Runners: Let’s not confuse Efficiency with Optimization

We should always be careful, as runners and athletes, when shopping around for new data to help us develop our craft. We should be even more careful when this data comes in a convincing format—scientific research—and alarm bells should go off when that research isn’t put in context.

Recently, I went to take the Pose Method Level 1 coaching certification, which I wrote a pretty popular review about. With this post, I want to begin diving a little deeper into the subject, starting by addressing one of the major scientific critiques towards the outcomes of minimalist running, forefoot striking, and the Pose Method: that these techniques are less efficient than heel-striking—namely, that they use more energy across the same distance.

Well, do they? Perhaps. Most likely, in fact.

However, seeking sheer reductions in energy use may be missing the point.

Let’s take a popular sport as an example: mountain biking. One of the first things you consider when buying a new mountain bike is whether you want dual suspension, or only on the front. This is a classic trade-off: the dual suspension lets you go on more rugged terrain, but it also means that less power from every stroke goes into driving the bike forward.

A dual-suspension bike is less efficient than a front suspension bike. That’s it, right? Front suspension bikes are superior. It’s a done deal.

Well, no.

Before I go on, let me be quite clear about the argument that I’m making. I’m not saying that less efficient options are better. I’m arguing that different options can’t—and shouldn’t—be judged on efficiency alone. I’ve seen it at least a few times in the running community: the studies on whether the Pose Method lowers running efficiency are presented in one stand-alone sentence, as if by itself, and without regard for the scope and depth of functions that the human body must fulfill, efficiency means something.

Efficiency alone means nothing. The questions we should ask is: what is it getting us, and what are we sacrificing by pursuing it?

Let’s go back to the mountain bike example.

Adding that rear suspension increases the capability of the bike to interact with more rugged terrain. If you land from a high jump with a dual suspension bike, you’re less likely to break the frame—or yourself.

Not a mountain bike, but I'd say that Danny MacAskill's legs count as suspension 1 and 2.
Not a mountain bike, but I’d say that Danny MacAskill’s legs count as suspension 1 and 2.

You’ll see this across all systems: increasing the dynamism of any system (which means both its capability to interact and its rate of interaction) increases its ability to interface with other complex systems (i.e. the environment). In order for this to happen, a dynamic system has to be working with sufficient moving parts, all of which take energy to function. If we just focus on cost-cutting measures—what gets me the least energy consumption, all else aside—we’re going to be undercutting that system’s optimization at some point.

That certainly seems to be the case in human locomotion, as suggested by this study (also cited above).

We’re making a very specific—and very generalizable—trade by adding a rear suspension to the mountain bike: we’re reducing its efficiency in order to optimize it to the environment.

Lowering the efficiency, however, does not immediately mean that you’re optimizing something. In fact, it’s typical to find that if optimization drops below a certain threshold, so does efficiency. A bike needs intact tires to function well. You can’t be riding on the rims during a race and expect to be very efficient.

Optimization, although more costly in the immediate term, is more cost-effective than hard-edged efficiency over the long-term. What happens if the bike frame breaks? The amount of power that goes from your downstroke and into the ground drops to zero.

We all live in this compromise: we want to increase our efficiency, but not at the cost of optimization. Let’s use a gait example. Is it more efficient to shut off your gluteus maximus, hamstrings and quads while running? Probably—those muscles are huge. They’re consuming lots of sugar and oxygen in order to stabilize the pelvis and move it over the femur and the knee joint.

In addition, they’re mostly only active from contact to midstance. They’re the biggest muscles in the body, and they don’t even help you push off. Less efficient? Sure! Why not just let momentum carry your GCM—general center of mass—over your knee joint while keeping the hip extensors quiet?

Because your femur would summarily come off your tibia, and your patella would pop off and land somewhere on the ground in front of you. Once again, the efficiency of your gait would drop to zero.

I’m not making an argument for any particular method or stride type. (I believe those arguments are there to be made, once we have satisfactorily defined what we mean by “stride type,” but not in this post). The takeaway, as I mentioned above, is that in order to optimize something to the environment—say, in order to allow our body to remain in a configuration which can adapt its footfalls to variable terrain—we’re going to be sacrificing some raw efficiency.

Is forefoot-striking or Pose the best way to optimize the body? Well, that’s a different question.

UPDATE: In this article, “Pose” refers to excellent pose technique. (This was brought up by a concerned reader on a Facebook thread.) Indeed, all running and all movement is an alternation of poses (think about the kata in martial arts). For better or worse, the question remains in the scientific and running communities: is excellent Pose technique the best way to run? Many try to detract from it by saying that it is less efficient. I believe that regardless of whether it is or not, that line of argument largely misses the point.

9 thoughts on “Runners: Let’s not confuse Efficiency with Optimization”

  1. Another great post, really enjoy reading this blog. Took my masters in Systems Theory so very glad to see this view applied to running.

    On an unrelated note: I really like your design. What technology did you use for this blog?

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    1. Thanks for reading, and for your comment. I’m glad that you’ve found my blog useful; there’s a very heavy analytic component in running research (and sports science in general) and not much
      synthesis occurring, or meaning being extracted. Systems thinking has been a great tool for me to put the research in context. (I only wish that I had an academic degree in it).

      In response to your question: I use the WordPress blog engine, which has a variety of templates available. I use the WordPress premium service (which has a little more freedom and options) for $99 USD/year. It’s a pretty good deal.

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  2. Good points! However, I only know of one study which showed a decrease in efficiency with Pose running. I wrote up a critique a few years ago about the study because in my opinion the design was deeply flawed. The runners were not trained properly, and there was no accounting for how well the runners implemented Pose technique. Of course, the study is quoted as gospel by people skeptical of Pose as “proof” of their views. However, they are really only proving that they don’t know how to interpret scientific studies.

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    1. Ken,

      True. I lumped in studies that show that forefoot striking is less efficient because of the strong association between Pose and forefoot striking. (There’s an argument to be made against what I did).

      Generally speaking, I agree with your sentiment, although it does seem logical to me that a running “style” that helps with injury prevention would also be sacrificing a little efficiency.

      That said, what I wanted to do here was to show that, often, even the strongest possible formulation of someone’s argument means very little when it’s answering the wrong question.

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  3. I agree completely. Ask the wrong questions and you get the wrong answers. I’ll make another technical point though, in Pose, the forefoot landing has little to do with efficiency. The pull is about efficiency. Personally, I think the forefoot landing is a wash for efficiency as long as one lands under one’s COG. If the runner land’s on the forefoot in front of his COG, then he probably takes a hit on efficiency. However, that is purely speculation on my part.

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    1. I’ll have to think about that. Off the top of my head it makes sense to me too. I’m seriously thinking of doing a master’s in engineering in order to move towards PhD studies in experimental physiology and biomechanics. The questions that Dr. Romanov and now you and I are bringing up are serious questions, and I don’t think that we (meaning what is established and accepted) have a theoretical framework set up that can deal with them.

      That’s why, in my opinion, there’s so much backlash and claims that “we can’t know.” I liken it to when the Greeks first proved that the Earth was round. People must have been saying “what do you mean it’s round? It’s clearly flat! Look at the horizon—that’s where it ENDS!”

      In part, that’s why I use systems—a synthetic science rather than an analytic one. I want to take it from theory into practice in the next years of my life, and apply it to experimentation, in particular to change experimental theory and design in the sports sciences. (Tim Noakes did a little bit of that with his Central Governor theory).

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  4. Over time, I’ve learned that there are many sources of misunderstanding about Pose and running technique in general. I think your point about the theoretical framework is spot on, and the most important. More on that when we talk.

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