Some of us live our lives like confined animals. Built to move, too often we put ourselves in a cage.
We have bodies designed for racing across the savannas, but we live a life style designed for migrating from the bed to the breakfast table; to the car seat; to the office chair; to the restaurant booth; to the living room couch and back to the bed.
It wasn't always this way.
Not long ago in the U.S., a man who worked on a farm did the equivalent of 15 miles of jogging every day; and his wife did the equivalent of 7 miles of jogging.
Nowadays, our daily obligations of work and home keep us tied to our chairs, and if we want exercise, we have to seek it out.