Running

More evidence on benefits of barefoot running

Dan Lieberman recently published two new papers on running.  Here's a good Wired article summarizing the findings.  I should note that these papers aren't about barefoot running so much as forefoot and rearfoot striking, plus minimalist footwear in the first paper.

I was a data point in the first study, Effects of Footwear and Strike Type on Running Economy.  It was fun.  They hooked me up to a breathing tube to measure my oxygen usage, which took a little getting used to.  I had to run with a forefoot strike in VFFs as well as conventional sneakers, and then do the same with a rear-foot strike.  Let me tell you, it's seriously unpleasant to run with a rearfoot strike in minimal shoes.

Here are the results and conslusions:

RESULTS: After controlling for stride frequency and shoe mass, runners were 2.41% more economical in the minimal shoe condition when forefoot striking and 3.32% more economical in the minimal shoe condition when rearfoot striking (p<0.05). In contrast, forefoot and rearfoot striking did not differ significantly in cost for either minimal or standard shoe running. Arch strain was not measured in shoes condition but was significantly greater during forefoot than rearfoot striking when barefoot. Plantarflexor force output was significantly higher in forefoot than rearfoot striking, and in barefoot than shod running. Achilles tendon-triceps surae strain and knee flexion were also lower in barefoot than standard shoe running.

CONCLUSIONS: Minimally shod runners are modestly but significantly more economical than traditionally shod runners regardless of strike type, after controlling for shoe mass and stride frequency. The likely cause of this difference is more elastic energy storage and release in the lower extremity during minimal shoe running."

The second study is even more compelling: Foot Strike and Injury Rates in Endurance Runners: a retrospective study.  Lieberman has been collecting data on the Harvard cross country team for years.

RESULTS: Of the 52 runners studied, 36 (59%) primarily used a rearfoot strike and 16 (31%) primarily used a forefoot strike. Approximately 74% of runners experienced a moderate or severe injury each year, but those who habitually rearfoot strike had approximately twice the rate of repetitive stress injuries than individuals who habitually forefoot strike. Traumatic injury rates were not significantly different between the two groups. A generalized linear model showed that strike type, sex, race distance, and average miles per week each correlate significantly (p<0.01) with repetitive injury rates.

CONCLUSIONS: 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 injury than those who mostly forefoot strike. This study does not test the causal bases for this general difference. One hypothesis, which requires further research, is that the absence of a marked impact peak in the ground reaction force during a forefoot strike compared to a rearfoot strike may contribute to lower rates of injuries in habitual forefoot strikers.

A 2X difference in injury rates?  That's HUGE.  It's only a matter of time until all collegiate cross country programs teach their athletes how to run properly, with a forefoot strike.

Caught in the crossfire: Is endurance running good or bad?

I'm finding myself caught in the crossfire of the Great Endurance Running Wars.  Think of it as Born to Run vs. Chronic Cardio.  The paleo/CrossFit world has basically rejected "chronic cardio" in favor of sprints, high intensity training, and weight training.  The barefoot running world has rejected modern high-heeled running shoes, but embraced endurance running as a core explanation of human evolution.  And then there's little old me, caught in the middle -- hosting barefoot running events AND deep in the paleo world.

So who's right?

  • In the blue corner....Born to Run.  We have Dan Lieberman at the forefront of the science, and Christopher McDougall as the great story-teller in Born to Run.  The argument goes: we've been eating meat for more than 2.5 million years.  We've only been making projectile weapons for some tens of thousands of years.  In the interval, we evolved from upright scavenger to endurance hunter.  We are slow sprinters compared to other animals, it'd be too dangerous to try to kill game with just spears, and we have lots of physical adaptations (like sweating) that point to endurance running as an adaptation to run down animals in the noon day heat, killing them of heat exhaustion (aka, persistence hunting).  There's a lot more, but that's the quick and dirty.
  • In the red corner...chronic cardio. We have folks like Mark Sisson, much of the CrossFit crowd, Art De Vany, Robb Wolf, and more.  Sisson gives a pretty good argument for why we didn't evolve to be endurance runners: why run when you can scavenge, a high risk of failure during a persistence hunt without easy access to carbohydrate, and alternate explanations for certain physical adaptations.  Persistence hunting is essentially a good trick that we learned, kind of like holding our breath for a long time to gather mollusks from the sea floor.  A clever way that some people have developed to get food, but not core to human evolution.  We went from weak scavenging (eating what animals left behind), to strong scavenging (scaring off animals before they eat their fill), to use our smarts to kill animals by ambush, running them off a cliff, or hell, throwing rocks at them.

