If you are a runner, it is recommended to get a new pair of running shoes each 300-400miles. What about tennis sneakers? If they don't have holes in bottoms, do you use them till you get holes? I am asking because last week I put on my barricades first time since ankle injury (happened in January). Well, it got my ankle again, nothing serious, but it hurt... It made me think about the shoes (barricades) - I play 3-4times a week and I wore those particular sneakers exclusively August through January (just under 6months). Could it be the issue? No support? How long should they last? They look like new... :?