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The Abdominal Superhero: Transverse Abdominus

For many of us, the abs often get superficial attention at the gym as that part of the body you work on so it’ll hopefully, maybe, one day, be chiseled and flat as a washboard, but that’s about where the thought ends. It’s time to take a dive into the core and see what it’s functional role is, and how you can tailor your core training to benefit your running7.

The core musculature actually extends far beyond what most of us think of as that visible “six-pack” some people are fortunate enough to own. The core muscles comprise several other groups that support the spine, hips, low back, ribs, and internal organs6. Needless to say, these groups have a big job. A weak or unsupportive core has real implications for runners2. Conversely, a strong core can have an über helpful impact on your running experience and longevity.

The Transverse Abdominus

The first muscle that arguably deserves the most attention is called transverse abdominus (TVA). It is a broad, thin muscle that is the deepest of the core musculature situated underneath rectus abdominus (the ‘six-pack’ muscles) and the obliques (side body stabilizers/movers)6. It serves a lot of important functions, not least of which is supporting and compressing your viscera. TVA also aides significantly in maintaining stable posture, since the muscle’s attachments span from the top of the iliac crest (upper portion of the hip bone) to your lower costal cartilages (ribs), to your pubic bone3,6. The TVA is often compared to a built-in corset or girdle since its function of ‘holding everything in’ is apt (Awesome, isn’t it? No need to go out and buy an actual girdle now you know you’ve already got one at the ready). 

Since TVA attaches to so many points throughout the front and sides of the abdomen and has extensive fascial connections beyond, it is implicated in running bigtime. While this muscle doesn’t actually move limbs or joints independently, it’s stabilizing function is key5. Without TVA functioning at its full capacity muscle compensation kicks in, and you’ll get smaller muscle groups taking on a workload for which they are not optimally designed. There have been studies showing a weak TVA to be a culprit in chronic low back pain, hip, and groin injuries1,2,3,4,5,7. Since a lot of runners spend consecutive hours or days out on the trail, TVA needs to be super strong and active in supporting your upright posture. A weak TVA can lead to maladaptation of movement patterns at the hips, low back, and groin. Symptoms and pain may manifest gradually over time as a constellation of issues originating with a weak or inactive TVA2,3,5,7. 

Here again is where I can unfortunately speak from past experience on just how far reaching the effects of a weak TVA can be. About seven years ago I experienced a complex array of neuromuscular dysfunction and pain throughout my pelvis that stumped repeated self-evaluation and physician after physician. I was experiencing severe shooting pains through my pelvis and low back, and walking, running, sitting, and standing became progressively more irritative to the point of almost being unbearably painful. After a plethora of testing, poking, and prodding and still no definitive answers as to what was causing my pain, I sought input from a Physical Therapist trained in dealing with the pelvis (these very specialized PTs can be difficult to find but are worth their weight in gold). After taking a look together at a diagnostic ultrasound of my core, I was astounded to see how flaccid and frankly pathetic my TVA and deep lumbar stabilizers looked.

The PT pointed out the hyper-compensation going on throughout my core and pelvis. We determined that a whole lot of my pelvic floor musculature was in prolonged spasm, hypertonic, and aggravating a multitude of pelvic nerves. The small muscle groups located within my lower pelvis were taking over the stabilization duties of my TVA and larger lumbopelvic stabilizers–all of which appeared to be on extended holiday. After eight long months of targeted rehab and zero running, I slowly crept back from this bizarre injury. And while my experience is an extreme and highly irregular outcome of a wonky and weak deep core, it’s a good illustration of how much the deep core really does matter. 

One of the challenging aspects of training TVA is that it requires a huge amount of subtlety and intentional activation. When you do locate TVA and manage to consciously activate it, you won’t feel a big movement or experience any outwardly visible motion (like with the pecs on a bench press). This is precisely why it is one of the trickiest and often disregarded muscles that needs training. We’ll get into how to locate and activate TVA later on in this blog, but for now suffice to say it’s the core muscle to add into your strength routine if you haven’t already.  

The Obliques

Moving from the deepest layer outward, the next muscle group we encounter after TVA is the internal obliques6. Over these lie the external obliques, and collectively they are responsible for enabling spinal flexion, twisting (rotation), and stabilization of the side-body6. These muscles are implicated in counteracting the rotational force that happens with arm swing or pole usage when you run. The movements here are not huge, nor are you likely to feel particularly fatigued in your obliques after a long run. But again, this mid-layer of the core needs attention and proper activation just like TVA1,3. It is also important to note that muscles and muscle groups do not act in isolation6. When we talk about the specific action of a muscle, it should be noted that in reality muscles are always working in a complex and fluid dance with their synergists (helper muscle groups performing similar actions), antagonists (muscles that relax eccentrically allowing for the opposing group to contract), and connective tissues (ligaments, tendons, fascia)6. 

