ExpeditionDan is absolutely correct.
It depends on what your definition of acclimatization is is.
Can you climb early on huffing and puffing not at your full athletic acclimatization and not suffer classic AMS symptoms like headache, nausea, etc. . Yes. Plenty of people do just that on Whitney with only one or two nights spent high first. Probably half. If they went back there after a week or two longer at elevation, they would find that they breathe easier, climb faster, and don't feel like they are pushing as hard.
The other half suffer BOTH the AMS symptoms and the aforementioned 'Mountaineers Foot."
Anyone who replies please do not get bogged down in statistics but rather the difference in physical presentations. Even the official definitions are not clear
