Achieving hunter-gatherer fitness in the 21(st) century: back to the future.

The systematic displacement from a very physically active lifestyle in our natural outdoor environment to a sedentary, indoor lifestyle is at the root of many of the ubiquitous chronic diseases that are endemic in our culture. The intuitive solution is to simulate the indigenous human activity pattern to the extent that this is possible and practically achievable. Suggestions for exercise mode, duration, intensity, and frequency are outlined with a focus on realigning our daily physical activities with the archetype that is encoded within our genome.