admin January 22nd, 2009
The first physiologic change happens within hours of arrive at altitude…you begin to breathe faster to compensate for less oxygen tension in the air. This helps up to a point where your ventilation lowers your CO2 level too much. Your brain says WHOA, stop breathing so fast!
At this point, the CO2 builds back up, but you are still not getting enough O2. The kidneys start to kick in by trying to get the PH of the blood back in order and start secreting bicarbonate ions, so the first few days yoru brain is fighting your lungs and your kidneys are trying to keep the peace.
all along your heart is trying to pump more blood to get more O2 around, and your vascular system responds by filling with more fluid that it sucks from the rest of your body. So you get a triple whammy of deydration…the air is dryer, you are breathing faster, and your vascular system pulls fluid out of yoru body into the blood vessels.
So, the FIRST thing you can do to help acclimitize is to drink TONS of water. I need 3-5 liters a day in teh first few days I go to altitude.
The worst days for most people are generally days 2-5. Day one feels OK, and after a week you start to feel better.
But the real long term adaptation is generating new red blood cells, which is a hormonal response to the decreased O2 tension. EPO is secreted by the kidneys which stimulates the growth of new baby red blood cells in your bone marrow. A previous poster was correct that this takes about 3 weeks to get into full force. Needless to say that in order to build blood cells you need to have the building blocks which includes adequate iron intake, folic acid and b vitamins, so nutrional support during this time is key. I get buffalo cravings during my first week at altitude (local pub serves yummmmy buffalo stew!)
You can speed this up by blood doping or taking EPO injections, but that’s not really advisable! LOL.
Legitimate, legal, medical ways to ease the transition include a variety of medications that assist along the pathways I mentioned above to help yoru body acclimate, but full acclimitization will not occur until the red blood cell production is back up to speed. Those medications include diamox, viagra (yes!), and ginko.
It takes me about 6 weeks to feel 100% at altitude, and even then I’m not as fast as I am at sea-ish level. The last 2 weeks I am there (I spend 2 months in the summer) I feel great, and wish I could stay longer.