Roleigh: I saw your Yahoo thread that this relates to, and have a couple of concerns. This is a completely anomalous case, and is not a good example of what can be expected of AMS at 10,000 feet. Also, you raised this along with your quote of the "rule" of climb high, sleep low. We really need to stop telling people there is any such rule. Climb high, sleep low is a saying among Himalayan climbers to describe a Himalayan assault survival strategy for approaches and summits above 19,000 feet. It minimizes time in the death zone. You climb to advance camp, set up, leave supplies and retreat, to minimize unnecessary time at extreme altitude. It is *not* an alpine acclimatization strategy.
But for acclimatization, it is well established that sleep at elevation is the best strategy. You acclimate to the elevation at which you sleep. It is also well established that you de-acclimate at about the same rate as you acclimate. That is why is does no good to prepare for Whitney by climbing Baldy the week before. By the same token, say you camp at 8,000 feet (Whitney Portal.) On day one, you spend 6 hours climbing to Outpost (10,000) and descending to WP. You Spend 6 hours acclimating to an average of 9000, then spend 6 hours deacclimating to 9000. Then you spend 12 hours sleeping and deacclimating to 8,000. The net effect is exactly the same as if you had spent the entire 24 hrs hanging around the portal store, eating pancakes and Mooseburgers. The extreme example of climb high sleep low would be to drive to the portal, day hike to Trail Camp at 12000, descend back to WP, go back to Lone Pine and crash at the Hostel. Next day, you would be perfectly acclimated to 3727 ft. Thus the rule, if you can call it that, is sleep as high as you are comfortable, because that's as high as you are going to acclimate for that day.
And this is not just theory (although it is evidence based). It is the result of a lot of folks experience with acclimating at Horseshoe Meadow rather than Whitney Portal for a Whitney ascent.
