Updated: May 14, 2020
I cannot even begin to count how many times I’ve been working with someone for an extended period of time only to one day randomly be hit with the inevitable “so… when are we gonna do some more ab stuff?” Early on for me, this was an incredibly irritating conversation to have. I was almost annoyed, or even a bit offended that I was getting this question having known that core training was heavily sampled in our workouts. But as I’ve grown, it actually creates more of a sense of inadequacy on my behalf than anything else. Almost as if I’ve failed them as a coach, and not because I haven’t been utilizing the right exercises, but because I haven’t properly explained this to them ahead of time. That, in my opinion, is simply unacceptable from a coaching standpoint, and that is not only relegated to this specific topic. Your athletes should always be informed before they’re asked to execute, period.
If I asked you how many muscles make up “the core”, how many would you say? 8? 15? 40...!?
Well, the answer you get would simply depend on the person you ask. If you were to ask your typical fitness enthusiast, you’d probably get an answer somewhere around 8. Ask a sport scientist or anatomist, and you’ll likely get an answer closer to 40. If you ask me, I would say there are somewhere around 15 muscles that make up the core. And for the record, if you’re one of those whose answer is around 40, please don’t waste your time reading the remainder of this article, as I assuredly don’t have anything beneficial to offer you.
For some reason unbeknownst to me, despite the countless positive steps we’ve taken over the last several decades in strength & conditioning, we somehow can’t seem to find much common ground on what exactly constitutes the “core” or how to adequately train this region. I don’t want to spend too much time on semantics, but it is quite remarkable that there is still so much debate over one of the most fundamental regions of the body. From the specific landmarks, or muscles, that should be included under the core umbrella, to the proper ways to train the core, a lot of coaches by in large still seem to be at odds with this. This topic stretches far beyond coaches bickering about proper core training, though, as the real trouble resides in our clients/athlete’s comprehension of what constitutes core training. So, let’s begin with what I feel is a fair definition of what the core exactly is.
I define a core muscle as a muscle that directly acts on (or attaches to) either the thoracic or lumbar spine, the pelvic girdle, or the rib cage. In my view, the core encompasses everything muscularly, between the sternum to the hips. And this, of course, includes muscles anteriorly, posteriorly and laterally. By using that as my definition, I came up with a list of 15 muscles that meet this criterion. So, for the sake of this article, we’ll roll with that as our baseline. Depending on your level of knowledge with anatomy/kinesiology, you may catch that I did not include a few muscles that technically meet this definition, however, I ask that you bear in mind that this is written for the perspective of strength and conditioning, so I wanted to focus on muscles that are reasonably trainable. Moreover, the purpose of this article is not to take a shit on whatever core training you’ve undertaken in your past or may currently be doing. However, I do intend to broaden your understanding of what the core really is, along with expanding your spectrum of training implements and modalities. That all being said, in this article I would like to cover three concepts pertaining to core training: (1) Anatomically observe the muscles that collectively make up the core, (2) examine the biomechanics of the core, and (3) provide an overview of my staples for core training.
Anatomically Defining the Core:
Let’s start simple. The muscles that make up the core extend far beyond the abdominals, and the muscular actions of the core, contrary to popular belief, are not relegated to just flexion/extension. But before we expand on the muscular actions, let’s go through the anatomy first. As we’ve already discussed, when most think of the core the thinking starts and ends with the abs. Now, make no mistake about it, I get it. No matter how frustrating it may be as a coach, I’ll never expect one of my athletes to come in the gym and say, “hey coach, can we hit some internal obliques and erectors today?!” I’m well aware that the “show” muscles will always dominate the interest of athletes. But again, a part of this article is recognizing the importance and value of informing our athletes, not just providing the best training possible.
If you were surprised by my number of 15 core muscles, what’s really going to throw you for a loop is that of the 15, only five (and really only two) are included under front-side of the body. So yes, about 65% of your core muscles are found elsewhere than the front side of the body. The chart below depicts a categorical breakdown of core muscles based on anatomical location. Broadly speaking, anterior muscles act as flexors, lateral flexors (and stabilizers) fall into lateral core, and extensors were placed in the posterior group:
**Disclaimer(s): I did not categorize the diaphragm, as it does not directly contribute to a muscular action beyond inhalation and exhalation. Also, I did not include pelvic floor muscles because I didn’t want to completely lose people on the point of focus.
Hopefully that chart helps to get my point across, but by now you should understand what I’m starting to get at here- there is a hell of a lot more going on with the core than just chiseling the six-pack. Next, with the invaluable assistance of Anatomy Atlas, let’s take a closer look at these some of these muscles. Take particular note of the origin and insertion for these muscles.
