@labbadia1: Yes, it certainly is painful. That’s why for me pool exercises, at least a few days per week as an alternative to standard PT, was a nice break. E.g. instead of standard leg lifts I did those in the water, standing at pool walls and doing Rockette type kicks. Same for side leg lifts. The resistance of the water, and the intensity with which you do those, helps with muscle development. As I mentioned, my pool routine was specifically designed to deal with aftermath of TKR, not just some fun time in the water. Also, since many people will not be able to resume their usual active lifestyle for a while, some nice and easy laps of swimming won’t hurt either.
I resumed my daily walks fairly soon after TKR, much abbreviated of course. First outing, about 3 weeks after surgery, I aimed for a slow 1/4 mile. Did it. And forgot that I had to walk 1/4 mile back as well.
After almost 3 years I consider the replacement knee about 85% as good as the original one. Still some limitations with kneeling, and twisting motions sometimes, but otherwise just fine.