Monthly Archives: October 2011

To wear or to bare?

A runner’s choice of footwear can be confusing and downright overwhelming. We’re fed mixed messages from shoe manufacturers that their latest motion-control, cushioned stability shoe with custom orthotics on the one hand – or maybe their lightweight minimalist shoe on the other – will guarantee our feet a smooth, fast ride. For years I believed that finding the right running shoe was like finding one’s life partner … we all have a perfect match out there somewhere, but it might take years of dating around to discover our sole-mate (sorry – couldn’t resist). Over the past several months I began to both test and question this idea in a recent personal experiment. But before sharing my discoveries, let me offer a bit of context …

I had been blessed with 14 years of essentially injury-free running. That is, until a fateful day in February 2010 when, while training for the Boston marathon, I returned home from my evening run with a torn achilles tendon. Needless to say, I did not make it to the starting line that April. The ensuing year was filled with a flurry of peroneal tendonitis, femoral-patella syndrome and trochanter bursitis (ie ankle, knee and hip injuries). Was my body just not designed to run this many miles (as my doctor informed me!) or was I doing something wrong?

Given many runners’ reports that going barefoot helped resolve their injuries, I began to look into the possibility that my shoes might be contributing to my own problems. Although initially skeptical of these seemingly radical claims, the more I researched, the more I found them intuitively appealing and scientifically sound. The logic was simple: the human body evolved to walk, run and jump perfectly fine without the need of external crutches like arch support or heel cushioning. It’s doubtful that our hunter ancestors had to slip on their Nikes before pursuing their next meal. Modern man has changed little from our predecessors, with one notable exception: for most of us a lifetime of shoe-wearing has fostered an epidemic of shoe-dependence. Held captive in footwear, our feet become weak, inflexible and ridden with bunions, fallen arches or crooked toes. We in turn attempt to correct these imbalances with more cushioned, structured and protective footwear, only perpetuating the cycle. The truth is, our feet are quite well suited to sustain the physical impact of these activities with their elegant support system of 26 bones, 33 joints and over 100 muscles, tendons and ligaments. Introducing an artificial support system like footwear transfers the impact burden from foot to shoe, which over time can 1) weaken our feet and lower legs, 2) alter our natural walking or running gait and 3) redistribute impact forces to place excessive stress on areas like knees and hips. While there is nothing inherently dangerous about shoes themselves (with maybe a few exceptions), the associated consequences of long-term foot support such as weakness and unhealthy gait are concerning. I’ll limit my explanation to this, in the hope of being minimally redundant with the countless articles already written on the topic. But I will refer the interested reader to a stellar investigation into the effects of shoes on foot-strike patterns and their associated impact forces, published last year by Daniel Lieberman and colleagues.

Thus, curious and excited yet still skeptical, five months ago I began to experiment with the natural potential of my own feet. This has not been a quest to become a barefoot runner per se, and I do not intend to provide a “how-to guide” for such a goal. Rather, it has been an exploration of my body’s response to removing my feet from artificial sources of support and protection. Heeding cautions that my feet would be weaker than expected, I began slowly … exceedingly slowly since I was concurrently training for another marathon and of course, stubbornly refused to compromise my mileage. My experiment involved the following core elements:

Walk barefoot. Babies aren’t born with the capacity to run without first developing the strength to crawl, then walk and finally run. Similarly, why would I expect to be able to run bare if I couldn’t first walk bare? On day one of my barefoot journey I lasted only a few blocks before my sensitive skin and tired feet screamed for shoes. But within just a few weeks I built up the strength and resilience to walk essentially everywhere and anywhere.

Run minimally. Various features of your typical running shoe can influence gait including cushioning, arch support and heel-to-toe drop, all of which were characteristic of my own standard running shoe. I therefore experimented with various shoes that minimize these factors to different degrees. Practically, this involved running most of my mileage in my standard shoe, while gradually increasing the percentage of miles run in a more minimal shoe. For instance, I began by running about 20% of my weekly mileage in a light-weight racing shoe and ramped up this mileage by approximately 10% each week. I also supplement my daily longer runs with one or two weekly short runs (1-3 miles) in minimal protection (huaraches or vibram five-fingers).

Listen and adapt. This has been critical for both the success and evaluation of my experiment. I’ve become increasingly aware of my body’s response to each new change and continue to adapt as necessary. When feeling strong I allow myself to increase my “minimal shoe” mileage. If I feel weakness or strain in my feet or calves, I introduce extra support until the issue resolves. For instance, I recently completed a marathon in a lightweight shoe but ran exclusively in a higher-support shoe for the entire post-race week to allow my strained feet and ankles to recover.

