Thinking in Systems, Ultrarunning

Endurance: the ultimate test of physiology.

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For a beginner runner to get into running because in 6-12 months they want to run an ultra-endurance race (or even a marathon) is—to put it mildly—folly.

There’s a reason the marathon is the final event in the Olympics: It’s by far the hardest. A recent The New Yorker article reports on one athlete trying to describe the experience of running a 2:10 marathon: “You feel like you will die. No, actually die.”

There are fundamental differences between the endurance sports and the power sports. Oftentimes, when discussing these differences, people think about what gives an athlete a competitive edge: for power sports, it’s higher concentrations of Type I muscle fibers. For endurance sports, it’s more mitochondria, and a greater oxygen carrying capacity.

This is important, but it’s not what I’m talking about. I’m talking about understanding the endurance sports by attempting to discuss what “endurance” is—not human endurance, or endurance at sports, but rather what “endurance” means in a fundamental sense. And for that, I find it best to discuss extremes.

Take a power sport: the 100 meter sprints, for example. Usain Bolt is a phenomenal athlete. There’s no question about it. And there’s no question that there’s a certain glory to be had in being the fastest human being on the planet—glory that is simply not available to the marathoner. Let’s set that aside. What would have to happen for Bolt to be unable to continue competing?  In other words, what would “catastrophic system failure” mean for Bolt?

My answer is: an ACL injury, or a torn hamstring, probably. In other words, something breaks.

Now let’s look at the marathon. Rarely does something break in that way in the endurance sports. There’s plenty of microdamage—achilles tendinitis, stress fractures, chronic fatigue, etc. But when something breaks, truly breaks to a point where the person cannot compete (in the “catastrophic system failure” sense discussed above), what does that look like? It’s typically the entire system that fails. Take a gander at a list (compiled off the top of my head) of the quintessential ailments you see in a marathon:

  • Extreme dehydration
  • EAH/EAHE (Exercise Associated Hyponatremia/Hyponatremic Encephalopathy)
  • Heart attack
  • Kidney failure
  • Heatstroke
  • Respiratory infections

What these issues all have in common is that they’re systemic failures—they’re what happens when the body as a whole, rather than a specific part (say, the hamstring) can’t cope with the event. In other words, they’re what you get when the body starts to come apart at the seams.

The best way to think of this difference is that when you bust a hamstring (or even break your spine in certain places) you can still use your body as a whole except for the part you broke. But when you get any of the illnesses that typically occur during a marathon, it’s the entire body that is put out of commission—sometimes permanently.

To put it simply, we can think of speed and power as a question of how powerful the body is. And while speed and power have tons of importance in the endurance sports, we can say that endurance is primarily a question of how good the body is at holding itself together. In other words, endurance is a test of the body’s fundamental integrity: of how much stress can you subject it to for how long without any substantial collapses in any critical processes.

And this is the main difference between the endurance and the power sports. In the power sports, the body has to be very, well, powerful, but it doesn’t have to be all that good at holding itself together—at least not in ways that relate to the ailments described above. After all, the power sports only ask the body to perform for a few moments: it stops before it becomes dehydrated, or before enough lactate builds up that the kidneys fail, or before the lungs become stressed enough that they become susceptible to infection (etcetera, etcetera).

But that’s not the case in the endurance sports. The body is going to be in activity for a very long time. If any of its systems (respiratory system, cardiovascular system, etc.) are working at different rates, some of those systems are going to get tired first. This is a problem: those systems were only active in the first place is because they were providing a critical service to the body’s endurance performance.

When one of those systems fails, some critical process associated with it also stops. If the body continues activity in this state, critical processes start falling like dominoes. And the body starts coming apart at the seams.

It’s not that endurance sport are “better” or “more of a sport” than power sports. But it is the case that being highly successful at an endurance sport takes much more time, much more consistency, and much more athletic maturity than to be highly successful at a power sport. This is why, for example, it is not uncommon to see 19 and 20 year old athletes competing in power sports at the Olympic level—the 400m, the 1500m, etc.

It’s usually those very same athletes who, 10 or 15 years later, are running marathons. Once their athletic career was already taking off, it took their body an additional 10 to 15 years to be physiologically organized and cohesive enough to run a marathon.

On the other hand, any athlete who is seriously contending for a medal at an endurance sport at 20 years of age, is a unicorn. Either they’re already so athletically mature that they’ll have a wildly successful career ahead of them, or they have already pushed themselves so far, so fast, that decades of chronic illness and overtraining are already on the horizon.

Principles of Training, The aerobic system, Training Ideas

It’s almost impossible to do an “easy workout” when you’re stressed.

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A while ago I read an excellent article titled Why heart rate always matters. It goes into great detail on a topic I’ve previously discussed here on running in systems: why the heart rate is always going to be an excellent representation of what is happening with the body’s stress response and energy metabolism. I think that some of the topics it discusses, as well as the excellent debate in the comments, are worth expanding on. Here’s an excerpt from it:

“Our fight-or-flight system often activates without any actual demand. When we get ‘stressed out’–engaged in a heated argument, mulling over a burdensome worry, or simply sitting in traffic–seldom is any physical task being undertaken. But the body is being activated. The engine is revving higher and tremendous sugar–the preferred fuel of fight-or-flight responses–is burned when under psychological stress, which is a major factor in ‘stress eating!’ We function as if we’re fighting an intense battle.

Stressed out and going for a run? Your body will perceive the cost of that run as higher (because it is already dealing with your life stress) and will activate a more intense energy system to cover all the demands. More energy cost!”

There was a particular comment in the article that I wanted to address:

“Very well written article and I agree with most of it.
However, I think you overstate the impact of activation level on energy expenditure…

…In my understanding, the energy demand dictates the energy production. And the energy demand is mainly dictated by the mechanical work of the muscles and all the side processes needed for that level of power output.
I agree, that the excitation level directly impacts the chosen energy supply system but as long as this system doesn’t actively provide energy, it’s [maintaining] cost will be relatively low.
Yes, a higher activation will have a higher energy demand but I don’t believe it’ll come anywhere close to exceeded mechanical [energy] demands.”

I agree with the commenter in that I, also, believe that the author was overstating the impact of activation level on energy expenditure. However, I think the author’s overstatement makes it difficult to observe 2 key implications of this discussion:

  1. Activation level  (a.k.a. stress) changes the type of energy metabolism, which means that it changes the ratios of fuel (fat and sugar) that it uses.
  2. Training stimulus is inextricably tied to activation level and energy metabolism. This means that the ratios of fuel usage have a much bigger say in how the body perceives the workout (as low-intensity vs. high-intensity) than the rates of fuel usage.

The point is that while the author does overstate the energy cost of the stressors he mentions, it doesn’t really matter—there’s things the athlete just can’t get out of training if their body is taxed in the ways the article mentions.

A lot of people think that low-intensity means “slow,” “easy,” or “consuming little energy.” It doesn’t. Low-intensity is when the workout is easy on the body—specifically, when the body is burning a majority of fats for fuel, and the sugar that is being utilized is burned wholly aerobically  (in the presence of oxygen). In other words, there is no substantive anaerobic work. Highly-trained endurance athletes, who burn fats at much greater rates than the rest of us, can run at very high speeds while remaining in a completely aerobic state. Such an athlete may be running blazing times in a workout that is for them, metabolically speaking, a low-intensity workout.

