Got a nice little umbilical hernia myself.....lets me opt out of carrying caskets at funerals.
My lovely 2 year old lady Labrador pulls hard on the lead. At 70 pound of muscle and bone, she gives me a real daily workout.
I use a 6 foot lead, have made a point of bending my arm, hanging on tightly and tensing across my chest from the lead arm to the opposite hip - a very solid isometric exercise. By constantly changing arms as she changes sides of the sidewalk/trail I keep balanced.. Over the last 2 years, the hernia has shrunk from about
3 inches in diameter to the size of a marble as my outer front muscular sheath has hardened. I was going to get a screen, decided to continue on as is for a while. Don't really want another surgery if I can avoid it.