A ‘Shoe Guru’ Perspective on Zero-Drop Running

In a sport like running, there is one tool that is by far the most important – a good pair of running shoes.  Or a lack thereof, depending on who you are.  While most people utilize the protective benefit of a good pair of running shoes, there are many factors to consider when thinking about the role that shoes play in an endurance sport like distance running. Abebe Bikila won the 1960 Olympic Marathon without any shoes at all.  That’s no small feat (pun intended).  Christopher McDougall’s well-written book Born to Run played a very important role in catalyzing the use of “zero-drop” shoes for running.  “Drop” is the difference in height between the heel and the forefoot.  Running shoes are traditionally made with a higher heel than forefoot, probably averaging around 8-10mm.  The “minimalist movement” was a swing of the pendulum in the direction of more natural running techniques, and shoes that allowed the body to run more naturally.  The drop in shoes came to exist, according to most sources, mostly to absorb shock in the heel since a majority of people are heel-strikers when they run.

More cushion in the heel means more absorption of impact, right?  Many runners, though, are not even heel-strikers.  Some runners make first contact on the ground with their midfoot, and some make first contact with the forefoot.  How does heel drop affect midfoot and forefoot runners?  The exact ways in which heel drop affects stride biomechanics are not horribly clear, but there is enough evidence to show that variation in heel drop definitely affects at least some factors of running form; a higher drop can increase the force through specific joints, and it can decrease stride length. This article by Alex Hutchinson, called “There’s New Research on the Science of Barefoot Running,” from Outside Magazine captures the essence of this idea. An article from ResearchGate titled “The effect of the heel-to-toe drop of standard running shoes on lower limb biomechanics” also suggests that there is a significant difference between someone running barefoot versus in zero drop shoes (see bottom of page for citation of this study).

One must also consider the fact that evolution has gifted the human species with bipedalism and some very intricate balancing/force-absorbing mechanisms (our legs/feet/etc.).  Bipedalism, which means walking on two legs instead of four for example, allows our lungs to function independently from our strides, while most animals on four legs have to inhale and exhale as their body extends and contracts with each stride.  This makes them more efficient at going fast for shorter periods of time and it makes us more efficient at going slower for longer periods of time. Why We Run by Bernd Heinrich was an influential book in informing me on the evolutionary science of running, if you want to learn more.

While it can’t be proven that we are adapted for distance running in particular (some die-hard scientists assert that we were adapted for distance running in order to “persistence hunt” and tire out prey by chasing them for hours), our bodies are capable of some intense stuff without any added modern conveniences such as shoes.  On the other hand, it is more convenient for me and for many people to run on man-made sidewalks and roads with shoes that can offer a layer of protection.  As someone who has run barefoot on many occasions, in 4mm (low) drop standard-cushioned shoes for over seven years, zero-drop shoes for a year, and who has tried other neutral (non-supportive) shoes with varying drops including 8 and 10mm, I can offer my personal take on how these shoes affect my running styles.

In high school, my team would occasionally do barefoot workouts on grass (starting with easier workouts at the beginning of the season to strengthen and stretch the unused muscles), and I think it was hugely beneficial for everyone who wasn’t experiencing an injury of some sort.  I feel that my biomechanics are always much more efficient when training with a combination of some barefoot training and mostly zero-drop standard-cushion shoe training.  I have also noticed that running in low or zero-drop shoes is better for my knees and my particular biomechanics because I am more able to control the landing position of my feet, and my knees don’t feel like they are stretched or strained with every stride as they do in higher drop shoes.  Specifically, I had no chronic knee pain when I was training barefoot, in the Saucony Kinvara (4mm drop), or in the Altra Escalante or Torin Plush (both zero drop), but I felt strain in my knees and developed chronic (but not incredibly severe) knee pain when I trained primarily in other standard cushion neutral shoes such as the Nike Pegasus 34 (10mm drop) for two months and the Brooks Ghost 13 (12mm drop) for a few weeks.  Of course, many people find success with both of these shoes (and they have since updated their cushion and build, etc.), and I may just be sensitive in this regard, but I don’t think I’m alone in my experience.  The human body is very adaptable, and it may adapt to any sort of contraption we can dream up and put on our feet to a certain extent, but I have determined that drop is probably the most important variable in decreasing my injury risk and increasing my speed, performance, comfort, and efficiency.

