I got up early today and went on a run with the Sunday run groups. The dumb part was that I went with the normal group, which was doing 23km. After about 15 minutes with the 3:30 pace group I realized I wouldn’t be able to keep up, and fell back to the 3:45 group. It was better, but I spent the entire run breathing heavy. I think (as a non-medical person) what is happening is that I have muscles desperately trying to keep my shoulder blade in place and so they are always tight. This prevents me from breathing in fully, so I’m running out of oxygen.
As it was, I abandoned myself about 7km away from home. I stopped running and walked (mostly) the rest of the way back.
My shoulder is feeling good though. As long as I don’t know anything intensive that requires breathing heavily.