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- Alex Hutchinson (@sweatscience)
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Three interesting blog posts that anyone interested in the ongoing debate over minimalist shoes will be interested in:
First, Amby Burfoot had a brief Q&A with Irene Davis, a top researcher and barefoot advocate formerly at Delaware and now at Harvard, in advance of last week’s ACSM meeting. She discusses a few bits of upcoming research, and the freshest wrinkle from my perspective was a study on balance with and without socks:
It was determined that a thin pair of socks causes a statistically significant reduction in balance, suggesting that they filtered out important sensory information.
We often talk about barefoot running and minimalist shoes like Vibrams as essentially the same thing — but maybe there’s something intrinsically superior about going totally barefoot in terms of “dynamic stability.”
Second, Ross Tucker at the Science of Sport has a lengthy post that sums up his take on the barefoot debate starting with a very basic intro — perfect for those who want to get up to speed but haven’t been following the debate closely. This post sums up my own positions on the pros and possible cons of barefoot running absolutely perfectly, so I highly recommend it!
One interesting point that Ross makes is the difference between running and training for high performance. As he points out, it’s highly unlikely that our caveman forebears ever tried running 120 to 200K per week at relatively high speeds. At those training levels, muscle fatigue may become a limiting factor:
The third presentation in the symposium showed some really interesting evidence that the loading on the joints and bones was HIGHER as muscles fatigued. This stands to reason, of course – muscle absorbs much of the impact force, and so tired muscle loses that ability, exposing the joints.
So those who are training for performance may struggle because of a muscle fatigue issue – the muscle is working differently, and harder in certain muscles, when barefoot, and that may be limiting.
Finally, Pete Larson at Runblogger has an epic post where he takes on the outspoken Asics researcher Simon Bartold (who I interviewed a few years ago for this article), with the discussion continuing in the comments section. What’s funny to me here is that I think the two of them are in pretty close agreement about the current state of evidence for (and against) normal and minimalist shoes — which is to say, there’s some suggestive biomechanical data but a complete dearth of convincing epidemiological or interventional data in either case.
The difference is in where they see the burden of proof. Bartold seems to hold minimalist advocates to a higher standard of evidence than he holds “current state of the art” shoes with a raised heel. Pete takes the opposite view:
Since evidence seems to be a popular word in this discussion, what evidence is there that this [shoes with raised heels] is safe? Shouldn’t the burden of proof be on the company making the product to show that it’s safe for the consumer? Isn’t this what drug companies have to do?
This is similar to what Blaise Dubois told me when I spoke to him a few months ago. But I’m not sure I fully buy that. Even if you accept all the evolutionary arguments marshalled in favour of barefoot running, I don’t think it necessarily trumps the experience of recent decades. Say you claim that sleeping in stuffy, poorly ventilated houses leads to respiratory infections, so we should sleep in the trees the way our ancestors evolved to do over hundreds of thousands of years. It might be true. But I’m not going to immediately give priority to a claim based on evolution (even if backed by logic and anecdotal support) and ignore the practical experience over the past few decades of people with whom I have a lot more in common than cavemen. These “modern” running shoes have been out there for the past ~20-30 years — and in that time, I’d bet that more people have run more miles successfully than in the previous couple of millennia cumulatively.
That doesn’t mean the shoes are “good,” or that we shouldn’t be eagerly and actively pursuing alternatives — just that they’ve earned a position as the default option, to be supplanted when something else is shown to be demonstrably better. If we’re using the lingo of drug trials, they’re the current “standard of care” that experimental treatments need to exceed in order to be adopted.
Alex,
Just to be clear, I was not making the evolutionary argument that barefoot is better. My beef with what Simon said was that ASICS was holding steady with a heel striking model based off a 10mm-12mm shoe and that the minimalist movement is nonsense. He went on to equate minimalist shoes with toning shoes. My take is that he has no proof that the 12mm model is optimal, so why not be open minded and experiment to a greater degree with other variants. I also do believe there is evidence suggesting that the “standard of care” when it comes to “prescribing” shoes in stores is faulty. Arch height and pronation control as assignment criteria have not held up to recent scrutiny (Ryan and Knapik research). Either that, or the shoes don’t work in a systematic way.
Don’t get me wrong, I believe shoes are going to be worn and are necessary for most people, I just want to see more options and better guidance when it comes to finding the right shoe for each individual.
