The Core: Guide To The Rectus And Transverse Abdominals

The Core (Abdominal Muscles) is a group of muscles in your stomach region that reach from your pelvis up to your spine. Your core stabilizes the spine and acts as an anchor for all movements. While the core is composed of multiple muscles, going through all of them in a single article would leave out too much precious information. Today, we are going in-depth into the transverse and rectus abdominals. Let’s get started!

Function

The core does three things best. Stabilize the spine, increase intra-abdominal pressure (compression), and support movement of your limbs. The transverse abdominis and the rectus abdominis are the primary drivers for these functions. Although, both have different abilities and uses.

Most of your vital organs are located in the core region and the abdominal muscles serve to protect them. This includes the stomach, liver, kidneys, pancreas, spleen, etc. Having a strong and healthy core, helps these organs function and increases their blood flow and honestly their overall ability. Understanding, how to properly use your core will help with digestion-related issues and bowel movements as well.

Rectus Abdominis:

This is the classic “6-pack” muscle. If you’ve ever seen an ab workout video on social media, this is exactly the muscle they are trying to target. Additionally, lower ab exercises, are mainly just exercises that target the lower rectus abdominis. It is a superficial (Surface) muscle that originates from the pubic symphysis, runs up the stomach, and attaches to the cartilage of the fifth, sixth, and seventh ribs. It is segmented by tendinous intersections which give off the infamous “6-pack” look. Everyone possesses this muscle but often you need to be at a low body fat % to see visible abs.

The main function of this muscle is to provide spinal flexion as well as to stabilize the spine. Spinal flexion is the act of flexing the spine, bringing your ribcage closer to the pelvis. This can be easily demonstrated by thinking about the classic sit-up exercise. The act of crunching the body forward while bracing the spine is all in the realm of the rectus abdominis.

Transverse Abdominis (TVA):

The TVA hugs the spine, wrapping around it, and is often referred to as a “corset” type muscle because of this. The primary function of the TVA is to protect and stabilize the spine. It also acts as an expiratory muscle, meaning it helps with getting air out of the lungs. And it is a very important part of the TVA function. The TVA increases the internal pressure by squeezing inwards when contracted and this allows for spinal stabilization while also decompressing the spine. The more compression the TVA can create, the more stability, and protection to the lower back. Thus, it is extremely valuable to learn how to control compression and properly contract the TVA.

Weak Abdominals?

The TVA is a natural back brace but is often extremely overlooked. Partially, because when the word “Abs” is said everyone instantly thinks about that legendary 6-pack and proceeds to bust out a couple sets of crunches. The rectus abdominis gets all the attention while the transverse is left out. Now, while there are plenty of cases of weak rectus abdominis muscles, it is very easy to correct and there is tons of material already out there. What I want to share with you is some more discreet information that is rarely talked about among the fitness community. What happens with weak TVA muscles?

Well, weak TVA muscles lead to a bunch of issues. Other than wreaking havoc on your posture and giving you a bloated look. Weak TVA muscles can lead to spinal injuries, poor digestive health, and shallow breathing. You see, the TVA acts with the diaphragm to ensure the proper function of exhalation. Now, when you cannot properly empty the lungs (because of a weak TVA) your body will take in less and less oxygen over time. This leads to shallow breathing and a heightened CO2 level in the bloodstream. Eventually, you will have a fraction of the energy you once had, so it’s very important to prioritize them. I would say, If you are not an athlete incorporating some form of training for the TVA is more important than the rectus (although you should be training both).

The main issue I’ve personally found with not training these muscles is the breathing issues. I have noticed a lot of deeper breathing automatically since added some form of training to my routine. Weak TVAs also lead to tight psoas which cause an array of performance issues (I’ll go into detail about this somewhere else). So how do you know if your TVA is weak?

Signs of a Weak TVA

Pain or inflammation in the abdomen, tight lower back, hemorrhoids, poor posture, and excess doming of the stomach. When the TVA is weak it cannot suck (compress) the stomach to its original position and this leads to kind of a bloated look. And yes, this still happens all the time even if you are diligent with your abdominal training. Additionally, I mentioned poor posture and what I mean by that is thoracic kyphosis and lumbar lordosis, this occurs because the TVA is not creating enough pressure to stabilize your spine and maintain an erect posture. And one of the main signs is shallow or chest breathing.

Training the TVA

To activate it we need to train pressurization. Sometimes this is referred to as abdominal compression. And it just means the force your abs exert via internal pressure which stabilizes the spine, you get it. Let’s start by locating the TVA, and trying to feel it. Try this short exercise:

Take a deep breath, very deep, now hold for a couple of seconds. Now slowly blow all the air out until you physically can’t anymore, and then continue to exert that abdominal pressure even if all the air is already out. The muscle you felt in your stomach during the last couple of seconds when you were struggling to get the air out. That is your TVA. You’ll find that even during exhalation, you can feel the TVA. If not, I encourage you to try and breathe without using it. You might be here for a while though.

Training the TVA gives you deeper breathing, better posture, a flatter stomach, and better internal health as well as a stronger spine. So how do we train it? You see, the TVA acts with the diaphragm and pelvic floor, so when it comes to the transverse they are designed to be synchronized. Deep breathing exercises will train these muscles and isolation exercises such as stomach vacuums and utilizing proper compression techniques will create a strong TVA. Below is a full guide on how to train like this. you should also check out the rest of our Core Content!