Cycling is VERY popular in Colorado and Utah. There are even some stretches of the interstate where bicycles are allowed. I could barely breathe just walking around at the top of the mountain - exerting myself by cycling? No way.
However, lots of cyclists come here to train. When you can ride in the higher altitude without having to stop every 20 feet to catch your breath, you can really kick ass when you're body's at a lower altitude and getting plenty of oxygen.
