My shoes (Aidas Trail Response) are too beat out for running after 300-400 miles. After that my knees start feeling it. The most miles I ever put on a pair was 600. My knees constantly hurt until I replaced them. I have a 3 phase program-new shoes for running, previous running shoes become walkin' around shoes, previous walkin' around shoes become lawn mowing shoes, previous lawn mowing shoes get tossed