I wasn't an elite athlete by any means, but I enjoyed crossfit as well as being able to lift weights, play with my kids
, spend long days sightseeing or shopping, etc. I used to row or walk or even sometimes jog for fitness, as well as lift respectably heavy weights.
My knee pain with normal walking and standing is greatly reduced, however I have not returned to the gym. A full day of walking (say, at the mall) has me icing my knee that evening due to pain.