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University of Colorado Barefoot Running Study

Posted by | Posted in Barefoot Running, Barefoot Running Shoes, Minimalist Running Shoes | Posted on 27-03-2012

 

The media is having an anti-barefoot running field day thanks to a study published by some people right up the street from me at the University of Colorado (BTW, I’ve been living in Boulder for 19 years and nobody has been able to explain why they call the university CU instead of UC.).

Each of the dozens of articles about the study has a distinct flavor of elementary school playground taunting, “Nah, nah, nah, nah, boo, boo… barefoot running isn’t good for you!” 

I mean, check out some of the headlines:

Debunking the Barefoot Running Myth – Sydney Morning Herald (barefoot running isn’t like bigfoot!)

Here’s Proof Barefoot Isn’t Better — Running Times (Ha! So there!)

It almost feels like the press is enjoying creating a backlash to all the “pro” barefoot articles of the last two years, even though in every barefoot article I’ve read the media insists on publishing “both sides of the story,” and includes some doctor who’s never run a meter in bare feet and wouldn’t know decent barefoot running form if it ran him over, claiming that running without shoes will hurt you, bring shame on your family, and accelerate the coming apocalypse.

So, let’s take a deep belly breath or two and have a chat about the study. In fact, let’s start by talking about studies, in general:

Designing a biomechanics study is not easy. Aside from deciding exactly what you want to explore and the best design of the study itself (how you can test it), finding enough of the right kind of participants is often tricky, if not impossible.

It’s even more difficult to design a study that isn’t artificial in some way. That is, it’s showing effects in a lab that may not be relevant in the real world.

And, even more, many studies, while interesting, may not be relevant to the broader population. (Whenever someone quotes a study, or even just the habits, of elite marathoners, I respond “Unless you’re 5’5″ and weigh 105 pounds and run at 13 miles per hour for two hours… WHO CARES what those guys do?)

Finally, the way the media picks up a study — this one or any of the previous barefoot studies — often adds some spin that isn’t in the actual study.

All of the issues I just raised are relevant as we take a gander at the CU study. BTW, if you want to see a lively and cogent critical look at the study, you can’t go wrong with reading the comments on the New York Times article about it. Frankly, this post probably won’t be as lucid as some of the comments there.

Okay, let’s jump into it… The gist of the study:

“In the study, 12 subjects with substantial barefoot running experience ran at 7.5 MPH with a mid-foot strike pattern on a motorized treadmill, both barefoot and in lightweight cushioned shoes (~150 g/shoe, 5.4 oz). In additional trials, they attached small lead strips to each foot/shoe (~150, ~300, ~450 g). For each condition, they measured the subjects’ rates of oxygen consumption and carbon dioxide production as an index of metabolic cost.”

And the results:

a) For every 100g (3.5oz) (the average weight of a deck of playing cards) added per foot, energy cost increases by approximately 1% whether running barefoot or shod.

b) Running barefoot and in lightweight shoes do not significantly differ in energy cost.

c) When controlling for shoe/foot mass, running in lightweight shoes requires ~3-4% less energy than running barefoot.”

Now, let the fun begin. Can you find the “confounds” (the factors in the study that might affect the results, or the interpretation of the results)?

I’ll start. Let me know if you find more.

1) How did they determine that the 12 subjects had “substantial barefoot experience?” Well, the study says, “8 km/week barefoot or in minimal running footwear (e.g. Vibram Five Fingers) for at least 3 months out of the last year.”

Does 3 months out of the last 12 really equal “substantial?” I’ve been barefoot for 3 years, and I’m STILL improving my form.

And if that three months was wearing VFFs or minimalist shoes, that counts as “barefoot experience” Uh…

As I’ve commented, and as the American Council on Exercise showed, and as Pete Larsen from www.runblogger.com captured on video: VFFs are not the same as barefoot.

Now the researchers did verify that the subjects all ran with a “midfoot or forefoot” landing. I know that Lee Saxby, the spokesman and coach from Vivobarefoot would have an issue with that. He doesn’t think midfoot is proper barefoot form (there’s some debate about that, but it’s besides the point at the moment).

