I'm at least 80 lbs overweight, and my OS said I had the best recovery he had ever seen. I had a very physical job, worked for Fedex the last 22 yrs and that involves lots of stair climbing, jumping in and out of truck plus heavy lifting. My OS never said a word about my weight and it didn't bother my recovery in the least. While I know the job contributed to my TKR, I also know it helped in my recovery, I had really strong quads. and I would advise you to do some isometric knee exercises to strengthen your quads. You can sit in a recliner while watching TV and work your knee. See an OS and make the decision to have the surgery. If you have a really great OS you will have to wait at least 2 months for surgery anyway, and that's a good thing, you want an OS who has done lots of TKR. Amazon has some great books on TKR and rehab, read them and do the exercises in them prior to surgery. Rehab isn't that bad. If you have a PT who knows what they are doing, they start you out slow and gradually ramp up your routine as you progress. Believe me, it is so worth it.