Exercise is an unconscious activity for animals, they take exercise to hunt for their food, to move to different grazing, to escape from an enemy, to pursue a mate.

Physical work and activity was equally the norm for human beings -hunting, farming, animal husbandry, child rearing. Men took pride in their strength and in their muscularity. A strong man was able to defeat his enemies,was a fierce warrior and a King was expected to lead his men into battle.

The industrial revolution gave man the machine but a lot of the work of machine minding remained hard and physical. For perhaps 2 billion people worldwide, life still requires hard physical labour and it is a struggle to get enough to eat.

In the last 50 years significant numbers of men and women take little exercise in the course of their occupation. The computer keyboard, the rise of private transport, the world by television, household "labour saving" devices mean that with the minimal of physical effort we can work and play.