Kilian Jornet reached the summit of Everest in 26 hours. A feat that was not without risk. Scarce oxygen can cause many problems.
Kilian Jornet was born 29 years ago in Spain, on planet Earth. His physical capacities are, however, superhuman. In just 26 hours, the athlete climbed Mount Everest, which rises to 8,848 meters. All without an oxygen cylinder or a fixed rope. A real feat, even for what the world calls “the ultra-terrestrial”.
The rise of the Spaniard is exceptional in more than one way. First, of the thousands of people who have reached the summit of Everest, “about thirty have gone without the help of artificial oxygen”, according to France Info.
Mountain sickness
Above 3,500 meters in altitude, oxygen becomes scarcer in the air. The body must then adapt to continue supplying the muscles and organs. Ventilation and heart rate accelerate. At the same time, the blood is enriched with red blood cells and thickens.
As a result of this physiological reaction, altitude sickness can occur. Edemas, headaches, nausea and even loss of appetite are the main symptoms. The faster the climb, the greater the risk of suffering from it. Which makes the ascent of Kilian Jornet all the more impressive.
But it is from 4000 meters that his record becomes riskier. Above this altitude, the risk of pulmonary or cerebral edema is high. It is then advisable to slow down the ascent. What the Spaniard did not do. “Up to 7,700 m, I felt really good, he says on his blog. But I started to feel smeared, probably from a virus in my stomach. “
The death zone
Yet even after 8,000 meters, the ultra-terrestrial continued its challenge. He crossed what mountaineers call “the death zone” where acute mountain sickness is likely to occur.
Despite these obstacles, Kilian Jornet has chosen to complicate matters even further. Instead of starting the ascent from the Nepalese side, he tackled the Tibetan side of Everest. For a seasoned climber, it takes three to five days to reach the summit. With this feat, the Spaniard completes his project Summits of my life which allowed him to break speed records during the ascent of the highest peaks of each continent.
This resistance is unusual in people living at low altitudes. The ability to evolve under an air scarce in oxygen is rather the prerogative of the Sherpas, an ethnic group from the Roof of the World. A British team has just explained why, in the journal of the American Academy of Sciences, PNAS.
Superhumans Sherpas
Sherpas are, in a way, an ultra-efficient power generation machine, optimized to operate when oxygen is scarce. In fact, their organism functions differently from populations of the plains, in part thanks to specific genetic modifications.
Researchers at the University of Cambridge (United Kingdom) have observed this superiority on the spot. 10 of them began an ascent of Everest accompanied by 15 representatives of the Sherpa population. Before climbing to the highest peak, all these volunteers took blood tests and muscle biopsies.
At low altitudes, Sherpas already have more efficient mitochondria. Oxygen is optimally used to produce ATP, the protein that allows muscles to contract properly. This tribe also tends to burn less fat for as much energy as an inhabitant of the plains.
But on the heights, it’s the phosphocreatine that makes all the difference. This molecule, used to regenerate ATP when it disappears, increases in Sherpas while it drops in others. This hill tribe also has fewer free radicals, which damage tissue.
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