Every technique you have ever thrown began somewhere other than your hands.

It began in the center.

The strike, the throw, the sweep, the takedown, none of these originate at the point of contact. They originate in the core. The hand delivers. The shoulder directs. But the core generates. Without it, every technique is a fraction of what it could be, a surface movement disconnected from the body’s true source of power.

This is the second installment in our ongoing series on structural conditioning for martial arts performance. In the first article we addressed grip strength in the hands and forearms, the final point of contact where technique either holds or collapses. Here we move deeper into the chain, to the structure that drives everything forward.

What the Core Actually Is

Most practitioners think of the core as the abs. This is one of the most limiting misconceptions in martial arts conditioning.

The core is a system, a three-dimensional structure of muscle, fascia, and connective tissue that surrounds the entire midsection from the base of the ribcage to the floor of the pelvis. It includes:

ANTERIOR CHAIN

Rectus Abdominis, External Obliques, and Transverse Abdominis. These are the muscles you can see and what many practitioners think of when training abs. They are important. but only a part of the picture.

POSTERIOR CHAIN

Erector Spinae, Multifidus, Quadratus Lumborum. These muscles, you cannot see but also cannot function without. These stabilize the spine under load and transmit force from the lower body upward through the torso. In martial arts, this chain is the difference between a strike that carries full body weight and one that carries only arm strength.

LATERAL CHAIN

Obliques, Hip Flexors, Iliotibial Structures. These govern rotation. In striking arts, every technique that involves a turn of the hips, which is most of them, depends on the lateral chain for speed, power, and control.

DEEP STABILIZERS

Transverse Abdominis, Pelvic Floor, Diaphragm. These are the foundation beneath the foundation. They create intra-abdominal pressure, which is the body’s internal bracing mechanism. Without them, the entire core structure is a building with no base.

SERRATUS ANTERIOR

The one most practitioners have never deliberately trained, or even considered part of the core at all. It should almost be considered first.

The serratus anterior runs along the lateral ribcage, a serrated band of muscle connecting the upper eight or nine ribs to the inner border of the shoulder blade. Its primary functions are to anchor the scapula firmly against the rib cage, drive the shoulder blade forward during protraction, and rotate it upward when the arm reaches overhead. It also plays a significant role in breathing mechanics under exertion.

In martial arts terms, this means the serratus anterior is involved in virtually every technique the body produces. Every punch that extends fully, every overhead guard position, every throw that requires the arm to drive forward and through, the serratus anterior is working like a wheel beneath all of it. When it is strong, the shoulder blade stays locked against the ribcage and force transfers cleanly from the core into the arm. When it is weak, the scapula wings outward, the shoulder loses its structural foundation, and the entire kinetic chain from the core to the hand is compromised at the point where the two meet.

It connects the core to the shoulder. It is the bridge between the engine and the delivery system. There is an argument, and it is a strong one, that no single muscle in the core carries more consequence for martial arts performance than this one.

Training the surface abdominals alone and calling it core conditioning is like training the grip and ignoring the forearm. The visible part is only the surface.

Why the Core Is the Engine

In physics, force has a source and a destination. In the human body, the core is the source.
When a practitioner throws a punch with full body commitment, the sequence moves like this: The legs push against the ground. That force travels upward through the hips. The core rotates and compresses, amplifying it. The serratus anterior engages, anchoring the shoulder blade and driving the arm forward with the full weight of the body behind it. The shoulder receives and aligns that force. The arm delivers it. The hand, as we established in part one, must be structurally prepared to transmit it without leaking.

Remove the core from that sequence and what remains is an arm strike. Remove the serratus anterior and the shoulder loses its anchor, the arm extends but the body behind it disconnects. An arm strike is perhaps twenty percent of what a fully committed technique delivers. The other eighty percent lives in the body behind it, and the body behind it is the core in its entirety.

