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#9006 - 11/06/10 08:36 PM Re: Marathon vs Whitney? [Re: Cindy Abbott]
AlanK Offline


Registered: 09/22/09
Posts: 583
Loc: Glendale, CA
Originally Posted By: Cindy Abbott
Here is the percentage of oxygen in the air (as compared to sea level) at these altitudes:
8000 ft 76%
10000 ft 70%
12000 ft 65%
14000 ft 61%
As a consequence of the lower amount of oxygen in each breath:
1. the body with have to use more anaerobic power to maintain power levels
2. the heart rate will increase in an effort to supply more blood flow to the working muscles

Actually, the percentage of oxygen in air is 21% at sea level and at higher altitudes. What changes is the air density (and pressure) which drops by the amounts listed. So, it is certainly true that one takes in less oxygen (and nitrogen, etc. too) at higher elevations.

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#9008 - 11/07/10 05:09 AM Re: Marathon vs Whitney? [Re: AlanK]
KevinR Offline


Registered: 11/03/09
Posts: 595
Loc: Manchester, NH
Originally Posted By: AlanK
Originally Posted By: Cindy Abbott
Here is the percentage of oxygen in the air (as compared to sea level) at these altitudes:
8000 ft 76%
10000 ft 70%
12000 ft 65%
14000 ft 61%
As a consequence of the lower amount of oxygen in each breath:
1. the body with have to use more anaerobic power to maintain power levels
2. the heart rate will increase in an effort to supply more blood flow to the working muscles

Actually, the percentage of oxygen in air is 21% at sea level and at higher altitudes. What changes is the air density (and pressure) which drops by the amounts listed. So, it is certainly true that one takes in less oxygen (and nitrogen, etc. too) at higher elevations.


I've sometimes seen that concept described as "the oxygen available to us at X elevation is Y".

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#9010 - 11/07/10 07:35 AM Re: Marathon vs Whitney? [Re: KevinR]
AlanK Offline


Registered: 09/22/09
Posts: 583
Loc: Glendale, CA
Originally Posted By: KevinR
Originally Posted By: AlanK
Originally Posted By: Cindy Abbott
Here is the percentage of oxygen in the air (as compared to sea level) at these altitudes:
8000 ft 76%
10000 ft 70%
12000 ft 65%
14000 ft 61%
As a consequence of the lower amount of oxygen in each breath:
1. the body with have to use more anaerobic power to maintain power levels
2. the heart rate will increase in an effort to supply more blood flow to the working muscles

Actually, the percentage of oxygen in air is 21% at sea level and at higher altitudes. What changes is the air density (and pressure) which drops by the amounts listed. So, it is certainly true that one takes in less oxygen (and nitrogen, etc. too) at higher elevations.

I've sometimes seen that concept described as "the oxygen available to us at X elevation is Y".

That works. Actually, I was not arguing with the original statement. I assume that what was meant is "compared to sea level, the amount (e.g., partial pressure) of oxygen in the air is 61% of what it is at sea level." The percentage of oxygen in the air is still 21%, but there is only 61% as much air.

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#9015 - 11/07/10 09:26 AM Re: Marathon vs Whitney? [Re: AlanK]
Cindy Abbott Offline


Registered: 09/24/10
Posts: 98
Loc: Irvine, California
Yup, that's what I meant.

Here are some stats from Everest taken from my journal:
Basics: normal illnesses: cough, digestive stuff, cuts do not heal, no oxygen to breath - you know: the usual.
Blood and heart rate:

April 19th after 3 nights at base camp 17,600 ft 91 o2, 77 HR
April 27th after 5 nights at Camp 2 21,500 ft 75 o2, 94 HR
May 2 after one night at Camp 2 64 o2, 94 HR
(stays same for five nights) so climbed Lhotse Face with these readings!
May 6th hiked from Camp 2 to Base camp 72 o2, 82 HR
May 8th after one night in Dingboche 13,500 ft 89 o2, 70 HR

I was not very happy with my O2 Sat the last round at Camp 2 and the Lhoste Face but I did OK.


Here are the oxygen levels in air (as compared to at sea level) - continued:
15000 ft - 58%
21500 ft - 45% (camp 2)
23500 ft - 42% (camp 3)
26100 ft - 38% (camp 4)
29035 ft - 33% (summit)

This is without supplemental oxygen. So it shows just how dangerous it is to climb at these higher altitudes without it and my hat's off to those who have and lived.

I would never attempt it for one major reason: the disease I have is vasculitis (imflammation of the blood vessels). Even Dr. Peter Hackett (world's leading high-altitude medical researcher) did not know what was going to happen when I went to altitude.
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#9019 - 11/07/10 10:04 AM Re: Marathon vs Whitney? [Re: Cindy Abbott]
wagga Offline


Registered: 10/07/09
Posts: 2249
Loc: Humbug Reach (Pop. 3)
Cindy, if you know your tidal volume & breathing rate you can use this calculator to estimate blood oxygen levels. Set the units to feet & enter altitude in feet.
If you don't change breathing rate and tidal volume, the magenta curve is pretty much a dead person.

