Like you, bags, I walk for the pleasure of being out of doors and seeing the wonderful scenery in my part of the Alps, but it has the secondary result of keeping my arthritic knees moving!
I don't think my type of walking would be classed as sport.
I was a very unsporty child and used to dodge PE and games whenever I could.
When I was 16, I started roller skating and learnt all the dances - waltz, tango, two-step, etc. My ex and I would go the rink five nights a week, and I only stopped when I was pregnant. I still have skates and boots and would love to find somewhere private to practise.
My snorkeling is, again, not done for the exercise, but to enjoy the wonderful world of coral, but I suppose it does count as a sport.
One of my daughters ran a couple of mini-triatholons after she became a grandmother,but she was only 42. Now, she spends a lot of time with her family, cycling, kayaking, walking, and 'wild' swimming (i.e. in lakes and rivers) as well as in the sea. She has a horse and spends many happy hours schooling her and riding. It does help that they live in a lovely scenic area of New Zealand.
I don't think she does any of her sports for anything but sheer enjoyment.
I can't imagine anything more boring than going to a gym and pounding away uselessly on an exercise machine.