This is true in every martial discipline. Throwing arts depend on core rotation and hip loading to generate the leverage needed to move another body. Grappling arts require isometric core stability to maintain position under pressure. Striking arts require explosive core engagement timed precisely to the moment of impact. Weapons arts demand sustained core endurance to maintain structural integrity through extended practice. In every one of these contexts the serratus anterior is working, stabilizing, transferring, connecting the center of the body to its reach.

The core is not a supporting character in martial arts performance. It is the protagonist. And the serratus anterior is the part of that protagonist most practitioners have been leaving untrained.

The Demands of Traditional Practice

In traditional Japanese martial arts, the concept of hara (腹), often translated as the body’s center of gravity or the abdomen, located approximately two inches below the navel, is foundational to how technique is understood and taught.

Hara is not merely anatomical. It is the seat of intention, the source of movement, the place from which all technique is said to originate. It is also the seat of ki (気), which is life force, energy, or spirit. Hara is also considered a person’t gut instinct suggesting intelligence aside from the head and heart. Psychologically and spiritually it’s the calm state of mind cultivated during rigorous training or other stressful situations. When a senior practitioner says a student is not moving from their center, they are not speaking philosophically. They are making a structural observation, the student is initiating movement from the extremities rather than from the core, and the technique is weak because of it.

Every classical movement pattern in traditional martial arts, the deep stances, the hip rotations, the dropping of body weight into throws and strikes, the explosive hip drive of a fully committed technique, the overhead weapon positions that demand full scapular rotation and serratus engagement, places specific and significant demand on the core structures described above.

This is why core conditioning for martial arts is not the same as conditioning the core for general fitness. The demands are different. The movements are different. The standards are different.

A practitioner who can hold a plank for three minutes but cannot generate rotational power through a throwing technique has trained the wrong things, or trained the right things in the wrong way. Muscling a technique is not the same as developing the deep core strength needed to move with proper kamae.

How the Core Fails in Martial Arts

Weakness in the core manifests in predictable ways that any experienced instructor will recognize immediately:

Loss of structure under pressure. When a grappler’s core is weak, their posture collapses the moment an opponent applies force. The technique that follows from a collapsed structure is compromised before it begins.

Disconnected striking. A striker whose core does not engage on impact throws with the arm alone. The strike lands but does not penetrate. It pushes with a winged scapula  rather than driving. When the serratus anterior is weak the shoulder blade lifts away from the ribcage during extension (like a winged scapula). This is visible, the inner edge of the shoulder blade protrudes. What is less visible but equally significant is what it does to technique. The arm extends but the shoulder has lost its anchor. The punch that should carry the full body behind it now carries only what the arm can produce on its own. In throwing arts, protraction of the scapula during the driving phase of a throw becomes unreliable. The serratus anterior is the muscle that holds that connection, and when it fails, the connection is gone.

Inconsistent balance. The core is the body’s primary balance system. A practitioner with a weak core is always slightly behind their own movement, compensating, adjusting, never fully stable.

Premature fatigue. The core stabilizes the entire body during any sustained physical effort. When it fatigues, everything else degrades, footwork, timing, guard, reaction speed. Core endurance is not separate from martial arts endurance. It is the foundation of it. An unstable body can only perform at a subpar level for so long before secondary and even tertiary support muscles become fatigued initiating rest before total exhaustion sets in. 

I remember in my early training says, my calves and feet would exhaust themselves much too early as my body compensated for a lack of pure unbroken force through my core.This compensation caused me to lean too far forward and backward at times which actually made performing some of the techniques exponentially more difficult.

Injury at the extremities. This is perhaps the least obvious consequence. When the core fails to stabilize the spine and scapula during explosive movement, the joints at the extremities, shoulders, elbows, knees, hips, absorb forces they were not designed to handle. Many chronic shoulder injuries in martial artists trace their origin not to the shoulder joint itself but to a serratus anterior that stopped anchoring the scapula, leaving the rotator cuff to compensate for a job it was never meant to do alone.

How I Condition the Core for Martial Arts

Core conditioning for martial arts is not random abdominal work. It is structured, progressive, and specific to the demands of the art.

