
  • Milad Madayeni,1,*
    1. Islamic Azad University, Tabriz Branch


  • Introduction: Hypoxia refers to the lack of oxygen available for normal tissue metabolism. If hypoxia is severe enough, it can disrupt nerve activity and sometimes even lead to coma.
  • Methods: Adaptability to hypoxia: An astronaut or a pilot never stays at high altitude for long enough to adapt to its conditions. But climbers and athletes who train at high altitudes make enough compromises to be able to survive and train at altitudes that are several thousand meters above sea level. Compromise is usually done in the following ways: 1- Increasing pulmonary ventilation: the oxygen deficiency mechanism in the control of pulmonary ventilation normally only increases the ventilation rate by 65%, but after the person stays at a high altitude for several days, this mechanism becomes more and more effective. Increases ventilation up to 400%. Therefore, more oxygen is provided to the bubbles. 2- Increase in red blood cells and hemoglobin: When a person stays at a high altitude for at least 2 weeks, hypoxia causes a sharp increase in the production of red blood cells. If an athlete starts training at altitude, based on the reduction of oxygen pressure and the body's need for it during sports activities, especially endurance activities, a hormone called erythropoietin is secreted from the kidneys and stimulates the bone marrow. With the increase of red blood cells, hemoglobin increases, and as a result, the decrease in oxygen pressure at altitude is compensated by the increase in the amount of hemoglobin, and the athlete can continue his training without feeling a lack of oxygen. One of the advantages of this work is that if such a person, who has trained for at least two weeks at an altitude of 2300 meters, is transferred to a lower place, as long as the adaptation effect is not lost, he has a higher oxygen transport capacity. and as a result will be more successful in endurance competitions.
  • Results: The main problem at altitude is the reduction of oxygen pressure. An ordinary person often gets sick at an altitude of 3,000 to 4,000 meters above sea level and his level of consciousness drops. At an altitude of 5,500 meters, a person's senses are disturbed so much that he loses the power of recognition, and at an altitude of 7,000 meters, if pure oxygen does not arrive, he will go into a coma within 20 to 30 minutes.
  • Conclusion: Oxygen therapy is used to improve some types of hypoxia. For example, this method is used to treat hypoxia caused by the reduction of oxygen in the atmosphere, reduction of pulmonary ventilation and diffusion disorders from the respiratory membrane. In any case, an increase in oxygen concentration causes an increase in oxygen pressure in the alveoli, and as a result, increases the release of oxygen into the blood. In different types of hypoxia, the main problem may be the reduction of oxygen transfer to the tissues or the reduction of the use and consumption of oxygen in the cells. In this case, oxygen therapy may not have much effect.
  • Keywords: Hypoxia , Oxygen , High Altitude , Red Blood Cells