The Balanced Runner Keys Series: Core Stability and Running–Get Your Core in Action!

If you’ve given even a moment’s thought to your running form in the past two decades, it was probably either to your footstrike or to your core.  My previous two posts in this series on The Balanced Runner Keys addressed the issue of footstrike; now it’s time to talk about core stability and running.

The conventional wisdom of this era is that core stability is critical for runners. The Oxford English Dictionary defines core stability this way:

The capacity of the muscles of the torso to assist in the maintenance of good posture, balance, etc., especially during movement…

However in my experience most runners and even some fitness/movement/coaching professionals interpret “stable” to mean “still.” (If you are a professional who doesn’t make this error, good for you! I know there are many out there, so please don’t take this personally.)

The muscle groups involved in core stability all control movement of the pelvis.

Notice in the image above that all the muscle groups involved in core stability connect to the pelvis. Any time the pelvis moves, the abdominal region moves, so I’m going to use the two interchangeably for this post.

What the Core Really Does

In my training to become a Feldenkrais practitioner I learned about the fundamental necessity for the pelvis to move to accomplish any well-coordinated action. This includes walking and running.

Once you can clearly feel and see the pelvis moving it becomes difficult to imagine not being aware of it. However, the current preoccupation with core stability has hidden this movement in plain sight.

We are generally unable to hold the pelvis entirely still when moving but we can substantially interfere with the movement, making it smaller, timing it poorly, and restricting it in specific directions. In addition, any injury that makes it uncomfortable to walk or run will cause you to alter how you move your pelvis to avoid putting weight on the painful side, and you’ll tend to continue using this movement pattern long after you’ve healed, thus interfering with healthy, comfortable, and enjoyable running.

Why is it necessary to move your pelvis? Because we have two legs (usually) and neither is in the middle, so if you want to balance first on one leg, then on the other, you will have to change the shape of your trunk to enable you to shift your weight and keep from falling over.

Remember how those “posable” action figures or barbie dolls you played with as a child were almost impossible to stand upright? Usually there was just one arrangement of limbs that would allow them to balance, and any other one resulted in a tumble. That’s because they couldn’t shift their pelvises (and in fact entire torso and head) to balance on different arrangements of legs.

In 2014 I realized runners needed a term to describe the movements of the pelvis and the action of the core involved in the counterrotation of pelvis and ribcage so we could stop using the misleading term “core stability.” So I coined the term “core action” to give us all a simple way to refer to the function of the core in running and allow us to focus on optimizing it rather than restricting it.

The Evidence for Core Action

Now what about the evidence that core stability in running is really about movement rather than restriction? In this study, researchers looked at the movements of volunteers’ lumbar spines and pelvises in walking and running at different speeds.  They found that they moved in all three planes of motion, and furthermore:

“…there is a strong correlation between the amplitude of transverse plane lumbo-pelvic rotation and stride length during walking and running.”

In other words, to increase your stride length you turn your pelvis more. Since each person has a preferred stride rate which they stick to regardless of speed, the difference between one running speed and another for you will be your stride length. If you’re working hard to prevent your pelvis from rotating when you run, you will be restricting your stride length and thus limiting your top speed.

So that’s a pretty concrete reason why transverse plane movement (or rotation) benefits you. How about the frontal plane?

Movement of the pelvis in the frontal plane, meaning if you’re facing yourself in a mirror you’ll see your pelvis tip side-to-side like a seesaw, is part of your spring system. Between footstrike and midstance your free hip (the side of your swing leg) sinks, causing that side of your waist to stretch and your stance side to compress. Through late stance towards toe-off this reverses so that your swing hip begins to lift upwards and the stance hip pushes downwards, directing force into the ground. In tandem with the straightening of your leg, this raises your center of gravity and moves you towards flight.

Here is a video of me walking on my butt to demonstrate the kind of movement your pelvis makes in running. Note that the size of the movement is not necessarily the same as in running.

Here’s a video of me running in a gait lab, demonstrating and explaining the elements of the pelvis movement in running.

How does your core action stack up against this video? In this blog post I help you evaluate the indicators that your core is too stable.

How to Get Your Core into Action

These movements of your core should not be done intentionally when you run, and definitely not forced in any way, but should be allowed to occur and be regulated spontaneously by your nervous system as needed for your speed, effort, fatigue, terrain, etc. in any given moment.

You also should not try to improve how you do these movements by trying to restrict anything, and especially not by trying to prevent your pelvis from tipping forward. As the study I linked to earlier showed, the pelvis also has to move in the sagittal plane, and furthermore the muscles that you would use to try to make your pelvis more upright are also muscles that need to work to create movement. They can’t hold and move at the same time, and especially not when you’re trying to control these actions consciously.

