I've been doing weight training for the past year or so, mainly with the chest area, and lately ive been experiencing pain on the left side of my chest.shoulder, esp. when stretching and is tender to the touch. I've been to my docter's a few days ago, and have been told that I've pulled my muscle pretty badly and possibly have torn it slightly. He suggested to massage the area and do stretches,also take pain killers if needed. Now, sometimes when i breath deeply it causes pain in that area, and I was wondering what could cause this? is it some sort of nerve issue or something? what could i do to recover, advice would be most appreciated. Thanks!