I just moved from AZ to boulder and have been here for about a week and my runs have been realy crappy lately. My question is how much will the altitude effect me? I have obviously slowed my runs down to get used to it but 45 minutes now feels like 2 hours and it feels like Im running 5 minute miles when I'm really running between 7 and 7:45 pace. I kinda expected it to effect me but not this much. When I lived in Phoenix I would stay up in Flagstaff for like 2 weeks and didnt seemed to be this bothered by it.