Years ago I worked for US West and they had a fancy research type facility in Boulder. For awhile I was going there several times a year, and would often stay for a couple of weeks.

They had this stair case in the lobby that I think would go up about 3 flights. On my first trip there, being accustomed to climbing stairs rather than taking elevators, I attempted to walk up the 3 flights. I don't think I've ever been so out of breath from taking stairs in my entire life. After that I learned to take the elevator and save the stairs for the 2nd week of my visit.

I used to give them crap when they'd run into difficulty solving some particular problem. I would tell them if the facility were located in a place with oxygen their brains would work a lot better.