Now let’s look at higher intensities: In order to produce the energy necessary to approach your top speed, a lot of changes have to happen within the body. One of these is that the body has to go from burning a greater percentage of fats (which burn relatively slowly and so provide energy at a relatively lower rate), to burning a greater percentage of sugars (which burn relatively more quickly and so provide energy at a much faster rate). So, in order to get closer to your top speed, a greater percentage of your energy has to come from sugar.

In order to release more sugar to the bloodstream (to be utilized by the muscles), the body releases hormones called glucocorticoids—glucose (a.k.a sugar) releasing hormones. The main glucocorticoid is cortisol, which many will recognize as the main stress hormone. Another hormone that is release during the stress response is insulin, which helps muscle cells avail themselves on the sugar that cortisol released into the bloodstream. Cortisol and insulin, then, work synergistically to produce (and increase) sugar metabolism.

To recap: want to run closer to your top speed? You need to release more sugar. How do you do that? By getting more stressed. But because of some of the body’s more complex molecular mechanics—fodder for another post—the body can’t release a bunch of sugar and still be releasing fats. What would happen is that you’d just flood the bloodstream with unhealthy concentrations of both fuels. So, when insulin is released or when anaerobic function (which is dependent on sugar) increases, fat-burning drops. If sugar-burning goes up, fat-burning goes down (and vice versa).

This works the other way around too. If you get more stressed because, say, you had a rough day at work, or you got into an argument, you’ve got more cortisol and insulin running through your body. But it’s not like the body can decide to release (and use) sugar only when the reason for cortisol and insulin release is because of increased athletic demand (a.k.a. athletic stress). For any other stress (work stress, etc.), cortisol and insulin become released, and increase carbohydrate metabolism. Research on the metabolic effects of social stress in fish supports this idea.

This, incidentally, is why people get tired after a stressful day at work or an argument that stretches for too long. They didn’t use up all their fat-stores at work, obviously. But because the stress put them in sugar-burning gear, enough of their sugar ran out that they start feeling tired. It’s not that they ran out of fuel, but rather that they ran out of the fuel they’ve been stuck using.

It also takes a relatively long time for the cortisol to get out of your system—and when it does, it’s not like you can just pop back into action and go for a run. The adrenal glands, which put out cortisol (not to mention various other mediators of the stress response) have been used up. They’re tired, and will resist further activity. And since you use all the glands in the body to one (significant) degree or another during training, it’s not a good idea to train with exhausted or depleted glands.

Asking your body to work out when you’re already out of a major fuel and your stress glands are tired is an even worse idea: the “same” workout is relatively much harder for a tired gland that’s nearly out of adrenaline and cortisol than for a rested gland. Training after a period of stress is, in physiological terms, almost exactly like doing back-to-back training sessions. Effectively, you’re extending the period of stress.

And if on top of that, your blood sugar is low (as usually happens after a period of stress), you’ll be asking those tired glands to produce even more cortisol and adrenaline than they would usually have to: in their already tired state, it’s not enough to simply produce enough cortisol to maintain blood sugar levels—they have to make up for the lack of sugar in the bloodstream.

If on top of that, you’re “stuck” in sugar-burning mode because you still have all that errant cortisol and insulin flowing through your system (since you’re still stressed), you’ll be depending on sugar—which you’ve substantively burned through—for the duration of your training session. Because the body is inhibited from fueling itself with fats (due to the insulin in your system), it has to rev up those exhausted adrenals even more to provide the requisite cortisol.

Insofar as your body is stressed, it will respond to what is normally an “easy” workout as if it were a “mini high-intensity workout.” In other words, you can’t really have a “low-intensity training session” when you’re stressed (and expect to accomplish your goals in any sort of way). 

This is why doing MAF training—exercising under the aerobic threshold—under stress (or after a period of stress) produces such a dramatic drop in speed/power output at the same heart rate. When you’re under stress, exercising at a rate that looks anything like the aerobic training you do when unstressed would mean elevating your heart rate far beyond your aerobic threshold. Because aerobic work output is so reduced in a stressed state, it’s a much better idea—and a much simpler fix to the problem—to simply rest for the day and do your “easy” training session tomorrow.

The aerobic system

What the hell is the aerobic system? Part 1

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Frequent readers of my blog know just how much I like to use car metaphors to describe the human body’s function. So here’s another one: the aerobic system is the body’s main powertrain.

(The powertrain is the chain of systems within the car that power gets channeled through: from the engine, through the gearbox, down the main drive shaft, across the differential, and into the wheels. The drivetrain on the other hand is typically understood as the powertrain minus the engine.)

When most people think of increasing aerobic function, they think of increasing the capabilities of the body’s aerobic, Type I muscle fibers (also known as slow-twitch fibers). While muscle fibers are hugely important—they are the main power producers of the body—they are one subsystem of many that need to be working synergistically and at similar rates for the aerobic system as a whole to be able to express any kind of power.

It’s important for us to realize that when we are talking about developing the aerobic system, we are talking about much, much more than just the aerobic muscle fibers themselves. Quite literally, the whole powertrain from beginning (lungs) to end (muscle fibers) needs to work and develop together for it to be of any use.

The body, unlike the car, stays on all its life. The car can shut off if it runs out of fuel. But if the same thing happens to the body, it dies. So any system that is going to take on the responsibility of being the body’s main powertrain has to be able to provide a stable flow of energy over a very long term.

The best way to accomplish this is by burning a cheap, safe, light, efficient, and plentiful fuel source: fats. (As I’ve discussed before, burning carbs/sugar comes with a lot of strings attached: it’s dirty, heavy, scarce, inefficient, addictive, and dangerous. The only real advantage it has—and it is a BIG advantage—is that it produces energy at a much greater rate than fats.)

Being the system that provides stable, long-term energy means that you need to burn the stable, long-term fuel. Because of this, the aerobic system has to burn fats in particular as its primary fuel.

In other words, I use Phil Maffetone’s rendition of what the aerobic system is. This means that while I like statistics such as VO2Max (maximum volume of oxygen utilization per minute) as measures of aerobic power, I don’t believe they are a measure of the functionality of the aerobic system. Why? Because you can consume far more oxygen when you’re burning sugars than when you’re burning fats. And besides, we’ve defined the aerobic system as providing energy over the long-term. Therefore, aerobic functionality has to do far more with fat-burning, which occurs in a big way at moderate percentages (55-65%) of VO2Max, than with sugar-burning (which occurs in a big way at 65-100% of VO2Max).

(Note that very highly-trained endurance athletes are often an exception to these percentages. Why that’s the case is for another post.)

One of the reasons this system has the name “aerobic” is because fats cannot be burned outside of the presence of oxygen. So, bringing oxygen into the body and enabling its efficient transport throughout is absolutely essential to our capability to use fat as fuel. In fact, this is one of the most important differences between fat and carbs: carbs unlike fats, can be burned both aerobically and anaerobically.

This may seem like an advantage, but it’s somewhat of a disadvantage—in the same way that the disadvantage of cocaine is how powerful it is. You’re far better off experiencing the feeling of reward in the less powerful, sustainable, and old-fashioned way.

This is not to say that sugar has no place in our utilization of energy: at any given point in time when we’re at rest or doing light activity, we’re burning a small percentage of carbs. But when sugar stops being your auxiliary fuel (and becomes your go-to fuel), you’re in trouble.

