Donating blood and acclimation

The problem with acclimatization is not so much the lack of red blood cells as it is the body adapting to the changes in partial pressures and using the oxygen that is available. That part isn't going to change. Either you adapt quickly or you don't. Apparently you normally do. Assuming you are otherwise in good health and fit, I'd guess you will notice little difference a week after giving blood and being at 10,000'. I'd also project that you might be a bit slower than usual. Chalk that up to being older and don't worry about it.   Just be careful of any program that you are involved in to get your body prepared.  No weight lifting for 24 hours at least - you don't want to spring a leak.  But keep running the next day if you must - if you have a running program - just make it an easy day and don't beat yourself up.  If you can schedule a rest day, do.  If you have been timing any runs, you will see the affect of being down a pint.  Probably not that much.

You have maybe a bit less than 10 pints in you.  You gave up 1.  You could expect (maybe) a max of 10% decrease in efficiency? (2% less after a week)  Maybe for a competitive event, but I'm not sure that is a deal breaker for a hike. If you have a rare event that causes you to have to carry somebody for a few miles quickly, you would probably wish you had that pint back. If down hill you wouldn't notice it. Besides, red blood cell replacement is not linear.  Like most emergencies inside your body, things happen faster to begin with then tapers.

Studies have shown that just reducing the amount of oxygen you get for an extended period of time (more nitrogen less oxygen through a mask 24/7) is not any help for adapting to altitude. That was even though they had higher red blood cell count. That probably can be extended to holding your breath. What is helpful, though is to spend time in an altitude chamber. Test subjects that spent time at an artificial 12,000' were better adapted for 14,000' than those from sea level. (DUH!)

If you are very fit (and have a high oxygen processing efficiency) you stand a chance of having more acclimatization problems since you can get higher faster.

To be truly FULLY acclimatized to any altitude you just need to spend time there. 6,000' about two weeks, 8,000' about 6 weeks, 10,000 3 months. 14,000' about 13 months. So for most purposes nobody is FULLY acclimatized if only a week trip. A VERY large percent of hikers/campers in the Sierra come from very near sea level and all of them are affected by the altitude.  Most will not have more than just minor problems such as a slight headache when the head is shaken; dizzy when they get up from sitting; breathless quickly; not so much interested in eating; not sleeping well. It is a testament to the robust adaptation response our bodies have. Unfortunately the body will be as sloth as it can. You loose what ever altitude you have adapted to very quickly when you go to lower altitudes.

Altitude affects are more pronounced if you spend a sleep cycle there. For example, un-acclimated fit hikers coming up from under 1,000' who hiked the 22 mile round trip to summit of Mt Whiiney as a day hike had about 70% fewer significant problems attributed to altitude as compared to those who spent overnight above 10,000' then took on the summit the next day. Significant symptoms included vomiting, head ache, disorientation, lassitude. Apparently it is like the Irish benediction that it is hoped you are in heaven two days before the devil notices you are missing. You want to be up and down before your body has a chance to notice things have changed. Also the reason for climb high and sleep low advice.

Being and staying hydrated has a lot to do with how you feel at altitude.

If you still feel a bit paranoid pack a few days worth of a prescription drug called Acetazolamide, sold under the trade name Diamox. It does alleviate symptoms but does not speed acclimatization. You will still be out of breath, but you will sleep better if you are prone to interrupted breathing called Cheyne stokes breathing. Search the Internet for the recommended dosage associated with AMS . Your physician may not know. Don't share drugs such as this (some are very allergic to sulfa drugs). The drug is a diuretic so you will really have to pound water down and still have a few sleepless periods at night.

The problem alluded to in the article was because they were at 17,000' to start with. At that altitude everyone is at risk for a lot of physiological things just for being there. No need to take any avoidable risk that would jeopardize your goal.  I was in an altitude study (at 14,100') where they took at least a pint of blood over a very short period with repeated blood samplings - even while walking uphill fast.  Other than sore arms, I didn't notice any additional problems.

Where are you going? And if you go sans blood, let us know if you noticed anything different...if you make it back (heh).

Ha, thanks for the confidence! Planning to go to the Winds, a real dream trip for me. Can't wait!