Also some partial pressure info here.

elevation oxygen % compared
Location feet to sea level
------------ ------ ---
Fresno 450' 98%
Half Dome 8800' 73%
Lone Pine 3700' 88%
Whitney Portal 8360' 75%
Mount Whitney 14505' 57%
Everest 29035' 33%


And at 367442' (SpaceShipOne's apogee), you might see the occasional oxygen molecule drift by.
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#9020 - 11/07/10 10:07 AM Re: Marathon vs Whitney? [Re: Cindy Abbott]
AlanK Offline


Registered: 09/22/09
Posts: 583
Loc: Glendale, CA
Originally Posted By: Cindy Abbott

Here are the oxygen levels in air (as compared to at sea level) - continued:
15000 ft - 58%
21500 ft - 45% (camp 2)
23500 ft - 42% (camp 3)
26100 ft - 38% (camp 4)
29035 ft - 33% (summit)

For those who might possibly care, one can get basically these numbers using the following simple equation, which is derivable from elementary physics:
P(h) = P(0)*exp(-h/h0).
Here P is barometric pressure, h is height above sea level, P(0) = 760 Torr is barometric pressure at sea level, and h0 = 7990 m = 26200 ft.

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#9024 - 11/07/10 12:36 PM Re: Marathon vs Whitney? [Re: wagga]
Ze Mane Offline


Registered: 11/05/10
Posts: 5
Loc: US
Originally Posted By: wagga
Cindy, if you know your tidal volume & breathing rate you can use this calculator to estimate blood oxygen levels. Set the units to feet & enter altitude in feet.
If you don't change breathing rate and tidal volume, the magenta curve is pretty much a dead person.


Was gonna link to this but looks like you've done that smile

Although the pressure of oxygen in the atmosphere is "only" reduced by 33%, the partial pressure in the blood drops down much more. At 8000m, there's like a 97% decrease in oxygen partial pressure!

The combination of the workload calculator with the oxygen pPressure could give an "effective" workload. Obviously 97% decrease in pace is significant! shocked

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#9029 - 11/07/10 04:30 PM Re: Marathon vs Whitney? [Re: Ze Mane]
Harvey Lankford Offline


Registered: 11/10/09
Posts: 1024
Loc: Richmond, Virginia
this thread is getting too scientific - but I will add to the pot.

One of the reasons man (or woman, Cindy) can survive (at least for a while) at extreme altitude (like Everest) is because of the mystery of acclimatization. These changes are far more pronounced than those that occur in well-acclimatized Whitney hikers.

Acclimatization involves multiple physiological changes that include these and more: altered ventilation, making more red blood cells, incompletely understood metabolic changes at the intracellular level, and shifts in the oxyhemoglobin dissociation curve. That is how extremely low pressure inspired air at extreme altitude can yet result in a higher useable level of O2 in the blood, and just as importantly, release of O2 from the blood into the tissues. Said another way, if all your blood did was pick up ambient low pressure gaseous O2 then you would be long before dead. The miracle of hemoglobin makes life possible over a wide range of O2 pressures.

This graph is the famous oxyhemoglobin dissociation curve. If standing on the top of Everest ( without using bottled O2) the horizontal PaO2 would be 25-30 range, incompatible with life. But on the vertical axis you see that with a high-altitude left-shifted curve, ones hemoglobin saturation % ("O2 sat") is a just barely life-possible 60%. I can tell you that it really doesn't feel good unless it is 75, and even that would be low enough to put you in the ICU back home.



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#9032 - 11/07/10 05:48 PM Re: Marathon vs Whitney? [Re: Harvey Lankford]
wagga Offline


Registered: 10/07/09
Posts: 2249
Loc: Humbug Reach (Pop. 3)
There is a genetic/acclimatization factor at work here, too. Some decades ago, I was dating a nurse at Loma Linda. She suggested that I donate blood, which I did. Several days later, the hospital called & asked me to come in for a visit. They told me that I had recorded the highest hemoglobin & clotting factor they had ever seen. We discussed my life-style, and when I mentioned that I was climbing 12-14 thousand-foot mountains several times a month, they asked me to give blood every 3 weeks, so that they could spin down platelets. And they paid me!

That was then. Now, after three blood-clot episodes, I just depend on rat-poison. Every day.
_________________________
Verum audaces non gerunt indusia alba. - Ipsi dixit MCMLXXII

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#9033 - 11/07/10 05:57 PM Re: Marathon vs Whitney? [Re: wagga]
Bee Offline


Registered: 09/22/09
Posts: 1261
Loc: Northern California
Maybe you should move to Tibet?

