Christopher McDougall

The 'Tarahumara' use their legs 'as designed.' By running at a young age with minimal footwear, they naturally develop the best biomechanical use of their legs. Cushioned shoes restrict foot movements and allow for over-striding. Short strides are natural.

Endurance, after all, is the only reason we even exist. We think of ourselves as nature's deadliest animals, but the truth is, a naked human is the biggest wimp in the wild. We have no fangs, no claws, no strength, and no speed.

By irreducibly complex I mean a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning.