With the arrival of spring you may have seen some people out running without any shoes on or wearing something that looks like a glove on their feet. Well the latest buzz around the fitness industry is—yes, you guessed it—barefoot running. While barefoot running is in the spotlight now, it actually has been around for quite some time. The running shoe wasn’t invented until the 1970’s so this is a relatively new piece of equipment when you look at how long humans have been running. And even since the running shoe emerged, the trend of barefoot running has come around the pike several times.
So why the sudden increase in interest again?
A new study published in the January 28th issue of the journal Nature shows that barefoot runners have a different running technique which may help to decrease the collision forces that act on the body. The authors analyzed the running styles of five groups of people—U.S. adult athletes who have always worn shoes, Kenyan adult runners who grew up barefoot but now wear cushioned running shoes, U.S. adult runners who grew up wearing shoes but now run barefoot or with minimal footwear, Kenyan adolescents who have never worn shoes, and Kenyan adolescents who have worn shoes for most of their lives. They found that most shoe runners strike their heels when they run, whereas barefoot runners tend to strike toward the middle or front of the foot.
So what is the big deal?
Well the authors found that heel striking causes a large and sudden collision force to act on the body which is often equal to two or three times the runner’s body weight. Because barefoot runners land more on the balls of their feet, less collision force develops. It is believed that the spring in the arch of the foot and the Achilles tendon help to mitigate the collision forces.
So less collision force has to mean less injury—right?
Well, not necessarily. Experts can’t seem to agree and there isn’t enough research to support the thinking one way or the other. The authors of this study hypothesize that forefoot or midfoot striking can help avoid or lessen repetitive stress injuries, especially stress fractures, plantar fasciitis, and runner’s knee. However, they are quick to point out that their hypothesis has yet to be tested and that there have been no direct studies on the efficacy of forefoot strike running or barefoot running on injury. Other experts believe that forefoot striking for long distances can actually lead to Achilles tendon issues, shin splints, and more knee pain. As you can see, the verdict is still out.
So what if you have been thinking about starting to run barefoot?
Barefoot running is definitely something that should be started gradually. Most people in this country spend most of their time in shoes whether it be walking in them or running in them. As a result, their mechanics and muscles within their feet and lower leg have developed differently. It is common to experience “tired” feet and very stiff and sore calf muscles when first beginning. Doing too much too quickly can lead to injury. The authors of the study suggest starting by walking around barefoot more frequently. Then they suggest no more than a quarter mile to one mile every other day the first week. From there they suggest increasing your distance by no more than 10% per week. If soreness remains they suggest NOT increasing the distance. Additionally, if there is pain, they always suggest stopping, letting the body heal, and seeing a physician if necessary. This information is not to take the place of information provided by a coach or physician and, as a reminder, there is no evidence that barefoot running is better for you so many experts believe there is no need to make this transition.
What about running surface?
Even on hard surfaces such as pavement, collision forces are low with barefoot running so barefoot advocates claim that it can be done on any surface. Because so many surfaces have debris such as glass, pebbles, and sticks, wearing a “minimal” shoe (those that do not have a heel cushion or arch support, that have a flexible sole) may be a good idea.
Of final note, anyone who has sensory loss to their feet (i.e. a diabetic) should not run barefoot or in minimal shoes. In fact, these individuals should probably wear shoes of some type at all times in order to protect their feet. If you have any foot-related problems, you should seek the advice of a medical professional before you start barefoot running. Hopefully with this latest interest, more research will be conducted that will provide more insight into the benefits and/or disadvantages of barefoot running. Lieberman, D. E. et. al. Foot strike patterns and collision forces in habitually barefoot versus shod runners. Nature 463: 531-565, 2010.