We are the biggest sissies in the jungle. Every other animal is stronger than we are - they have fangs, they have claws, they have nimbleness, they have speed. We think Usain Bolt is fast - Usain Bolt can get his ass kicked by a squirrel.
There is a growing subculture of barefoot runners, people who got rid of their shoes. And what they have found uniformly is you get rid of the shoes, you get rid of the stress, you get rid of the injuries and the ailments.