I've never been much into exercise or any kind of sports.
I've also struggled with a bad low back since I was a young adult. Over the years, I learned some physical therapy exercises for my low back. I've also done yoga as well as some simple Tai Chi. But every time I would get a good routine going, I'd re-injure my back (either doing my exercises or doing yard work or home maintenance projects.) And by the time it would heal I'd have lost the motivation to continue on.
The best thing I did for my low back problems though was simply to walk. And that's what I still do. We have a small dog. But we don't have a yard. So he goes for long walks a couple of times a day regardless of the weather.
Our doggie is getting older now & I don't know how much longer we'll have him.
(Hopefully a long time yet.)
However, once he's gone (assuming I'm still among the living) I may try to fire my old yoga practice back up. I'm a reclusive old geezer. So I have no interest in classes.