Let me just say that when I first read Born to Run and Lieberman's Running Man hypothesis, I hated it.  It went against everything I believed from living a few years in the paleo world (and importantly, what I had been telling other people).  That's wrong, I thought.  But the barefoot concept made a lot of sense (modern high-heeled running shoes are actually bad), barefoot running seemed like fun, and I gave it a shot.  I also heard Dan Lieberman speak at the Harvard Club of NYC, and his lecture was compelling.  I started Eating Paleo in NYC in July 2009.  I started Barefoot Runners NYC four months later, in November 2009.

Here are a bunch of beliefs I hold:

  • Some of the injuries that we associate with "chronic cardio" and distance running are actually due to high-heeled running shoes.  And to the bad form that it engenders.
  • The American jogging / jogging shoe fad of the past four decades does not represent barefoot running in the same way that the weight lifting that goes on in Bally Total Fitness does not represent CrossFit.
  • It's healthier to go barefoot or minimalist in a wide variety of activities, whether standing, walking, or running.
  • Barefoot running is fun.
  • Barefoot running is psychologically engaging, particularly on trails (where you have to pay closer attention to where you step).
  • You can still injure yourself even if you run barefoot.  Particularly if you transition to quickly, get caught up in competitive running, and don't listen to your body.  Barefoot running is not a foolproof method to never get injured.
  • Simply because running is a repetitive motion doesn't mean it's unhealthy. The concept of a repetitive stress injury really only makes sense in relation to whether the creature evolved to do that motion.  Fish don't get repetitive stress injuries from swimming, a bird doesn't get repetitive stress injuries from flying.  The problem is performing a movement more frequently than your biological design specs are prepared for.
  • Frequent injury among healthy minimalist runners would militate against the importance of endurance running.  We'll have to see.
  • Endurance running should never be your only form of exercise.  (Nothing should ever be your only form of exercise.)
  • Lieberman has marshaled a lot more evidence in favor of his Running Man Hypothesis than has percolated onto the internet or into a typical article.  I'm not going to give an exhaustive catalog, but from thermo-regulation (sweating, the distinctive shape of the human nose, hairlessness) to biomechanics (tendons in the foot, stabilizing muscles for the head, and other parts of the body that tend to appear in the endurance runners of the animal world).  This is not a "tired argument", but a completely novel one from the past 5 or 6 years.  And he's not "full of crap".  Write this guy off at your own risk -- he is more careful than you are.
  • At the same time, we could all point to LOTS of academics who get tons of shit wrong.  Don't think Lieberman is right just because he's a Harvard professor.  Harvard Shmarvard.
  • Persistence hunting was not the be all, end all of survival.  It would not have been a daily occurrence.  It would not have ever been the only source of food, or even meat.  And it would have been harder outside of Africa where it's cooler, and the terrain isn't as open and flat (not that all of Africa is open and flat).
  • Lieberman has not made any claims for the optimal way to exercise, beyond suggesting that a forefoot strike will reduce your ground impact compared to a heel strike.  And whether we evolved to be endurance runners or not, it doesn't mean it's the most effective way to be healthy and train.
  • HIT (high-intensity training) and strength training can improve performance in endurance activities, but the reverse doesn't hold.  You can get better at marathons by doing CrossFit, but you can't get better at CrossFit by running marathons. 

