Core training is one of the most popular and often misused phrases in the fitness world today. For some people, core training means doing crunches until their abs cramp. For others, core training means doing all sorts of complicated moves on various pieces of equipment that look better suited for a circus than a gym. There have been volumes written on core training with almost every author offering a different theory (some research-based, others are pure fiction) on the best way to achieve the elusive six-pack.
With all of this information, it can be difficult for the average fitness professional to determine the most effective core training program for a client. The big question is, “which way is the right way to do core training?” To get to the solution, we must first have an understanding of what the core muscles actually do during upright movement patterns.
The musculoskeletal structure of the human body is designed in such a way that it operates most effectively when standing upright while reacting to the forces caused by gravity and ground reaction. In general, the core refers to the center of gravity which, in most people, is just below the belly button. To fully understand how the muscles of the core are designed to function, all we need to do is observe the human gait cycle.
Just like a computer has a default operating system to make it work, the default operating system of human movement is the gait pattern. When watching the gait cycle, notice how the pelvis and thoracic spine rotate opposite of one another; as the right arm swings forward, it causes the rib cage to rotate to the left on the thoracic spine while the left leg is simultaneously swinging forward causing the pelvis to rotate to the left. The muscles of the core are designed to facilitate this multi-planar action to make it smooth and efficient. That’s right; the actual purpose of our core muscles is to work effectively and efficiently while the body is in an upright, vertical position.
With this basic understanding, let’s take a look at the popular crunch exercise and ask: Is this really the most effective exercise for the core? The main purpose of the crunch is for aesthetics since shortening the rectus abdominus (RA) in the sagittal plane does very little to prepare it for the dynamic forces it experiences during upright motion.
While your clients might be interested in using crunches to sculpt their abs, the fact is that the core is the transmission of the body responsible for transferring forces from the ground, through the legs and trunk and out through the upper extremities.
Effective core training requires using exercises that integrate the hips, trunk and shoulders to efficiently distribute the forces (gravity, ground reaction and momentum) caused by upright movement.
Look at the action of thoracic spine on pelvis rotation while the arms and legs are moving opposite of one another during the gait cycle and then look at the standard crunch, which requires lying on the ground to move in a single plane of motion. What does the crunch exercise do? It merely brings the rib cage closer to the pelvis, which causes the spine to flex in the sagittal plane; hence we are mistakenly taught that the RA flexes the spine, which it does ONLY when the human body is lying supine.
Go back to the gait movement pattern; if the RA was truly designed to perform spinal flexion then we would flex our spine to bring our rib cage closer to our pelvis as we walk. The fact is, that is opposite of what happens during gait; as the right leg transitions from mid-stance to heel-off (passing under the center of gravity), the right side RA is working eccentrically to decelerate the anterior rotation of the pelvis (caused by extension of the right femur) while the left side RA is working eccentrically to decelerate thoracic extension (created by extension of the left shoulder).
Keep in mind that those are only the sagittal plane actions of the RA; in the transverse plane the RA is lengthened by the left rotation of the rib cage (with right leg in extension) and the pelvis rotating to the right while in the frontal plane the RA is lengthened by the pelvis shifting laterally relative to the femurs and the rib cage moving laterally relative to the pelvis. This means that when we are moving in an upright position, the RA is working in all three planes. Now, does the crunch look like the most effective exercise to train the tri-planar nature of this muscle?
Next we look at the obliques (both internal and external); traditional oblique exercises involve lying supine and rolling one side of the body to the other like a turtle stuck on its back. Is that really how they work as the human body is walking? During gait, the right side external oblique is working with the left side internal oblique (and vice-versa) to control the rotation of the rib cage over the pelvis. The fact is that if we are designing core training programs with exercises that emphasize lying supine on the ground then we are cheating our clients by not training them to maximize movement efficiency from their bodies.
That said, it is necessary to do some ground-based exercises to create core stability. But, once that is achieved in the initial stages of a program such as during the stability and mobility phase of the ACE Integrated Fitness Training™ (ACE IFT™) Model, then it is time to challenge the client by progressing their core training to emphasize upright movement patterns and dynamic balance (the center of gravity moving over an unstable base of support).
If we truly want to train the core the way it is designed to work, we need to get off the floor and train the muscles from a standing position so they learn how to stabilize the body in a field of gravity. Some of my favorite core exercises include (this is not a complete list, just a few exercises to establish core stability and enhance integrated strength):
- For initial core stability:
- For integrated core strength and dynamic balance:
Once a client can do these exercises, I'll progress to a circuit based on one of Gary Gray's functional core-training sequences.
Despite how many integrated core exercises are used during a training session, my experience has taught me that if I don’t include at least a few sets of crunches then my client’s lower lip will start to tremble, their eyes will start watering and they’ll be complaining that we skipped core training. To avoid this awkward interaction, my recommendation is to use stability ball crunches as an active recovery interval between more challenging core exercises. The cushion of the ball will minimize the pressure on the lower spine during flexion and allow a greater range-of-motion, both beneficial for any client.
To learn more about core training and how you can use it to help your clients meet or exceed their goals we have a recorded Core Training webinar and I’ll be teaching a session called “Core off the Floor” at our Symposium here in San Diego this November.