Thanks for continuing the discussion!
Pete
Thanks for the comment, Pete! And let me clarify that I’m not agreeing with all of Bartold’s comments, which I thought were overly dogmatic. If I were ASICS, you bet I’d be experimenting with shoes with a lower heel.
Although I do think he makes a fair point: it’s a big marketplace, and virtually every shoe company is rushing to offer minimalist shoes. Why does ASICS need to do the same thing? If it does turn out, as seems likely, that different things will work for different people, maybe it makes business sense — and isn’t incompatible with good science — to stake out a different corner of the market. A market where every entrant pursues the same goals at the same time is one infected with groupthink. If they’ve got it wrong with this “late pronation” stuff, then the market will ultimately punish them — but it seems premature to judge that outcome in advance.
To put it another way, you may be right that he has no proof that the 12mm model is optimal. But there are 1,000 elements of modern running shoe design that aren’t backed by any proof, from the threading of the laces to the shape of the last. So he/they are making decisions on what the most fruitful areas to push their research in, and those decisions disagree with your analysis (and also disagree with where most of the other companies are pushing, though let’s be honest: most of the big companies are being driven in that direction my marketing, not research).
“I also do believe there is evidence suggesting that the “standard of care” when it comes to “prescribing” shoes in stores is faulty.”
So do I. But the way you replace a standard of care is to find an alternative that outperforms it in the same test, not by going back to first principles. That’s the follow-up study Ryan et al. are doing now. They showed that prescribing traditional shoes based on static foot type didn’t produce any measurable benefits. Now they’re essentially repeating the study but including a minimalist shoe. If the minimalist shoe outperforms the “standard of care,” then we’re in business!
My problem with ASICS (and I ran in ASICS almost exclusively for 2 decades) is that the company seems to have put blinders on. ASICS evolved into dominating the highly-engineered, pronation-control shoe market. If ASICS were still controlled by an open-minded management, it seems to me that they would be willing to experiment with and market less-structured shoes other than racing flats. The dogmatic response of the company indicates a fear of losing a market sweet-spot rather than a reasoned response formed on real research. It saddens me to see a company that I still have loyalty to decide to “stand on the sidelines” and, worse, jeer those who have decided to experiment with minimalism.
Alex,
Thanks for the response, and I do agree with most of what you have said. In fact, I made the point in my post that I don’t really care if Asics goes in that direction as plenty of others are. That’s their decision, and as you say, the market will ultimately make that decision for them.
My reaction was that Bartold’s post was overly dogmatic, as you said, claiming no evidence where in many places there is some, albeit nothing is certain or particularly strong at this point. When a prominent figure at a prominent company in the industry calls minimalism, Chi, Pose, or whatever else “nonsense,” it begs a response.
In a perfect world we will have lots of options, and shoes do have lots of things that can be varied. It’s just that until recently, with the exception of racing flats that have largely been inaccessible to the recreational runner, most shoes were largely variants on very common theme.
Some people are always going to need the big, bulky shoe, but others seem to do better in something else. At an n=1 level, that is important.
Pete
I thought Ross’s 3rd counter-argument was particularly interesting: it’s risk homeostasis again! That is, maybe injury rates are stuck at 70% because 70% is the injury rate we are willing to tolerate. In that case, even a shoe that is effective at reducing the risk of injury for a given individual, ceteris paribus, would not reduce the population rate of injury because it would draw in more injury-prone individuals at the margin. Alternatively, it would enable one to run a marathon with less training for a given level of risk.
I would like to add a comment to the performance argument because I’ve heard it a few times and it doesn’t make sense to me. Every race from the 100m to the 10,000m raced by an elite athlete is done in spikes and I’ve never seen an athlete wearing spikes heel strike. If we’re going to race forefoot striking, shouldn’t we be training with the same foot strike?
@Phil Koop
My thoughts exactly.
“more people have run more miles successfully than in the previous couple of millennia cumulatively”
That sounds like the paradigm case of risk homeostasis: The ammount of fatalities per km traveled has dropped since the 1930’s, yet the amount of fatalities per head of population has remained the same.
With injury rates like car accidents, more people making more km’s.
If the analogy is correct (big if…), cushioning, motion control and the like in modern trainers are true innovations like ABS, crumple zones and safety belts.
You discount the Tarahumara people.