So here's my take:

  • I think the paleo world -- like Mark, Robb, and Art -- have a better understanding of what actually works on the ground to make people healthy.  And I think the most effective and efficient way to workout, in order to minimize risk of injury and maximize health and longevity, is based on a HIT-based method with a lot of variety, like what that they recommend.
  • But I think Lieberman knows a hell of a lot more about evolution.  Though I'm not saying he has everything exactly right.  But I enjoy barefoot running and the benefits from it, and I think running can be one part of a healthy and fit life.

What do you think?

Podiatrist attacks barefoot running, calls for more orthotics

Get ready for some bullshit.  A podiatrist, Dr. Robert A. Kornfeld, just posted a detailed criticism of barefoot running over at Huffington Post.  This should be fun -- let's see how it stands up.

Fads come and go. 

Thanks for starting with a softball.  A fad?  Humans have been running barefoot or in minimalist footwear for, oh, millions of years.  Humans have been running in high heels for four decades.  Which would you say is normal?  Which is the fad?

We are in the midst of another passing fad of products, this time designed to mimic or support "nature." And who doesn't want to be more natural these days?  Barefoot running shoes are designed to re-create a "natural," barefoot running dynamic on "unnatural" surfaces like concrete, asphalt, red top, black top, etc.  

"Natural" and "unnatural" are very squishy terms that are easy to abuse.  The point of barefoot running is not to be natural in some hippy-dippy sense, but to run in the way that humans are best adapted to run based on the science and evolution of running.

How can we have a barefoot running shoe? Doesn't barefoot denote without shoes? 

Apparently, Kornfeld specializes in pedantic podiatry. 

Barefoot running shoe manufacturers believe that the human foot, unimpeded by synthetic surfaces and restrictive running shoes, should function at its best. That is a correct assumption, save for the fact that the human foot was designed long before the paving of roads. In fact, uneven, grassy surfaces are the most natural surface for the human foot...

 First, nature isn't one big grassy lawn or well-manicured golf course.  There are rocks, roots, and all different types of surfaces (hard/soft, wet/dry, even/uneven).  Second, most barefoot runners will tell you that it is more difficult to run on grass than on concrete.  It's hard to see where you are stepping -- grass often hides objects and uneven surfaces.  So we're not pursuing "naturalness" at all costs.  Furthermore, when you are running on a difficult surface, it's more important to run with a forefoot strike, because then you have the ability to shift your weight more quickly if you land on an object or uneven patch.  Third, Lieberman's work has shown that the force generated while running has more to do with the foot strike than the surface.  You can run on steel plates gently.  And the steel plates will give you better feedback about your form.

It is this dynamic -- the decrease in heel strike -- barefoot running shoes seeks to achieve. This is precisely why this technology is failing its mission. The lack of heel strike on unnatural surfaces is not mimicking the way the foot would perform barefoot on natural surfaces. For this very reason, these shoes will eventually come up short, as the foot requires either cushioned heel strike on an unnatural surface or minimal heel strike on natural surfaces.

If you look at podiatry text books, they often still teach that walking and running use pretty much the same bio-mechanics.  A heel-strike followed by a transfer of weight forward.  As it turns out, running and walking use different bio-mechanics.  Walking uses a reverse pendulum motion, where you plant your heel and pitch yourself over.  Running uses a spring motion, where the energy from each stride is stored in the tendons and ligaments and released in the next stride.  Heel-striking is normal for walking, but a forefoot strike is normal for running.  They need to update the text books.

Then he writes about some specifics of metatarsal flexibility which I don't know much about.

As for injuries:

We will see things like first metatarsal phalangeal joint pain, pain under the second metatarsal head, Achilles' tendinitis, plantar fasciitis, posterior tibial tendinitis and/or peroneal tendinitis. Eventual stress fractures of the metatarsals may occur in addition to knee, hip and back problems. 

Funny, these all sound like injuries that runners were already getting while running in heavily-cushioned motion-control shoes.  It's true that it takes time for your foot to strengthen, your achilles to lengthen, and to learn good form -- so people who transition too quickly are putting themselves at risk.  Of course, a podiatrist is only going to see the people who have problems and none of the people who used to have knees problems running conventionally, but who now can run again (like me).

