My wife and I used to walk often but she has arthritis in her legs and one of her feet now which restrict her but she does like to walk as much as she can.
She's had one knee replacement and the other one will be done eventually but, unfortunately, nothing can be done for the foot apart from the occasional injection which doesn't last very long.
We just have to adapt but as you say, spotit, those of us who can walk without restriction are very fortunate..