Tag Archives: sports

In defense of the endurance running hypothesis, part 1: how we think about evolution.

The endurance running hypothesis is the idea that humans evolved primarily as endurance runners. The argument goes that the human physique evolved and took its shape and function from the primary adaptive pressure of persistence huntingthat of chasing down our prey until its body shuts down.

However, this hypothesis is not without its detractors. A significant amount of scientists provide an array of counterevidence to the endurance running hypothesis. (And the debate continues.)

Take for example the case of the human gluteus maximus (butt muscle). Lieberman et. al. (2006) claim that the human gluteus maximus evolved its shape and size due to endurance running.

However, another article in the Journal of Comparative Human Biology finds that the gluteus maximus grows much more in high-force sports (weightlifting) and high-impact sports (such as soccer), than it does in endurance running. In fact, they also show that the butt muscle in endurance runners is no larger than in the non-athlete population.

What I disagree with is their conclusion, which is paraphrased in the “What does this mean?” section in the image below:

“The human gluteus maximus likely did NOT evolve through endurance running, but through varied explosive and forceful activities.”


My disagreements with the article (and the image) are primarily about how and why we interpret the science to mean a certain thing.

At first blush, the fact that endurance running doesn’t enlarge the gluteus maximus as much as other sports seems to detract from the idea that the muscle takes its shape from endurance running. But I think it actually adds to it.

By my analysis, these findings show that the basic, untrained shape and size of the gluteus maximus—it’s “factory specifications,” if you will—assume that it’s going to do the amounts of cutting, jumping, weightlifting, and sprinting that a habitual endurance runner might need to do. But it requires aftermarket modification to meet the (literally) outsize power and stability requirements of soccer or weightlifting.

Let’s say that a muscle evolved under a particular adaptive pressure. This means that its shape and size literally evolved to do that thing. If you take a muscle that usually doesn’t do a thing for which it evolved to do, and you ask it to do that thing, you are asking it to do something that it has prepared to do for millions of years of evolution.

In order to fit a function that it has been designed to do, the changes in shape and size that the muscle should have to undergo should be smaller, not larger. You would expect a muscle to change far more if you ask it to do something that is less aligned with its evolutionary job description.

Let’s illustrate this by looking at the arm and hand.

We probably all agree that one of the things that specifically sets us apart from our hominid cousins is the ability to coordinate the thumb with the rest of the fingers in order to grasp and manipulate objects to a high degree of dexterity. In its simplest form, this is the capability to oppose the thumb and the fingers—to make an “OK” sign with the thumb and each of the fingers of each hand.

Now let’s take a snapshot of the people who take this unique human ability to its very pinnacle: string musicians, graphic artists, etc. Their livelihood depends on the degree to which they can explore the potential of one of the major evolutionary functions of the human hand.

Compare the forearm muscles of a violinist or painter with that of a weightlifter. The weightlifter’s arms, hands, and shoulders will be much larger and more powerful. (I trust I need not cite a scientific, randomly-controlled study on the matter.) Why? Quite simple: weightlifters engage in activities that develop the body to phenomenal proportions.

But if we go by the conclusions of the article, the fact that the arm and hand get bigger through weightlifting would mean that it didn’t evolve for the kind of fine motor control that you produce in the arts. (Or that lifting heavy objects is its primary evolutionary role). A particularly ambitious version of this argument would be to suggest that one of the core functions of opposition is to become better able to lift heavy objects. But all these suppositions break down when you realize that our primate cousins were not only quite able to grasp branches and use them ably, but that opposition emerges at the same time that hominid arms were becoming smaller (and less powerful), not larger (and more powerful).

Of course, the human hand (and upper extremity in general) still needs to be able to grow and develop in order to be able to lift heavy objects—and can indeed grow to a huge degree to exhibit that function. But its core evolutionary function is to produce the unparalleled dexterity of the human being.

Furthermore, the fact that the non-painter’s hand remains relatively unchanged in size compared to the painter’s hand means that the non-painter’s hand is already relatively set up to perform that kind of dextrous function—because that’s what it presumably evolved to do. This should serve as evidence (not counterevidence) that the hand is primarily for painting (and other fine motor tasks), not for weightlifting.

We should think the same of the gluteus maximus.