Interesting comments — thanks everyone! I hadn’t thought of the shoe question as a sort of societal risk homeostasis. That’s a very interesting way of thinking about it, and could well be true. Or it could be totally false. Unfortunately, I don’t think we have good enough injury prevalence data over long periods of time to be able to tell.
@Richard: Well, I ran 3:42 for 1500m in spikes, heel striking all the way. I’m not recommending this approach — just sayin’. 🙂 You say: “If we’re going to race forefoot striking, shouldn’t we be training with the same foot strike?” Leaving aside the question of whether everyone is going to race with forefoot striking, I’m still not sure the answer to your question is obvious. Let me ask this question: “If we’re going to race at 60s/400m, shouldn’t we be doing all our training at the same pace?”
@Tori: No, I don’t. There were almost as many people running at the Ottawa Marathon last weekend as there are Tarahumara people alive on the planet today.
You do because you claim “more people have run more miles successfully than in the previous couple of millennia cumulatively.” What do you mean by successfully? Many modern runners succumb to foot injuries and tribes such as the Tarahumara are prime examples of how barefoot running or minimalistic running is beneficial.
“If we’re going to race at 60s/400m, shouldn’t we be doing all our training at the same pace?” Interesting question and the short answer is mostly yes, as much as you have the energy to do so with proper rest and periodization. That’s what Roger Bannister did to run a 4 minute mile. He thought that if you could run 10 x 60s/400m intervals that he should be able to sustain 4 back to back and he did. The importance of sport specificity seems to be undervalued in running, whether it’s form , foot strike, speed or intensity. The majority of Emil Zátopek’s workouts were intervals. He said that he already knew how to run slow but needed to teach his body to run fast and that’s what he did – tons of intervals. 100 x 100m, 40 x 400m type of thing. I think the ideal long run, suppose 2 hours, should be done in 1-3 minute intervals with full recuperation in between, not steady effort. This might seem like a contradiction because you should race at a steady pace but it’s not – if you’re running intervals for 2 hours, you’re running 1 hour at race pace. And running 1 hour at race pace over a 2 hour period is a more effective workout than a 2 hour run with with nothing at race pace. Easy recovery runs are just that, recovery runs, not workouts and those could be replaced by any other exercise like cycling or swimming because their purpose is not to train the body for the event. Their purpose is to enhance recovery and so sport specificity is not as important.
I’m confused here, Richard. First you suggested that if we’re going to race in minimalist shoes (like spikes), we should do all our training in minimalist shoes — rejecting the common paradigm of doing easy mileage in “regular” shoes and hard workouts in flats or spikes.
But now, in response to my analogy, you’re saying “Easy recovery runs are just that, recovery runs, not workouts and those could be replaced by any other exercise like cycling or swimming because their purpose is not to train the body for the event.”
Isn’t that precisely the thinking behind doing easy runs in “regular” shoes?
“Isn’t that precisely the thinking behind doing easy runs in “regular” shoes?”
Yes, if you’re a heel striker. I think my points of form and recovery are getting mixed.
You’re implying that running in “regular” shoes, the ones with large heel padding, is easier on the body than minimalist shoes and that they’re needed for easy runs. That’s only true if you’re a heel striker. “Regular” shoes hamper the recovery of a forefoot striker by restricting ankle movement and lower leg muscle activation. I also wouldn’t change my running form to heel striking during easy runs for reasons other than recovery. I think keeping the same form whether running fast or slow is good for muscle memory but this is a different subject.
@Richard Ayotte
To be clear, I have no idea whether Ross’s point about serious competitive runners potentially running into trouble at high training loads will turn out to be true. I would imagine it doesn’t apply to people who grow up running barefoot (e.g. the Kenyans). However, for someone who grew up in regular shoes, then switched to minimalist in their 20s, say, and after a couple of years pushes their training up to 220K/week with a significant portion of this done at fast paces, it’s conceivable that they may find that two years, or even five years of the “new” form hasn’t been enough to fully eliminate any weak spots left from an initial lifetime of big shoes.
If that’s the case, you could argue that it’s the big shoes that are the root cause of any problems that emerge. And that’s fair enough. But from a practical rather than philosophical point of view, the result is the same.
So to reiterate: I don’t know if Ross’s suggestion is true. Neither does he. He’s just raising it as a possibility, and I’m passing it along. But as counterarguments go, I don’t find “If we’re going to race forefoot striking, shouldn’t we be training with the same foot strike?” very compelling. Ultimately, we can’t deduce what will happen to competitive runners in an Aristotelian manner — we have to try it and see. And that’s what’s happening right now!