2) They ran on a treadmill. Look, I get that testing runners on an actual track is hard and expensive, but running on a treadmill is not the same as running on the ground, end of story. It may give some useful data, but if it walks like a duck and quacks like a duck, but the duck is on a treadmill… hmmm, that analogy isn’t quite working, but you know what I mean.

I did some high-speed video analysis of my running at the Monfort Human Performance Lab. I hit 21 mph on that treadmill. I can tell you that when I’m on a treadmill, my stride is different than on the track. I overstride so I can “catch” the treadmill belt, for example.

3) To simulate a running shoe’s weight, the researchers put lead weights on the top surface of the runners’ feet. Do you think some small weights pressing down on your foot is different than having that same amount of weight distributed evenly, and mostly under your foot, thanks to the design of the shoe? I do. Does that matter? Could be. Is there a way to check… not easily.

4) The runners were at 7.5 miles per hour. That’s slow for an elite runner –  about 200 meters in a minute, a quarter mile in 2 minutes, a mile in 8 minutes — but fast for most casual runners. This raises a few questions:

a) How was that pace compared to the runners’ usual training pace?
b) Does speed make a difference?
c) What about turnover, or cadence? Were those controlled and the same when the runners were barefoot vs. shod?

Got me. But, suffice it to say, we’re seeing the artificial quality of the study.

5) Oh, this wasn’t mentioned above, but I’ll give it to you now: the runners were wearing yoga socks. ““For the duration of the experiment, subjects wore very thin, slip-resistant yoga socks for safety and hygienic purposes.”

Hygienic purposes? Uh, some 409 and a paper towel would handle any “hygiene issues.” And “safety”? If you read the study, one aspect of “safety” is “avoiding blisters.”

Boy, where to start on that one? We know that socks does not equal barefoot, and we also know that if you get blisters when you run barefoot, you’re doing something wrong. So, this brings us back to number 1 — how experienced were these runners really?

6) The study measured oxygen consumption and carbon dioxide production. Okay, that’s a fine way to measure efficiency, based on the idea that using less oxygen and producing less CO2 means you’re using less effort, and that equals being more efficient.

But here’s a question: So what?

For one: does using less energy equate to faster times? It seems like it might, but that’s not a given.

Does the amount of extra energy being used by *some* of the barefoot runners have any relevance to the average runner? Someone for whom 7.5 mph is too fast… or even too slow?

7) Oh, here’s a favorite. The runners in the study wore an ultra-lighweight racing flat. Most runners wouldn’t wear those. And most runners with no barefoot experience wouldn’t find those any friendlier than being shoe-free.

8) One other thing: A hallmark of the scientific method is reproducibility. Just because one lab gets a result, that doesn’t mean the question is resolved. When a study is reproduced in independent labs and the same (or very similar) result is obtained… then you know you’ve got something.

What if the study is correct, though? What if barefoot running is less efficient than shod running?

The only answer I can come up with is: Who cares?

I don’t mean that it’s not important to know. I mean, literally, who should care?

If you never race, you’ll never notice any difference in efficiency (assuming, again that “decreased efficiency” = slower times).

Besides, there are MANY other reasons to run with bare feet than the idea that it’s more efficient… many that have barely been touched on (Dr. Michael Merzenich and I have had some interesting chats about how being barefoot could help the elderly in various ways). Personally, I didn’t make the switch for efficiency’s sake. In fact,  for me, as a sprinter, I know I’m more effective in spikes than barefoot. I switched because it helped me correct some form problems, eliminated injuries I was getting, turned running from a chore into an enthralling discovery, and, more importantly… WAS FUN.

Don’t get me wrong, I’m thrilled that my Boulder neighbors are researching barefoot running. And while this is the first published study, I know they have more coming and I’m looking forward to those.

And I’m certainly not blaming them for how the media is handling the story.

My only interest is the continued exploration, conversation, and understanding of efficient movement, running for speed and/or distance, and the ways of teaching and exploring barefoot running (and walking and hiking).

No one study can perfectly address all of the open questions. But the almost combative attitude where everyone wants to jump on some one-sided “We’re better!” bandwagon certainly doesn’t help.

Suffice it to say, this study is not the death knell of barefoot running that many media outlets are portraying it to be (because, you know, controversy is more important than truth if you’re trying to sell papers).

