Unless you live next to the beach, barefoot runners are an uncommon sight. Maybe you’ve spotted one in the wild — he’s “that guy”, the overtanned specimen with long gray stringy hair waiting in the corrals at the marathon start.

Vibram’s famous FiveFingers, the closest you can get to bare soles without ditching your kicks entirely, gave birth to a new generation of “that guys” when they made barefoot running a hit a few years ago. The barefoot craze has also led to the popularity of extremely lightweight and minimal running shoes, which are best for those not quite ready to go fully naked.

If...