Here at Fitness Lying Down, we see the “core” being made of up to 35 muscles. This might sound like more than you’d originally thought! There are a lot of misunderstandings and myths when it comes to core training. One of those myths surrounds the role and function of the obliques.
We have two sets of obliques – internal and external – on each side and the muscle fibers run in diagonal directions. At first glance anatomically, one could conclude in theory that their function is to twist the trunk and pull the trunk into lateral flexion (bending to the side). However, in practice it’s actually the opposite – resisting rotation and resisting lateral flexion! To some, this might not seem like a huge difference and you’ll carry on doing Russian twists and lateral side bends. With both of these exercises mentioned there’s a lot of motion being created in the spine. Although, yes, we do need to create these motions in our trunk, doing so under load isn’t going to give you the best results, and over time can potentially cause injury.
This is why it's core training and not an ab workout!
From a neuromuscular standpoint, this can send messages to the brain that are interpreted as “danger” which in turn tell muscles to tighten to create stability. This can perpetuate muscle tightness and joint stiffness and lack of flexibility. You don’t want that! For better oblique training we need to circle back to their intended purpose – resisting motion and stabilizing the spine.