I did weights and aerobics and stretching regularly right up until the night before my surgery. It helped tremendously in my recovery. I'm at 14% body fat. My urologist advised no strenuous execise until a full six weeks after surgery, including lifting anything heavier than a gallon of milk.
The abdominal incision through the skin, fat and muscle layers should not be stressed too soon post-surgically. Recovery is rapid and healing takes place in two stages: (1) A thickened inflexible scar forms (2) The scar tissue becomes flexible and adapts to movement. Healing must be allowed to occur to prevent a weakness in the scar line and potential rupture or herniation of the abdomen thru the weakened muscles.
I followed these instructions to the letter, but did lots and lots of walking, which was advised. I'm back doing aerobics and weights again, although starting out light and gradually increasing the weight. I won't begin high intensity interval training until later in my recovery. I don't want to risk any problems by doing too much too soon. I lost about 10 lbs shortly after surgery but have regained about 6 lbs, which is fine. I'm not over- or under-weight.
Best to you on your surgery and recovery. Looking back, nothing was as bad as I imagined it would be.