I have severe arthritis on my kneecaps although the rest of the joint is apparently in good condition. The consultant told me to stop running as it's too high impact - I was only doing 5k three times a week but that seemed to be keeping the flab at bay ... I've definitely put on weight since my knee started to play up
I'm not a great swimmer and I can't do breaststroke any more as my knee catches but that was the only stroke I'd managed to get the hang of the breathing. I cycle but more to get places rather than for exercise and if I do it too much my knee doesn't like it.
I can't afford to go to the gym but walk the dog once or twice a day for at least an hour at a time (he gets two walks but it's not always with me) - I average 15-16,000 steps a day.
However I'm gradually putting on more and more weight.. I'm vegetarian, barely drink alcohol, only have water or tea, no juice or fizzy drinks and eat very little cheese. I'm in my early 50s and assume I must be heading into the menopause (no symptoms so far) so I realise that losing weight is harder but there must be something I can do which will give me a workout without knackering my knees