Altitude adjustment is a special problem. I grew up at high altitudes (7100 ft. in winter, 10,000 ft. and higher in summer) and never thought much about it. But after many years at sea level, I need to acclimatize like everyone else. Trying to climb a 14 thousander right off is not a great idea. Instead, plan your trip so that you either climb high, sleep low for several days or so that for the first several days your sleeping place is no more than 1,000 feet (net) higher than the previous night's. Altitude affects everyone differently. It has been fairly well proven that being physically fit doesn't necessarily mean an easier altitude adjustment. Of course starting out unfit is much harder at any altitude!

I planned this year's trip to Wyoming's Wind Rivers using the second criterion, but since my dog got sick I have no idea if it would have been successful. I do know that at 8,000 ft. I had no problems; it didn't seem any different to me than 1,000 ft. Next year, I want to do two shorter trips rather than one long one. I'll rest up (and do laundry and such) for 2-3 days in between. For the first trip I'll focus on acclimatizing; for the second I'll start at ~9400 feet and go right up, hoping that the first trip will have taken care of the problem. Lord willing, of course (gotta add that caveat at my age!).