To understand abdominal exercises and pick the right approach for you, it's important to understand the physiology of abdominal muscles. Let's start deep and work our way to the surface.
Transverse Abdominals (TAs or TVAs) are the deepest layer of abdominal muscles. They connect into a sheet of fascia in the front that goes under your rectus muscle. This fascial layer has the ability to glide separately from your rectus (6 pack muscle), which I think is pretty cool; it means that for good or bad, our abdominal muscles can work more independently from each other than one might think.
Internal Obliques (IOs) are the next layer up, and they run diagonally on the sides. The IOs split and form part of the fascial layer below the rectus and part above it. They truly sandwich the rectus muscle. You’ll get more deep abdominal fascial layering on top of the rectus as you go down toward the pelvis.
External Obliques (EOs) are the most superficial layer (closest to the surface) and they run diagonally on the sides like putting your hands in your pockets, opposite of the IOs. The EOs attach to fascia that runs over the rectus muscle. This top layer of fascia is very interconnected with the rectus, unlike the bottom layer of fascia that can glide.
Rectus Abdominis (RA) is the muscle we think of as the 6 pack muscle. It's often the one most targeted by traditional abdominal work (think front planks, crunches and situps). The issue is that this muscle must stay in balance with the ones on the sides, and to make it even harder, the side muscles all need to show up equally as well.
To simplify, the TAs and IOs are more of your stability system, and the EOs and RAs are more of your moving system. If we're all movement and no stability, the body gets cranky. Likewise, if we're all stability and no movement, that too can create tightness and pressure issues.
So yes, there is such a thing as too much TAs. I know -- crazy, right?! Everything must be in balance, even our deep stability system. Patients I've seen with too much TAs tend to have very tight QLs. The QLs (quadratus lumborum) are broad, flat muscles that make up your low back. So if the sides of your back always feel tight, you might have an abdominal imbalance. To get the QLs to let go, you'll need more EOs.
Alright, let's break down a crunch and find out why doing it wrong will make your stomach bigger and create more pressure, whereas doing it with a more balanced focus in mind will make your abs flatter and better manage pressure. (I probably should have led with that statement…!)
