Commenting on several of the previous posts…
“Climb high, sleep low” is the default approach for an expedition on a big mountain. Climbers typically carry some of their gear and supplies partway up the mountain and then return to a lower camp to sleep. The next day, they may move camp to where they cached their stuff the day before. On really big mountains, it may take several carries to move camp. They repeat this sequence until they are high enough to get to the summit and back in one day.
Classic “Climb high, sleep low” doesn’t really apply in the lower 48. All the 14ers are routinely climbed as dayhikes, though many people will camp somewhere between the trailhead and the summit. To avoid AMS, JMT hikers probably shouldn’t camp on top of high passes or summits, but the best campsites and water sources are usually lower anyway.
“Climb high, sleep low” does not mean that you sleep as low as possible (e.g. Lone Pine). As saltydog said, “sleep at the highest elevation at which you are comfortable.” And as others have said, the more nights you spend high, the better.
Some people just tolerate altitude better than others, and I’m one of the lucky ones. I’ve been symptom-free in the lower 48 since day one, though acclimatization helps my performance. Dayhike the MR in January after sleeping at Alabama Hills? A ton of work, but I hardly noticed the altitude. The “Unofficial Guide” shed some light on why. It said oxygen saturation can drop by 15-25% from 11,483 to 18,045 (3,500 to 5,500 meters). I once measured 92% above 14,000, while I typically measure 94-96% in Reno.
