Wednesday, June 18, 2014

Barefoot or Shod? A Question of Faith & Science: Science Says It's Safe and Economic, Practitioners Say "It's Making Me Faster & Helped Me Get Rid of Nagging Injuries!"

Minimal or no shoes, trendy, healthy and performance enhancing?
Honestly, I am not even sure if it's a question of faith and science. I think for many people out there it is more a question of faith or science. Now some of you may think: "Well, of course, science says: It's bullocks. Faith says it's 'right' to run barefoot." Right? Wrong!  No, I don't want to tell you what to do. I want to tell you about the scientific evidence in favor of barefoot running. Evidence as it is presented in "Barefoot running survey: Evidence from the field" a recent paper by David Hryvnial, Jay Dicharry and Robert Wilder that's about to be published in one of the upcoming issues of the Journal of Sport and Health Science that's based on data from more than 500 runners (Hryvniak. 2014).
Not everyone will do his HIIT sprints barefoot, I think, but maybe minimally shod?

Never Train To Burn Calories!

Tabata = 14.2kcal /min ≠ Fat Loss

30s Intervals + 2:1 Work/Rec.

Making HIIT a Hit Part I/II

Making HIIT a Hit Part II/II

Triple Your Energy Exp.
Prior studies have found that barefoot running often changes biomechanics compared to shod running with a hypothesized relationship of decreased injuries. The study at hand, which reports the results of a survey of 509 runners and does therefore represent both the "faith" and "science" appears to confirm these findings, as the majority of respondents report benefits and/or no serious harm from transitioning to barefoot or minimal shoe running.
Figure 1: Impact of switching from shod to barefoot-running on performance (Hryvniak. 2014).
As the data in Figure 1 clearly confirms, 67% of the surveyed runners reported noticeable improvements, 19% even say their performance increased significantly.
There is evidence from controlled trials that running barefoot reduces the oxygen cost and thus the running economy (Hanson. 2011)
What does previous research say? Where barefoot and shod populations co-exist, as in Haiti, injury rates of the lower extremity are substantially higher in the shod population (Robbins. 1987). The same often-cited study by Robins & Hanna does also confirm that running-related chronic injuries to bone and connective tissue in the legs are rare in developing countries, where most people are habitually barefooted. Whether these associations are of correlative or causative nature, however, is hard to tell, because controlled trials are rare.
This, in turn, is in contrast to studies on running economy most of which shown that wearing shoes increases the energy cost of running (Burkett. 1985; Hanson. 2011, cf. figure to the left) - in other words, it made the runners run more efficiently.
What's even more intriguing, though, is the injury balance. While 64% of the runners report that they have not had any injury, foot injuries (reported by 20% of the participants) may have become slightly more common.
Figure 2: Barefoot runners don't run barefoot, all the time, but there is hardly a terrain they avoid.
Unlike the grassy fields, which are the most frequented running grounds, city streets and sidewalks are not exactly "safe" places to run are where the study participants run more than 50% of their weekly mileage. Against that background it's also surprising that the number of knee injuries, injuries of the hips, lower back and ankle decreased in spite of the absence of the highly advertised "buffers" professional running shoes are supposed to offer.
Figure 3: Answers to the question " Did you have Achilles or foot pain when you initially began the transition to barefoot" (Hryvniak. 2014)
Bottom line: Just like most of the more recent experimental evidence the quasi-anecdotal data from the 509 runners Hryvniak et al. surveyed for their latest paper suggest: Running barefoot is safe and effective.

And while it took 45% of the study participants some time to get used to the increased achilles tendon stress + foot pain, Hryvniak. et al. say that "those that did primarily experienced foot and ankle injuries indicating the need to progress slowly so that the new areas of loading can adap"t (Hryvniak. 2014). In conjunction with the reduction of previous injuries after starting barefoot running programs, the result of the survey at hand should thus provide an incentive to try and see how you fare without / with minimal shoes, as well - I mean, what do you have to lose?
  • Burkett, L. N., WENDY M. Kohrt, and R. I. C. H. A. R. D. Buchbinder. "Effects of shoes and foot orthotics on VO2 and selected frontal plane knee kinematics." Medicine and Science in Sports and Exercise 17.1 (1985): 158-163. 
  • Hryvniak, David, Jay Dicharry, and Robert Wilder. "Barefoot running survey: Evidence from the field." Journal of Sport and Health Science (2014).
  • Robbins, Steven E., and Adel M. Hanna. "Running-related injury prevention through barefoot adaptations." Medicine and Science in Sports and Exercise 19.2 (1987): 148-156.