Barefoot Versus Shod Running: Which Is Best?
Previous research has shown that adding 175 g of weight to each running shoe required 3.3 percent more metabolic energy at a 6:22/mile running pace and adding 100 g of weight to each shoe required 1.2 percent more metabolic energy at a 7:00/mile pace.40,41 Another study focused on running in light diving socks with weights added in shod running and barefoot running.15 The study found that the higher metabolic cost of running in shoes was only due to the extra mass induced by the shoe itself and not due to any other mechanical property of the shoe.
With research indicating that barefoot running is more metabolically efficient than shod running, running barefoot should theoretically be faster than running shod since any mass added to the foot increases the oxygen cost of running. However, as mentioned earlier, since nearly all elite runners race in shoes and not barefoot, the increased metabolic efficiency of barefoot running doesn’t seem to equate to faster racing speeds for elite runners. These facts then lead to the following question: why aren’t more elite athletes racing without shoes if barefoot running is more metabolically efficient than shod running?
One possible answer is that faster running speeds, such as those that occur during race situations, will generate significantly higher peak vertical and peak shearing forces on the plantar foot with each foot strike.42-47 The increased ground reaction force that occurs at racing speeds over surfaces of various temperatures, surface contours and textures may deter the elite athlete from risking injury to his or her foot by running barefoot. Another possibility is that the shorter stride lengths forced by barefoot running may limit running velocity sufficiently to limit racing speeds. Another intriguing possibility is that elite runners choose to race in shoes since the running shoe companies that often sponsor elite running athletes offer significant monetary incentive for these elite athletes to race in their shoes rather than racing barefoot.
In regard to whether barefoot or shod running is best, the scientific research evidence to date supports only that barefoot running is more metabolically efficient than shod running. However, the rarity of barefoot runners breaking the finishing tape in all types of running races also points to the fact that there must be other more important factors at work that prevent the vast majority of athletes from running their fastest races while barefoot.
With this in mind, one should advise each runner-patient on the potential risks and benefits of barefoot versus shod running before they attempt to emulate their unshod ancestors by running barefoot. With so many questions remaining unanswered regarding barefoot versus shod running, further research will be necessary to further illuminate this fascinating subject.
Dr. Kirby is an Adjunct Associate Professor in the Department of Applied Biomechanics at the California School of Podiatric Medicine at Samuel Merritt University in Oakland, Calif. He is in private practice in Sacramento, Calif.