When I started running, I bought myself a pair of Dinamo trainers (very simplistic trainers of old Soviet design)(http://www.fsidinamo.org/details.php?id=16 htt

When I started running, I bought myself a pair of Dinamo trainers (very simplistic trainers of old Soviet design)(http://www.fsidinamo.org/details.php?id=16 http://www.fsidinamo.org/details.php?id=16) by the advice of an old runner. By the same advice I 'modded' them by putting a piece of porous resin inside, under the heel. I use them for running, 5 km daily, all year round; and also for hiking. I get ironic grins when I mention that I run in them, because these are supposedly definitely obsolete and uncool, but I don't care. I don't have any problems. What am I doing wrong?