By primarily using a fuel that is very powerful, it’s much easier to use only that fuel. Why would you use the other, less powerful fuel? (Sure, because it’s lighter, cleaner, safer, and more efficient.) But there’s also this: since carbs burn way quicker, the body can get lazy and forget about maintaining its fat breakdown and transpo systems, with little short-term negatives—but huuge long-term drawbacks.

By the time that the downsides of relying primarily on sugar begin to roll around, the body is hooked and the systems that burn and transport fat are in utter disrepair. The body can only store about 2,000 calories of carbs at a time (compared with some 120,000 calories of fats on the low end). When it prefers sugar over fats, it has to be eating all the time.

In layman’s terms, this is known as a “metabolic SNAFU.” (That acronym fits particularly well here, just because of how ubiquitous and “normal” this situation is.)

So what are these systems? Let’s trace the flows of oxygen and fats to find out.

Fats have to be broken down from fatty tissue, transported through the blood vessels, and burned by the mitochondria—the cell’s aerobic motors.

Oxygen comes into the body through the respiratory system, then gets transferred to the circulatory system, and finally permeates into the muscle cells where it is used as a reactant to convert the fats into energy.

But if we’re going to talk about flows of materials (oxygen and fats), it’s not enough to just discuss the parts that they flow through (and the systems that convert them into energy). We have to talk about the parts that regulate those flows, for the simple reason that if those regulatory systems stop working, chaos ensues. So these regulatory systems are as critical to the function of the aerobic system as, say, the car’s computer is to the function of its powertrain. It’s a part of it, pure and simple.

Let’s look at oxygen.

As any asthmatic or person with hay fever will tell you, those regulatory systems make a difference. The reason a lot of people start wheezing when they run too hard for too long is because the part of the nervous system responsible for increasing the body’s activity levels (known as the sympathetic nervous system, or SNS) gets too tired, and its function collapses. A crucial part of increasing activity levels is to open up, or dilate, all of the body’s ducts (a.k.a the airways and blood vessels) so that more stuff can flow through, at a faster rate. So, when the SNS becomes exhausted, its ability to keep the airways dilated goes away. Its opposing system—the parasympathetic nervous system, or PNS, whose job it is to shut the body down—takes over. One of its jobs is to constrict the airways—and so they close up (hence the wheezing).

Regulation of fat-burning functions in a very similar way. The system most directly responsible for regulating fats is the endocrine (a.k.a. hormonal) system, affecting primarily (and IMO most critically) whether or not, and at what rate, fats are broken down. This process is known as lipolysis: lipo = lipid (fat); lysis = breakdown.

Lipolysis is accomplished partially thanks to a hormone called leptin. In healthy humans, leptin exists in the bloodstream in a big way only when the body is at a reasonably low level of stress. So, one of the reasons that fat-burning starts going down at an exercise intensity even slightly over moderate—which is known in the biz as the AerT or aerobic threshold (go figure)—is because the increase in exercise intensity puts out stress hormones that inhibit the activity of leptin. As exercise intensity increases beyond the aerobic threshold, lipolysis begins to slow down.

So it doesn’t really matter if the muscles have a whole bunch of mitochondria that were developed by training at a high intensity (remember: a.k.a. stress), and burning lots of sugar in an aerobic way. If the body’s lipolytic systems haven’t been trained, it’s going to burn very, very few fats during exercise. So it doesn’t really matter what’s going on in the muscles. Muscles (even aerobic muscles) get really big really fast and their ability to consume fuel increases very quickly—but the rate of lipolysis takes much longer to improve.

The rate at which the body is capable of breaking down fats (rather than the rate at which it can burn them, or the rate at which oxygen can be supplied) is typically the bottleneck. And that’s why “fit” people all too often manage nary a shuffle when they start running under their aerobic threshold: they’re sugar-burning beasts, but under the AerT the hormones are optimized for burning fats, not sugar. Those powerful muscles they have? They’re being fed fats with a teaspoon.

And one of the reasons it feels so slow is because they’re exercising at a relatively small percentage of their oxygen intake and transpo capacity. Why? Because they’ve trained it primarily in concert with their sugar-burning system. Their fat-breakdown system needs to become waaay stronger before it’s going to break down fats at a rate that is challenging or even meaningful to their present oxygen transpo capabilities.

Understanding which systems comprise the aerobic system is far less important than grasping the point that the aerobic system really is the entire powertrain. It’s far less critical to know whether your car has a carburetor or a fuel injection system, than to know that you should consider how the entire powertrain (and the car as a whole) is going to behave when you decide to upgrade some particular component.

If you’re going to swap your L4 engine block from with a V8, you also have to swap out the fuel pump and a host of other systems (not to mention the entire chassis)—or you’re going to end up with a V8 engine getting fuel at a rate meant for an L4. The understanding that you need to go look at the whole picture, instead of just at the muscle fibers (or whatever)—will inevitably take your search in the right direction.

There’s a bunch of other parts of the aerobic system left to cover. In my next post I’ll talk more about how the fat-burning process goes down and why it’s impossible to burn more fats when the rate of sugar-burning goes up. I’ll also get more into why the body is wired to rely more on sugar as stress levels go up (hint: because sugar burns faster). In later entries I’ll talk about how the various other parts of the aerobic system interact with each other, and why aerobic function can really only be developed and optimized at relatively low levels of exercise intensity.

Biomechanic Issues

Synthetic perspectives on the running human body: Improving running economy is not the be-all, end-all.

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Looking at the body from a synthetic perspective is a lot like looking at it from an evolutionary perspective.

As I described in a previous post, a “synthetic account” of the body—there is no such thing as a “synthetic analysis”—is one that looks at the human animal in its whole context in order to understand why it does what it does, (and what it is attempting to do).

A few theories have a strong synthetic component: Pose Method (which looks at the mechanics of the body in the context of the Earth’s gravitational field), Tim Noakes’ Central Governor Theory as well as his discussion on thirst and hydration, and Phil Maffetone’s MAF Method (which observes that prolonged athletic achievement cannot be produced without safeguarding and promoting the body’s health).

But most accounts of athletic performance out there look at the human body in a very narrow analytic sense. They typically only measure a few variables germane to athletic performance: running economy (also known as efficiency), speed, power, endurance, etc. In other words, they look at the body in the same way you might look at a race car: you analyze how the race car functions and how it performs while on the track. But you don’t worry very much about what it’s doing or what’s happening to it elsewhere.

In this vein, it is often argued that one running form (one particular set of kinematics) is better or more advantageous than another on the grounds that it is more efficient. Take a look at the title of these articles: A Novel Running Mechanic’s Class Changes Kinematics but not Running Economy, and Effect of a global alteration of running technique on kinematics and economy. 

The body has to worry about a number of things beyond running economy: it has to save itself for future battles, quickly rest and recover in order to fulfill any number of foreseen and unforeseen functions beyond the scope of the athletic event, like for example to be unstressed enough to be able to engage smoothly and creatively with social environments.

So, when sports scientists come along and suggest that the best form for a particular athletic movement is what’s most efficient (in the sense of minimizing energy expenditure during the athletic event), they are ignoring some of the body’s broader imperatives.

Why? The simple answer is that the body’s lifelong goal of protecting itself is far more important to it than the very bounded goal of winning some particular athletic event (or chasing down some particular deer) at any cost. It doesn’t just want to get the deer. It wants to benefit from having gotten it.

