@robcfl I am 67 and way overweight and worked construction all my life. We worked very hard most the time and it kept me employed most of the time also. My doctor is bigger than me but no knee pain at all and he says mine is mostly from the hard work. I got my own stem cells for both knees and the extraction site on my hip hurt bad for three weeks ( 8-9 ) pain level but kept working anyways while it healed. For about the last 8 years I haven’t been able to mow the front or back yard in one go, having to take breaks to let the pain subside a bit before mowing again. The last couple of months I haven’t been able to do the front or back yards in one go and just last week I mowed both front and back in one go. I still have pain ( 5-6 ) but my knees do feel better. I had the stem cell shots in the middle of April. Follow the instructions for heat/cold applications to the letter on the extraction site and rest while you recover if possible!!!!