Christopher McDougall began his wildly popular book “Born to Run” by asking a fairly simple question: “How come my foot hurts?” This led him on a quest that ultimately brought him to the conclusion that running shoes were the problem, and that he’d be better off throwing his regular shoes away and running barefoot or in something more minimalist like the Vibram Fivefingers. If you’ve paid any attention at all over the past year, you’re probably well aware of the fallout from McDougall’s book, and whether you like his approach or not, it would be hard to argue with the fact that he’s done more to stimulate discussion in this area than any of the academic researchers or medical professionals (or running pros for that matter) that we typically look to for guidance when it comes to deciding what to put on our feet.
Over the past few days I’ve thought a lot about the pros and cons of shoes vs. no shoes, and I keep finding myself asking the converse of the question that McDougall posed to himself – “How come my feet haven’t been hurt?” I’ve been running off-an-on for most of my adult like, and for the past 3 years I’ve been running regularly and quite a lot, probably averaging around 20 miles per week, with highs pushing into the 50 mile-per-week range during marathon training. Although I’ve had my share of aches and pains, I’ve been fortunate to have avoided any injuries significant enough to sideline me for more than a few days (it’s with great hesitation that I write this sentence, for the superstitious side of me feels like I’m asking for trouble!). This has led me to wonder why I’ve been so lucky, when others have reported that as many as 75% of runners get injured each year?
With this introduction, permit me to wildly speculate a bit, for thinking out loud is one of the best ways for me to mull over ideas. Let me start with some observations:
1. Many, but not all, running injuries are repetitive use injuries. As an example, stress fractures result from chronic repetitive loading to a bone that produces accumulating microdamage at a rate faster than the bone can remodel to repair it. Accumulation of damage can be exacerbated by fatigued muscles due to overtraining/lack of rest since they are no longer effectively capable of assisting in the absorption of shock to the legs/feet. The point here is that if you expose your legs to the same type of shock over and over without variation or adequate rest to allow for tissue repair, you’re asking for trouble.
2. Many of the aches and pains that we experience as new runners or when changing shoes (or running barefoot) may be a direct result of the body adapting to the new set of forces it is being exposed to. Taking the barefoot example, there is good research showing that our gait biomechanics changes when we run barefoot or in minimalist shoes like the Vibram Fivefingers (see De Wit et al., 2000; Divert et al., 2005; Squadrone and Galozzi 2009; Lieberman et al., 2010), and this is likely why it’s very common for people trying out this style of running to report delayed onset calf soreness and other forms of pain when first starting this style of running. Similarly, this is alos probably why metatarsal and tibial stress fractures have been reported in people jumping into barefoot or minimalist running and doing too many miles without adequate rest (i.e., poor training decisions).