The Rectus Abdominus

The most superficial muscle group of the core is the one we’re all familiar with that creates (for some) what looks like a neatly stacked row of bricks on either side of your midline. This is the rectus abdominus group6. And while it by no means is unimportant to a globally strong core, it is the easiest to see, pinch, activate and agonize over in front of the mirror- therefore it gets the most attention. The rectus abdominus primarily acts as spinal flexor (the ‘C’ shape your torso achieves in a standard crunch is the rectus abdominus at work).  

Ok- now that we’ve taken a tour of our collective midriffs, let’s talk about activating that all important TVA muscle. The best way to begin your search for the TVA is to lie on your back with your feet planted on the floor. Take a couple deep abdominal breaths to settle down and relax those core muscles as much as possible. Next, you’ll need to locate your ASIS (anterior superior iliac spine(s)), which are the pokey bits on the front of your hip bones that are highly palpable when you’re lying on your back. Next, move your fingertips about one inch horizontally inwards towards your belly button and then one inch downward (inferiorly) toward your pubic bone. Bingo! You’ve found your TVA, now it’s time to try and get it working. First things first with activation- sucking in your stomach is not activating the TVA. Also, if you feel contractions of your rectus abdominus under your fingers (do a small crunch and note what this feels like if you’re unsure) this is also missing the target. Since the TVA is tied to the pelvic floor, you will probably feel activity in your pelvic floor when you try to activate TVA- like if you had to stop peeing mid-stream. Initially this is ok, but the goal eventually is to isolate TVA as purely as possible and differentiate it from the pelvic floor. 

To start activating, keep your fingertips on TVA and imagine slowly drawing your navel in toward your spine via a string attached from your spinal column reaching only to that innermost layer of core muscles (TVA)- do this on the exhale. As you inhale again try to maintain the contraction you’ve achieved thus far to the best of your ability, and on the second exhale contract TVA further (tighten that corset!). The contractile movements under your fingers may feel extremely small or barely recognizable- that’s ok, this will take repeated practice. I realize how impossible this sounds, but it really can be done. 

There are a few other helpful ways to think about TVA activation I came across during my own rehab journey. The first is the plastic wrap analogy. Imagine your viscera (internal organs) are all bound in a layer of plastic wrap. Your goal is to squeeze those organs further only using TVA. Think about the internal organs being compressed whilst the outer core remains unchanged. Essentially, you should see no movement, bulging, or other contortion in your abdomen. It’s visually about the most unexciting exercise ever. This takes a lot of patience, and it may help to pull up an anatomical diagram of the core musculature to help with this. The second analogy is the belt notch trick. When you are lying in the starting position imagine a belt strapped loosely around your TVA, with each exhale+contraction of TVA, your goal is to tighten the belt one notch. Again- if you feel action in the obliques or rectus abdominus stop and try again. 

While the extreme subtlety of activating TVA can feel a little infuriating, it will pay dividends to your running health be persistent, locate that badboy and strengthen it. Below you’ll find some exercises that are targeted toward TVA but will also give a great workout to your obliques and even your rectus abdominus as well. 

  1.       Plastic wrap TVA activation
  • No video 
  1. Prone Plank w/ progression
  1. Side Planks w/ progression
  1. Side swipes
  1. Russian Twist
  1. Wood Choppers
  1. Reverse Crunches
https://youtube.com/watch?v=vaTHkV2R13c
  1. Dead Bug

References:

  1. Bråten, M., Andersen, L. A. (2019) “Hva er uavhengig kroppsarbeid?” Norge Olympiatoppen. Available:https://www.olympiatoppen.no/fagstoff/teknikk_motorikk/teknikk_motorikk/page1687.html [Accessed: 27 November 2020].
  1. Hodges, P. W.; Richardson, C. A. “Delayed postural contraction of transversus abdominis in low back pain.” Journal of Spinal Disorders 1998, 11 (1), 46-56.
  1. House, Steve, Scott Johnston, and Kilian Jornet. Training for the Uphill Athlete. Patagonia Books, Ventura, California, 2019.
  1. Leetun, D. T.; Ireland, M. L.; Willson, J. D.; Ballantyne, B. T.; Davis, I. M. “Core Stability Measures as Risk Factors for Lower Extremity Injury in Athletes.” Medicine & Science in Sports & Exercise 2004, 36 (6), 926-934.
  1. Mangum, L. C., Henderson, K., Murray, K.P., Saliba, S.A. “Ultrasound Assessment of the Transverse Abdominis During Functional Movement.” Journal of Ultrasound in Medicine 2018, 37 (5), 1225-1231.
  1. Schünke, M., E. Schulte, and U. Schumacher. Thieme Atlas of Anatomy. Edited by L. Ross, and E. Lamperti. Thieme Medical, Stuttgart, 2006.
  1. Vincent, H.K., and Vincent, K.R. “Abdominal Bracing for Minimizing Excessive Pelvic Motion During Running.” Current Sports Medicine Reports 2018, 17 (4), 111.

Cate Airoldi brings over a decade of training and racing experience to Aspire, with first place finishes in distances ranging from 50 to 120 miles. With an educational background in Physiology, Kinesiology, and Sports Performance, she has been training individual and team athletes since 2011. Cate holds CPT and LMT certifications, and is a current MSc graduate student in Sports Performance Coaching.