The "Core" Of The Matter

You've probably heard this a million times in yoga class. I know that I have. But what exactly is it that we are supposed to be engaging? The elusive “core” is something of an enigma. It’s like the Bigfoot of fitness. A ton of people believe in it, but no one really seems to know what the f*ck it is or where to find the damn thing. It is not only one of modern postural yoga’s biggest clichés, it’s also arguably the least understood principle in the fitness world.

So before we pretend to engage it, we might do well to understand what the core consists of, what its true purpose is, and finally, how to know when we are training it competently.

So let’s begin by debunking the biggest misconception: the core isn’t simply your abdominal muscles. The picture that often springs to mind when we think of the core is a washboard set of abs but it’s high time we send this definition of the ‘six-pack’ packing. While the abs play an important part, they are not the only member in the band; the core is a complex and interconnected series of muscles extending far beyond the abdominal wall, including muscles in your back, around your pelvis, and even includes the diaphragm. Together they function as a synergistic whole, each playing an important role in maintaining stability of the spine, balance of the body, strength to exert and absorb force, and critically important but rarely discussed, providing abdominal pressure.

Unfortunately, this ‘core equals abs’ misconception has created a big imbalance in most garden variety vinyasa classes, at best providing marginal benefit, and at worst, leading to injury due to a lack of diversity in training. If you’re not sure what I mean, let me ask you a question...

When you think about “core-work” in yoga class what comes to mind? I’d be willing to bet that it’s bicycle sit-ups and plank pose. What I like to call the Tiresome Twosome. While these exercises certainly have their purpose and place in any strength regimen, to focus solely on these two exercises as the defacto solution to core strength is a mistake we ignore at our own peril. This is due in part to the fact that these exercises primarily target what are called global muscles. More on that in a moment. The danger of this one-dimensional approach to core strength is the creation of muscular imbalances which can lead to pain and injury. Overworking one set of muscles while neglecting others can never provide the well-rounded strength and stability that a healthy core requires.

To draw an analogy, think of the body as a bustling city, and the core as the intricate network of highways, streets and boulevards that keep the city moving. Just like a city depends on infrastructure to move, well… everything, the core is involved in virtually every movement of the body. Depending on the anatomical source you’re referencing, the definition of core may include more or fewer muscles. Some definitions of the core include all muscles that attach to the vertebrae. Others stick to only the deep abdominal muscles like the transverse abdominis. In short, there is no reliable consensus on which list of muscles constitutes “core.” So let’s re-frame the argument…

Think Global and Local

To truly understand the core, we need to understand the distinction between global and local muscles. Global muscles are typically long, powerful prime movers like the rectus abdominus, erector spinae or psoas major. These muscles produce significant torque and are responsible for substantial movement. Think of these muscles as the highway system of our busy city.

Local muscles are typically shorter, attach directly to the vertebrae, and focus on spinal stability. They include the transverse abdominis, the quadratus lumborum, and the multifidus. These muscles are the streets, cut-de-sacs and alleyways of our city, providing essential support to every address in the city.

Just as a city can’t function with only highways and no local streets (or vice-versa), our bodies can’t optimally perform without a balance of strength and stability. A well-considered strategy for core development should therefore provide more than a boost in athletic performance and abs so sharply defined that you could grate cheese on them. It should at a minimum improve balance and stability, reduce risk of injury, correct postural deficits, and by extension, increase breathing power and efficiency.

Typical yoga class today often place too heavy of an emphasis on the Tiresome Twosome and their saltine cracker variations to increase core strength. Exclusive focus on them is like designing a city with only highways. To remedy this requires the strength and coordination of local as well as global muscles. And never forget to add the tried and true spice of life: variety! This helps keep muscles on their toes and boredom at bay.

Forget the core. Engage your canister.

Now let’s address a significant insight that fitness and healthcare industries (including yoga) often overlook- the role of abdominal pressure in core stability. Time for a new analogy! Imagine a cold, refreshing can of Coors beer...

(I grew up in Golden Colorado so suck it you craft-brew quaffing millennials!)

Set a fifty pound kettle bell on top of an unopened Coors can and do you know what you got? A kettle bell sitting on a can of beer.

Now, pop the tab on that delicious, frosty, thirst quenching can of Golden goodness and place a fifty pound kettle bell on top of it. Know what you got now? A kettle bell on a crushed can of wasted beer.

Hopefully this visualization helps to wrap our heads around the core ‘canister’ concept. Just as a filled and sealed can of beer is stable due to its internal pressure, our core gains stability from the intra-abdominal pressure maintained by the diaphragm at the top, the muscles of the pelvic floor at the bottom, and the abdominal, oblique and back muscles forming the sides. Picture your spine glued to the inside wall of your bodies “beer can” and hopefully the importance of internal pressure will come into immediate focus.