Now, if you’ll pardon me, I have to burn off some of my frustration by putting on some yoga socks and minimalist shoes and going for a barefoot run.

p.s. (added on 4/4/2012): 

I just realized that the conclusion of the study was WAY off base!

Here’s why

The researchers think that the improved efficiency of the shoes came from the PADDING absorbing some of the stress that the muscles have to handle when you’re barefoot.

In other words, the ENTIRE efficiency effect could be ALL about the padding and have nothing to do with weight. The weight issue would only be valid if they tested multiple shoes of the same weight with different types of padded outsoles and got the same results.

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Comments

There are (19) Comments for the University of Colorado Barefoot Running Study

  1. [...] on 28 March 2012 Thank you, Steven Sashen, founder of Invisible Shoes for sharing much-needed clarity on a topic that is as polarizing as health care legislation, or [...]

  2. I sympathize with your frustration. Science reporting is fickle, and these kind of studies really seem to betray a lack of subtle understanding about what is barefoot running.

    Small point: My best guess is that CU is called CU because the University of California system is a very big system that dominates the name UC. That said, most UC schools use their specific school like “UC Berkeley” or “UC Davis.”

  3. [...] Go To: University Of Colorado Barefoot Running Study [...]

  4. “We know that socks does not equal barefoot.” Could you give me a Link of an article about socks and barefoot, please?

  5. Very well put! I’ve been running barefoot for years (20 races bf in 2010; 21 races bf in 2011) and have never understood how people with shoes or sandsls on their feet can claim so proudly to be running “barefoot.” Yet the designers of this study made the same bizarre assumption, conflating barefoot running with use of VFFs.

    They didn’t study “experienced barefoot runners” at all, so it’s not good science. Sadly,”Garbage in, garbage out.”

  6. Runnersworld had a story on this study a month ago, written by presumably a shoe happy author. His stance was sorta like, “Eh, nice info, the jury is still out on this debate though.” My thought was, “Interesting information, hardly relevant, except for possibly saying that huarches are better than barefoot for running! Although then again, ummm.” Lol

    Actually, you’re close enough to where they are that you might be able to find some better participants, have better testing protocol, maybe have some of your shoes for testing [invisibleshoes are now lab tested! ;) ], and have get a run at it again. What do you think of that?

    Clyde

  7. I don’t think O2 consumption is why we run barefoot. It is comfort and injury prevention. (BTW…CU is Colorado, UC is U of Cinci or Cali which schools are usually followed by location ie UC Irvine, MU = Missouri vs UM Mich typically just M., UK Kentucky vs KU, Kansas, OU is Oklahoma, UO is Oregon)this is to create less confusion between the major schools although it is not a perfect system.

  8. There’s a link in the article, above, to a post I did about minimal not equally barefoot… I would hope it’s self-evident that socks fall into the same category because: a) The affect the sensation (especially yoga socks which have little rubber balls every 1/4″), and; b) They slide about rather than giving a solid connection between your feet and the ground.

  9. Ken Skier,

    Yeah, barefoot has no equals. It has near equals, but it can only be replicated by itself. But remember that the (traditional) Tarahumara run not barefoot, but in minimalist sandals.

    My two main reasons for wearing invisibleshoes are to be able to get somewhere that requires shoes, and so that I can be outside considering that my dad doesn’t want me out barefoot. This is a compromise so that I can actually go running, and they are WAY better than vffs. I tried some recently for a side by side comparison. Barefoot would get first place, these sandals second, and the vffs would be fourth or fifth behind something else. Even the thinnest most flexible they have. It’s full foot protection, but not the same feel as the invisibleshoes. Something about that built up heel…

    And another thing pertaining to the article, while I strive for efficiency, injury prevention is why I got into the barefoot/minimalist stuff anyway. A year later, it’s way better than the old padded heelstriking way. Not going back.

    Clyde

  10. Besides the excellent points you have already made, I want to comment on the specious argument that the more “efficient” mode was therefore better. Except for races, people don’t run to get the most efficient use of their energy. Feeling better and not creating injuries are far more important than being able to go (Dx1.02) meters rather than D meters with the same number of calories.