What does this mean? That benefiting from getting a deer means that it might be better to wait until a slower deer comes by. Let’s suppose you don’t have enough energy to run at the speed and distance you’ll need if you want to catch the deer you want, and still be able to run with the form necessary to protect your body while doing so. You might end up catching the deer, but you might also end up with a blown knee or a damaged achilles. You might be put out of commission for a month or two.

Now let’s suppose that someone else uses a slightly more expensive form—expending more energy to maintain proper movement. They’ll be proportionally slower, but they’ll also be able to move much more and recover much faster. Over time, they’ll become the more powerful runners. Three or four years down the line, they’ll be catching much faster deer, much more consistently.

Of course, it’s important to be as efficient as possible: refining the way muscles work, and aligning them to work with gravity and impact forces (and not against them). But pursuing efficiency is not at all convenient past the point where the only way to get more efficient is to risk tearing tendons, degrading cartilage and connective tissue, and abrading bone.

This brings up another important point: while the safest form has a high degree of efficiency, the checks and balances necessary to produce it (and maintain it at high speeds or over many miles) also means that it is typically more expensive to produce than the “most efficient” form.

 Let’s say that the runner who blew his knee by going after the very fast deer has form X. Form Y might be more expensive, but it would also allow him to get faster over time. But let’s say that instead of getting injured by going faster, he decides to only chase the slowest deer, or run exclusively for fun. He might display the same injury rates as runner Y. But if we only look at injury rates without looking at speed, or running economy without looking at speed, or efficiency without looking at performance improvement over time, we might end up concluding that the wrong ways of doing things are actually better (or worse, that there is no “best” way of doing something).

Being faster (or fast for longer) is great. But that’s not good enough either. The same things that we said about efficiency can also be said about speed. Running with the form that lets you be fast safely, recover quickly, and improve consistently, is waaay better than “just running fast.”

Biomechanic Issues, Defining our Terms

The role of downforce in forward motion.

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There are two main camps in the argument of exactly how we manage to move forward as we run. The traditional camp says that the body uses the muscles to “push against the ground.” The other—constituted almost solely by Dr. Nicholas Romanov’s Pose Method—proposes that we move forward thanks to the action of gravity on our bodies.

This second camp suggests that what the muscles do—their primary function—is to convert the downward force of gravity into net forward movement.

But how is it possible that the body can convert a downward force into horizontal movement?

Part of the answer lies in the fact that the running movement isn’t really horizontal. It consists of a wave-like movement of the hips and torso—an oscillation—that only seems to be a straight line if we’ve zoomed out far enough. If your model (incorrectly) assumes that the body is trying to convert a downward force into a force that travels on a horizontal linear vector, you’ll end up quite confused.

(But that’s a discussion for a different post.)

Let’s get to the issue I want to talk about: Proponents of the idea that runners “push off” often understand Dr. Romanov’s argument—that gravity is the “driving force”—as claiming that gravity provides “free” or “additional” energy (a.k.a. net energy) if we adopt a certain technique.

I believe that’s a rather shallow misrepresentation of what Dr. Romanov’s Pose Method has  actually suggested. Pose’s main message regarding the action of gravity in running is quite a bit more profound. To explain why this is—and what I believe the main message of Pose is—let’s abstract away from mentions of “gravity” for a second and talk about a more general concept: downforce.

Instead of runners, let’s look at race cars. What are the necessary factors in making them go?

First and foremost, a race car needs a powerful engine. Without an engine, it’s going nowhere. But an engine is not enough. As any connoisseur of modern racing will tell you, there came a point in the evolution of car racing in which the engine’s ability to turn the wheels exceeded the ability of the best tires to grip the best track.

Why? Engine power eventually exceeded the car’s weight (defined as “how much force is generated as gravity accelerates its mass towards the ground”), and the capacity of the tires and the track to covert that weight into friction.

This reveals an important truth about the car: the engine actually isn’t for moving the car forward. The function of the engine is to spin the wheels. (While this results in driving the car forward, actual forward motion only occurs insofar as the power with which the engine spins the wheels coincides with the extent to which gravity keeps the car on the track.)

At this point, the only way to achieve greater speed was for engineers to somehow find a way to add to the downward force that gravity exerts on the car. How did they solve this dilemma? By adding the ugly inverted wings we now see on the back of every Formula 1 and drag racer: spoilers.

By redirecting the flow of air upwards at the tail end of the car, spoilers create another significant downforce. This reveals that strictly speaking, it isn’t gravity that allows race cars to move forward. It’s downforce. (Gravity just happens to be the quintessential downforce on Earth.)  But the point is this: no downforce, no movement.

Let me spell out the implications in the strongest possible terms. Muscle power is NOT the driving force. It is the intermediary force. It converts a downforce into a quasi-horizontal oscillation. The driving force—the thing that ends up as movement—is gravity. Muscle power (a.k.a. metabolic energy expenditure through muscle use) is what lets gravity end up as movement. Gravity could provide zero net energy (zip, nada) and still it makes sense to call it the “driving force.”

The important question to ask about running isn’t really whether one running technique “uses” gravity to run—all running necessarily does so. Let me be even more specific: all overground movement is a result of expending energy in order to convert some downforce into a quasi-horizontal movement. The degree to which movement occurs is commensurate to the degree to which the organism/machine is harnessing downforce in real time.

Running according to the tenets of The Pose Method gets you “free energy” from gravity in the same sense that a car that never fishtails also gets “free energy.” In other words, Pose offers the cheapest way, all things considered—speed, agility, endurance, resilience, performance consistency, performance frequency, metabolic flexibility, recovery, longevity, etc.—to convert as much downforce as possible into overground movement. The critical observation offered by The Pose Method, then, is about how the body’s “engine”—its musculature and various systems—work best to harness the force of gravity to produce forward motion.

If the car weighs too much for the engine, it stays put. If engine power exceeds grip, it spins out. In other words, car’s absolute theoretical speed limit on Earth isn’t set by the power of the engine, the design and engineering of the transmission, or the materials it’s composed of. The maximum horizontal speed that any object can achieve is set by the theoretical limit to which it can harness the few downforces available to it on Earth. Once the car’s power and engineering causes it to reach speeds at which it is impossible to stop the air around it from supercavitating (creating a vacuum around the skin of the car), no aero kit will allow it to go faster, and no further improvements to the drivetrain will do it any good.

Of course, unlike race cars, the human body is not set up to use wind as a downforce—and we couldn’t run fast enough to make it matter anyway. Our running speed is a function of our ability to harness one downforce: gravity.

For a runner, improving efficiency by harnessing the force of gravity can mean 2 things:

  1. Removing power leaks and other muscle use that does not contribute to harnessing gravity. (The race car example would be to swap in better and better parts, and to make sure that you don’t throttle up enough to drift the car).
  2. Increasing top running speed: a runner with good form (a.k.a a runner whose movements and stances maximize the harnessing of downforce) can do so to a greater degree—in other words go faster—than an identical runner whose movements and postures do not effectively harness downforce.

Note that #2 is a hidden efficiency: it only reveals itself insofar as the runner goes faster. Both the inefficient runner and the efficient runner may be using a very similar amount of energy at lower speeds, but only the more efficient runner can get to a faster speed.

