Mid May trip questions

[justiner]

Every reputable source

Can you point to any of these sources? I feel like this is one of the topics that is endlessly argued over. If there is an actual consensus, that would be valuable to share (and even add to the site in the FAQ or somewhere)

[astranko]

Every reputable source

Can you point to any of these sources? I feel like this is one of the topics that is endlessly argued over. If there is an actual consensus, that would be valuable to share (and even add to the site in the FAQ or somewhere)

I linked one in the comment, for one: A review paper on the merits of different types of acclimatization strategies for athletes. From that:

Performance decrement at altitude appears to decline with each day of altitude residence(up to *14 days)

Here is a manual from 2004 from the US Army Research Institute of Environmental Medicine: https://usariem.health.mil/assets/docs/ ... nguide.pdf

Pages 5-10 are of particular relevance. The army doesn't even recommend staging (i.e. active, not in combat) unacclimatized troops above 2500m/8200ft.

For a different kind of source, the CDC: https://www.cdc.gov/yellow-book/hcp/env ... lness.html

Aspen Valley Health: https://aspenvalleyhealth.org/healthy-j ... -altitude/
AVH recommends an intermediate day in Denver before coming to Aspen.

I'm also interested in the basis for the implied counterpoint. I don't think anyone is saying that acclimatization doesn't happen. So... where is the disagreement located? That it's better to not acclimatize? That it doesn't matter? I guess mtree is commenting that it doesn't matter, which is a value judgement.

The consensus that I would claim is:

• Acclimatization happens when exposed to high altitude.

• It is a series of physiological process that occurs in progressively more complicated stages over the course of hours to weeks.

• Acclimatization increases your capacity for work at altitude relative to your unacclimatized baseline.

• Acclimatization decreased your risk for altitude related illnesses relative to your unacclimatized baseline.

• The acclimatization process is best taken in stages to reduce the chances of altitude related illness and loss of performance.

If someone looks at that and goes: Yeah, and? Then I guess I wouldn't know what to say to them. It is self-evident from those claims, at least to me, that spending more time at intermediate altitudes before attempting a 14er increases your chance of success and reduces your chances of AMS/HAPE/HACE. The mechanism would be by increasing your capacity for work and decreasing your risk of illness.

If there is evidence that contradicts the above points and subsequently the conclusion I've drawn I'm open to it. These things are complicated and paradigms do shift.

[jrbren_vt]

Here's a few sources from a quick google search on "acclimatization profile" or similar :
https://health.clevelandclinic.org/unde ... tain-trip/
https://coloradotrail.org/acclimatizing ... ado-trail/
https://wwwnc.cdc.gov/travel/yellowbook ... ood%20flow.
https://www.webmd.com/a-to-z-guides/altitude-sickness
usariem.health.mil

Go to any guide service web site and look at their itineraries for treks to high altitude. They do this for a living (getting people from low altitude to high altitude in a short amount of time in relative comfort). Look at the various YouTube videos & web sites that compare the routes on Kilimanjaro for success rates and why. 1 or 2 days can make a huge difference. Better yet, ask your local travel clinic. Do not go to Facebook or an internet message board. This web site is the only one I have seen where people advocate skipping acclimatization days. It may take months to acclimatize to 100%, but you don't need to. You just need to be far enough on the curve so you don't get sick climbing up a really big hill. I like the army paper (much of it I don't understand, but I think I get the jist of it) because it is one of the few I have seen that shows the shape of the acclimatization curve. The process starts as soon as you get off the plane. You may never reach 100% because I think that is approached asymptotically. It is what goes on in between that is important to someone coming from sea level to hike 14ers. There is not a one size fits all answer, but I think these links provide good guidelines. My personally experience from when I lived at ~100' and did Colorado trips was 3-4 four days in I was good enough to do 14ers. I did lower elevation hikes in the mean time, which are in many ways nicer than the 14ers.