Some people are surprised to see that a mountaineer with a successful sporting career has to make such a great effort to achieve a summit, even when they are just a few hundred meters from their objective. They may not know that altitude has a big influence on physical performance. As we ascend, the atmospheric pressure decreases, and so does the oxygen.
This means that at an altitude of about 5,400 meters, the body only has half the oxygen pressure it has at sea level. As a result, we can suffer from altitude sickness, with the effects becoming severe at extreme altitudes. Physical performance is also affected.
The human body can adapt to high altitude through acclimatization. However, increasing altitude decreases your aerobic performance. At 2,000 meters the performance goes down just a little bit to 97%, but at 4,000 meters drops to 80%. When we climb up to 6000 meters, the sport performance drops to 60% due to lack of oxygen. What about high mountains like K2 (8,611 meters)? It is believed that no human body can acclimatise at that altitude and physical performance will just be 12% comparing to sea level.
In these conditions, putting one foot in front of the other and to continue ascending requires a superhuman effort. Taking all this into account, we value every step taken towards the summit; towards our dream.
Drs. Kepa Lizarraga and Josep Sanchís in collaboration with IMQ..