I'm with Velvis. If it ain't chasin' me, or I ain't chasin' it, I ain't worth it.
I'm sure it would be interesting to see if I could actually push myself that hard, but I don't know if I'll ever find out.
Billy, if you really want to do some training at altitude come on up to Aspen (7500 feet). I used to live in Telluride where biking and running was a lot of fun at 8700 feet. All of the trails started in town, and immediately went up 2000 feet. Not good for a boy from the swamps.
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong, it usually turns out to be impossible to get at or repair."
-Douglas Adams, Mostly Harmless