The human cardiovascular system evolved as part of the physiology of [prehistoric] hunters, who ran for their lives.

Man is a distance runner as a consequence of hundreds of thousands of years of chasing antelopes, horses, elephants, wild cattle, and deer.

The natural world is not only a set of constraints but of contexts within which we can more fully realize our dreams.

The human cardiovascular system evolved as part of the physiology of [prehistoric] hunters, who ran for their lives.

All around us, aspects of the modern world - diet, exercise, medicine, art, work, family, philosophy, economics, ecology, psychology - have begun a long circle back toward their former coherence. Whether they can arrive before the natural world is damaged beyond repair and madness destroys humanity, we cannot tell.

Men are born human. What they must learn is to be an animal. If they learn otherwise it may kill them, and kill life on the planet.

When men do not run they are likely to die prematurely from dysfunction of the heart and vascular systems or from disabling chronic disease.