Many running shoe stores and companies recommend retiring your running shoes after 300 to 500 miles as the materials begin to break down. While I agree that a fresh pair of trainers is always delightful I have to suggest that taking advice from the party that will be taking your money might be a bit foolish. So I've started a new club. And just today this pair of New Balance joined the last pair of Adidas as its only members - two in a row to 1000. Will the new Mizunos be next?