So who should be using barefoot running shoes? The answer is very few people should. Only those people with stable (not flexible) first metatarsals will do well with these shoes, as well as those with very powerful lower leg musculature (although even those with powerful lower leg function will ultimately go on to some type of pathology). 

Tell that to the Kenyans.  Oh wait, they don't use barefoot running shoes...they just run barefoot.

So let's get real. If you are a serious runner, you need to see a podiatrist who is also trained in functional foot typing, as developed by Dr. Dennis Shavelson to find out if barefoot running shoes are for you. If not, you can safely wear conventional running shoes manufactured by companies who have spent years on research and technology with the addition of a proper running orthotic.

Ah, I guess we owe a big thank you to the shoe companies that have spent years on research and technology -- and have nothing to show for it.  As Lieberman published his research in Nature and as Born to Run took off, the shoe companies have not published a single study showing that all their fancy over-engineering prevents injuries.  Even the military has called bullshit on them.

Sadly, the podiatrist ends his article in a completely predictable way: selling orthotics.  Take his advice and you'll need them.

The definition of jogging (and why not to do it)

Below is the dictionary definition of "jog".  You'll see why I don't like the term.  It's a word that means to shake, jerk, nudge, push, or jolt.  There is nothing fluid or gentle about it.  Don't go jogging.  You'll be jogging your knees, jogging your feet, jogging your head, jogging your ankles, jogging your body.  Jogging is bad.  Run, chase, pursue, walk, hunt, or stalk -- anything but jog.

Hat tip to Barefoot Ken Bob for pointing this out to me.

 

jog

1    [jog]  Show IPA verb, jogged, jog·ging, noun

–verb (used with object)
1. to move or shake with a push or jerk: The horseman jogged the reins lightly.
2. to cause to function with a jolt for a moment or in a series of disconnected motions: He jogged the motor and started the machine.
3. to push slightly, as to arouse the attention; nudge: She jogged his elbow when she wanted to be introduced to one of his friends.
4. to stir or jolt into activity or alertness, as by a hint or reminder: to jog a person's memory.
5. to cause (a horse) to go at a steady trot.
6. Printing . to align the edges of (a stack of sheets of paper of the same size) by gently tapping.
 
–verb (used without object)
7. to run at a leisurely, slow pace, esp. as an outdoor exercise: He jogs two miles every morning to keep in shape.
8. to run or ride at a steady trot: They jogged to the stable.
9. to move with a jolt or jerk: Her briefcase jogged against her leg as she walked.
10. to go or travel with a jolting pace or motion: The clumsy cart jogged down the bumpy road.
11. to go in a desultory or humdrum fashion (usually fol. by on  or along ): He just jogged along, getting by however he could.
 
–noun
12. a shake; slight push; nudge.
13. a steady trot, as of a horse.
14. an act, instance, or period of jogging: to go for a jog before breakfast.
15. a jogging pace: He approached us at a jog.
 
Origin: 1540–50;  b. jot  to jog (now dial.) and shog  to shake, jog (late ME shoggen)

Barefoot running is not hardcore

The biggest misconception about barefoot running is that it's hardcore.  I'm going to let you in on a little secret: it's not.  Barefoot running is actually softcore.  Soft.  Gentle.  Delicate.  Light.  Starting to sound less macho?  I know, that's why I almost kept this to myself.

Jogging is a contact sport.  Hit the road, hit the pavement, pound the pavement, pound out a few miles.  Ever listen to most runners?  Thud, thud, thud, thud.  Injuries galore.  Knee problems, shin splints, orthotics, plantar faciitis.  Remind me -- what is so easy and painless about jogging?  Sounds pretty hardcore to me.

If jogging is for the strong, barefoot running is for us wimps and cripples.  For people who have no choice but to run softly.  To minimize pain...and effort.  To glide over the ground.  To run, not jog.  To move silently, stalk, and pursue.  To minimize impact and maximize efficiency.  Sounds pretty soft and weak.