Pit my Toyota Tacoma against a Ferrari. Both would perform quite similarly at lower speeds and wide turning radii. If you ask both of us to make a wide sweeping turn at 60 miles an hour, we’d perform almost identically. You’d say “Whoa! Correcting for weight, they’re equally as efficient!”

But this observation only holds at lower speeds. If you increase the speed to 160 mph and tighten the curve, my Tacoma would start to spin out or come off the track, forcing me to reduce my speed. In other words, even if you doubled the horsepower on my Tacoma, I wouldn’t be able to match the Ferrari because of its stiffer suspension, better tires, lower profile, and aerodynamic design (in other words, it’s much better at harnessing downforce).

I believe that the discussion of “saving energy through the use of gravity” is meant to help us recognize—for starters—that we move forward only to the degree that friction and muscle power meet. It also has a few other implications (to put it mildly), but those are best left for another post.

 

 

UPDATE: Check out what I’ve written on The Pose Method:

About Pose theory of movement in running.

About Pose theory of movement in all sports.

About the “unweighing” principle of Pose theory.

Thinking in Systems

Strengths and weaknesses of analytic and synthetic thought, explained through tacos: The real “about this blog.”

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About a year ago, Craig Payne from Running Research Junkie leveled a (fair) criticism at my blog in the comment section of another article: that I don’t do “analysis.”

Craig is right: I don’t (and I don’t claim to). Judged as analysis, much of my thought process on this blog is indeed poor. One of the reasons I don’t is because too many people in the run-o-blogosphere already offer excellent analytic thought—of which the highest expression might be Craig’s own blog.

But another reason I don’t offer analysis is because of an emerging field that is very dear to my heart: systems science (and specifically systems thinking).

So what is it that I offer here?

I offer synthesis.

Systems thinking—and other emerging fields that depend on its tenets (such as psychoneuroimmunoendocrinology, or PNIE)—are synthetic sciences. What they do is best is tell a coherent story about a system or supersystem by making sense of all of its features and bugs, strengths and weaknesses, to postulate an argument about its functional purpose: why it does what it does.

Run PNIE through tests that establish whether a particular form of analysis has value, and it will be found wanting.

It joins seemingly unrelated domains—the mind and the immune system, society and hormones—by telling a story about why it makes sense that they interact.

It factors in phenomena that create turbulence in the system (but by themselves have no lasting impact on the system at large) by suggesting how they could conceivably be interconnected through a  long line of effects on parts and properties of the system—some, like thoughts, emergent; others, like killer T cells, not.

(I imagine analytic sciences staring with incredulity at PNIE, thinking: “Are you insane?!”)

While a field like PNIE can produce a consistent narrative, what it cannot do is reconcile every specific variable with every other specific variable. Evolution, for example, is imperfect at best. It gerrymanders structures that performed one function at some point into structures meant to perform a different one.

Modern accounts of biology observe this basic evolutionary reality: human physiology, for example, is far from the physical consummation of the divine form, or the expression of cherry-picked mathematical constants (as alleged by the Classical paradigm). The human body is best described as a hodgepodge of systems and parts, twisted and tweaked by evolution to perform a specific function (or series of functions) at the expense of countless others.

We can’t rely on analysis of specific strengths and weaknesses to come to conclusions about what structures do. It just isn’t possible for the (decidedly imperfect) tales told by PNIE, systems thinking, and other synthetic sciences to have fewer imperfections than the gerrymandered biological structures they examine.

What analytic sciences ask for, synthetic sciences simply cannot give. For analysis, the devil is in the details (but so is everything else). For synthesis, while the details must be addressed, imperfections in the story do not always mean that the story is imperfect in and of itself. Instead, as long as the gestalt remains intact (in the face of newly discovered details), imperfections in the story may speak to corresponding imperfections in the structure it describes. 

Here’s a great example: tacos. As most of us know, the filling falls out of tacos all the time. Sometimes it falls out the ends. Sometimes the tortilla gets soggy and breaks apart. Even then, the general consensus is that the purpose of a taco is to hold stuff in (despite the fact that it can only do so imperfectly).

The story we tell about the taco—that its functional purpose is to hold stuff in—is imperfect: in just about every instance of eating a taco, stuff falls out of one. (To analysis, this seems paradoxical: these two realities about the taco seem to be contradicting the idea that the taco is meant to hold stuff in.) But synthesis shows us that the reason the story is imperfect is not because the purpose of a taco isn’t to hold something in. It’s imperfect because the taco is only imperfectly capable of performing its functional purpose.

This tells us something very important: just because a structure is meant for a particular function does not mean that it can (or should be able to) produce it perfectly. Trade-offs and inefficiencies do not mean that the structure was meant to produce a different function.

In other words, there are better ways to hold in the filling. For example, we can fold in the edges of a taco, but doing so alters its essential nature: we’ve turned it into a burrito. But it also isn’t the case that the burrito is the better taco, and that as such, taco vendors are just behind the curve. There are (at least) 2 specific advantages to preserving a food’s “taco-ness”:

  1. Versatility: By tolerating the disadvantage that a taco has a hole at either end, you gain the advantage of being able to stuff it with more veggies and sauce from end to end and still being able to pick it up without getting dirty. (Try re-folding a burrito that is already filled to capacity.)
  1. Modularity: By putting up with the fact that your basic taco shop will give you nothing but meat on a tortilla, you are able to go to the veggie and salsa bar and build it however you like. Depending on how good you are harnessing the (imperfect) modularity of the taco, you’re also able to (imperfectly) swap out any ingredients you may not like.

Similarly, the fact that an imperfect structure produces any given function with some degree of difficulty does not entail that the structure is not meant to produce some particular function in some particular way: A taco isn’t completely versatile, excellently modular, or perfect at holding stuff in.

Furthermore, the advantages that the taco holds over the burrito—versatility and modularity—were bought at a steep price: it’s ability to effectively contain cheap meats and vegetables pales in comparison to that of a burrito. But all those disadvantages and compromises don’t mean that those aren’t intended features of the taco, or that there aren’t gastronomical situations to which the taco is better suited than the burrito.

For the taco (like for the human body), convenience and function—instead of the pursuit of efficiency in a few arbitrary parameters—drive evolution. As Noam Chomsky said about human communication, “languages do best what people do most.”

(What they don’t do is what’s most efficient.)

In order to explain the cobbled-together, evolutionary Frankenstein monster that is the human body, we need to rely on a mode of thought that is not allergic to paradox—and attempts to reconcile it instead of simply describing it. (While plenty of paradoxes have been reconciled successfully within analytic sciences, doing so has always been the result of synthetic thinking.)

We need to become storytellers of physiology and bards of biomechanics. To describe what human bodies have been observed to do is as dour as it is noble. To spin a story of what this depressingly imperfect, infinitely complex machine is attempting to do—in all its flawed glory—is the endeavor I want to be a part of.

 

 

A much-needed disclaimer:  I recognize that Craig does not need (and probably doesn’t want) my opinion that his blog is the “highest expression of analysis.”

A second, much-needed disclaimer: I embark on this post sequence only because (1) I deeply care for these themes, (2) I believe that there exists a functional, coherent story to be told about running, (3) that’s what synthetic thought is built for, and therefore (4) it is my opinion that analysis par excellence is simply is not enough in our collective attempt to give a complete, functional account of the running human body.

