Crunches, Russian Twists, and a Plank for 30s. If I get these done at the end of every workout I’ll get a strong core, right?

Unfortunately, that might not be the case. Let me first describe what I mean when I say ‘core.’ I am admittedly being non-inclusive with my definition. I am solely talking about the muscles of the anterior abdominal wall. Or, the muscles in the front of your abdomen. These muscles include the rectus abdominis (6-pack muscle), internal oblique, external oblique, and the transversus abdominis.  

All of these muscles have important actions. Their main purpose might seem simple; however, it gets a little more complex once you dive deeper. When we look at the typical core routine, we see a lot of bending the spine up from a lying position, as in a crunch. This is called trunk flexion. We also see a lot of rotation in this flexed position, as in a Russian twist. I do not mean to disregard these exercises as being a waste of time in developing a strong core. There are many ways to achieve this goal.

Before I continue, I would like to note the main function of the core muscles. Based on the direction that each of these muscles go, their individual thicknesses, as well as other factors, the core muscles primary goal is to flex and rotate your trunk, stabilize your lower back and pelvis, compress the abdomen, and hold a neutral lumbar spine. All of these actions are designed to improve posture, reduce unnecessary force on your lower back, brace your pelvis and spine to protect them from injury, and allow other musculature to perform optimally.

The core musculature is designed to flex the trunk,. But, it’s main goal isn’t to bring us from lying to seated. Although that is one of it's main functions. The other primary core function is to try to keep our lower back from being overly extended and hold it in a neutral position. Watch me do this Dying Bug drill above. Although it may look like my core isn’t doing much work, if you’ve done a Dying Bug properly, you’ll know how hard my core is working to keep my lower back from extending. It is flexing, but unlike a crunch, I am flexing isometrically. This means that the distance between the two points that my core muscles attach isn’t changing. I am holding my pelvis neutral and eliminating any unnecessary stress on my lumbar vertebrae and sacral vertebrae in my lower back.

The same applies to any sort of plank position, or as I like to call them, bridges. In this video I am performing a High Plank while doing a high knee. If you look at my lower back, you’ll see it remains neutral even as I drive my knee up. This move requires a lot of isometric flexion torque. I might even argue that it requires more flexion torque than a traditional crunch.

I do not want to forget about rotation, as it is also a crucial role that the obliques (and a minimal role by the transversus) play. You might be thinking that a crunch where you touch your opposite side elbow to your knee would be a great drill. There is rotation and flexion involved and those are good things. Although this is true, I would argue there are better exercises to spend your time on. I prefer to put my athletes in a position where neutral spinal positioning and breathing are paramount while they perform the rotation. Check out this video of me using a medicine ball with my tennis athlete to increase his rotational ability. I split his stance halfway through to change the musculature involved.

After all of this, how do I approach core training with my clients?

Everything is centered around bracing, breathing (a discussion for another day), and maintaining neutrality. So, Dying Bug and Bridging variations are my go-to’s for core training. To address rotation, I utilize Palloff variations, Chops, and Medicine Ball work in various stances. If I can get a client to remain neutral during these drills, I can be confident they can apply this to their squats, deadlifts, pressing, and pulling. Most of the dedicated core work will come at the beginning of training, typically to prepare those muscles to do their job later in the session. Occasionally, core training will be sprinkled in throughout the workout where it fits.

Sources

Neumann, D. A., Kelly, E. R., & Kiefer, C. (2017). Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation (3rd ed.). St. Louis, MO: Elsevier.

Gilroy, A. M., MacPherson, B. R., Voll, M., Wesker, K., & Schünke, M. (2016). Atlas of anatomy (3rd ed.). New York (NY): Thieme.

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