So here I am in Cusco Peru after completing the Larez trek with g adventures.
This was my first trek and just wanted to share a brief overview of my personal experiences related to the side effects ,I experienced on this trek. We landed in Cusco on day 1 and stayed there 24 hrs to help acclimatize to the 11500 ft. Or 3400mtrs. Initially we and the group were short of breath. Some handling it better than others so we walked around Cusco getting used to the elevation. The following day we bused it to Ollyantaytambo 2790 mtrs and stayed 1 night before heading to Larez to begin the hike.
Day 1 Larez to base camp a short hike with 6kg backpack from 3200 to 3600mtrs
Slept one night then started day 2 ( of 3)
Day 2 base camp to the peek which on my gps showed approx 4800 mtrs.
I was the last in my group to get to the peak and experienced the following:
- dizziness
- inability to move legs or arms at speed. I wanted to but it wasn't happening.
- high heart rate 170+ per 10-25 steps upwards in the final steep section over approx 1 hour.
- at the peak an infrequent loss of emotion approx 4 times until we continued to decent of below 4600mtrs.

After descending to approx 3700 mtrs to our next base camp my energy levels, mental alertness and emotional stability had returned to almost normal levels with some minor fatigue.
The hike continued on day 3 arriving back to Ollyantaytambo.

I had some questions regarding this schedule and events.
-Is this safe to ascend from 3600 mtrs to 4800 within 6 hours ?
- are the symptoms I was showing normal for the scent distance and time?
Many of the team members arrived about 40 mins before me and only complained of shortness of breath, nothing else.

Any feedback appreciated
Cheers
C

Depends on the individual and numerous other factors such as fitness, hydration, nutrition, and sleep. If this is your first climb, I'm not shocked you had altitude related issues. However, the 3600 to 4800 is not an unusual distance to cover. Odds are you were going to experience those symptoms to some degree or another. I regularly do 1400m to 4000m as a quick day trips and feel few if any ill effects.....but I do it alot. Even then, on a rare occasion I'll feel lethargic or get a headache. Altitude illnesses are a very hard thing to quantify and some people are just genetically more susceptible than others.

I agree WyomingSummits

Many things depend on individual physiology

Fitness state extremely important, may it be that non-fit persons' fast ascend to 3000 or 4000m end up in a Oxygen Debt, Air Hunger and many other problems

One has to check the Oxygen Tension on different altitudes and adjust ascend rate to one's personal abilities (one may need acclimatization on 2000m too)

Thats pretty odd to have 3000m dizziness and loss of control of limbs, but nothing to be afraid of, I would recommend family physician visit

Based on your experience, it's a safe bet that you live at or near sea level. If you had arrived in Cusco 1 or 2 additional days before the trek, you would have had more time to acclimatize to the altitude. There are some things you can do to help speed the process, which you can Google. Drinking plenty of water helps, as does avoiding alcohol and caffine. Had you done that, your altitude symptoms probably would have been less severe, or possibly non existent.

aleksi wrote:I agree WyomingSummits

Many things depend on individual physiology

Fitness state extremely important, may it be that non-fit persons' fast ascend to 3000 or 4000m end up in a Oxygen Debt, Air Hunger and many other problems

One has to check the Oxygen Tension on different altitudes and adjust ascend rate to one's personal abilities (one may need acclimatization on 2000m too)

Thats pretty odd to have 3000m dizziness and loss of control of limbs, but nothing to be afraid of, I would recommend family physician visit

Thats a cool graphic but wondering if the P02 mm/Hg scale is correct?

I'm not surprised at all by your symptoms. My group spent a full week hanging around Cusco to acclimate, and at the end of that we still weren't quite normal (took some effort to get up "Viva Peru hill" outside town).

>Is this safe to ascend from 3600 mtrs to 4800 within 6 hours ?

The usual recommendation is that you should increase your *sleeping* height by no more than 300m per day, (starting around 3000m or so) but you can *climb* much higher than that if you come back down within a few hours. Doesn't mean you'll be comfortable at the top, just that the serious forms of altitude sickness are usually a gradual process, and descent is a quick cure. "Get out before the Devil knows you're there."

If it was six hours just to ascend, that's a significant span of time well above your (sort-of, not really thoroughly) acclimated altitude. I don't think I'd recommend that to somebody who hadn't been to altitude before. As your teammates prove, lots of people can handle it, but there's really no telling who will cope well and who won't.

radson wrote:
Thats a cool graphic but wondering if the P02 mm/Hg scale is correct?

Looks about right (other than the notation: there should be no "/"), at least for Peru. See Figure 1 and/or Table 1 here:
http://www.the-aps.org/mm/publications/ ... st-pdf.pdf

Note that the barometric pressures shown here are
higher than those found in some textbooks of medicine
and physiology, which use the so-called standard atmosphere (5). The aviation industry introduced the standard
atmosphere in the 1920s to refer to average conditions in
the atmosphere. However, it is now appreciated that most
of the high-altitude areas frequented by humans, including
the Himalayas and the South American Andes, have a
higher barometric pressure than the standard atmosphere
indicates.

The two models are basically in agreement for 4000m, it's when you get up above 7000m that they really differ.

NARTREB

Your suggestions are right about the slopes and PO2s given in picture

basically many different books provide many different numbers, mismatch averaging on 200mmHg

I have a very basic and rock solid textbook for alpine medicine where these numbers correlate close

Many alpine clubs define altitude more that 4500 - 5000m as HIGH and pracctice "acclimatization" for newbies

A question: can we state that appearance of altitude sickness is multifactorial, especially below 5000m (I think) and these factors are prone to be modified by the individual him or herself?

We can state that altitude sickness is not well understood. Which means it's almost certain to be multifactorial, because if it were really simple, we'd have figured it out.

I can't find the reference offhand, but maybe a year ago somebody published a statistical analysis suggesting that what we call AMS is actually clustered into two distinct syndromes. What that might mean for treatment/prevention is anybody's guess.

I take issue with this statement:
>these factors [can be] modified by the individual

That's too facile. We simply don't know what all the factors are, or which ones are important (except for altitude itself). For example, it sounds very logical that highly trained athletes should handle altitude better than other people, but studies can't find any evidence for that. I'd still say get in shape before climbing a mountain, but don't expect it to prevent AMS.

hard to disagree

what physicians can advice so far is: get in shape, and increase one's cardio-respiratory fitness

thats it

somehow once I have been told by professional climbers, at altitudes, people who feared (mostly newbies) had a terrible sickness

dunno if phsycho is involved, but will not be suprised if connection will be found

nartreb wrote: For example, it sounds very logical that highly trained athletes should handle altitude better than other people, but studies can't find any evidence for that. I'd still say get in shape before climbing a mountain, but don't expect it to prevent AMS.

As a gross generalisation, in my experience, youngish super fit guys were the most susceptible to AMS. Not due to physiological factors of course

radson wrote:

nartreb wrote: For example, it sounds very logical that highly trained athletes should handle altitude better than other people, but studies can't find any evidence for that. I'd still say get in shape before climbing a mountain, but don't expect it to prevent AMS.

As a gross generalisation, in my experience, youngish super fit guys were the most susceptible to AMS. Not due to physiological factors of course

Having a fear of height, and not really realizing it, causes a lot of nausea and dizziness

that causes increase in Oxygen demand, which basically is worsened by the low Oxygen tension up there