I'm rotating 3 pair right now. (Yes, I know I have a problem!
) Most recommendations I've seen say you should replace them every 300-500 miles. Of course that is a very wide range. I can tell that mine are wearing out because I'll start to get achy knees and hips. For me and the kind of shoes I run in that happens between 350-400 miles. I usually make them last longer by relegating the old ones to recovery runs or wet, sloppy, muddy days.
My three pair right now have 43, 195, and 358. I don't smoke any more and don't go out drinking nearly as often. Running shoes have become my new vice. Almost time to buy a new pair.
