takotruckin wrote:AlmostThere wrote:Acclimation doesn't work that way - each trip you start over again when you go back down to low elevation.
I have not found that to be true. I usually get a little sick my first 1 or 2 weekend trips of the year (over 7 or 8k), and then I am fine the rest of the summer.
I'm only quoting literature for wilderness medicine coursework... There's a quite detailed description of what happens to a body at high elevation in NOLS Wilderness Medicine. Among the pages it also says
"The body undergoes numerous changes at higher elevation in order to increase oxygen delivery to cells and improve the efficiency of oxygen use. These adaptations usually begin almost immediately and continue to occur for several weeks. People vary in their ability to acclimatize. Some adjust quickly; others fail to acclimatize, even with gradual exposure over a period of weeks. In general, the body becomes approximately 80 percent acclimatized after 10 days at altitude and approximately 95 percent acclimatized by 6 weeks. The respiratory rate peaks in about 1 week and then slowly decreases over the next few months, although it tends to remain higher than its normal rate at sea level. When we descend, we begin losing our hard-won adaptations at approximately the same rate at which we gained them; 10 days after returning to sea level, we have lost 80 percent of our adaptations."
"Altitude illness results from a lack of oxygen in the body. Anyone who ascends to high altitude will become hypoxic (the condition of having insufficient oxygen in the blood). Why some people become ill and others don't is not known. It is known, however, that most people who become ill do so within the first few days of ascending to altitude."
Advice given is to eat a high carb diet, as they require less oxygen to metabolize, eating fats and proteins on rest days - but not at night as that increases risk of altitude illness, as the combination of decreased respiratory rate during sleep and increased requirement for oxygen to metabolize fats/proteins is a double whammy. Climb high, sleep low. Ascend slowly. Hydrate. Avoid sleeping pills.
The advice about carbs is echoed in Mountaineering: Freedom of the Hills as well.