I was at the “Klein Matterhorn” (Swiss/Italian border) - at an altitude of roughly 14,000 ft (4,000 m). It took three gondola lifts to reach the top, and they recommended resting for at least 15 minutes before boarding the next gondola to get used to the thinner air.
At the top I was fine - except on slopes or stairs where I felt a definite shortness of breath.
I was watching a video of life in La Paz (Bolivia) a city of almost a million people at 14,000 ft. I’ve wondered how a long-time resident of La Paz would react to sea level conditions. Any breathing difficulties or other bodily functions reacting differently?
When I was living in Montana, the biggest way I noticed it was that, if I went home to Cleveland for a few weeks and let myself get de-acclimated, when I came back, all of the hills would be steeper. When folks came to visit me, most of them found they had less stamina for things like hiking. Oddly, though, my father never showed any effects at all.
I felt that effect. I flew to Salt Lake City, and went later that day to try some light hiking on the nearby mountains. Oh my God! Walking “up” a gently sloped parking lot was difficult. The trail I’d wanted to hike was actually closed for the season, so my friend and i walked around in the mountains, mostly neither climbing nor descending. It was a surprisingly fun day, involving surprise snowballs (in July.)
Then i spent 4 days square dancing in Salt Lake City. (And eating iron-rich food.) And went back to the same trail (now open) on my last day in the area. Walking around the parking lot felt like… walking around a parking lot, and i didn’t especially notice that it was sloped. It made a huge difference. We made it up to the little lake at 2 miles of elevation that had been my day 1 goal.
Since the FQ question is answered, a few minor points on Altitude sickness tools, tricks and expectations to anyone who visits us here in lovely Colorado (especially along the Rockies).
First, most people have the worst symptoms after the first night. As usual, you’re respirating at a lower pace during the night (duh), which means that any conscious efforts you may make when away to breathe more deeply/rapidly do not apply, which often ends up with severe symptoms the next day. In general, healthy people with good lung function are better in 48-72 hours, though it’s not a given. And yes, there are prescription pills you can get ahead of time that will reduce or eliminate the effects, though they have side effects of their own.
My houseguest who was a long time resident here who has now lived in Austin TX for decades, has to take such pills or they’ll spend he first 48-72 hours miserably sick. So we speak from experience.
A related but different problem for most of our guests is that Colorado tends to the very dry. Semi-arid in many areas, especially recent years. Combine that with the rapid breathing and you can get dehydrated FAST, which contributes to the altitude sickness. So please drink. The water’s darn good here.
My brother lives in Denver, so I’ve been there a couple times. As a ~45 year old, I didn’t have any problems waking around the house or town, but we went up to Red Rock and climbed up, and that did get me a bit winded. Of course I want aware at the time I was developing asthma, which didn’t help.
But a couple of times as a teenager we drove from Arkansas to Santa Fe, NM, on ski trips without any problems. And once in my 20’s I made a flight to Denver on a ski trip that visited Copper Mountain and Vail without noticeable breathing problems.
Yes, adaptations three body makes in hemoglobin improve oxygen uptake.
That’s why athletes like to train at higher altitudes, or wear breathing restriction masks when training to improve lung function.
It’s also why professional sports like cycling test the blood hemoglobin and set limits, because one performance- enhancing technique is to boost hemoglobin artificially.
I read “Into Thin Air”, and Krakauer describes some of this and how it shaped the Everest trip. The trip takes about a month, because they flew in to Kathmandu halfway up the mountain and then spend the next couple of weeks hiking around at lower altitudes, slowly increasing their altitude, to transform their body chemistry to support hiking up to the summit.
Even then, all of the guests used supplemental oxygen on the actual summit attempt, and even then were barely functional.
Those masks do nothing to improve oxygen uptake.
If possible, athletes train at low altitude and live at high altitude(or use sealed low pressure rooms or even a full house).
Training at altitude reduces training volume and intensity.
The low pressure is the trigger for adaptation not air restriction.
The lower octane is to keep knocking to a minimum… and adjust for a leaner burn, since the air pressure is lower. This affected older cars with carburetors more than newer computer controlled fuel injection systems.
I looked it up; Aspen’s altitude is about 7,900 feet. Not unlikely, although the food probably didn’t help.
When I went from just above sea level to 7,000 feet to do rotations in the Four Corners region in 1994, I couldn’t walk briskly without getting winded for the first few days I was there.
The military had to give us at altitude extra time for our runs and there were restrictions of how long after returning before you could be tested to assure acclimation.
As has been answered, nothing is different outside/inside. You can find little bottles of oxygen for sale in a lot of places. Take a couple of hits can help. There are also oxygen bars when you get to elevation (the mountains).
