Barefoot running: Is it good, bad … or who knows?

Ever since the mainstream running world went bonkers over barefoot running about three years ago, it’s become de rigueur to slim down footwear or even shed shoes completely – sometimes without thinking about training, education or considering whether it’s the best thing to do.

Forget springs, cushions, gels, foams or all that jazz that was pumped into midsoles underfoot because even the companies that had put the most there have slipped under the fence to the other side and are spouting the barefoot or minimalist speak as if those prior developers were their evil twins.

So no wonder when two more studies came out earlier in January 2012 by the researcher who helped bring this to the scientific forefront – and who happens to have a webpage summarizing all-things-barefoot (http://barefootrunning.fas.harvard.edu) — that the running world started tweeting, buzzing and posting.

In sum, on their surface, the studies, by Daniel Lieberman from Harvard University’s department of evolutionary biology, seem to be another round of rousing support for barefoot running. But one has to look a little below the surface to recognize the questions that still exist. Not to say of course that these studies won’t end up being another peg in the board that in the end indeed support barefoot and minimal running. Before we all get too excited, though, we need to realize barefoot/minimal running boom and its accompanying research are still very young, even though running barefoot is not – think Zola Budd at the 1984 women’s 3,000-meter race — ; and numerous other elite athletes before and since. What is new is the marketing push, not only with flashy shoes and ads, but by extending the reach to the Joe/Jane Everyday Runner. Since it took two+ decades for people to begin to question beefy shoes, support and cushioning, we have some time to wait for definitive answers.

Back to the two studies. In early online releases — ahead-of-print — published in January 2012 by the well-reputed, peer-reviewed Medicine and Science in Sports and Exercise journal by the American College of Sports Medicine, Lieberman concluded two things:

Minimally shod runners are modestly but significantly more economical than traditionally shod runners regardless of strike type (from the study titled, “Effects of footwear and strike type on running,” with the free abstract at http://www.ncbi.nlm.nih.gov/pubmed/22217565), and

Competitive cross-country runners on a college team incur high injury rates, but runners who habitually rearfoot strike have significantly higher rates of repetitive stress injuries than those who mostly forefoot strike (from the study titled, “Foot strike and injury rates in endurance runners: a retrospective study,” with the free abstract at http://www.ncbi.nlm.nih.gov/pubmed/22217561).

(For the record, per protocol, Lieberman in the full studies read by Adventure Network®, declared outside funding, including a gift from VibramUSA, the makers of Five Fingers, which were key to kicking off the barefoot revolution. The gift is rumored to be in the five figures. Certainly Harvard is an institution that allegedly does not abide by any type of conflict of interest, thus this statement printed with the studies: “None of these funding sources had any role in the research design, and its analysis and publication.” It is also made public on his website.)

In the first study, 15 runners (13 men and two women) who had been running in barefoot or minimal shoes for an average of 2.1 years (0.6 to 4 years) but said they were still “comfortable” in traditional shoes were asked to run in both types of shoes in two five-minute sessions: once using a rearfoot strike and once using a forefoot strike. The result: “no consistent or significant pattern of difference between running economy” either in forefoot or rearfoot striking in either minimal or standard shoes. However, comparing the same strike type, researchers reported subjects were 2.41 percent more economical with a forefoot strike and 3.32 percent more economical with a rearfoot strike in minimal shoes compared to traditional shoes. The difference in energy cost, however, ranged in the 15 subjects from nearly 10 percent more economical to nearly 7.5 percent more costly. (Ed. Note: Being “more economical” in running means you use less oxygen and therefore less energy and that should reportedly mean you are faster and tire less easily.)

Regarding this study, we are not sure that 15 runners who report they are “still comfortable” in traditional shoes but run in barefoot/minimal shoes and who run for five minutes in each trial type are a proper pool for global conclusions. This is one piece of the puzzle only and frankly the results are really only applicable to this group, not the entire population of widely differing runners.

In the second study, 52 members (men and women, approximately 18-22 years of age) of the collegiate cross-country team at Harvard University, all of whom competed at the NCAA Division 1 level, completed logs during three months of fall training noting training, footwear, injuries, etc. Each runner was classified as either a forefoot or rearfoot striker with video measurement either on a treadmill (31) or on the track (28), although the study does note that “It is not possible to assess precisely the percentage of different foot strikes each runner uses throughout training, but we can measure the predominant foot strike used for the majority of miles run.” Nearly three of four runners had reported a moderate or severe injury each year, while those deemed as rearfoot strikers had twice the rate than those labeled as forefoot strikers.

There is no note in this study about the type of shoes used by each and if the injury rate had varied perhaps once arriving at Harvard. In addition, we wonder if the testing was done with team members on hand, leaving it open to competitive peer pressure – since Lieberman is not an unknown entity at Harvard. In addition, although the study has been highly circulated in running arenas, Lieberman writes “future studies with larger sample sizes will be necessary to extend these results to specific injuries, and we caution that since many factors probably contribute to each type of injury, these factors likely differ between injuries. As a result, we do not predict that a single nominal variable such as foot strike type can ever explain a high percentage of the variance for specific injury.”

I for one can’t be compared to a lithe national-class Harvard runner! We will await more from the barefoot running researcher.

Still wondering just what is a barefoot shoe and what is a minimal shoe? And what are others saying? Adventure Network + Total Fitness Network has more coverage on this hot topic coming in the days and weeks ahead, so stay tuned.

–Therese Iknoian

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The “Coach,” Therese Iknoian, has her Master’s degree in kinesiology with an emphasis in exercise physiology and is an American College of Sports Medicine-certified instructor. To read more about Therese’s coaching, outdoor and fitness background, click here.