However you can optimize your ability to supply these movements by doing core training and movement learning experiences (a.k.a. Feldenkrais lessons) that help you feel how to coordinate them better. In over twenty years of experience helping runners from beginner to Olympian, I have found this is the most important thing you can do to improve your running.

Here are some of the key effects:

  1. Because it uses both the flexors and extensors to perform, this action of your core balances the effort in those muscle groups and thereby regulates your footstrike, preventing you from landing with an exaggerated heel or forefoot strike or overstriding excessively.
  2. Because it shifts your weight properly from leg to leg, it helps increase the support and power you get from your legs, improving your speed.
  3. Because it allows you to shift your weight to wherever your legs need to be (within reason) it improves your versatility and especially your ability to run on uneven terrain such as trails.
  4. It also makes your running at least subjectively more economical by reducing the efforts you make to fight yourself.
  5. For all the above reasons, it generally makes you feel fluid, free, and fantastic when you run.

To dive even deeper into the core action and its ramifications check out my entire YouTube playlist on the topic:

When I use Feldenkrais lessons in workshops to help runners feel how to move their core better they tend to PR in their next race.

I’m not kidding, it’s that powerful.

So forget about core stability and running, and get your core into action instead! This free mini-course will help you start learning how.

15 thoughts on “The Balanced Runner Keys Series: Core Stability and Running–Get Your Core in Action!”

  1. “… any injury that makes it uncomfortable to walk or run will cause you to alter how you move your pelvis to avoid putting weight on the painful side, and we tend to continue using this movement pattern long after we have healed, thus interfering with healthy, comfortable, and enjoyable running.” <–that's me!

    Have just found your website and this post spoke to me quite a bit. I got a total hip replacement 16 months ago but had lived with the hip arthritis for 3+ years before that, and tried to continue running and walking through the pain (I was in denial!). Not recommended! The surgery fixed the hip and I have since resumed running and full activity, but am finding lingering issues with running habits formed while trying to avoid pain, and am now having to work through various imbalances one by one. I think more core action will go a long way toward getting back in alignment and will try to be more conscious of that. I was definitely avoiding weighting the painful hip for a long time, and that caused all sorts of messes. Thank you for this article!

  2. Hi, Jae.

    Just wondering what you think about Ken Bob Saxton’s (and a few others’) approach of planting your feet right under the centre of your body as if you’re running along an imaginary line (as opposed to each foot landing further out to the left or right) to avoid too much vertical drop of the free hip. It made sense to me.

    • Hi Chris. I think that idea is a really poor one. The assumption is that a vertical drop of the free hip is a bad thing, but in fact in the right amount it’s a good thing and part of your spring system. The price of running as if on a tightrope is that not only do you lose the ability to have an appropriate hip drop; you also lose the ability to pronate your feet appropriately and use your big toes. It also makes you work harder and slows you down.

      • I totally agree with you Jae. We don’t want to be controlling movement of the pelvis, but letting it go instead – tilting, shifting, hiking, rotating as needed in the cycle.
        The tightrope gait is characteristic of feet stuck in pronation, that therefore cannot access any more, nor supination. Hip extension begins with loading appropriately through the first MPJ and the rotation necessary for good hip extension also begins here.
        These people will often not be able to shift the pelvis well and are often unbalanced.
        Equally, a really wide gait is not helpful either and often indicates an inability to shift weight from side to side or rotate the pelvis to get length in the stride.

        Just came across your site and really impressed. I’m not a Feldenkrais practitioner as such but use some similar approaches in the work I do with runners – focusing on movement first and slowing everything right down to change the brain.

        Great work – keep it up!

  3. “any injury that makes it uncomfortable to walk or run will cause you to alter how you move your pelvis to avoid putting weight on the painful side, and we tend to continue using this movement pattern long after we have healed, thus interfering with healthy, comfortable, and enjoyable running.” <–that's also me.

    I had an ACL reconstruction 10 years ago, and though i have gone back to playing football (soccer) and Martial arts, i keep getting regular injury on the knee. The last was a suspected cartilage tear. After one session of balancing the hip flexors my tight hips have released and i was able to run further pain free this morning. I am hoping when i start playing again in three weeks these issues are sorted. thank you very much for this information.

    • That’s great, Mark! Thanks for taking the time to write and let me know.That sounds like great progress, and I hope you enjoy your return to football. If you do find you’re still having any trouble, we have lots more resources to help you.

  4. Hi Jae,

    I am trying to improve my running stance. I always read to have a neutral or slight forward tilt with the pelvis to keep it from going “back” like sitting in a chair. Is this not correct? I can’t image having my bootie sticking out while running, but I need to find a balance so I can improve. I’m trying to find ways to use the glutes more than my quads. Thank you.