Sorry to be off topic but I just have to get this straight with people or to throw this out there so that folks can have their say.
The word “minimalism” gets thrown around a lot but I think some people might be referring to different things. The Blur 33 and Kinvara are minimal shoes but they encourage 2 completely different types of running techniques. I think this needs to be addressed more often or terms should be used correctly because there is a lot of confusion out there. People automatically think that a minimalistic shoe is a shoe that encourages or more “natural” running technique when that is not true.
There are three types of shoes:
1. Traditional Shoe – one with a significantly higher heel than forefoot. Often it encourages a heel strike. Example would be the ASICS Nimbus.
2. Minimal Shoe – A minimal shoe is one that has little technology or material involved in its construction but still may have a significant heel. For example, the ASICS Blur 33 is a minimal shoe. It still has the heel to forefoot offset of a traditional shoe just without all the extra technology. Therefore it would encourage heel striking yet it is still a minimal shoe.
3. Natural Running Technique Shoe – This shoe has a relatively low heel to forefoot offset. It can also be a minimal shoe but doesn’t have to be. Natural running shoes typically encourage a more mid-foot strike. Examples are the Kinvara, Minimus, Newton shoes, Vibram, etc.
4. Barefoot Running – No shoes. Period.
Does anybody follow me on this?
First, thank you for the continuation of this discussion. It has definitely made me question my beliefs but has yet to convince me to change my position.
Interesting that you find “If we’re going to race forefoot striking, shouldn’t we be training with the same foot strike?” not very compelling. Is that because you’re not a believer in the specificity of training? http://coachsci.sdsu.edu/csa/vol12/table.htm
Good point, Andrew. When I talk about “minimalism,” I generally mean categories three or four in your breakdown above: either barefoot, or a shoe that allows a fairly similar stride (i.e. with low heel). I hadn’t heard that second category called “minimal” before, but I may well be out of step with the terminology others are using, so thanks for clarifying.
Rich, thanks to you for the comments. Because you’ve been reading and commenting for a long time, I’m hoping that you take my responses in the spirit of an interesting debate (which it is, to me), rather than me believing that I have all the answers!
“Is that because you’re not a believer in the specificity of training?”
I’m absolutely a believer in the specificity of training, but I’m also a believer in the complexity of training. This is what I was trying to get at by bringing up the idea of doing all our training at race pace. From the point of view of specificity, this would obviously be ideal. That’s the basic thinking behind intervals. It’s what Bannister did, as you pointed out. And other coaches and athletes took his ideas even further — Igloi was almost all intervals, even twice a day.
But if you look at the training done by top runners today, we’ve taken a step back from Igloi’s approach. Most runners mix intervals with much longer runs at paces ranging from very easy to very hard, with the vast majority of the week’s training (~90%, according to some studies) slower than race pace (at least for distances shorter than HM).
Does this mean these runners and coaches don’t believe in specificity? Of course not. They certainly do some training at race pace, and specificity is one of the reasons. But they’re also balancing other training principles — the need to recover, the adaptions that result from sustained efforts, and so on, and trying to find an optimal mix that makes them faster. Specificity of pace is just one part of that mix.
That’s the point I was trying to make, by analogy, about your argument that specificity of foot strike means we should always train with the same shoes/foot strike that we plan to race with. From the point of view of specificity, you’re perfectly right. It’s just not obvious to me that there aren’t other factors that might come into play — like Ross’s hypothesized increase of injury risk in advanced stages of fatigue. I don’t KNOW that it’s true, but I don’t KNOW that it’s not, so I remain agnostic.
And, for that matter, this is where I differ with Pete Larson. You might say that I’m fundamentally conservative in my approach. I trained at a relatively high level for many years using the “standard” approach of regular trainers for most runs, and flats or spikes from workouts. And I trained with or knew literally hundreds of runners who did the same with great success, some of whom went on to run at the highest levels, including the Olympics.
On the other hand, I personally don’t know a single person who grew up wearing shoes, switched to running barefoot-style, and has competed at that level. This says nothing about whether such a thing is POSSIBLE. But it sets my “default” position. For Pete, the default is that cavemen ran in bare feet, so the onus should be on shoe makers to prove that their shoes are actually beneficial to runners. For me, the default is that I’ve known hundreds of elite runners training in regular shoes, and none who’ve trained in bare feet, so I’m waiting to see some examples before I’m convinced that it’s possible, let alone optimal.
