Well finally ticked off W7R3 this evening, 11 days after W7R1, having had delays from twisted ankle, over-lunged buttocks (don't ask) and an aborted attempt at R3 at the weekend that ended in disaster at 14 mins.
My legs are definitely much stronger now. Don't even feel any aches at all running 25 mins, but the last few runs I have done I have real problems breathing deeply enough after only a few minutes. It is not my lungs that are the issue, it feels like my stomach has tightened up too much for me to breathe from the diaphragm. As if I were wearing a really tight wetsuit or a huge elastic band around my middle. It is not a pain like a stitch, just like my stomach muscles have all turned to rock. When I feel my stomach it is really tense too. This prevents me from breathing deeply so I am doing shallow breaths. My lungs aren't burning or anything and it comes on well before the point where I would expect to start getting gaspy. I manage to run with it, but it is as if my breathing is stuck in first gear.
This is really beginning to annoy me. I feel sure if I could just get my stomach to relax I could fly through the run.