Hi Tyson.

Gotta say man... back off it. You're going to push yourself in to crisis and a hospital stay and that's a ton worse than what you're going through right now. Take it easy. Walk, use your pillow (if you've had a full sternal thymectomy) but back it off. Don't start running until your thoracic surgeon tells you you can.

I was almost a year after my thymectomy before getting into the gym; I did a pile of walking between the thymectomy and being able to get into the gym, but ... it was a year.

Cheers.

Brian.