I ran a half marathon this weekend and felt great while running. I've been using the strengthening program outlined in The Cool Impossible and so far, so good. I'm currently running in Brooks PureConnect2. I felt great while running, no pain at all. After the race I felt great, then I sat down for about an hour. When I got up my arch, on one foot only, was killing me. After I walked for a few minutes it seemed to work itself out. Is this something that more strengthening will help with? Are there post run stretches that could help? Any insight would be appreciated!