The “five fingers” shoes are minimalist footwear that more closely resembles barefoot running when compared to regular shoes. These shoes may allow for higher performance, as they weigh less; thus you expend less energy every time you lift a foot. However, this lightweight design also exposes the foot to more stress, and you may put yourself at a higher risk of stress fractures.
Similarly, studies have shown that there are higher stresses on your feet when running on asphalt as opposed to running on grass. (Here’s one such study: In-shoe plantar pressure distribution during running on natural grass and asphalt in recreational runners. V. Tessutti, et al., Journal of Science and Medicine in Sport, January 2010.) This suggests that runners who are prone to stress fractures may be at a higher risk of injury while running on pavement than while running on softer surfaces such as grass, a rubberized track, or a treadmill.
The risk of foot injuries has been correlated with an increase in miles run, certain foot types, running experience, previous foot injury, and some footwear. I would recommend changing running shoes at least every 500 miles, as after that distance, a shoe’s ability to absorb the shock of running decreases, which may increase the risk of foot injuries. If you have never used the minimalist footwear, I would start slowly on softer surfaces and then gradually build up the distance.
Keep aware of the possibility of foot pain and stress fracture and see a professional if either of these develops.
Dr. Mark Drakos is an orthopedic surgeon at Hospital for Special Surgery who specializes in disorders of the foot and ankle as well as sports-related injuries. He did his undergraduate work in biomedical engineering at Harvard University and received his medical degree from SUNY Stony Brook. Dr. Drakos is the author of more than 50 peer-reviewed articles, book chapters, and presentations involving orthopedics. He has directly provided care for high school, collegiate, professional, and Olympic athletes.