The fact that most of what I do here is synthesis (and not analysis) is an issue aside from whether my attempts at synthesizing information—or anyone else’s—make any sort of sense. (But that’s a different issue.) But if, having read this post, you still tell me you believe that synthetic thought (or science) should play no part in explaining the human body’s function, I bid you a good day.

Principles of Training, Thinking in Systems

Speaking the body’s language: simplifying training stimulus.

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As your understanding of athletic training becomes more sophisticated, one of the first concepts you come across is that of training stimulus. In simple English, training stimulus refers to what the body gets out of a particular workout.

Discussion of training stimulus abounds in circles that use MAF (Maximum Aerobic Function)—also known as the Maffetone Method—as their main framework for training.

The overarching mandate of the MAF Method is to protect the body. That is the best way for it to tolerate stresses, grow from training, and produce a great race performance. The party responsible for these functions is the body’s aerobic system, which oxidizes fats (burning them in the presence of oxygen) to provide a stable and long-lasting energy supply.

In endurance events, “protecting the body” means that the aerobic system must provide almost all the energy utilized during exercise. In power events, the aerobic system should be buttressing the function of the anaerobic system—which provides vast amounts of quick energy by burning sugars without oxygen—and still be strong enough to take charge for the duration of the recovery period.

For those who have already committed to developing their aerobic systems (by training at a low relative intensity), an issue inevitably arises: in long workouts that should occur theoretically at a low intensity, people accidentally (and often) end up rising above the desired intensity for a few seconds.

This brings up a crucial question: does this change the training stimulus?

There are several ways of answering this question. We can observe whether our speed at the aerobic threshold decreases after a month of training. We can go out and get a heart rate variability app that tracks our body’s autonomic readiness. We can even go get lab tested to see if our VO2 Max has decreased.

(If these terms mean nothing to you, don’t worry. Unless you’re an elite athlete who redlines for a living, they don’t need to. That’s the point.)

The body isn’t a black box. Action and circumstance affect it in ways that we can readily experience (when we know what to look for). A critical caveat: In this post, I’m only discussing the interpretation of experience before and after a workout. Using our subjective experience to measure and manage training stimulus in real time brings a whole other level of complexity.

Let’s abstract away from training for a second, and leave all that exercise terminology behind. Suppose you are on a long, leisurely birdwatching hike. You stop every few minutes to take notes, and you loiter every now and then with your binoculars as you try to make out the species of a bird in the distance. But 4 times over the course of this hike, you saw a novel bird just around the bend. Excited, you raced to take a picture.

How do you return from that hike? You are energized, renewed, invigorated. In spite of those few short sprints, the hike was a “low-intensity” experience.

Here’s another example: you’re back in your hometown after 5 years on a family visit. There’s been parties and get-togethers every day, and you’ve had ample time to catch up with all your friends.

But two things happened: the second day, you had the great misfortune of being mugged. And then the day after that, a former business partner caught up to you at a stop sign. He’s had a spell of bad luck—and in that short encounter, saw fit to threaten you and your family (over what you had thought was water under the bridge).

99% of the time, everything was pleasant and relaxing. But, for 10 minutes, the ground shook. That was enough for you to leave town with a new and unexpected wariness. Even the language—“two things happened”—tells you what the primary experience was.

This is also the case in athletic training. Put another way, the same body that has to glean meaning from that unexpectedly stressful visit (in order to be able to adapt to the next threat) is the same one that you take to the gym or out on the trails. That same body has to figure out whether it makes more sense to treat a particular training event as an “endurance workout” or a “strength workout.”

When a run feels “rejuvenating”—it’s very likely that’s exactly what it’s doing for your body. (The opposite holds true as well.)

You can break down the experience of being mugged in ever finer detail, and identify sensory and psychological stressors, and observe their physiological and neurological effects . . . but you don’t really have to.

Don’t get me wrong—you’ll get far more data about the effects of a divorce or a family vacation if you go get an fMRI every time something happens. That is a fact. (You can probably make better lifestyle choices when you know for sure whether your amygdala lights up when you see pictures of your former spouse.) But you don’t need an fMRI to be spot on—in a general sense—when asked what either experience did for your mental and physical health.

You can say the same about phenomena such as autonomic readiness (of the nervous system), which contributes to produce our subjective feelings of readiness for a wide variety of tasks.

Our experience of readiness doesn’t just happen to co-occur with our physiological readiness. Look at it from an evolutionary point of view: we didn’t have heart rate variability apps or monitors “waaay back when.” Our experience of readiness has to emerge from the fact that our nervous system, metabolism, hormonal system, and motor capabilities are actually ready for whatever it is we feel ready for. This is essentially the same line of argument that Tim Noakes (in his immortal book Waterlogged) uses to argue that the best measure of physiologically relevant dehydration is the subjective experience of thirst.

(In the same book, Noakes also argues that the fact that this even needs to be argued shows just how disconnected from the obvious we’ve become.)

If the subjective and the physiological weren’t part and parcel of the same system (to say that they’re “linked” is a gross misrepresentation), we’d all be dead. In other words, our heart rate variability monitor isn’t really going to change until we feel ready—and if it does change but we still don’t feel ready, we can be quite sure that there’s some other measurable physiological parameter out there that explains why.

The biggest mistake we can make is to listen to our pet parameter while disregarding the conclusion of a built-in measuring device capable enough to have outcompeted every other life form on the savannah—a device without which Neil Armstrong would have made it to the orbit but not the surface of the moon.

Principles of Training, Training Ideas

Verticality, Part I: Basics of uphill trail running

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“Verticality” is a term I’ve heard loosely thrown around in rock climbing and mountaineering circles. It means, well, just about exactly what you’d expect it to: sometimes it describes the sheerness (a.k.a. the slope) of a rock face, and sometimes it describes the skill of being able to interact with that face.

I use “verticality” in the second sense, to think about trailrunning.

I’m currently training for the McDonald Forest 50K trail run here in Oregon, which has a ridiculous amount of elevation change—for a road runner like me. My challenge, then, is to learn how to interact with the variables that make the typical trail different from the typical road. These are:

  • Slope (Uphill vs. Downhill).
  • Variability (rugged terrain, rocks, roots, mud, etc.)

In other words, I’m not training “endurance” or “power” for this trail race. I can’t really expand them significantly when so little time is left before the event. But what I can develop, of course, is verticality.

Particularly in trail races, I think that a person’s ability to interact with the many variables present in trailrunning is a much bigger determinant for success than, say, power. While power is still very important, our ability to interact with the trail determines whether we get to use it or not.

Essentially, the added variables in play means that the skilled runner—the runner whose body understands those variables and knows how to use them—will see their physiological advantage magnified over the runner who doesn’t. (I use the term “advantage” because skilled runners also tend to be both more physiologically powerful and more experienced in different slopes and terrains than unskilled runners, because they usually have spent more time running).

Trailrunning is an immense can of worm, so I’ll discuss each part in a separate post. In this one, I’ll deal solely with uphill running.

The typical runner facilitates uphill running by bending forward at the waist much like one does during acceleration.

This seems like a pretty good idea on the surface: by leaning forward, you are able to cruise up the hill faster without working harder. But there’s a trade-off: you compromise the stacking of your ankle, hip, shoulder, and head. Specifically, this means that you put a lot of strain on your lower back, similar to the strain a person experiences when they bend from the waist to pick up a heavy object.

