Whoever decided altitude sickness is a thing was cruel indeed. I think riding was messing up the acclimation process - it was like a 5 day hangover. Kind of got in the way of enjoying Colorado a bit. The house we had was almost 7000 feet above home and we were riding 6 hours after arrival. #genius
I'd still ride Trail Ridge Road in Rocky Mountain National Park again, even with nausea and a headache, though. Scratch one bucket list item.
I don't know how anyone west of Denver in CO survives any strenuous activity.