Barefoot running has become a popular topic in recent years. Although participants run entirely "unshod" in its truest form, shoe manufacturers have developed minimalist "shoes" (more like gloves for the feet) to protect the feet. To some, barefoot exercise is a chance to get closer to our primitive selves, a chance to get back to nature. To a few scientists, barefoot running is a way to take advantage of how the human foot has evolved. The actual science behind the argument for unshod running is weak, though.

Barefoot running is more than just running without shoes; it involves a modified gait pattern, where the foot strikes the ground at the forefoot (ball of the foot), rather than on the heel. There may be some real benefit to such a running style, shod or unshod. One research study found the impact on the foot and leg is less when a runner strikes the ground at the ball of the foot instead of the heel. Some elite runners use this strategy even when wearing sneakers. But proponents of barefoot running have made more widespread claims. A simple internet search will result in assertions that barefoot running is more natural; after all, our prehistoric ancestors ran all the time with no shoes, didn't they?

Unfortunately, these claims border on misinformation. Dr. Greisberg has seen a number of barefoot runners with stress fractures in the foot. While any runner can get a stress fracture, there are certain features of barefoot running that might increase the risk.

Primitive humans lived in a natural world, where the ground was relatively soft. Our modern environment is entirely artificial; asphalt, concrete, hardwood floors, and stone maximize the impact on the foot. This impact is one of the key ingredients when making a stress fracture. Modern footwear diminishes the impact. Furthermore, there is no evidence to support claims that prehistoric humans ran all day. In fact, the human body is well built for walking great distances, not for prolonged running. It is probably more accurate to propose that prehistoric humans often ran for short distances; long distance running is not an effective strategy for individuals trying to survive in a natural environment.

(Persistence hunting is a technique used by some modern humans to wear down prey. The question is whether persistence hunting was the norm for primitive people, or if it is a small side path in the road of human evolution.)