It's been 5 months since my last surgery. A couple weeks ago, while doing weight machines at the gym, I started having an intense pain at the very top of my vertical incision(about 1-1.5 inches above my navel). The pain stopped when I stopped lifting. The pain re-occurs only on certain machines (shoulder lift, abdominal, torso rotation to the left--but not twisting to the right), but it also happens occasionally when I roll over in bed at night.

At first I was afraid I was getting a hernia, but there is no bulge. Is this just scar tissue stretching? Or is it the beginning of a hernia?

Not sure what that could be. I lift too and have not had any issues. I would take it easy and see what happens. I would not over do it. I hope the pain does not come back.