Long before dawn on the south pass of Everest (8,848 m.), on September 25, 1992, the Gipuzkoan brothers Alberto and Félix Iñurrategi went out into the cold outside on their way to the stratosphere. They were at about 8,000 meters and had decided not to use artificial respirators. “We were kids and we went to the top with fear, not of the mountain but of what such altitude could cause in our organisms”, Alberto is sincere. When they reached the height of 8,700 meters, they communicated by radio with the base camp to announce that in approximately half an hour they would be at the top. They saw it so close… it finally took them three hours to cover 150 meters of unevenness. “We reached the top at three in the afternoon. It was very hard for us”, recalls the mountaineer, who was barely 23 years old. Until 1978, medicine and science considered it impossible for human beings to survive on the roof of the planet using only their lungs, but then Reinhold Messner and Peter Habeler arrived and proved otherwise.
From the conquest of Everest, in 1953, until the year of the arrival of the pandemic, 2019, a total of 306 people have left their lives on its slopes: almost a third died of exhaustion, altitude sickness or illness. The doctor specializing in sports medicine and researcher at the University of Barcelona, Anna Carceller, considers that “exposure to altitude is a huge stressor for the body. If the subject is untrained and has no ability to move through the bush, the stress factors add up. In addition, if he is not trained, he will be slower (for the same acclimatization state) and, therefore, he will spend more hours exposed to the hostile environment, he will not be able to cover large slopes, and he will be forced to sleep more times on top. Recently, Dr. Carceller, whose area of interest is extreme physiology, published an interesting article in the magazine Fissac, in which he defends the alpine style to face the highest mountains on the planet as a highly efficient way of facing the challenge of hypoxia (decreased oxygen available to the body’s cells). But on the commercial routes to Everest, its participants are light years away from being able to assume the alpine style, that is, without fixed ropes, high-altitude Sherpas, well-stocked camps with equipment and food and, of course, oxygen. artificial to baskets. The alpine style demands two variables: lightness and speed. Anna Carceller recalls, however, that “carrying oxygen is not the same as exercising at sea level. It will depend on the flow carried by the climbers, but the minimum height they will feel will be around 6,000 meters above sea level. With which, all the conditions of altitude apply, although to a lesser degree…”, and it is this impossibility of escaping the consequences of altitude that kills many. Simply, his body is turning off while his mind only thinks of the top.
a brutal attack
“Somehow you have to consider that the body makes constant efforts to maintain its balance, also at sea level. It regulates the temperature, the availability of nutrients, wakefulness… All the processes that guarantee our survival. It’s kind of like a constant stress-recovery dance. In extreme environments, this dynamic struggle to maintain balance takes on a superlative role. It requires more energy to be carried out and consumes most of the body’s resources. If the external stress is greater than the body’s ability to maintain balance and the body does not have the ability to recover, but remains constantly exposed to aggression, then disease, failure to acclimatize, and even death occur. ”.
It is suspected that many of the roughly explained deaths recorded on Everest are actually due to exhaustion, which triggers multi-organ failure. The challenge is unbearable for certain subjects. Even the most experienced can die. Anna Carceller considers that everything becomes unbalanced as soon as there is an “exponential increase in energy expenditure: it takes energy for the body to compensate for environmental conditions, such as hypoxia and low temperature. And here a multitude of systems are involved, from the cardiovascular, respiratory, endocrine, etc. The body detects a threat and fires messengers alarm, fight. This is the sympathetic nervous system, which actively reacts to aggression. The secondary processes to this (the heart beats faster, blood pressure rises, we breathe more times) consume energy”.
The mountaineer has to face new problems, such as the decrease in energy intake, which has to do with the difficulty in eating food, as well as the difficulty in hydration because more water is lost at altitude through the skin and breathing. And this is very serious”, explains Anna Carceller. Juan Vallejo, who also climbed Everest without oxygen, could only ingest coke in height.
More problems: the exercise of ascending itself. “If we start from a low atmospheric pressure, it is much more difficult for oxygen to reach the cells in acceptable quantities. And our cells depend on oxygen to function. In fact, when we measure an athlete’s ability to exercise, we measure his VO2max, that is, his maximum ability to take oxygen from the atmosphere and transform it into energy. Well, this in altitude falls miserably from 1,500 meters. So not only is living more expensive energetically, but any physical exercise that would be simple at sea level, up there supposes a much greater effort, even greater than the subject’s maximum capacity. In other words, everything causes greater fatigue,” says Jaceller.
“For this reason, at the summit of Everest (where the atmospheric pressure is a third of that of sea level) and using all our available energy, with these levels of cellular oxygen, most of us mortals could not do anything else. to be still and breathe, in the best of cases, ”explains the doctor.
Alberto Iñurrategi recalls that the VO2max of Messner and Habeler was around 78 ml/min/kg and, warned, the two Gipuzkoan brothers began to train scientifically to measure themselves on Everest. Alberto came to give values slightly higher than 80 ml/min/kg (Kilian Jornet offers values close to 90 ml/min/kg): “I think that many himalayistas have not taken into account that to face eight thousand It is not necessary to know how to climb, but to have a great aerobic capacity, to train to be much more efficient”, observes Iñurrategi.
If energy is equal to the sum of nutrients and oxygen, the human being loses out in altitude, even using bottled oxygen.
But the pathology derived from hypoxia is often a spectrum that is difficult to dissect, says Dr. Carceller: “Above a certain altitude, everyone suffers its consequences to a greater or lesser extent. The brain is the organ most sensitive to lack of oxygen and nutrients, and its functional alterations include apathy, lack of motivation or ‘abandonment’. Day after day, the deleterious effects of altitude take their toll on the climber and result in lack of sleep, malnutrition, dehydration, muscle atrophy, lack of training and digestive problems, without forgetting that the hypoxic environment clouds judgment, motivation and decision. of decisions. It is an inevitable degeneration that the body pays for being in an environment in which it can barely survive.
The unfavorable cocktail becomes highly flammable, and when it explodes, it leaves a body adrift in a terribly inhospitable setting. With luck, and if you have paid a lot, a platoon of Sherpas will be able to get you down from the mountain. The usual thing is to die at the place of collapse.
The muscles fail
Fatigue also manifests itself in the muscles because the distribution of blood to these tissues changes. “Since the respiratory muscles require so much energy to maintain hyperventilation and oxygen is a scarce commodity, it implies more difficulties for muscle function. It must also be taken into account that the muscles are exercising with less oxygen, which leads to an earlier onset of fatigue. This is called peripheral fatigue and it already happens from moderate altitudes”, considers Anna Carceller.
One of the nightmare scenarios for a wannabe Everest summit is to run out of bottled oxygen supply right off the bat. In this case, “the body cannot defend itself because it does not have reaction time and the aggression is too intense”, illustrates Carceller, who proposes a different strategy. “It is interesting to see the role that the timing and intensity of the stimulus plays. If you go up little by little, letting the body adapt to its rhythm and minimizing the stressors as much as possible, you have a much better chance of success compared to exposing yourself abruptly, especially if you are so poorly trained that the activity would already leave you defeated. at sea level. If stress increases, the body redistributes energy to those systems that are essential for survival, but it will carry an intrinsic energy cost, and if this is not covered, the system collapses”. And this cataclysm feeds an important part of the deadly statistics of Everest.
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