Let me conclude by saying that nothing I’ve written here means that the gluteus maximus evolved exclusively for endurance running. Indeed, there is ample evidence suggesting that the architecture of the gluteus maximus is uniquely multifunction as far as muscles go. (In future posts, I’ll delve more into the nuanced view of the gluteus maximus that I proposed above: that it owes its shape and size to the fact that it is a muscle designed for the kinds of “varied explosive and forceful activities” that a bipedal, primarily endurance running animal expects to have to do.)

But what we can say is that the fact that the gluteus maximus gets bigger through a particular stimulus has no bearing on its core evolutionary role, (or on the evolutionary story of the organism as a whole).

Runners: “Aerobic training” is not the same as “Endurance training.”

It’s common that training which develops the aerobic system is equated with training that increases the body’s endurance. It’s understandable: the aerobic system burns fats in the presence of oxygen in order to provide long-term energy for the body—exactly what it needs for endurance. But the problem is that a powerful aerobic system isn’t the only thing necessary for increase endurance.

The most important difference between “aerobic training” and “endurance training” is this: the former trains a critical supersystem of the human body (the aerobic system), while the latter improves the product of the successful interaction between the aerobic system and many other parts and functions of the body (endurance performance).

What runs isn’t the aerobic system—it’s the entire body. While the aerobic system can be powerful, it can’t perform on its own. Whenever we talk about “performance,” even when the subject is endurance performance, we’re talking about how (and how well) the body uses its aerobic power to create one particular kind of athletic movement.

Roughly, endurance means: “how long the body can produce a particular movement or action without falling below a minimum threshold of performance.”

Another way to say this is that the aerobic power is general, and endurance is specific. Geoffrey Mutai (elite marathoner) and Alberto Contador (Tour de France cyclist) both have extraordinary aerobic systems. In both athletes, all the parts that enable their muscles to be fueled for long periods of time are extremely developed.

It should be noted that in both athletes, we are talking about developing essentially the same parts, developed to comparable levels and talking to each other in very similar ways. Both these athletes also obtain fundamentally the same general physiological benefits—a greater ability to recover, better health, longer careers—all despite competing in wildly different sports.

However, their endurance in specific sports varies wildly. We can expect Mutai to be a proficient cyclist, and Contador to be an able runner, but we can expect neither to have world-class endurance in the other’s field. In other words, Mutai’s endurance is specific to running, and Contador’s is specific to cycling. This is because:

  • Both sports use different sets of muscles: runners use a larger set of muscles for stability than cyclists, since the latter have so many more points of support. Cyclists have the handlebars, pedals, and seat, whereas runners have at most 1 foot on the ground.
  • They load joints in different ways, and use very different ranges of motion: cyclists keep their waist and hips relatively flexed, while runners keep the same joints extended.
  • They use different neuromuscular mechanisms to facilitate endurance: running economy depends on a powerful stretch-shortening cycle, while cycling economy does not.

In my opinion, the stretch-shortening cycle is the most important piece of the running puzzle (and also one of the most overlooked). Running shares a lot of pieces with just about every sport—and developing them is very important if you want to become a good runner. But without an increasingly powerful stretch-shortening cycle, all the power that you develop in any other system (cardiovascular, respiratory, etc.) doesn’t translate into actual running performance increases.

As discussed above, the aerobic system is responsible for sustaining endurance. The best way to exclusively train the aerobic system is by running at a physiologically intensity (below the aerobic threshold).

This is a problem for less aerobically-developed runners: it takes a lot of juice to run the stretch-shortening cycle effectively. In previous posts I discussed how the minimum requirement for running properly is to be able to produce a (very fast) cadence of around 180 steps per minute (spm). This is because the muscles’ stretch-shortening cycle hits peak efficiency around that cadence.

So, these runners often need to run at a higher intensity: they’ll use the maximum output of the aerobic system at max and engage some of the anaerobic system in order to produce a cadence of 180 and properly activate their stretch-shortening cycle. If they fall below their aerobic threshold with the goal of doing “aerobic training,” their cadence falls and the stretch-shortening cycle will largely deactivate.

When I talk about hitting 180, I mean hitting 180 at an average step length: It’s possible for a weaker runner to shorten their stride to artificially increase their cadence without going above the aerobic threshold. But I consider this a rather useless hack, since in my experience it doesn’t really get runners the performance benefits expected of reaching “the magic 180 mark.” (More on this in a future post.)

For a workout to be “running performance training” (endurance or otherwise), it needs to train the key pieces necessary to improve running performance. So whenever you’re not actively training the stretch-shortening cycle, you’re not really doing “running performance training” in my book. “Running endurance training” would be about teaching the body how to run for longer, at a lower intensity, while maintaining a reasonable cadence.