  5. A question on this statement: “Since each person has a preferred stride rate which they stick to regardless of speed, the difference between one running speed and another for you will be your stride length.”

    This isn’t entirely correct is it? Speed is a function of both stride rate and stride length and rate varies with speed, doesn’t it and one of the main criticism of running techniques like the Pose Method is that it emphasizes that you should stick to 180 steps per minutes no matter your speed? After soon 20 years of regular running, I tend to have natural stride rate of 172-174 running eight minute mile pace. Running faster however my stride rate increases easily. Running six minute mile pace with stride rate is most often in the 185 range.

    • Thanks for your comments, Staffan. Over the years I’ve seen varying research on this. It’s clear that runners generally accelerate by increasing their stride rate, but then it tends to go down at least somewhat once they’ve established a new speed. The post reflects the best research I’d seen when I originally wrote it, and I didn’t review that research before updating this blog post, but I will go do that now. I also suspect there’s some of variation between runners on whether they prefer to alter stride rate or length to run at different speeds.

      In my own clientele, I’ve found that my competitive runners who track their gait parameters find that their stride rate will often drop a little, at a given speed, especially if they’d been actively working to maintain a high stride rate. However, with this change their speed goes up and their heart rate goes down.

      I think the real question is whether you’re able to organize the movements that would be optimal for you at a given speed. As I said to Dan here in the comments as well, it’s really worth looking at the studies on runners wearing torso casts in the “How to tell if you have too much core stability” blog post, because they demonstrate clearly that restricting core movement sends all gait parameters in a negative direction, and one associated with a shortened stride length. “Shortened” rather than “shorter” because it is shortened from what the runner would otherwise do by the restriction of their core action.

      • Thanks Jae, interesting answer and topic this! My own limited experience is not that I just use stride for acceleration but maybe it goes down a bit, I don’t know.

        For me personally after completing the Balanced Runner online camp and another pretty extensive, pretty detailed and well known online running technique course here in Sweden, I feel that I have a whole new toolbox when it comes to running form and making changes and feeling the effects of them. It’s made running more holistic and often more fluid and harmonius, but not really less hard and pulse is about the same as it’s always been.

        In the past I was a runner that focussed pretty much on maintaining a given speed by maintaining a high stride/turn-over of my legs. Now it’s like I’ve got another method to run also, more utilizing the power that comes from my armswing and shoulder motion, my core action and “hooking my hip up” (expression from the Swedish course) above my feet in midstance allowing my hip to move up/down and also front/back (“Kayak hip” is another expression from this course referring to the name of the padle used to drive the kayak forward).

        This has resulted in my cadence being a bit lower as compared to the past, and I think perhaps my stride length a bit longer but I have no evidence for this.

        However, it’s also like I don’t really know sometimes which method to use and sometimes it’s like I feel I was a better, faster, more efficient runner a couple of years ago, just focussing on the cadence, although all my new tools should make me more efficient with more power hitting the ground etc. Results-wise, I haven’t really achieved my usual level for a couple of years, although I am still a decent competetively masters runner, although my training is the same. But that may also be the problem, that my training is the same and that I’m just started to experience some age deterioration at the age of 52, I don’t know. I think it’s very difficult to evaluate the role of running technique here, but hopefully it’s not that important after all. I’m inury free as always and able to enjoy running about five times a week, and at the end of the day, that’s a gift and not something I can take for granted.

  6. Great post! I do think the part about stride length is missing something (depending upon how you define stride length). If I hit the ground harder I will travel further in the air. The distance between landings will be greater even if I fail to increase the rotation of the pelvis. Your comments would be appreciated.

    • The devil is in the details on that one, Dan. If you look at my blog post on how to tell if you have too much core stability ( you’ll see that I discuss a series of 3 studies where researchers measured gait parameters, muscle activity, and oxygen consumption of a group of runners both with and without a cast on the torso to restrict core movement. The results are very clear: the increase in impact that the runners show when casted is followed by less–not more!–forwards acceleration and vertical oscillation. Their stride time and swing time went down (indicating shorter stride length) and their oxygen consumption went up (showing they were working harder). So to say that runners with restricted core action did not benefit from hitting the ground harder is putting it mildly. And that’s with approximately a 50% restriction in core movement–not 100%!

  7. The referenced studies are very interesting. I think the sample sizes are small, but they are of the type of work needed in movement research. They certainly do support the approach you have taken in running, and the importance of pelvic movement which seems to be at the center of Feldenkrais’s work. Thanks for your response.


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