SportsOneSource Media: March 22, 2012
According to a study conducted by researchers at the University of Colorado in Boulder, running shoes make running physiologically easier than going barefoot. The study, published online in the journal Medicine & Science in Sports & Exercise, began by recruiting 12 well-trained male runners with extensive barefoot running experience.
The New York Times indicated that a few previous studies have indicated that it’s easier to go barefoot in terms of physiological effort since more effort is required to handle the extra weight of a shoe.
In the new study, Runners were asked to run multiple times on treadmills while either wearing shoes (the Nike Mayfly at 150 grams) or unshod. When unshod, runners wore thin yoga socks to protect them from developing blisters and for hygiene purposes for the treadmills. Next, according to the Times' article, 150 grams’ worth of thin lead strips were taped to the top of runners’ stockinged feet. Adding an equal amount of weight to the bare foot promised to reveal whether barefoot running was physiologically more efficient than wearing shoes.
Researchers found that when barefoot runners and shod runners carried the same weight on their feet, barefoot running used almost 4 percent more energy during every step than running in shoes.
“What we found was that there seem to be adaptations that occur during the running stride that can make wearing shoes metabolically less costly,” Jason R. Franz, a doctoral candidate at the University of Colorado who led the study, told the Times. The researchers believe that when barefoot, forces generated by the collision of foot and ground shift to the leg muscles absent the cushioning provided by shoes.
Moreover, the study found that even when unweighted barefoot running was compared foot-to-foot with running in the Mayflies, 8 of the 12 runners were slightly more efficient wearing shoes, even though they added more weight.
The study only looked only at the metabolic efficiency of wearing shoes, versus not. The scientists didn’t evaluate whether barefoot running lowers injury risk.
The Times article concluded in part, that "serious racers might want to mull over the trade-off between having less mass on their feet when barefoot versus having greater potential strain on their leg muscles."
But for the average runner, Dr. Franz recommends that a more lightweight model might be better for many given that some cushioning spare leg muscles from extra train yet avoids the metabolic cost to wearing heavy running shoes.