So, whenever an aerobically weak runner trains under the aerobic threshold, I consider it to be quality aerobic training but NOT “running performance training.”

It’s not that their running performance won’t increase—it will. Let me illustrate with a rather extreme example: If playing checkers is the only active thing someone does, playing checkers is better for their running performance than not doing so. But because it doesn’t train the critical systems for running, I don’t think of it as “running performance training.”

Of course, running at a low cadence shares a lot more with running at a high cadence than playing checkers does. But the idea here is to set the highest possible bar for what “running performance training” should mean: training the key systems that running performance rests on. And running without substantially activating the stretch-shortening cycle really doesn’t meet that criteria.

(We can say that running without the stretch-shortening cycle still helps you to improve your running—to a point. But you can’t hope to maximize your performance gains without it.)

For a competent runner (someone who can engage their stretch-shortening cycle at low physiological intensity), “aerobic training” and “running endurance training” become identical: just about all of their training provides all the benefits they need to maximize their running endurance.

What is a less-powerful runner to do with all this information? If I could say only one thing:

Jump rope! Jumping rope (on both feet, alternating feet, on one foot, spinning around, crossing the rope, etc.) is training primarily the stretch-shortening cycle up and down the body, almost identically to the way it’s used in running. IMO, if a runner does only one other thing besides running, it should be to explore and master the jump rope to its fullest potential.

UPDATE Nov 18, 2016: Another (great!) article on the mechanics of running, also touting the potential of jumping rope.

But there’s a lot more than this. Now that I’ve covered all the theoretical ground I absolutely need to cover for my following posts to have any real substance, I can begin to discuss concrete strategies that the runner can use.

Addendum (for the curious): Why do I focus so much on fleshing out the principles (and, more importantly, taking so long to get to the processes)?

Because the idea, of course, isn’t to “balance” aerobic training with performance training. (That’ll only increase endurance.) The idea is to potentiate aerobic training with performance training. (That’ll maximize endurance.) And to turn balance into potentiation, it’s necessary to already have understood the “why.”

Running, writing, and athletic expression.

It doesn’t serve us to think of running as we generally think of “sports.” Instead, let’s regard running as a form of expression. When we approach an activity we see as a “sport,” we typically ask: “what’s the goal here? Is it to get from A to B as quickly as possible? Is it to get the ball into the net?” And we put our bodies and minds in service of answering that question.

But there’s a problem with that: if we approach a sport with neural, muscular, or skeletal issues (which pretty much all of us westerners have, to one extent or another), our bodies will find ways around those problems for the purpose of achieving the stated goal.

That means that the body will find a less efficient way to conduct mechanical energy through the body, as long as the job gets done. Too much of this and you’ve got yourself an injury.

But suppose that instead we treat running (and other sports) as forms of expression. Then we enter a path of self-discovery, where improvements in speed and power are achieved as a by-product of increasing our efficiency, and our knowledge of the deep principles of our sport.

Continue reading Running, writing, and athletic expression.

(Re)defining the notion of “sport” through an argument from biomechanics.

In my opinion, a “sport” is any activity for which an increase in the relevant hip extension abilities is a necessary component of developing greater performance in that activity.

(“Hip extension” is the ability to move our thighs back and forth. When we consider what function the act of moving our thighs back and forth has in relation to the whole system, hip extension amounts to the ability to push on a surface or object with our feet by using our thighs and butt as the primary movers).

But why would I define “sport” that way? Because I’ve looked at which activities we tend to label as “sports,” which we don’t, and which fall somewhere in the middle. Furthermore, I’m interested in what ideas we use to categorize these activities. In my opinion, the idea that most people use to categorize activities as sports—or not—is whether hip extension (the ability to move our thighs back and forth) is a central component of that activity.

Admittedly, I believe that when they categorize activities in this way, most people aren’t aware that their parameters for defining a “sport” are tied much more closely to the presence and importance of hip extension, than, say, to whether it is goal-oriented or physically strenuous.

However, for most people, a big part of calling something a “sport” comes from the notion that it is—or must be—physically strenuous. But that alone is not enough: although we certainly consider football, baseball, the decathlon, weightlifting, and sprinting to be sports, what about going to the gym and lifting dumbbells?

As opposed to the first examples, lifting dumbbells seems like “working out,” or like “exercise,” but not like a “sport.”

Why is that?

And for that matter, how about ballet dancing, yoga, and other forms of physical expression?

