Core Training- Refocused

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