Sorry about the rat poison....Cumadin & its counterparts are most unpleasant.
_________________________
The body betrays and the weather conspires, hopefully, not on the same day.

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#9034 - 11/07/10 06:20 PM Re: Marathon vs Whitney? [Re: Bee]
wagga Offline


Registered: 10/07/09
Posts: 2249
Loc: Humbug Reach (Pop. 3)
Whoever wrote "Keep your friends close and your enemies closer" was perhaps thinking of coumadin aka warfarin.
_________________________
Verum audaces non gerunt indusia alba. - Ipsi dixit MCMLXXII

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#9035 - 11/07/10 06:20 PM Re: Marathon vs Whitney? [Re: wagga]
Harvey Lankford Offline


Registered: 11/10/09
Posts: 1024
Loc: Richmond, Virginia
Originally Posted By: wagga
highest hemoglobin & clotting factor they had ever seen.

Warfarin Rx for blood clotting disorder would be unlikely for simple mild polycythemia (extra red blood cells) associated with frequent trips to moderate altitude.

Then again, there are some folks who get Chronic Mountain Sickness. This is unheard of in casual Sierra hikers, but seen in those who live their lives at say 10,000 ft and usually higher, like in the Andes. The other name for CMS is Monge's Disease, after the South American MD who described it.
http://en.wikipedia.org/wiki/Chronic_mountain_sickness

Note: CMS is far, far different than the AMS we often discuss here.

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#9036 - 11/07/10 06:48 PM Re: Marathon vs Whitney? [Re: Harvey Lankford]
Bulldog34 Offline


Registered: 11/12/09
Posts: 1255
Loc: Atlanta
Wow - who would have thought that? You think of folks living their entire lives at high altitude and what incredible aerobic machines they must be, but there's generally a downside to everything.

wagga, I feel for you bud. In a previous life - like 1975-1979 - I was working my way through college as a pharmacy technician, and I recall hearing horror stories from patients on Coumadin. Nasty stuff, and far too often a lifelong regimen. Classic case of the cure being almost as bad as the disease. I remember one patient telling me that she only brushed her teeth twice a week or so 'cuz she bled from the gums for hours afterwards.

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#9053 - 11/09/10 09:00 AM Re: Marathon vs Whitney? [Re: Harvey Lankford]
Cindy Abbott Offline


Registered: 09/24/10
Posts: 98
Loc: Irvine, California
Originally Posted By: Harvey Lankford
This graph is the famous oxyhemoglobin dissociation curve. If standing on the top of Everest ( without using bottled O2) the horizontal PaO2 would be 25-30 range, incompatible with life. But on the vertical axis you see that with a high-altitude left-shifted curve, ones hemoglobin saturation % ("O2 sat") is a just barely life-possible 60%. I can tell you that it really doesn't feel good unless it is 75, and even that would be low enough to put you in the ICU back home.



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Perfect Harvey smile I wish that I would have taken my O2 sat at the summit but quite frankly - I did not care!!!!
My focus was on getting back down to Camp 4 at 26,000 ft. It took 18.5 hours from Camp 4 - summit - back to Camp 4 (because of the crowds). Crazy stuff!
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#9054 - 11/09/10 09:24 AM Re: Marathon vs Whitney? [Re: Cindy Abbott]
Rod Offline


Registered: 09/22/09
Posts: 660
Loc: Santa Clarita, Ca. USA
Originally Posted By: Cindy Abbott
Perfect Harvey smile I wish that I would have taken my O2 sat at the summit but quite frankly - I did not care!!!!
My focus was on getting back down to Camp 4 at 26,000 ft. It took 18.5 hours from Camp 4 - summit - back to Camp 4 (because of the crowds). Crazy stuff!

That is what is making Everest so frighteningly dangerous.The enormous crowds all clustered at the Hillary steps and on the narrow ledges make for a dangerous wait to get up and down.18.5 hours RT from Camp 4. WOW!!!

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#9074 - 11/10/10 07:57 AM Re: Marathon vs Whitney? [Re: Rod]
Cindy Abbott Offline


Registered: 09/24/10
Posts: 98
Loc: Irvine, California
The crowds slowed us down but we had a set turn-around time. I always pick safety over summit. At the Hillary step it was quit dangerous but we were able to pass each other in a operative manner - I thought it was very amazing at that altitude (the operation between strangers). Speaks well for climbers smile

This season the weather had held everyone down and there was only at 3 day window at the end. So everyone had to go up or go home.

Again, I was impressed with the cooperative manner of all the climbers. It reinforced my belief in the the general goodness and caring of all humans.
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Keep Dreaming
www.reachingbeyondtheclouds.com

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