So what has come of the early stages of my experiment? I now exclusively walk barefoot, as I’ve grown to love the sensation of my foot contacting the earth as well as a heightened awareness of my environment. In fact, I find it rather awkward to walk in shoes and can’t imagine going back. While I won’t go so far as to claim that discarding my shoes has been a panacea, I’ve discovered that footwear significantly affects my lower leg strength, running form and overall running experience. Perhaps most remarkable has been the transformation in my gait. Trained as both a dancer and sprinter before taking up distance running, I developed an unusual tendency to excessively forefoot strike and supinate. But in zero-drop footwear I find myself engaging my entire foot – from ball to heel – and striking with better lateral balance. As my form corrected, the demands on my upper leg shifted lower, resulting in remarkably stronger feet, calves and shins as well as reduced tightness in my hips, quads and IT band. Generally, the less support and cushion under my feet, the lighter, smoother and more balanced I find my gait. That said, I appreciate some form of protection from rough terrain, as this frees my mind from worrying about rocks, sticks, or other potential dangers so I can simply enjoy the ride. Yet I still find value in a traditional shoe, particularly in providing extra support to keep me running through periods of soft-tissue weakness or strain. As conservatively as I tried to pace myself, my progression was just aggressive enough to ensure my share of achy feet, stressed tendons and tight calves. These past months have debunked the myth that any one shoe – or lack of shoe – is ideal. In fact, I currently alternate among 5 different models of footwear, depending on my support needs …

My embarrassingly large array of running shoes, from handmade huaraches (so fun!) at left to classic supportive sneakers at right.*

My barefoot / minimal journey is still in its infancy and I’m excited to witness its continued evolution over the coming years. These preliminary “data” indicate that for me, less is indeed more. Less shoe equals increased strength, a more balanced foot-strike and an overall more liberating running experience. However, the heterogeneous reports from others suggest that this is not a universal experience and that the runner, rather than the shoe, is the critical ingredient. So whatever you choose to – or not to – wear, if you’re healthy and happy then you’re probably doing something right.

* Although I try not to promote any particular product, I will gladly share my opinions if you contact me directly.
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n=1

The fundamental motivation driving most scientific research is simple: to discover the truth. To accomplish this goal, researchers attempt to find reliable patterns that explain why something is the way it is. But as hard as we might try, it is exceedingly difficult to boil down reality to simple rules and laws. More often, we might discover an effect that holds some of the time, under some conditions, depending on a multitude of frequently unpredictable or unidentifiable factors. In our quest for answers we therefore aim to control for the irrelevant variability across our sample in order to reveal meaningful differences related to our variable of interest. Although this variability can be the frustrating source of a finding that hovers just above the (arbitrarily) coveted .05 alpha, it can also be magnificently informative.

Recently, there have been growing efforts to integrate scientific understanding of human physiology, biomechanics and metabolism into the realm of athletic performance. While I entirely support and encourage every runner to self-educate from well-conducted scientific research, it can be dangerous to accept every claim without a certain level of skepticism. Peruse the countless running blogs, forums, magazines and books and you will find self-proclaimed experts confidently backing their particular running shoe, diet, training plan, pre-race routine, blah, blah, blah as the healthiest or most effective. Why, then, is much of the running community stuck battling frequent injury, fatigue and discouragement? As much as we try to generalize into tight, clean categories, the fact remains that immense variation exists between runners in terms of ideal nutrition, biomechanics and training. When was the last time you heard a claim along the lines of “The majority of people report increased (insert effect Y here) from (insert cause X here)”? Many will readily infer a universal, causal relationship between X and Y while overlooking that in a subset of individuals X did not increase Y. Again, variability can be informative. Assuming that such claims are based on properly designed and conducted studies (watch out – this is not always a valid assumption!) a likely explanation for such differences is that individuals have distinct responses to X. We like to assume that if it works for you it will certainly work for me, while forgetting the not-so-insignificant detail that we are different people. My best advice to become a stronger, happier runner is to value your own experience above that of others. In fact, you might want to stop reading this blog right now. The most informed expert about what will benefit you … is you.

Over the recent past I have approached my lifestyle as an experiment with n=1 and made the fascinating discovery that what works for my optimal health and happiness is often drastically different from what the media, coaches and even doctors traditionally advise. This exploratory period was sparked largely by a 6-month journey through Asia and Africa during which I ate, slept and exercised erratically. Upon returning to the U.S. I appeared thin, weak and scraggly. Paradoxically, I clocked each of my 7 post-travel marathons faster than my 3 pre-travel marathons, with an average 20 minute post-travel improvement (p < .0001; yes I am just that nerdy that I ran the stats). How had months of exposure to intense physical stressors and a clean break from running, all while abandoning conventional health advice left me with greater strength and endurance than ever before? It turns out I may not in fact be a freak of nature; rather, a wealth of research has demonstrated that mild to moderate stressors such as physical activity, caloric restriction or intermittent fasting, social or environmental stress are associated with diverse benefits including improved cardiovascular health and cognitive function, increased hippocampal neurogenesis and longevity (Lyons et al., 2010, Mattson & Wan 2005, Minois 2000Parihar et al., 2011) .

While I by no means advocate abusing or shocking your system into super-human running condition, there seems to be a delicate balance between positive and negative stressors that varies from person to person. Using a mindful approach of starting from the conventional center and slowly testing my limits, I am continuously discovering my individual zone of comfort, health and strength. In future posts I hope to share observations from my personal experiments with injury prevention and treatment, nutrition, footwear (and lack of) and training tactics. To any runner looking to these posts or any other resources for advice, I strongly suggest you take them with a grain of salt and then conduct your own experiment of one.

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