The Core Issue

These days you can't be in a fitness club more than fifteen seconds without hearing someone reference the core. I see leg raises, crunches, twists, planks (which I'm still convinced is just miming a park bench), side planks, and side bends. Some of them are done on balls, hanging off pull-up bars, or rolling back and forth on what looks like a dolly movers use. The list of core exercises reads like a chapter outline in the Karma Sutra.

What does the core do? The abdominals are tasked with the crucial job of keeping the lumbar spine as stable as possible. The core is not suited for generating great force, so it's debatable whether loading this muscle is a good idea.

Since the core is mostly slow twitch muscle fibers, it's ideally suited for preventing the lumbar spine from moving. Exercises like crunches and twists create tremendous compression on the intervertebral disks, and repeated compression over time causes irreparable damage.

There's several ways to move the spine that causes compression, but it appears that lateral flexion causes the most and should be avoided. Goodbye loaded side bends. Perhaps the most convincing argument that the core is an anti-rotation subsystem is the way the internal and external oblique fibers run. Take a close look at the fibers of each muscle. The externals run diagonally one way while the internals run diagonally the other, like tightly woven fish netting. This suggests that the body is extra cautious about spinal rotation. Rotation creates a shearing force on your disks, grinding them down. Keeping these precious shock absorbers safe is important, they don't regenerate once worn down.

The link below shows you where to begin timing work for the core. Remember, the core is designed to maintain spinal stability whenever the extremities leave the mid line of the body, so this exercise is an ideal place to start.

https://youtu.be/tY2EFBB4jMA

To effectively challenge the core, start by changing as many movements in your program to single leg or arm. A single arm dumbell bench press forces the core to keep the non-loaded side in place. Any leg exercises done on two legs negates the use of hip stabilizers like the glute medius and inner thigh, so incorporate single leg movements into your program.

Core progressions can be challenging. The planned progressions I write into clients' programs incorporate the core into as many exercises as I can, below is an example. This progression is only possible after you've determined you have all the stability needed to maintain perfect push up position throughout the movement. Any movement of the hips is a compensation and should be avoided.

https://youtu.be/UQdy1ezLab0

Lastly, be careful of instructors and trainers advising you to draw the belly button in to activate the core during exercise. Stabilizers are reflex muscles and should not require any thought on your part to fire. This is why I emphasize core programs address timing. If you get in quadruped position (all fours) and lift your knees slightly off the ground, you'll feel your core brace. This is timing. The core's almost instantaneous reaction to the spine being loaded is what great cores do. There is actually decent evidence that the draw out is more effective in activating core muscles because it creates intra-abdominal pressure. Powerlifters have used this technique for years. They push their guts against weight belts or powerlifting suits to get the extra stability from their core to manage the force created by their prime movers.

Core training should not be a supplemental. Most people include it at the end of their workouts. Incorporate the core into every exercise and you'll find it doing what it does best, keeping a very important part of your foundation safe and secure.