At this point you may be thinking, “WAIT. Aren’t I supposed to breath? How am I supposed to be a sealed can of beer and breath and stuff?”

Inside this question lies the core of “core” understanding. You see, unlike most other muscles of the body which perform a single function, many of our core muscles designed to stabilize the spine also do double duty as respiratory muscles. But as the saying goes, this a feature, not a bug. Breathing and core stabilization are intimately connected by design. That is why the forefathers of the vinyasa practice we enjoy today were so big on breath matching movement.

But then you may ask, “what is proper breathing Scott?” Great question, let’s keep the answer simple. Although it’s helpful to remember that a can beer is filled from bottom to top, air is not subject to gravity. Therefore, we want to practice what is called three dimensional breathing: the ability to fill the lungs in every direction. Up and down, from the center to the side bodies, and from the center to the front and back. Filling slowly through the nose, emptying through the nose. (The slower and longer your exhale, the more you will feel the trunk muscles activate)

During inhalation, the diaphragm contracts and moves downward, expanding the chest cavity and creating a vacuum that draws air into the lungs. As the diaphragm descends, it also pushes down on the abdominal organs, causing the abdominal cavity to expand. This expansion creates an increase in intra-abdominal pressure.

Simultaneously, the deep abdominal muscles, including the transverse abdominis, obliques, and pelvic floor muscles, also contribute to abdominal pressure. These muscles act as a corset around the abdomen, providing stability and support to the spine. Think of this as an internal weight belt.

Proper breathing coordination involves synchronizing the diaphragm's descent with the activation of the deep abdominal muscles. As you inhale, the diaphragm descends, and the abdominal muscles should engage to control the expansion of the abdomen and maintain stability. This coordinated action optimizes the generation of intra-abdominal pressure, providing a solid foundation for spinal support and overall core stability.

Balance Breathe Brace

As we have seen, while the Tiresome Twosome can help us develop muscular endurance and strength, they do not necessarily promote core stability. Plank pose primarily targets the rectus abdominis and erectors. Bicycle sit-ups focus on the rectus abdominis (again) and obliques. What they have in common is an inadequate ability to activate the deeper local muscles which are critical in real world situations.

A truly strong, stable core must be able to respond dynamically and reflexively to a multitude of movement challenges like running, lifting a heavy object or maintaining balance after an awkward mis-step. These demands are not just about static endurance (like plank) or repetitive, unloaded movement (like bicycle sit-ups), both of which can be done with little attention to form or breath.

Developing core stability for real world living begins by mimicking the unstable and un-aligned demands of real world living. The best way to achieve this is not through isolated exercise alone. Nor does it depend on being on a yoga mat or a machine at the gym. Remember, true core stability is not just about strength, but our ability to coordinate and control it when it matters most- in life.

That’s why you might be surprised to find out that the best place to improve core stability is the one place most humans spend the least amount of time: on our feet! When we are upright and moving, we are using the body as it was designed through evolution to function.

A study by Behm et al. (2010) entitled "The use of instability to train the core musculature" highlights the importance of exercises that mimic real-life, functional movements in enhancing core stability. The study emphasized that training that includes performing standing exercises (which introduces instability similar to what we would experience in our daily activities) can more effectively improve core stability than exercises performed in stable conditions (like sit-ups or planks).

Another study conducted by McGill, S.M. et al. (2009) entitled "Core Training: Evidence Translating to Better Performance and Injury Prevention" stated that functional core training should involve standing exercises, as they challenge core stability in ways that are closer to the demands of everyday life and sport.

Finally, the multi-planar challenge of standing exercises is described in a review by Borghuis, J. et al. (2008) in "The Importance of Sensory-Motor Control in Providing Core Stability". This study describes how core stability is not just about strength, but about control in multiple planes of motion.

Ultimately, these scientific insights suggest that we do ourselves no favors by being a thick, strong tree trunk if we don’t have sh*t to speak of when it comes to roots. Roots are our stability, and the “root” of foot-to-core strength. Roots are what keep a tree from toppling during heavy wind. Roots are what allow the tree to extend mighty branches in every direction. Oh, and we also mustn’t forget, trees breathe.

I don’t know about you, but I think it’s high time to shed our need to be shredded and take ‘core’ off the floor. And we don’t need a six-pack so much as we could use one good canister, and we gain that by balancing breath with function. Cultivating stability by breathing through the lack of it. Finding power by searching for poise. In short, replacing the words “engage your core” with three more useful ones.

Balance, breath, brace. And that, dear punks, is the core of the matter.