Transitioning to running in zero drop shoes may require some time for adjustment because it takes at least a few weeks to develop flexibility and strength in your calves and shins.  Continuing on the thread of my preference to err on the side of naturally allowing your body to regulate the dispersion of forces and propulsion of the running motion, I think that zero drop shoes allow one’s body to better balance the anterior-posterior muscles used in creating the rubber-band-like force that propels us forward.  Having ruminated on these thoughts during many long runs, it seems to make sense that wearing a shoe with a higher drop (think of a high-heel as an extreme example) causes the calf to stay in a more contracted position for the entire duration of the stride, potentially shifting more of the propulsive load to the front of the leg, putting more force through the shin and knee.

It’s also interesting to think about how the vast majority of runners wear zero drop spikes or flats and lightweight shoes while racing, which requires different biomechanics from training with higher-drop shoes.  If your body responds well to training with lower drop shoes, why not train your muscles to function in the same way that they’ll be positioned while racing in order to increase your efficiency in spikes or flats? I do think this argument only extends so far, and I don’t advise doing the majority of your training in neutral shoes if you need support to counter over-pronation.

I recommend that all runners experiment with zero-drop shoes, and I think that almost everyone would benefit from a little bit of barefoot training on soft surfaces as well.  Obviously, making the leap to only barefoot or zero-drop training after having been in higher-drop shoes is not a wise choice, and the transition should be made slowly.  Also, if you typically run in a supportive shoe because you over-pronate (your ankles tilt inwards, leading to tracking issues in the knees and hips if left uncorrected), there are a few options out there for zero-drop supportive running shoes such as the Altra Paradigm and Provision, and inserts can also be added to provide a bit more support.  A final consideration for any runner is that strength training of the entire body is incredibly important regardless of the shoe, and that injuries are often the result of weaknesses in your body’s kinetic chain.  Glute and hip strength is hugely important for a runner’s body, as this is the center of much of the body’s rotational stability and where much of the force of running comes from. Visit your local running specialty store for more personalized advice. 🙂

I am so much more comfortable running in Altra’s zero-drop shoes, and I hope that others may be able to find the same improvements in comfort and efficiency in their athletic activities and for everyday use.  Keep on getting out that door to experience the joys of nature, physical activity, and the power of your body!

-Josh

For further information and explorations of this topic, I highly recommend reading Christopher McDougall’s Born to Run (great storyline and perspective) and Bernd Heinrich’s Why We Run (a more scientific approach). For more experiential learners, try grabbing a pair of Altras or another brand of a low-drop shoe for yourself!

Sources:
-Christopher McDougall, Born to Run. Published by Alfred A. Knopf, New York, 2009.
-Alex Hutchinson, “There’s New Research on the Science of Barefoot Running.” Outside Magazine, 2/26/2019. https://www.outsideonline.com/2390686/barefoot-running-biomechanics-study. Accessed 6/12/2020.
-Florian C. Richert, Thorsten Stein, Steffen Ringhof, Bernd J. Stetter, “The effect of the heel-to-toe drop of standard running shoes on lower limb biomechanics.” ResearchGate, July 2019. https://www.researchgate.net/publication/334156109_The_effect_of_the_heel-to-toe_drop_of_standard_running_shoes_on_lower_limb_biomechanics#:~:text=The%20isolated%20effects%20of%20heel,increase%20stride%20length%20during%20running. Accessed 6/12/2020.
-Bernd Heinrich, Why We Run. Published by Harper Collins, 10/6/2009.