When you compound this across thousands of steps, and the lower back becomes significantly tired, the hamstrings have to step in to provide hip stability (say). Without going into the details, this essentially creates a snowball effect that increases the difficulty of running, and therefore the likelihood of injury.

In a popular video, ultrarunning god Scott Jurek explains how one of the key features of correct uphill running is to keep your hips in neutral position, or correctly stacked over your shoulders. This might lead us to say that the key is to lean forward “from the ankle,” like many suggest. That’s somewhat true, but doesn’t really describe the best strategy for running uphill.

Looking at elite ultrarunners like Kilian Jornet (2:35) and Dakota Jones (1:15), we can see that their strategy for climbing steep slopes is by pulling their foot from the ground and back under their hips very quickly. An easy way to observe the effect of this pulling action is by seeing just how much they raise their thigh. Even though they’re covering comparatively little horizontal distance, their foot has to come up quickly enough that their thigh gets almost parallel with the horizon before their foot lands on the ground.

UPDATE: The raising of the thigh—also known as “thigh spread,” is just an obvious marker. For running to be effective, the focus must be on pulling the foot from the ground back under their hips. While this is fodder for another article, let me just say that one of the reasons runners should focus on the foot and not the thigh is because if we control the movement of the foot, we also control the movement of the calf and thigh (but if we control the movement of the thigh, we do not necessarily control the movement of the foot or calf).

kilian dakota

Instead of “powering up” the trail, skilled runners “fall up” the trail in the very same way that during a lunge someone falls further forward by increasing the flexion of their swing leg. (A lunge, of course, doesn’t have the same “pulling” action as running—the foot of the swing leg moves ahead of the center of gravity, instead of staying under it.) But the point is that in both movements, the degree of flexion of the swing leg determines the amount of distance covered.

While the hip extension of the back (stance) leg is greater in a deeper lunge or a higher step, a greater flexion of the swing leg is actually what accomplishes this. (In running, this means “pulling” the foot; in the lunge this means reaching forward). As far as the back leg is concerned, the difference between a shallow lunge and a deep lunge is not in ankle or knee extension—both shallow and deep, the stance leg knee is in near-full extension and the ankle is close to neutral. As far as the stance leg is concerned, the difference is in the degree of hip extension.

Lunge - fall

Like for the lunge, in uphill running it’s not the prerogative of the back hip to extend as much as it wants, whenever it wants. If the front leg remains relatively more extended during the stride, it’s impossible to (1) open up the compass, or to (2) lean forward “from the ankle” as I discussed above: the slope gets in the way. But if (3) the swing foot is pulled faster from the ground, it can cover a larger distance.

Uphill - Fall

A simpler way to say this is that hip extension of the stance leg occurs in function of flexion of the swing leg.

The key to uphill running, then, is (a) to lean forward only insofar joint stacking isn’t compromised, (b) to pull the foot up faster, and (c) to maintain stride rate, as Dr. Nicholas Romanov (founder of the Pose Method) points out in an excellent video. (Maintaining stride rate is a result of a quick and efficient pull).

Of course, this brings an additional level to the discussion: pulling the foot faster means that the runner has to be that much more powerful, or at least have that much more of a conditioned pull than someone who runs on more moderate slopes.

But if the degree of pull of the swing foot gets to determine how much hip extension of the stance leg you get, this means that the rule for uphill running also applies to regular running. The faster person on level ground will also be the faster person on the uphill.

One final point: the slope doesn’t lend importance to the pull. It magnifies it. (Put another way, the same rules apply to a slope of .003 percent than to a slope of 15. The magnitude of the slope determines how apparent they are.) The greater the slope, the more powerful a pull you need to be able to move continuously, smoothly, and successfully up it.

This has dire implications for the runner who has trained under the paradigm that “pushing”with the stance leg is the primary form of propulsion: insofar as this is the case, the degree of effort it takes to run uphill will be that much greater. The greater the slope, the faster the pulling runner will pull ahead* of the pushing runner.

(What does the pulling runner have to do to win an argument about running physics? Find a hill.)

*Pun intended.

PS. Here’s a great article that discusses several pulling drills!

PPS. Here’s another great video by Dr. Romanov discussing foot-strengthening exercises for uphill running!

Biomechanic Issues, Principles of Training

The Running gait, Part 2: Movement logic and The Pose Method

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It seems to me that nobody can quite agree on exactly what is happening during the running gait.

The running gait is characterized by an alternation of support: at one point, your body is supported on the ground by your left leg, then you’re suspended in the air, and then it’s supported by your right leg (and then subsequently back to your left leg). It’s how you get from these support phases—also called “stance phases”—to being suspended (and back again) that people vehemently disagree on.

Many in the running community say that the motive force of running is produced by a strong push of the leg muscles against the ground. But Dr. Nicholas Romanov of The Pose Method suggests a different—and in my opinion, far more parsimonious—interpretation of what happens: instead of “pushing,” the body accelerates its center of gravity by repositioning itself relative to the point of support (the foot on the ground).

UPDATE # 1: All repositioning occurs due to muscle activity, and the speed and effectiveness with which the body (or a specific body part) can reposition is commensurate to the power of the relevant muscles.

We typically think of “acceleration” as “the thing that makes cars go from 0 to 60.” But even a slight weight shift is an acceleration. When the slowest snail takes one tiny step, it’s accelerating it’s body (and then promptly decelerating it). Similarly, a slight weight shift constitutes an acceleration of the part of the body that moved. A greater weight shift is an even bigger acceleration. If you string together enough tiny weight shifts (or big ones) in a close enough sequence, you get a really big acceleration!

In this post, I’ll argue that the most logical way of producing a human movement (and that of any segmented organism) is by shifting the most easily-movable part first.

If you look at the body from a design perspective, you’ll see that it’s a stack of different parts (feet, calves, thighs, hips, etc.), all separated by joints. In the standing posture, each of these parts provides support for the part above it, much like a stack of bricks. But the difference is that the body’s joints let each brick move semi-independently of all the other bricks. The question, then, isn’t “how do we run?” It’s waaay more basic than that. The question is: to get from A to B (over and over again), how does a stack of things have to move?bricks.jpg

You could simply lift the bottom brick—along with all the bricks on top of it—and move it that way. That’s not particularly convenient, though: it requires a lot of energy in very little time. But there’s another way: start from the top brick. That way you only have to move one brick at a time, shifting bricks in quick succession.

This is the logic that your body (and the body of any segmented organism) uses to move. If you’re standing on two feet and want to lift your left foot, you don’t start by lifting your foot. You start by shifting your weight—starting by your shoulders, and moving down the body—onto your right leg, effectively removing all the weight off your left foot.

(This takes all the top “bricks” off the foot first.)

I’ve just described to you a process intrinsic to any human movement, which Dr. Romanov calls unweighing. This is the simplest process: if you want to move a limb, you first shift all the weight you can off it first, and then you move that limb. What makes Dr. Romanov’s theory parsimonious is that you need very few ideas to successfully describe human movement as a whole. Case in point: the movement of the entire body is simply a large-scale version of unweighing.

If you want to move, you create a forward weight shift in the direction you want to go. This effectively takes your weight off your feet and puts it in the space ahead of you.