“These “modern” running shoes have been out there for the past ~20-30 years — and in that time, I’d bet that more people have run more miles successfully than in the previous couple of millennia cumulatively.”
What is the basis for qualifying success? Isn’t the average annual injury rate close to 100% for shod runners?
The general public believes that shoes are the default option because that is what the marketing tells them. Meanwhile, in many other parts of the world people continue to go on running barefoot or in little more than scraps of rubber. And they beat us at the marathon almost every year.
@David Csonka
“Meanwhile, in many other parts of the world people continue to go on running barefoot or in little more than scraps of rubber. And they beat us at the marathon almost every year.”
I am not really convinced that growing up barefoot is the only, or even the most important factor.
First of all, the success of (mostly) Kenyans is e relatively recent phenomenon. It is no age-old truth chiselled in marble. Secondly, I don’t suppose that Kenya and Ethiopia are the only countries where many people grow up barefoot. I think it is safe to assume that in all third world countries a significant proportion of the population grows up barefoot. Yet, it is only these nations that beat ‘us’. Of course, one could argue that other lightly shod or unshod nations are held back all sorts of things, like a lack of training infrastructure, sports culture etc, but that would be assuming the initial point.
It is not an uncommon phenomenon that certain countries produce superior athletes for no immediately apparent reason*. Just think of the favellas of Brazil, that have produced and still produce masses of brilliant soccer players for decades.
Or on a larger scale the US, that has about 5% of the world population yet it consistently produces a significant portion of the top athletes in almost any sport. I’d say that that is a fact that cries out for an explanation rather than some nations of the other 95% have better athletes in one sport at this point in time.
*) If I had to take a guess, I’d say it seems to be the combination of a soccer/running culture, a lucrative market for talent and, sadly, poverty, that prevents the most talented from choosing a career that offers a secure income rather than pursuing a sporting career with a 0.1% chance that they will make it to the top.
Same here Alex, a good debate and no feelings hurt. I’m leaving the emotions completely out, I’m definitely a scientist at heart and looking forward to being proven wrong and expand my knowledge. 😉
I didn’t know about Igloi’s training but I’m definitely looking into it.
I also don’t know of anyone who went from regular shoe to “Natural Running Technique Shoe” as Andrew termed it, and achieved elite level. But if I can set a PB this year in my Trail Gloves… it won’t be elite level but I shouldn’t really be setting PBs at 38 either.
Oh and in closing, can you guess who finishes first in this photo?
http://www.iaaf.org/mm/photo/competitions/competition/05/95/83/59583_full-lnd.jpg
The notion that the Africans beat the world because they have run barefoot is…well… Far more likely, it’s because of a combination of genetics and training. After all, how many Africans race or train barefoot today? Too much is at $take.
I’ve read and re-read your article and you are flat out wrong about burden of proof. The burden of proof goes to the person asserting a claim or making a positive argument. The fact is shoe manufactures are making the positive claim stating that their product is better than running barefoot or being barefoot (the natural position). I’m not stating that barefoot running is better, simply it’s the natural state of things. Like for example gloved vs. un-gloved. Being un-gloved is the natural default state, not the gloved. Shoe manufactures have failed to live up to the positive claim that their shoe is better. Fact is no shoe manufacturer has done the studies to indicate weather shod running is less injury prone or more beneficial than barefoot running.
Also I wouldn’t want to compare numbers when you say “more people have run more miles successfully than in the previous couple of millennia cumulatively”. Assuming an evolutionary link to distance running which you say you do, would entail that most people who have existed in the past would have been running in some form or another (ie. Persistence hunting). Considering that 120 billion people have existed on our planet, only a small number would have been around for the last 20-30 years and have access to modern running shoes that you mention. A vast number of people would have, either been barefoot or wearing minimalist type shoes for running.
One other minor point is that you mentioned our ancestors hundreds of thousands of years ago lived in trees. I think the number is closer to 5 million years or more, a much more vast difference than the 1.5 millions of years that Leiberman and Bramble are assuming. Not to mention the adaptive traits associated with distance running are still found in modern humans.
At least it seams we both would agree that more research is necessary. I can’t wait to see the outcome of the upcoming study proposed by Richardson, and Bartold!