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A recently published abstract in the journal Wilderness and Environmental Medicine helps scientists get a little closer to understanding who will perform best at altitude. A quick exercise study conducted at the base camp of Aconcagua yielded physiologic predictors that correlated with summit success. Of course, a lot more goes into successful summits than simply performing well at altitude - among the variables that must be considered are whether guides and/or porters are used, use of supplemental oxygen (not common on Aconcagua, but a crucial variable in some 8000m mountains,) mountaineering experience, weather, etc. However, a simple test could be a great screening tool for many reasons ... helping guides to plan ratios of guide to client, planning prophylactic medication use, planning rescues, etc. We've reproduced the abstract below and hope to see more research in the future.

Conclusions

Climbers who successfully reached the summit of Aconcagua were less hypoxic and performed better on 6MWT compared with those who did not. Future studies with larger sample sizes are needed to validate these results.

In the end, this seems like an obvious conclusion but I understand the need for scientific testing to reach it.

I would like to know if anyone has looked at how BMI / bodyweight affects hypoxia and / or AMS. Would seem excess power output for a given frame size would would worsen more quickly under hypoxic conditions.

What is SA02?

I used to ski with a doctor who had done some research on physiology and altitude performance. He swore that the best predictor of high altitude performance was the condition of a person's small blood vessels in the eyeball. By examining the person's eyeball with an opthalmoscope, he claimed he could predict how well that person would perform at altitude.

KAI- What was the doctor looking for in the eye ??

Check out the American Alpine Journal a few years back. There was an article on where the field of high altitude physiology was headed. Some of the factors being studied was endothelial function and vascular tone, among many.

Personally I would like to see a larger population of climbers evaluated, over many expeditions on several mountains. Using on mountain, Aconcagua and the individuals who choose to climb it may inadvertantly be an inclusion/exclusion criteria. I should check the full journal article, but did they try to understand the previous high altitude experience of the individual and previous history of HAPE/HACE/AMS. Although trials which include self reporting of medical history of always been suspect since there are a variety of reasons why an individual may lie about prior history.

Vascular "leaking" has a big effect on developing pulmonary/cerebral and overall edema. Vascular tone may be the key to controlling leaking of fluids to the outside of blood vessels, but again the question arises - genetic or environmental and is there a pharmaceutical solution. Consider that the higher you go, the less atmospheric pressure is exerted on your entire body - this also explains hypoxia. At higher elevation and lower atmospheric pressure, the reduced pressure diminishes passive distribution of oxygen into your blood via your lungs. A common misconception is there is less oxygen in air at increasing altitude. Although the air is less dense, the percentage of oxygen (21%) does not change in the atmosphere.

A completely different factor is the ability of the body to digest and utilize energy at different altitudes.

Guru of high altitude medicine, Dr. Peter Hackett is the man! The only conclusion I've ever come up with is the only constant in physiology is change!