Climbing at Extreme Altitude

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Climbing at Extreme Altitude The physiological problem The amount of oxygen in air decreases linearly with ascent and very approximately there is about half of sea level oxygen present at 5500m. This falls to roughly one third at the summit of Everest. It is important to appreciate that the partial pressure of oxygen at the summit of Everest is very close to the limits at which human beings can survive at all. Permanent human habitation ceases - due to lack of oxygen, not terrain - above 5400m. Whilst acclimatised man can survive for several weeks or months at 6000m, deterioration is taking place steadily, by the apparent reversal of the very process of acclimatisation that has enabled ascent possible to these altitudes. Mountain Logistics, Altitude and Acclimatisation Going above 7000 metres is a very unique experience. The success of an expedition is a lot to do with the team adhering to an accepted general philosophy regarding issues of acclimatisation and mountain logistics with respect to health and safety. In mountaineering, much that happens and many decisions depend on factors such as weather and conditions on the route. The most important individual responsibility on an expedition is balancing personal needs so you maintain your strength and health while still performing in accord with the groups’ desires and objectives. Therefore it is vital to build up a good foundation of experience over the days and weeks at high altitude but not to over-stress the body. Climb high, sleep low When climbing it is good to adopt the adage of climbing high and sleeping low whenever possible. At lower elevations our bodies can recuperate from previous days of work with sleep and food. However there is little advantage in sleeping above 21,000’ to acclimatise, since it is now accepted that above 21,000’ there is no acclimatisation, only debilitation. In prolonged oxygen-deprived atmosphere, working to capacity, lactic acid and other waste products build up in the muscles, which produce weakness and fatigue. Sleeping and Eating The ability to sleep after hard work is an indication of the body properly adjusting to altitude. Difficulty falling asleep indicates the need to reduce the stress on the body and slow the rate of ascent. If you can maintain a normal pulse rate and rehabilitate by sleeping well, you should work until you feel a pleasant tiredness, even at altitude. Sleeping and eating at high altitude, one cannot replenish the body’s energy stores or eliminate waste. Digesting complex foods at high altitude, the body actually spends energy, and many foods cannot be digested in that atmosphere. A fit body is naturally resilient and responds to rest at lower altitude. Fatigue The mountaineer must listen to his or her body, to feel it intuitively. You can overcome fatigue with inner motivation early on, but too much work is unnatural and can affect resilience over a long period. Serious fatigue can go unnoticed by someone who is physically fit, and no dramatic effect from overwork will be noticed until it is too late. Fatigue subtly accumulates in the body, only to manifest itself at the most stressful moments, usually up high, leaving you without strength and the ability to perform.

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Climbing at extreme altitude


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