The media always gets this wrong.  Every time a reporter wants to talk about barefoot running, it's always, "Wow, you must be sooooo tough."  As a 27-year-old male with healthy testosterone levels, it's hard not to play into this.  And I'll admit that I get a kick out of the exclamations and attention when I'm running in Central Park.  Girls always notice.  20% of the time they think it's gross, 80% of the time they starting throwing their sports bras.

An older lady stopped me on the way back from a run last week.  60-something years old -- and well, let's just say she didn't look like the athletic type.  She told me she had been running barefoot on the indoor track for a year now and loved it.

And that's exactly what concerns me -- if all the out-of-shape seniors all start running barefoot, then the gig is up.  No more babes, no more sweaty sports bras.  Can we keep this just between us?

Dan Lieberman on the science of running

Vibram posted three portions of an interview with Harvard professor Dan Lieberman.  I've also posted the profile of Lieberman and his work from when it appeared in Nature.  All short and worth watching.  

And personally, Professor Lieberman is a great guy.  I had the opportunity to hear him speak at the Harvard Club last fall.  Awesome presentation -- can't wait for his book.  He's done all sorts of cool research on how different parts of the human body give us clues as to what types of movements we're adapted to.  Like we have a muscle in our necks to keep our head from bouncing around that running animals tend to have.  He's currently in Kenya, or as he put it to me, "in the land of barefoot runners".  

 1. On a heel strike vs. a forefoot strike.

2. On "compliance", or your body's give. 

3. On the modern running shoe.

4. And the slightly longer profile of Dan Lieberman and his work done by Nature.

It's hard to sprint on a treadmill

Ever notice that it's nearly impossible to sprint at max speed on a treadmill?

This week I wrote about how refrigerator design reflects (and influences) what we eat.  Well, so too with our gyms.  The rows and rows of treadmills and ellipticals are a sign of our chronic cardio habit -- and the treadmill itself reinforces the habit by making it hard to do anything other than jog in a straight line at a moderate pace.  Spend too many years in a gym and you almost forget that sprinting is even an option.

I actually sprint on a treadmill sometimes.  Other people in the gym get nervous because nobody ever sprints on a treadmill.  There must be rules against such a thing!  They get worried that I'll wipe out.  And I do hold back just a little, just in case I don't find the Stop button on the first try.  (But only a little.)

Probably better to just go to the park and do some sprints.  Of course, I rather enjoy blasting the zombie joggers out of their treadmill stupor.

Zombie Joggers (or, Why running barefoot makes you more alive)

Many joggers run mindlessly and monotonously.  I call them Zombie Joggers.  I used to be one.
 
Zombie joggers can be recognized by their blank stare, exhausted and hunched over posture, and a heavy-footed, plodding pace.  Their mind has drifted off to a distant place -- as if lobotomized and motor control handed over to the reptilian brain stem, issuing the same simple commands over and over:  "Right foot, left foot, right foot, left foot".
 
Here are a few reasons why joggers zone out:
  • There's little need to pay attention to where you're stepping.  (You've got shoes on.)
  • No need to change in direction.  (Don't want to twist an ankle.)   
  • Little change in pace.  (No reason to change speeds.)
  • It doesn't take any skill. (Just will.)
Running barefoot, on the other hand, forces you to focus.  Focus on where you are stepping, focus on the changing terrain, and focus on how your feet feel.  Somewhat rocky trails are awesome because they really challenge your mind and body to find good places to step.  Here comes a rough patch, slow down a bit and step lightly.  Zig zag a bit to find the best footing.  Okay, the terrain just evened out -- accelerate.  You have to focus hard, you have to BE THERE, and almost immediately you enter a state of flow.  Challenging, but achievable.  
 
Today our running group ran parts of the bridle path in Central Park, alternating between the rough trail and the smooth road.  Great contrast.  Very satisfying, very fun.
 
And while we ran, we become more aware, more conscious -- and more alive.
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