1.) Rectus & Transverse Abdominis (anterior)
2.) Internal & External Oblique (lateral)
3.) Quadratus Lumborum (posterior)
4.) Multifidus (posterior)
5.) Psoas Major & Minor (anterior)
6.) Iliocostalis Lumborum (lateral)
7.) Spinalis Thoracis (posterior)
Examining Core Biomechanics:
Now that we’ve taken a look at the anatomy, let’s put these muscles into action. Recall that we have three conventional planes of movement- sagittal, frontal and transverse planes. Sagittal plane refers to “front-to-back” movements (i.e. walking, lunging, sit-ups), frontal plane refers to “side-to-side” movements and transverse refers to rotational-based movements. Although this concept is fairly well understood, what is less commonplace, is viewing human movement from six degrees of freedom. If that doesn’t make sense, take a look at the images below:
The key takeaway here is that we have multiple planes of movement, but when it comes to exercise programming and selection, we often relegate ourselves to just the three conventional planes. Think about damn near any athletic movement- swinging a baseball bat, throwing a football, swimming, shooting a basketball. I can go on and on, but when you analyze movement a little more closely, you begin to see that although one plane may be the dominant path of motion, there is really movement occurring in multiple planes almost all the time. Thus, it’s important that this is reflective in our training. I divide core training into four main categories, as outlined below. Generally speaking, I don’t place more or less emphasis on one of the four. There are the obvious cases where someone is living in constant excessive lumbar extension (lordotic posture), in which I would place an emphasis on flexion-based and anti-extension-based movements. But let’s not get side-tracked with specific examples and speak more to the generalities here.
We should all be familiar with flexion and extension patterns, but people are often confused by the “anti” movements (i.e. anti-flexion, anti-extension), so here’s about as simple as I can make it. Think of the steel suspension cables and the support beams beneath that hold a bridge in place. Now think of someone performing a traditional plank. When in the plank position, the erectors (primarily) act as anti-flexors, because they resist us folding into flexion (ass hiking up to the sky) by contracting. Conversely, abs act as anti-extensors because they prevent us from falling into extension (hips sagging to the ground) by contracting. This occurs in a similar fashion with the bridge- the steel cables (anti-extensors) support the bridge from above, while the beams (anti-flexors) prevent the bridge from folding in on itself. In a nut shell, flexors are synonymous with anti-extensors and extensors are synonymous with anti-flexors.
Before I breakdown some of the exercises listed above, here are my basic “rules” associated with core training, assuming that there are no medical or biomechanical stipulations to govern otherwise.
1.) Carry things, carry them often, carry heavy things, carry them in different ways
-According to multiple EMG studies, no exercise elicits greater rectus & transverse abdominis activation than heavy farmers carries. Now, I know EMG activation isn’t the end all be all, but it does provide reasonably objective validity that makes it difficult to argue against.
-Everyone, literally, should perform some kind of carry variations in their training.
-Carry variations possess flexion/extension, anti-flexion/extension, and even anti-rotation qualities. This is about as good as it gets when you think “bang for your buck”
2.) If you spend most of your day standing, use a 2:1 flexion:extension ratio
-Don’t overcomplicate things when you don’t need to. It’s really this simple, whatever your day-to-day looks like (athletic population or otherwise) should be complimented in your training.
-Standing throughout the day puts you at a greater risk for developing a hyper-lordotic resting posture (excessive arching in low back), which is also creates susceptibility for anterior pelvic tilt, which can lead to hip impingement among other unwanted issues. These are corrected by an emphasis on flexion-based movements.
3.) If you spend most of your day sitting, use a 2:1 extension:flexion ratio
-The same concept here as point #2, but in the opposite manner.
-Sitting for the bulk of your day increases the likelihood of developing what is known as a kyphotic posture, where the shoulders and upper back round forward.
-Over time, this weakens the lower back muscles, and shortens (or tightens) the front side core muscles. So, solution for this is to put an emphasis on extension-based movements.
4.) Everyone needs to rotate
-Based on biological demand, we are constantly reliant on anti-rotation.
-With each step of our gait cycle, our core’s responsibility is to resist the lateral (or rotational) momentum created by each step. Therefore, it should be something we take into consideration with training. People often misconstrue “rotational training” as something reserved for athletes, this is untrue and shortsighted.
-Another point to consider, is the “weakest link in the chain” principle. Meaning, if we neglect our necessity to rotate/resist rotation, the muscles naturally responsible for flexion/extension will start to take over for a weak lateral core. By doing so, we’re increasing our risk for a bevy of other issues.
5.) Variety is everything
-For some, designated core training can be a bit tedious or even “wasteful” similar to stretching and mobilizing.
-Get creative with what you do, whether you’re a coach working with athletes, or just in your own training, try new things.
-Do the same fundamental exercises with slightly different angles, different lever lengths, different exercise equipment. Keep things tasteful so they stay in the fold of your training.
-Train core muscles synergistically. Meaning, don’t feel like you need to only train one movement or motion at a time. Find ways to blend flexion/rotation, extension/anti-rotation, etc.
