Running is often thought of as a young person’s sport, but at the age of 39 Bernd Heinrich won his first marathon, as a complete unknown.  

It was only the third marathon he had ever run and his first in five years. 

Since then, the now 81-year-old has done everything from holding American records in four different distances – and the world records for those same distances in the masters category – at age 45, to outrunning a spitting cobra on the African plains. 

Bernd joined the show to talk about running and his new book - Racing The Clock - an in-depth look at running, aging, and the body, exploring the unresolved relationship between metabolism, diet, exercise, and age.