Purpose and Function of the Core Musculature

All movement originates from the core. The core is comprised of twenty-nine different muscles attached to the spine and hips. There are two primary functions of the core: stabilization and movement. The stabilization system of the core is composed of the transverse abdominus, internal oblique, lumbar miltifidus, pelvic floor muscles, diaphragm, and transversospinalis. The movement system of the core is comprised of the latissimus dorsi, erector spine, illiopsoas, hamstrings, hip adductors, hip abductors, rectus abdominus, and external oblique.

Training the Stabilization System

The stabilization system has two primarily functions: to statically resist force and dynamically transfer force. During high velocity locomotion such as running, the core dynamically absorbs and transfers ground reaction force throughout the body. When the heel strikes the ground, energy from the ground is absorbed by the leg (stance phase) and transferred through the thoracolumbar fascia, and out the opposite side arm (swing phase).
The core statically resists force as well. For example, wrestlers must posses tremendous isometric strength. During activities such as wrestling to avoid take-downs, the competitors must neutralize the attacks of their opponents. They accomplish this by coordinating their arms, legs, and core to resist and overcome the force of their opponent’s attacks which are attempting to bring them to the ground in submission.
Lack of strength at the core can cause power leaks. Power leaks occur as a result of an inability to maximally contract at the core, as well as a lack of coordination between the movements of the limbs and the activation of the trunk. In order to eliminate power leaks at the core, we must first strengthen the ability of the core to maximally contract. Second: we must increase the coordination between the core and limbs. With these two goals in mind we will begin to design our core training program.

Increasing Maximal Contraction

In order to increase the ability of the core to maximally contract, we must first be able to draw-in. One way to teach this is with the drawing-in maneuver. To perform the draw-in maneuver, get on your hands and knees and draw your belly button toward your spine. Maintain tension and a flat back throughout this exercise. Inhale and exhale; with every breath attempt to make your waist smaller. A contraction should be felt in the core. Maintain this contraction throughout the exercise. As inter-muscular coordination increases, the ability of a muscle group to fire optimally, this contraction should become more intense.
Surprisingly, many people struggle with this exercise. But once drawing- in is mastered, we can move on to more advanced exercises. One of the most popular exercise progressions of the drawing-in maneuver is the plank. We will take this exercise and progressively make it harder. To perform the plank, lift your torso and legs off the floor, supporting yourself only by your forearms and toes. Maintaining a straight back, contract your torso and thighs. For some this may be an aggressive starting point. In such a case, they can perform a less intense variation of this exercise. The main goal is to find an appropriate starting point and progress from there.
Contractions should be maintained for between five and seventy seconds. Contractions maintained less than five seconds will not produce significant endurance adaptation, and contractions maintained more than seventy seconds will fail to increase strength gains. When an exercise can be preformed for seventy seconds without breaks, move to a more difficult exercise progression.