Rotational Resistance Training

The macebell introduced in part one is one of the most effective tools for this work. Its offset weight creates rotational demand through every movement, the body must resist, control, and generate rotation simultaneously. This is precisely the pattern the core must manage during a fully committed throwing or striking technique. Single and double hand swings, halos, and rotational presses all engage the anterior, lateral, and posterior chains together rather than in isolation.

Serratus Anterior Activation and Loading

Because this muscle is so rarely trained deliberately, most practitioners must first learn to feel it before they can load it. Wall slides, pressing the forearms against a foam roller on the wall, roll your shoulders forward driving the shoulder blades apart. From this starting point roll the foam roller up and down the wall. This movement focuses more on the muscles lining the rib cage, which often get over looked. From there, resistance band protraction work, serratus push-up variations, and overhead reaching patterns under load progressively build the strength and endurance this muscle needs to function under the demands of martial arts practice.

The resistance bands listed in the training tools section serve this purpose directly, band-resisted protraction and overhead extension patterns isolate the serratus anterior in a way that translates immediately to striking extension and weapon overhead positions. Place the resistance band across your upper back (scapula) then hook your thumbs on each end of the band. Push your arms and shoulders forward and backward without bending your arms. Your shoulders will be flexed but thats to hold up your arms, but the muscle responsible for the forward and backward movement is the serratus anterior. You can also step on one side of the resistance band on the floor and push the other end over your head in the same motion to work them that way as well.

Anti-Rotation Work

This is the category most practitioners skip entirely. Anti-rotation training, isometric holds that resist rotational force rather than produce it, builds the deep stabilizers that protect the spine under load. Resistance band Pallof presses, single arm holds, and asymmetrical loading all fall into this category. They are not dramatic exercises but they produce dramatic results.

Hip Hinge Patterns

The hip hinge is the mechanical foundation of every throwing and sweeping technique in traditional martial arts. Romanian deadlifts, single leg variations, and kettlebell swings all develop the posterior chain connection between the glutes, the hamstrings, and the lumbar stabilizers that make hip-driven technique possible. Hip thrusts and clam shells wearing the small resistance bands at the knees and ankles are excellent for strengthening these patterns. A practitioner who cannot load and express force through a hip hinge pattern will never throw with their full body behind them.

Compression and Bracing

Developing intra-abdominal pressure, the body’s internal bracing mechanism, requires specific breathing and tension practice. Diaphragmatic breathing under load, breath holds during heavy movement, and deliberate bracing practice teach the deep stabilizers to activate reflexively at the moment of impact. The serratus anterior contributes to breathing mechanics under exertion, which means a practitioner who has conditioned it properly breathes more effectively under pressure, an advantage that compounds over the course of a long training session or a sustained confrontation.

This is the difference between a practitioner who tenses up when they expect impact and one whose core activates automatically, every time, without thought.

Sustained Isometric Endurance

Core endurance in martial arts is not about maximum strength, it is about structural integrity maintained over time and under fatigue. Plank variations, hollow body holds, and static compression work build the capacity to keep the core engaged through an extended training session, a long kata, or a sustained grappling exchange.

Five to ten minutes of deliberate core conditioning daily is enough. The goal is not exhaustion. The goal is structural reliability, a core that does not fail when the technique demands everything from it.

The Tools I Use

Core conditioning does not require a full gym. It requires the right tools applied with intention. The specific equipment I use in my own practice, including the macebell covered in part one and the resistance bands that serve both grip and core training, are listed on the Martial Arts Training Tools page.

Everything there has been used personally. Nothing is recommended lightly.
→ View my training tools here

A Final Word

The hand delivers the technique. The core creates it.

Everything we built in part one, the grip, the structural integrity of the hand, the tendon conditioning behind each of the Sixteen Striking Treasures, depends on a core that can generate and transfer force without leaking it along the way. And at the center of that core, anchoring the shoulder blade to the ribcage and connecting the engine to everything the arm must do, is a muscle most practitioners have never once trained with intention.

Train the serratus anterior. Train the full core system behind it. Everything on the outside gets stronger because of it.