There is a vast amount of confusion regarding some of the most frequently used phrases and concepts in the fitness industry. There is a complete lack of universally accepted definitions regarding what constitutes the core as well as proper descriptions of core-stabilization and core-strength. Another concept that seems to cause frequent discussion is the description of what defines functional training. What separates a functional exercise from a non-functional one?
I would like to take the opportunity to explain what my definitions are to avoid any confusion when reading my material.
The core is made up of the Diaphragm, Pelvic floor, Internal and External Oblique Abdominal muscles, Rectus Abdominis, Transversus Abdominis and the Lumbar Extensor muscles.
Core stabilization is the Intra-Abdominal Pressure (IAP) that develops when the diaphragm contracts properly and pushes down into the abdominal cavity, and which is opposed by a sufficient eccentric contraction of the entire abdominal wall. The increased intra-abdominal pressure supports the spine from the front and is balanced at the back of the spine by the activity of the lumbar extensor muscles. The synergistic activity of the diaphragm, pelvic floor, abdominal muscles and lumbar extensors stabilizes the lumbar spine via IAP and also creates a central anchor point for the limb movements. Core stabilization develops from the inside out!
Core Strength describes the amount of loading the core can be subjected to and still manage to support the lumbar spine. Good core strength makes it possible to perform heavy training without running the risk of losing the internal support of the lumbar spine. Ideally the core strength should match and preferably exceed the strength of the extremity muscles. It is the strength of the core that determines the ability to perform heavy lifts like a maximum squat or dead-lift without allowing end-range flexion of the lower lumbar spine.
Core-training can be divided into core-function or core-component training. Core-function is the combined activation of all the parts of the core. Core component training is any training that specifically strengthens any of the individual parts of the core. Strengthening the diaphragm or the abdominal muscles by themselves will improve the strength of the core. There are discussions whether to train the core first or last in a work-out. This exemplifies the problem with definitions and the general understanding of the core-concept. Once the core stabilization function has been properly activated it should be an integral part of all activities in and outside the gym. The inability to activate and utilize the core properly often contributes to lower-back problems and pain syndromes. The key to proper core activation is to simultaneously perform the dual functions of the diaphragm (respiration and stabilization), where stabilization is maintained throughout the normal breathing cycles.
All exercises are core-exercises once the core is properly activated. Many of the traditionally used core exercises with loading applied from different directions and angles as well as single limb exercises, are excellent methods of training both core- component and core-function combined.
Functional Training is describing any activity that is performed with proper stabilization and good movement patterns. There have been discussions over what constitutes a functional exercise and some suggestions have been that activities which mimic daily activities are functional. The first step is to establish that there are no functional exercises, only functional people. It is not the selection of exercise but the execution of it that decides if it is functional or not.
There are certain criteria that have to be filled before an exercise can be described as functional. First up is the proper activation of the core to stabilize the spine and provide anchor points for the limb movements. The core stabilization (IAP) should be maintained throughout the exercise even when the breathing function becomes challenged. All functional training should initially be focused on proper activation of the diaphragm’s dual function.
Joint centration is when joints are held in an ideal alignment where they provide the maximum ability to transfer load across the joint surface. Improper joint-centration leads to over-load injuries and leakage of power from the kinetic chain. Proper joint-centration is an important factor of functional training.
Adequate stabilization of joint motion maintains the joints in a centrated position throughout the movements. The better the stabilization the greater range of movement possible under load and the larger the load that can be carried across the joint. The weakest point of stabilization of the system determines the level of loading possible.
Big compound exercises are often described as functional while isolated joint movements are regarded as non-functional. There is no argument against the fact that a properly executed compound exercise often is far more beneficial than the isolated joint movement. The key words in the previous sentence are “properly executed” which completely determines the value of the exercise. Poor form without joint centration and with insufficient stabilization turns all exercises into non-functional exercises.
Functional exercises are often described as activities that mimics sporting or normal daily activities. The key factor that determines what is functional is the quality of the movement and stabilization pattern not the exercise in itself.
Corrective exercises are aimed at changing non-ideal postures and dysfunctional joint movements. Posture plays an important part in the ability to move and stabilize joints properly. Non-ideal curvatures of the spine and faulty positions of the ribcage and pelvis are common postural dysfunctions that often have to be corrected. Non-ideal centration of feet, ankles, knees, hips and scapulae are other common dysfunctions where corrective exercises are utilized with good effect. Corrective exercises can include strategies to improve movement of joints with restricted range as well as stabilize unstable joints. Corrective and activation exercises are often so called isolation exercises where the movement is concentrated at one specific joint at the time to enhance ideal mobility and stabilization.