I'm 9 months out and stairs hurt every day, every time. I exercise 3x week at a gym and one of my exercises is the Stairmaster to get some cardio after lots of stretching and prep. The knee inflames and takes till the next morning to calm down w ice and NAB. The other 4 days I walk or bike ride & the knee inflames after either exercise so it's just a question of how much pain I'm willing to endure to maintain some fitness. FYI, I'm 5'10" 172. If I gain any weight, knee pain gets worse. Right after the TKR, the pain was so intense I couldn't eat or sleep so my weight dropped to 165 and then the pain was less. Based on my observation, weight is a major factor in pain generation from this procedure. Originally, I intended to TKR both knees but fortunately, those plans changed. The non surgical knee is being treated with Hyaluronic acid which is providing some relief but after 9 months and endless PT, I achieved NO material gain from TKR. My unofficial survey says thin people who are sedentary will benefit from TKR but if you are not thin, and/or you intend to dance or exercise, my experience has been relentless pain and remorse. Sorry.