Thomas Jefferson (3rd US President) once said: "Walking is the best possible exercise. Habituate yourself to walk very far."
When we get older, jogging is neither the pleasure nor the possibility it was when we were greener in years. But for 99% of us, walking is still an option even if we need a walking stick.
In fact, walking may be better for one's body than dozens of vitamin and health pills. I know of many cases, including my own, when peopled stopped a twenty year habit of high blood medication after renewing routine walking.
If you don't have an easy or safe place to talk, go shopping, hold on to a cart, and walk up and down the aisles (resisting picking up unhealthy foods) until your legs and lungs have had a work out.
Legs are like all muscles: use them or lose them. For older men, walking is the new jogging.