    And a much more important note, I think using CU for the abbreviation of the Univ of Colorado is a rather clumsy solution. Connecticut uses “UConn”. Why not “UCol”?

  11. Not to mention that some people run barefoot in order to use MORE of their muscles and get MORE of a workout. What are they going to do next, compare barefoot running with riding in a car? But riding in a car takes way less effort…lol…
    Also, I must be doing it wrong. Cause I tried barefoot walking on a treadmill earlier today and only lasted 8 minutes before I put on socks. I’m not sure how to lift my foot or push off of it so that it doesn’t turn at all and get some friction. Guess I will have to look at the forums more! But I am very new to this still, 6 months or so, so I’ve got some learning to do! :-)

  12. Tammy,

    Six months in? But you should be a pro by now! ;) I think you see what Steven was pounding on as them not necessarily being very proficient barefoot. It took me 3 months just to get over the sore muscles of walking, and probably another 6 to perfect my running form that I just filmed and found that I still have a little work to do on my jogging stride. Let alone go from couch potato to recreational runner with at least 10 miles a week.

    But back to your question. If you have equipment that will do it, you would benefit from filming your feet from the top in front of you, maybe two or 3 steps would get in. Then, you play it back one frame at a time on your computer and look for twisting. You may need to get the sides and back filmed too, but this is just one way to try to fix it.

    In fact, I’d been having a hotspot on my left foot by my big toe and figured out accidentally from filming me running up the stairs in my huarches that it was a matter of residential carpet combined with the shoes putting more torque on my foot than would occur barefoot. And I knew this because I had just filmed myself on the road in huarches, so I had a basis of comparison therefore and I’ve been fine after I made that discovery. No more hotspot.

    But another way to figure this out that I use often is to stand on a solid flat surface, and carefully watch my feet while slowly walking and tweak as necessary. But something I wouldn’t have been able to do like that was figure out why my right foot slapped louder than my left when running in my huarches, if it’s slapping while barefoot, you’ve got a big problem. I found that my right foot was turned out just a tad. Fixed that and I was much quieter. Pitter-patter instead of flop-flop.

    Hope that helps! And btw, I’ve been going barefoot for a year now.

    Clyde

  13. I just loved that there were a whopping 12 runners in the study…did anone happen to see the particluars of the control group they used?…ridiculous. This type of study is what’s making me slowly lose faith in the ‘scientific’ community. How did this even get published?
    For me I’ll be sticking with my own personal experiences of barefoot/minimalist running…when I get an injury I’ll let you know.
    Great article Steven (as is the Vibram lawsuit one I just read before too).

  14. The part about putting weights on barefoot runners and then saying they ran more inefficiently was a no brainer. Why would I put weights on my barefeet and then go running? Duh!

  15. Barefoot Dawsy… scientists are still scientists outside the medical field. Having been involved on both sides, there are basically no similarities between the two. In physical science you have objective data and objective conclusions. In “clinical” studies it is about as “scientific” as a discussion on Fox News.

  16. If you’re following this thread still… read the very end of the article again. I just added a postscript that might TOTALLY pull the rug out from underneath the argument in this study.

  17. Thanks for that addition!

    I’ll definitely be curious if they follow through with that idea and try different types of minimalist shoes under the same conditions for the same people, even though we already know that more padding is actually worse for overall health of the body.

    FIAT LUX!

  18. You raise some good points. The study isn’t perfect, and your commentary raises some points about how it could be improved. I think the issue has to do as much with how the media over-inflates the study’s meaningfulness (what – now no one should run with a forefoot landing style?) instead of what the study actually did and said.

    Why is it called “barefoot running” though instead of “forefoot-landing”? Do you distinguish between the value and benefits of the two? Do you have to be barefoot?

  19. Well, Ron, “barefoot running” is sort of shorthand for “barefoot-style running”. And, yes, there is a difference between forefoot landing in shoes and forefoot landing barefoot, if for no other reason than the amount of padding and the amount of feedback you get from the ground. The debate is still going on about better/worse, and whether you can more easily learn a mid- or forefoot landing by running barefoot (my experience is that it is). Some would also argue that merely being barefoot confers benefits that being shod does not, again because of the type and variety of sensory input you get when you’re barefoot.

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