When it comes time too boost your running performance, altitude training has to be on the top of that list. Distance runners flock to places like Flagstaff – for the cool town, yes, but also for the 7,000 feet at which Flagstaff sits. 
Besides the great views and the amazing trails, Flagstaff offers runners an interesting way to get fit and in shape for a race: elevation. I’ve been doing a bit of reading about training at altitude lately, and while I’m no longer chasing PR’s, I got a great glimpse into why so many athletes jump to higher ground for their training. The two main reasons are:
Less oxygen available, which therefore improves the delivery of oxygen to the muscles.
Increased red blood cell production which helps process oxygen more efficiently.
While I wouldn’t expect everyone (or anyone) to pack their bags and move to Flagstaff, it is cool to note that a lot of runners (serious or not) benefit greatly from the high elevation that Flag dishes out. Before you’re “retired” from running, you should try running at altitude – just to see what it’s like. You will come away with a new respect for all those who train and race that high up.
TrainwithMarc 