Tag Archives: endurance

The Runner's Catch-22, Thinking in Systems

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

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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.”

Principles of Training, The Runner's Catch-22, Training Ideas

The Runner’s Catch-22, Part 1

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I’m calling this series of posts “The Runner’s Catch-22” to address a very common problem in the running world. A lot of beginner runners—let’s face it—want to run long. Very long. But in attempting to do that, they get ill, injured, or overtrained. And their hopes of running long (and doing so consistently) get quashed.

Running isn’t just about running (as every injured runner knows). It’s about how to run well. But in all sports—in fact, in all movement—there’s a minimum power requirement that must be met: if you want to stand (correctly), your legs, along with your core and spine, have to be able to move into a standing position and be strong enough to support you. If you want to walk (well), your leg joints have to be able to flex and extend to a certain degree, and one leg has to be able to support more than your bodyweight while the other travels through the air. And if you want to run (properly) you have to be able to meet an even more demanding set of requirements. And this is where the story of the “Runner’s Catch-22” really begins.

A lot of things have to be working well for a runner to be powerful—form and movement are vital, for example. Having proper form feeds into your ability to produce power (in the same way that it would work for a weightlifter or a baseball player). So with poor form, you might never be able to meet the power requirement—or go significantly beyond it. So, what is this power requirement?

The body must be able to produce a habitual cadence in the ballpark of 180 steps per minute (spm). 

The body is most efficient at around 180 spm: this is the cadence that best engages the tendons’ elastic component, maximizing the amount of energy that can be taken from the previous step put into the next one. (This is a concept also known as energy return).

UPDATE: For people who are new to running (particularly those who only started being active as adults), meeting that power requirement usually requires a lot of power training, which is a problem for beginners. Experienced runners often are able to produce a cadence of 180 spm easily and habitually, for runs of any distance. (In fact, hitting 180 easily is how I would define “experienced.”) If that’s you, most of this post won’t apply to you.

Power training uses and develops the body’s anaerobic system, which is very powerful, but also produces negative by-products that, in large quantities, are ruinous to the body’s tissues. The anaerobic system is counterbalanced by the aerobic system, which disposes of those harmful by-products and allows the body to remain in activity for long periods of time.

So if you want to be able to train without trashing your body, you need a powerful aerobic system to support the anaerobic system. Just one little problem: while the anaerobic (powerful but dirty) system grows extremely quickly, the aerobic (less powerful but clean) system grows veeery sloooowly.

This is the runner’s Catch-22: Until you have a well-trained aerobic system, it is almost impossible to safely do large amounts of anaerobic training. Trying usually means burnout, illness, injury, or overtraining. But if you can’t do a lot of anaerobic training, you can’t develop power to the point that you can produce an efficient cadence (of 180 spm) at the kinds of low intensities where you can develop the aerobic system.

The wrong move—the one that so many runners take—is to lower their cadence to run more distance. Why? Because they’re set on running, or because they don’t know that there’s better ways to train the aerobic system when you’re not powerful enough to ballpark 180 spm:

  • Cycling/Spinning
  • Walking
  • Rowing

(I’d add bodyweight circuit training to this list, but it’s typically far more aerobically demanding than running would be.)

It’s important to realize that the other option—running at an inefficient cadence while the aerobic system develops—is NOT a neutral, “eh, screw it,” kind of option. It’s not very bad—the aerobic system will probably still develop in time—but it’s not the fastest way to train, and certainly not the best way to guarantee you’ll achieve your goal.

(There’s ways to produce a cadence of 180 at slower speeds, such as shortening your stride. But that opens another can of worms—to be featured in another post of this series.)

Learning a movement pattern the wrong-slash-less powerful way—yes, they really are the same thing—is the best (and probably least-discussed) way to prevent you from performing at a high level. If you learn how to throw a ball by releasing it far forward of your body instead of at ear level, you’ll very quickly plateau in terms of how much force you are able to put into it (meaning that you’ll never throw at 60 mph, let alone 90).

Your body develops through movement. If you don’t move, you don’t use your muscles, which means that your metabolism doesn’t develop.  If you can’t throw a ball faster than 60 mph (because of poor mechanics), your muscles won’t be able to grow in strength beyond what it takes to throw the ball at 60 mph. So your metabolism (aerobic or anaerobic) will never need to grow beyond that.

It’s impossible for your metabolism to grow to be able to produce an energy expenditure that you don’t have the biomechanic possibilities to harness.

Slow or low-cadence running isn’t a death sentence. Slow runners with relatively few biomechanical problems or muscle imbalances do increase their cadence and low-level strength by slow running . . . in time. So it’s often the case that people do end up running much faster and at a much higher cadence after a few months (or years) of slow running. But your power (and your cadence) won’t improve with slow running as fast as it could with actual power and cadence training.

How to get around the Catch-22? Below is the short answer. (The long answer will take a few posts).

  • An overwhelming amount of aerobic training (in sports where you can meet the power requirement).
  • A small amount of running-specific power training (mostly plyometrics).
  • A small amount of running at a cadence in the ballpark of 180 spm.
  • Monitor metrics including HRV (heart rate variability) and MAF (Maximum Aerobic Function) Test to determine your short- and long-term physiological readiness for power training.
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.