Originally Posted by
PepeM
Yes, I'd say it is mostly about getting used to the feeling.
I am from Mexico City. When I used to live there, going to ~9,000ft (Toluca) or even higher (Nevado de Toluca) didn't feel that different. I am sure someone going from sea level to those altitudes would feel it much more. Heck, nowadays when I go back home it takes me a few days to feel normal, although I think pollution has a lot more to do with it than the altitude.
It is/was interesting to me that the latest and fastest world hour record was set near sea level, while Eddy did his at Mexico City.
Seems Sky thought the aerobic issues were more important than the aero ones. I expect that that decision was not made on a whim and if they thought altitude would be better, they would have done it.