Yesterday I was told by a friend that, her wife had two back surgery due to a herniation, she was about to have her third surgery, but they started to walk just for the feeling of well being, nothing fancy like 30 minutes around the block walking. And in 1.5 months her back was pain free and she did not have surgery but she keeps walking a few times a week to keep healthy.
Ps: My friend does not exercise or he does not have any interest in fitness related stuff, he has no point of view on these matters or nothing to prove. It was an anecdote for him so there is no exaggeration in this story. Of course it might be useful for very small number of audience, I don’t know.