I flew to Pensacola last Friday, from Burbank. I spent the weekend without my glucosamine (I forgot to pack it) and I didn't do the arthritis exercises (lazy lazy lazy!). But I did spend a fair amount of time in Pensacola standing and walking around. So the trip was a bit of a trial for my knees.
And I'm doing all right. I think the hardest thing for my knees is driving. Whenever I make long trips in the car I feel it that night. But it isn't awful.
Overall, the improvements in my knees seem to be holding, even when I fall off the routine.