I'm on W3 R2 and so far I'm really enjoying it! (Never thought I would say that about running) One problem though is my knees are really hurting after a run. They ache a bit during the run, but nothing that would make me stop. But as soon as I stop running and the following day, they seem to have almost seized up. I stretch before and after a run and do the full warm up and warm downs that Laura recommends. What am I doing wrong? What can I do differently? Any advice would be great - I really don't want to have to stop running as I feel in this short space of time I have really made an improvement and achieved something. Help!