This is where the line begins to get murky, and, in the opinion of some, with good reason. Yoga and dancing are, at first blush, not goal-oriented. There is no competition involved. And yet, the intuitions of many people would squarely place these disciplines within the boundaries of the concept of “sport.”

Those intuitions strongly correspond with the knowledge that dancers and practitioners of yoga have: that these arts are as goal-oriented as “typical” sports—if not more. Most “sports” have a single goal: winning in one form or another, whereas these pursuits have a multitude of goals. Posture, consistency, and strength are all goals of dancing and yoga. But let’s look at a deeper difference (or similarity—however you look at it): other sports also value posture, consistency and strength. It’s impossible to become an elite athlete in just about any discipline without mastering these. Except that they are placed in service of an external goal. For dancing and yoga, the aesthetic qualities that appear through function are ends in themselves.

So, there seems to be quite a bit of overlap between dancing, yoga, and “typical” sports, even on commonly-contested grounds. But let’s discuss a more interesting topic: why do some people have such strong intuitions that these activities are sports? In other words, what is it about yoga and dancing that prompts people to try and classify them as sports in the first place?

Superficially, the argument is simple: there’s something about the mechanical particulars of yoga and dancing that should put them in this category, alongside running and football. After all, they are somehow different from, say, chess, (which is more “typically” goal-oriented).

To throw a kink in my argument, the International Olympic Committee does consider chess to be a sport. I don’t—and not because I don’t think it’s worthwhile. I’d call instead that chess is an athletic endeavor (the greek word athlein means “to contest for a prize”). I don’t include chess in my list of sports because I’m interested picking apart the intuitions that underlie the common usage of the term “sport,” which emphasizes the physical use of the body.

In that sense my argument does massage institutionalized notions of what a “sport” is.

However, we can still make the argument that chess is physical, in ways that are both obvious and non-obvious. The obvious, of course, is that we use our hands to move the pieces. That observation is also uninteresting. But there is also the non-obvious: in The Art of Learning, former chess champion Josh Waitzkin talked about how his rivals would often tap the board in a certain rhythm to quicken his thought process and make strategizing more difficult. In other words, competitors in chess often find themselves in physical battles of some sort. But enough to term chess a “sport” (beyond its obvious status as an athletic endeavor)? That’s a long shot.

Then what makes yoga and dancing different from chess, but similar to “sports”?

Simply stated: hip extension.

I turn to a discussion in a book by editor Ian Jeffreys, Developing Speed. Jeffries writes:

“During a sprint, forces are developed initially through the hips, then the knee joint, and finally through the ankle joint. Therefore, activities that maximize the triple extension abilities of the athlete should play a large role in the training to enhance speed and acceleration. Exercises such as the squat, Olympic lifts, and hip extension exercises such as the Romainan deadlift should form the basis of a strength and power program for speed enhancement.”

In other words, one of the most important components of increasing the level of performance in sports is to develop the hip extension characteristics necessary for that sport. Different sports will need different hip extension characteristics, such as strength, flexibility, explosiveness or dexterity, but they all center on hip extension.

This brings us back to my definition of a “sport:”

A sport is any activity for which an increase in the relevant hip extension abilities is a necessary component of developing greater performance in that activity.

For clarity’s sake, let’s reiterate this backwards: if developing some kind of hip extension ability is not necessary to become increasingly skilled in some activity, it is not a sport.

For reasons that I will discuss in the future, the center of gravity (and therefore the mechanical center of the body) lies in the hips. In order to achieve proper flexibility, and range of motion of the entire body, practitioners of yoga must emphasize the flexibility, range of motion and strength of the hips (as well as the core). But no amount of core strength and flexibility will allow a yoga practitioner to climb the tiers of difficulty—that can only be achieved by increasing the relevant hip extension abilities: flexibility and strength.

The same goes for all varieties of dancing. Expressing the body against the ground (and fine-tuning that expression) is centered around the speed, power, and explosiveness of hip extension.

The hips are present in all sports: martial arts, wrestling, even arm wrestling. Hence the following saying:

“Have you noticed that whatever sport you’re trying to learn, some earnest person is always telling you to keep your knees bent?”

-Dave Barry

(Bending the knees stretches the gluteus maximus, such that all subsequent movements depend on its contractions).

In conclusion, I believe that because we have intuitive (and often completely unconscious) knowledge that certain activities engage the mechanical center of the body (the hips), we lobby to categorize those activities as “sports.”