One reason that some of the best long distance runners are from Africa is because they train barefoot. I can't remember the exact number, but by doing this trains & triggers the nerve endings in your feet to react and respond quicker, causing the leg and thigh muscles to be more responsive.
I worked for Nike years ago and use to train sales people on shoe technology, so I also had to learn about foot / ankle / knee injuries in addition to shoe technology. I'm barefoot whenever I can, mostly because I'm Asian and the shoes come off whenever you're in a house. I have an office job so when I'm at the desk, my shoes are off. The VP of Engineering walks around in flip flops in the office but only puts shoes on when customers visit or if he's out on the manufacturing area.