My Top 5 Core Exercises (if I were forced to list them):
1.) Hollow-Body Holds (Anterior core/Flexion-Based)
I’ll come right out of the gate and say it- I am not a fan of sit-ups, or even crunches really, at all. In my opinion, sit-ups/crunches are about as low as you can get when analyzing “risk-reward” and/or “bang for your buck”. This becomes even more true when we’re considering a non-athletic population because most people spend the majority of their day in flexion anyhow. If you breakdown the biomechanics of a sit-up, you’ll quickly notice that this is a horrible exercise for flexion-based individuals, as sit-ups put a great deal of strain the hip flexors and low back (i.e. most peoples “problem areas”). Moreover, by putting unnecessary strain on a damaged area, we’re also mitigating the (little) redeemable value sit-ups offer to begin with.
Insert the hollow-body, which can be performed isometrically, dynamically, and in numerous other ways once proficient. If you take a look at the video, notice the position of the spine and the angle of the torso. We’re getting even better anterior core activation than we would with a sit-up, without jeopardizing the spine or pissing off the hip flexors. In my opinion, this should totally replace any sit-up or crunch variations you’ve been doing.
2.) Deadbugs (Anterior core/flexion & anti-extension-based)
I simply can’t write on the deadbug without shouting out my man Vern (Twitter/Instagram: @vernongriffith4). Vern has unintentionally become known as “the deadbug guy” in select S&C circles and it’s been awesome for me to see him progress the deadbug along the way. I can’t even begin to name off the hundreds of variations he’s come up with, but seriously, just spend 5 minutes on his social media pages and you’ll have deadbug options to get you through to next year.
But let’s talk about the benefits and applications of even the most fundamental deadbug variation. At its root, we are getting anterior flexion, and contrary to the sit-up, although we are working the psoas with the deadbug, it’s not in a state of constant isometric flexion. Rather, we are getting good lengthening without loading. This is an absolute must for just about anybody to have in their training rotation. The deadbug also works very well as a warm-up or “prehab” exercise on lower-body days. The additional benefit to the deadbug is the element of general motor control, which is often the most challenging aspect for most.
3.) Farmers Carry Variations (anti…. everything?)
So, where Vern is the king of the deadbug, I like to think I explore carry variations in a similar fashion. Ask any strength coach worth a shit about carries, and you’ll quickly realize this is another one that should be an absolute staple in just about anyone’s programming. I don’t have nearly enough time to explore carries in full scope in this article but allow me to touch on the main points.
It’s difficult to categorize carry variations, similar to a plank, because in reality we’re getting a little bit of everything. Not falling on your face= anti-flexion, not falling back and getting concussed= anti-extension. In all seriousness, though, we’re getting an anti-everything effect, including anti-rotation. As I mentioned above, according to EMG studies, no exercise elicits a greater effect on abdominal activation either. For now, just take me for my word on this one- carry heavy shit, carry it often, and carry it in different ways.
4.) Palloff Presses (Lateral core/anti-rotation & flexion-based)
Palloff presses are probably the most fundamental anti-rotation exercise I can come up with, maybe with the exception of a side plank. Nevertheless, this is another where even the most basic variation offers tremendous redeemable value, and on top of that, Palloff presses can be progressed in a myriad of ways.
Positioning is critical on Palloff’s to get the full effect. Take note of the posture in the video above- rigid vertical spine/torso, keeping a neutral head, 90 degree angles at the hip/knee/ankle on both legs, and (if standing) keeping soft knees (do not lock knees out, as this propagates excessive lumbar extension). As we press the band out, we’re resisting rotating towards the band by engaging anterior and lateral core muscles. Palloff presses can be done standing, tall-kneeling, half-kneeling (shown above), or in a single-leg fashion.
5.) Band Anti-Movement (Everything-based)
Band “anti-movement” is another phenomenal exercise I wish I could take credit for, but I stole this directly from Vern. An important caveat that I want to mention and is fitting with this exercise is the importance of training the core muscles synergistically. It's important to recognize that no muscle works in isolation, unless you’re a body builder, I guess. But this is especially true when it comes to core muscles, and the band anti-movement is an excellent way to truly feel this in action.
The objective of this exercise is simple- you try to be a statue while someone violently moves the band in random, unplanned directions. By “keeping the body like a statue”, we’re getting a ton of global activation, and forcing the smaller stabilizing muscles to activate. Similar to the exercises listed above, this can be done in a multitude of ways. I will use this in a tall-kneeling and ½ kneeling position, standing bilaterally and from the split position.
I hope that this was helpful to provide some clarity and insight to your core training. Again, the purpose of this article was not to take a shit on conventional or even popularized core exercises. But the more people that I continue to work with, and the more I venture outside of the status quo with core training, the more I can assure you that this approach will lead you down the right path. No matter what you do, or what you train for, it cannot be overstated enough that your success will be governed by the strength of your core muscles.
*NOTE: All anatomy images were extracted from the Anatomy Atlas app. Biomechanics images were extracted from Human Kinetics.