Hi Mr. Mel, I too am over 50, 55 actually and hear where your coming from with the knee problem. I try to set goals for myself like trying to walk down the hallway to the elevator, I live in an apartment building, at least twice a day. It's not a big deal but it's something. I also believe in just stretching or trying to touch your toes. You'll be amazed with a constant rep of strectching each day and bending what it will do for you. It's not hard either. Do it maybe 10 min. a day. As you go along it will become easier. I'm just getting back into Atkins but love the fact that it really works. I just keep telling myself it took me 28 years to have packed on this much weight so if takes two to take it all off then so be it. I'm tired of shopping in catalogs and tired of not being able to walk to the store. Running was something I always loved but I don't think I could run if my life depended on it right now. I would be able to get to the elevator though. Keep on keeping on.