Arthritis then two total knee replacements – one in 2018, the other in 2019 – knocked a lot of my fitness and also suppleness back quite badly. I can't kneel fully now, so getting down on the floor and rising again are not easy.
As I found yesterday evening when trying to fit two small brackets to the workshop floor in a cramped space behind the horizontal mill. (The brackets anchor parts of a frame to hold the machine's motor and drive I need build – and a right so-and-so of what should have been a simple task, it was, too.)
I used to be able to walk miles at quite a rapid pace but still manage much more gentle walks locally, with the bonus of finding places I had never seen before, within a mile of home, in a area I have lived in since 1959! It now takes me twice as long to walk to town two miles away as it used to, even using an asphalted former railway that cuts off a big corner in both azimuth and elevation.
Though never a very good caver, counting myself as experienced but not skilled over 40+ years of it, I certainly can't visit the sort of caves I have in the past but when pandemic restrictions allow I'm still involved with a particular cave "digging" project on the Mendip Hills. Not digging the cave as such but creating a route through boulders blocking what we hope is the way into a significant cave. Over 150 feet down so far, and still digging… The oldest member of the team is 70, in fact I think 73, but a darn sight fitter than me!
I even found a small cave in a very unexpected spot near home, back in June. Since it is small and I was on an Officially Approved Lockdown Exercise Walk when I spotted it and managed to crawl in for my full length, so that's not far, I christened it Exercise Cavelet. This in an area providing very attractive walks by the sea.
I deliberately use a corner shop some distance away as well as the Nisa (ex Co-Op: same company) about 100 yards from home, to give a walk of perhaps a mile, but often extend that by various detours.
Cycling? I have considered buying a second-hand cycle again but it would have to be a small one, possibly a ladies' bike with step-through frame, as most cycles are much too high for me and I cannot swing my leg over them even with the aid of a high kerb. Those acrobatics on the move most cyclists use, were always impossible for me. The deterrents are first a busy, uphill main road not safe for cycling, and secondly, having nowhere sensible to keep it. I have a large shed but someone's gone and filled it with hefty machine-tools and a part-built third-scale steam-wagon. (My executors are going to have an interesting problem there…)
Swimming? I can't swim because I only just float in sea-water and not at all in fresh.
So, yes, keep exercising. As well as we can, however we can; both physically and mentally.