I call bs
I was in the army here and I think I was pretty active. Some people it just doesn't bother, the affects take time to show and for those that feel it immediately they are typically out of shape to begin with. I'm not going n to argue about it because I know the facts. O2 at 20k feet Yeh no kidding. I do 14'ers and never needed o2
Yes, I laugh at O2 on the sideline
I live in Colorado also
This.
When I first visited out here, like I've said before, it is noticeable. For me it was, anyway. But you rapidly adjust.
I regularly play golf and run out here,with no problem. (I walk playing golf, I do not use a cart except in extreme heat!)
My sister, on the other hand, can't and won't, indulge in the altitudes. She literally gets sick, and the last time she did that, she slept for 22 out of 24 hours in one span. For some reason, her body just won't take it. (She currently resides in that sea-level state, Florida.)
Personally, I think any endeavor above 13,000 or 14,000 feet would require O2, but unless you're an out-of-shape 300 pounder, oxygen is rarely, if ever, required at 5,280.
But again, one's physiology is the overriding determining factor here.
For most of these guys, it won't be an issue, especially given the forecasted weather report for Sunday.