Let’s talk running. During stance, one leg has the entire “stack of bricks” on top of it, and the other one is suspended in air (and already traveling forward), with nothing pulling it to the ground but its own weight. (UPDATE #2: In terminal swing, that leg actively reaches for the ground in order to provide new support). But when one leg is in early stance and midstance, which do you move? Do you push with the leg that has all the bricks on top of it, or do you move the foot with nothing holding it in place—the “topmost” brick?Running bricks

That’s the question Dr. Romanov answers with the Pull. The Pull describes the process of getting the back leg off the ground, and recycling it forward to produce the next step. But part of the hidden importance of the Pull is that it is also a weight shift: whereas in the previous weight shift you drifted your shoulders a few inches to one side, in the Pull, you aid the elastic recoil of your tendons in pulling your foot from the ground. This brings the mass of your entire leg ahead of the foot currently supporting you on the ground.

Galen Mo
Like this, but not as effectively (and with far less flair).

In a proper landing, your foot will touch the ground just ahead of your hips, torso, and head. There’s a slight deceleration due to the foot’s contact with the ground, but the body as a whole continues to travel forward, vaulting over the support leg. If the leg that just came off the ground—the “Pull” leg—moves forward fast enough, the body can add more of its mass ahead of the point of support.

We already know that a small weight shift—drifting the shoulder to one side—causes you to move (read: accelerate) slightly to that side. Now imagine how much more acceleration you can create by pulling the leg and moving its mass ahead of the body.

Mainstream thought questions whether this kind of weight shift can create enough momentum to offset wind resistance, plus the braking effect of landing, plus any power leaks that the person might have. The argument goes that if it can’t, the “pushing” argument is more likely the correct one.

But I hope I’ve convinced you that the best way to move a stack of things is by moving one part at a time in order to tip the stack in the direction you want (and then continue to move the parts in order to create more acceleration). Supposing that this—the best way to move a stack of things—somehow wasn’t enough to overcome wind resistance and the braking effect of landing, there’s no way that you could do it with pushing (a.k.a. moving from the bottom brick) because, well, it isn’t as effective.

So if the question of running is “what is the best way to offset wind resistance and braking?” the answer would still be to reposition the most easily movable limb in order to create a weight shift to move the body in the desired direction.

Read my initial take on the Pose Method here, and how the Pose Method applies to all other sports here.

Biomechanic Issues, Uncategorized

The Running Gait, Part 1: Contralaterality

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All gait is a contralateral movement. Although It seems like the most obvious statement (perhaps to the point of being boring), it often astonishes me just how unexamined it remains. Discussing both the theoretical and practical implications—what it means for our training—is what this series of posts is all about.

To say that a movement is contralateral is to say that when something happens in one side, the opposite will happen in the other side. During gait, if our left leg moves forward, our right leg moves back. But our gait is also reciprocal, meaning that the limbs in the same side move in opposition to each other, to balance their movement. If our right leg, supporting our body during the stance phase of gait, moves back, our right arm swings forward in a passive motion meant to balance out this movement.

This kind of reciprocal action is very similar to the kind of activity that you find in a lot of modern machines. Let’s take the internal combustion engine as an example. To make this simple, let’s look at a flat twin engine like the one mounted on a lot of BMW motorcycles:

Boxerengineanimation

In the image you can see two pistons, each moving in opposition to each other around a crankshaft. This movement is—or should be—a lot like the movement of the legs around the hips. By the way, this imagery isn’t just a metaphor: there are important similarities between the mechanics of the piston system and the mechanics of the hips and legs.

I liken the lowest point in the piston’s rotation to when the leg (the right) is in swing (1). The apex of the piston’s upswing corresponds to midstance, where one leg (the right) is fully supporting the body (2). At the same moment, an opposing piston must be in the lowest point of its downswing in order to balance the mechanism.

Piston Mo
By Zephyris – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=10896588

Any problems in the balance of the pistons or the crankshaft can cause something to go horribly wrong. The same goes for the body, in order for its movement to be in balance. As the left leg clears the ground behind the body, the right (opposite) arm must be ready to initiate the upswing. And the right leg should be ready to start reaching for the ground below.

Insofar this is the case, the movement can be said to be contralateral.

Let’s look at the pictures of Mo again (taken as he is sprinting down the final stretch of his gold-medal performance in the 10,000 meter event of the 2012 Olympics). As you can see from the right arm in (1) and the left arm in (2), both pictures are taken at the same moment in gait (from the frame of reference of the arms).

MO Mo

By comparing both pictures you can see a bit more flexion in early stance for the left leg (1), than for the right leg (2). At this moment in gait, the right leg trails further behind the body (1) than the left leg. (The left calf (1) is also at a larger angle than the right (2).) Without getting too far into the mechanical details, it would seem that Mo’s having a little bit more trouble stepping forward with the right leg than with the left.

In effect, in picture (1) his left leg is flexed because it’s waiting for the trailing right leg to catch up. And if you look at the orientation of his forearms, you can see that the right elbow (1) is far more flexed than the left (2), mimicking, to almost a perfect degree, the angle of the opposite knee in each of the pictures.

The point is that it wouldn’t matter where you look at the piston system (of an internal combustion engine) from. Whether you observe the piston system from the frame of reference of the piston head, the main axis of the crankshaft, or the counterweights, you would see that the entire system is balanced. Each counterweight remains perfectly opposite to a piston, and the pistons remain perfectly opposite to each other.

This is so important that much of what makes sports cars—particularly “traditional” sports cars like Ferraris—and race cars cost as much as they do is the technology to keep the engine block balanced to the picogram. The better this is accomplished, the more torque can go through the engine without breaking apart the block.

Mo Farah is not some amateur. For the past few years, he has set the highwater mark for excellence in distance running up to the 10,000 meters. And even then there are differences.

Why is this happening? The “big” answer to this question probably isn’t in some esoteric discussion of biomechanics. Quite simply, the 10,000 meters are run on an oval track, and this is the final stretch. For more than 24 laps, he’s been turning into his left leg. It’s probably a lot more tired than his right, so it’s having a harder time supporting his body during stance. (Hence the flexion).

If we asked Mo to keep running for a few more laps (not that he would) we’d find that his right leg would continue to trail a little more, and his left leg would flex even further. If you look at the video you’ll see that even down the final stretch he’s compensating quite well by driving forward with his right shoulder every step.

But as he becomes more tired, we’d see that this strategic compensation stops being enough. We’d probably observe his left foot taking increasingly longer to leave the pronation (flattening) that occurs during the stance phase. The supination (pointing) which occurs towards the end of the stance phase, would come too little, too late, possibly creating a heel whip for the duration of the race.

pronation & supination.png
Pronation and Supination

As this is happening, the huge amount of forces that go into his body as his feet strike the ground will travel through it at increasingly odd angles. There is a potent compounding effect here: The more experienced, fitter, and more rested body aligns itself correctly with the forces of running. The less experienced, less fit, and tired body does not.

For the weekend warrior with the New Year’s resolution, running a marathon is biomechanically a far more hostile experience than it is for the skillful runner. Some people overpronate from the get-go. Others start with a tight hip. Over the course of 40,000 paces, this brings nothing but disaster.

Physics favors the trained runner much like the Greek Gods favored the heroes of mythology, by further increasing their already formidable advantages in battle. The skillful runner already comes into the race with stronger muscles, denser bones, a more resilient nervous system, and a more robust metabolism. As a final reward for their training efforts, the impact forces of running fall into place and work with them, not against.

 

Biological, psychological, and social systems affect our development of speed, power and endurance. Let's discuss them candidly.