I play my recorder to exercise my lungs.
I can exercise back and legs by reclining the sofa and clicking it back upright again.
I go up and down the stairs in the house quite a lot, and shove a vacuum cleaner round now and again.
I carry the shopping upstairs, having got the internet delivery van man to bring it to my door.
I get out of my seat in my consulting room to call the next patient in, and also walk up the stairs for coffee at half time.
When my knee injury was playing up, they put me on all those horrible gym machine things *shudder*. Why they have to make apparatus to oppose us doing movements which may or may not actually be part of our natural repertoire is beyond me- I really would rather do sport for its own sake than climb onto a heap of designer metal and repetetively bash out series of movements. Trouble is, very few sports actually appeal to me. Most of them end up with pain and breathlessness, and I don't like the sensation of either. Of choice, I'd do ice skating (okay, very very sore when one falls over, but I'm good enough to manage to avoid falls much of the time), skiing (but currently have injured anterior cruciate ligament), trampolining (ditto) or sailing (but it's rather cold to do that one up here)*. I was a not very good gymnast as a kid, and loved hurling myself around, but I'm already paying the price in arthritic joints, which further makes me unenthusiastic about heavy exercise.
Swimming? Hideous. It's cold, wet, requires rather skimpy clothing in a public space, and is fairly rubbish for anyone with lots of dioptres of myopia

.
*I realise all of these require silly equipment too. The difference is the freedom to practise and develop a range of skills, not just doing the same thing all the time.