You necessarily run that way when you run barefoot, because hitting with your heel would be unbearably painful.

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Mr. Carrell points to alternatives for members who want to run barefoot.

WSJ: Barefoot Jocks Keep Gym Members on Their Toes

But who is going to run barefoot in the modern world?

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Cold weather "is probably the biggest challenge for people who want to run barefoot, " says Tamara Gerken, the 46-year-old founder of the Atlanta-based Barefoot Runners Society.

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Whereas a conventional shoe, like a Nike Air, is built for heel-striking when you run, barefoot throw you onto your sole.

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In what can only be described as a podiatrists worst nightmare, the vast majority run long distances in plastic sandals, flip flops or even barefoot.

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