We just bought a house between Denver and Ft Collins because my other house at 11200 feet was getting to be two much for my 64 year old lungs. The snow got to be too much to handle as well. About 1/4 of the people that visited us from out of state got oxygen sickness. Feels like your coming down with the flu, or so I’ve been told, never got it myself. My blood oxygen saturation was getting too low though. My Dr. wanted me to go on oxygen. That sort of sealed the deal for moving. That and I’m over the snow.
The key number is partial pressure. Atmosphere is about 21% oxygen at 14.7psi (sea level) so the oxygen partial pressure our body is used to is about 3.1psi.
If I remember my first year chemistry rates of reaction, the important number for assorted chemical reactions is how likely one component of a reaction is to bump into a corresponding opposite component. So basically, partial pressure in this case is sort of measure “how many O2 molecules hit my lung membranes in a second?”. (Which is why fires happen much worse in an oxygen-rich environment)
At 6000’ air pressure is 11.8psi, with corresponding drop in oxygen partial pressure
10,000’ it’s 10.1psi
14,000’ it’s 8.6psi
18,000’ it’s 7.3 psi (about half)
The rule IIRC is that pilots in unpressurized aircraft need oxygen above 12,000 feet; since you need to be more than just alive, you need to not be disoriented or confused.
I recall reading something about how the native inhabitants of the high altitude areas of the Andes have better lung capacity, probably a combination of genetic selection and their body’s adaption.
I went to a talk by people who offer both Seregeti safaris and also treks up Kilimanjaro. They mentioned that altitude sickness - lack of acclimation to altitude - can hit anyone, and it’s luck of the draw who does and does not have problems, occasionally severe. Normal healthy young people sometimes get it, and plenty of older folk have no problem climbing to 19,000 feet. (And it’s up to the guides to decide if you are well enough to continue, since disorientation can be one symptom.)
I hiked to 18,000 feet in Nepal, but we had two weeks to acclimitize as we hiked from 3K to 14K before the big day going over the pass. While many people had low level headaches and poor sleep, only a small percentage had actual AMS (Acute Mountain Sickness).
However, nearly everyone was moving very slowly and out of breath. Acclimitization only goes so far in allowing you to perform at altitude. A few lucky folks operated really well, but the majority of us walked in zombie mode. The locals (guides/porters/tea vendors) were seemingly unaffected.
In Denver, if you come from sea level that day you’ll notice it when climbing stairs, trying to do anything athletic, and probably when drinking alcohol. But you are unlikely to notice anything if you are sedentary.
Glad you found a place to stay in-state. Colorado 'Doper’s unite!
That was my experience getting altitude sickness - I spent a summer at sea level as a teen, then flew to Denver, and drove to Leadville Co (just over 10k) to work on some stuff for my father. It was like an intense 48 hour respiratory flu. Then, more or less normal. But that was as a teen. Similarly, my houseguest I mentioned upthread has to take pills that fundamentally pre-prepare your system for the changes in chemistry or they’ll be sick as a dog.
My father (86 now) used to spend summers up in Cotapaxi, but after a nasty infection, had slightly reduced lung capacity in the year before Covid, so he too couldn’t spend the time there without oxygen, so they sold that property. He’s dreading the doctor further changes things, because where they live in Las Cruces, NM it’s right about 4k. And he spends a lot of time in Silver City NM during the summers, where it’s right around 6k (same as here in Colorado Springs). And it’s already become rougher for him to visit here and have any level of activity.
I’ve got a question about the lowered octane levels in higher altitudes. We spent a few weeks in Colorado last year, and I wasn’t sure about the 85 octane “regular”. I checked the truck’s manual and it said very clearly that 87 was the minimum, and had no wording or instructions regarding high altitude octanes. Since we were towing a heavy trailer I stuck with the 87 and paid for mid-grade the whole time.
Was that actually necessary? If it matters, the truck is normally aspirated (no turbo).
Part of a discussion of the altitude - octane argument from a prior thread of mine:
So… IMHO, a holdover from 40-50 year old figures, though there is still some effect. For that matter, most modern computer controlled ignitions will compensate to a large degree. My calculation was using the math in the video presented, at Colorado Springs altitude (6k) there was still the argument for about 1 octane’s worth of difference, but… LOTS of different information online.
The FAA’s rules say supplemental oxygen is required:
for passengers when above 15,000’
for flight crew when above 14,000’
for flight crew when above 12,500’ for more than 30 minutes
Glider pilots (who in the western US regularly fly high in unpressurized aircraft) increasingly regard these limits as “anti-conservative”. Most will be on supplemental oxygen at 10,000’, or lower.
The glider pilot I knew gave up on working while traveling to events as an airline passenger (8000 ft), because he found that a ground level, he wasn’t happy with what he had written at altitude. Also, he cried during movies at 8000’.
I’ve always wondered if the choice of Colorado Springs for the US Air Force Academy was deliberate for the sake of high altitude performance or if it was just an unwanted drawback.