Your core is not weak.
I know that contradicts what you’ve been told. Your physical therapist said to strengthen your core. Your trainer says your core needs work. The internet is saturated with core workout programs that promise to fix your back pain, improve your posture, and finally give you that flat stomach.
But after working with hundreds of clients, many of whom have been doing core work for years and still have the same back pain they started with, I’m confident in this: the problem is not weak core muscles. The problem is a core that doesn’t know when, how, or how much to engage.
Your core is confused. And you can’t fix confusion with more planks.
The Core Myth
Somewhere in the 1990s, the fitness and rehabilitation worlds latched onto a compelling narrative: back pain is caused by a weak core. Strengthen the core, solve the back pain.
It was elegant. It was simple. It gave practitioners a clear treatment protocol and gave clients something concrete to do. Planks, dead bugs, bird dogs, Pallof presses, cable chops, ab rollouts. An entire industry of “core training” emerged.
And the results were, well, mixed.
Some people did core work and their back pain improved. Some people did core work and nothing changed. Some people did core work and actually got worse. The research, when you look at it carefully, supports a rather humbling conclusion: core strengthening programs are not consistently better than general exercise for back pain.
A 2016 Cochrane Review by Saragiotto et al. found that motor control exercises (a more sophisticated version of core training) were not clearly superior to other forms of exercise for chronic low back pain. A meta-analysis by Smith et al. (2014) in BMC Musculoskeletal Disorders reached a similar conclusion: core-specific training produced outcomes comparable to general exercise programs.
This doesn’t mean core muscles don’t matter. They matter enormously. It means the framework of “weakness” is the wrong lens.
What the Core Actually Does
Let’s back up and talk about what the core actually is.
It’s not your abs. Or more precisely, it’s not just your abs. The “core” is a three-dimensional chamber. The diaphragm on top. The pelvic floor on the bottom. The transverse abdominis wrapping around the front and sides. The multifidus and deep spinal muscles in the back. The obliques layered over the transverse abdominis.
These muscles don’t exist to produce force. They exist to manage pressure and provide responsive stability.
This is a critical distinction. Your core is not a prime mover. It’s a stabilizer. Its job is to create a stable base from which your limbs can move powerfully and efficiently. It does this not by being maximally contracted, but by modulating its tension in real time, anticipating, responding, adjusting, millisecond by millisecond.
A well-functioning core is like a good stage crew. You never notice it. It works behind the scenes, setting the stage before the actors move. A split second before you reach your arm overhead, your deep core muscles activate to stabilize your spine. Before you step off a curb, your core adjusts to manage the shift in load. Before you catch a ball thrown to you unexpectedly, your core braces just enough, and not too much, to handle the impact.
This anticipatory, responsive, proportional activation is what the research calls “feedforward control.” And it’s what goes wrong in most people with back pain.
Bracing vs. Responsiveness
The fitness industry’s answer to core dysfunction is bracing. Tighten your abs. Brace your core. Create rigidity.
For heavy lifting, some bracing is appropriate. If you’re squatting 300 pounds, you need intra-abdominal pressure. No argument there.
But bracing as a default strategy for daily life is a disaster. And that’s what many people have learned to do.
I see it constantly. A client walks in, and before they even move, their abdomen is rigid. They’re holding their belly in, clenching their abs, gripping through their trunk as if they’re about to be punched. They do this all day. They do it unconsciously. They were taught to “engage their core” and they took it to mean “never let go.”
This chronic bracing pattern creates a cascade of problems.
It restricts breathing. If the abdominal wall is clenched, the diaphragm can’t descend fully. Breathing becomes shallow and chest-dominant. This alone creates a host of issues, from neck tension to anxiety to poor spinal mobility.
It reduces spinal movement. A rigid core means a rigid spine. The spine is designed to move segmentally, vertebra by vertebra, with fluid rotation, flexion, and extension. A braced core prevents this. It turns the trunk into a block. Over time, segments that don’t move lose the ability to move, and the segments above and below them have to compensate.
It inhibits the pelvic floor. The pelvic floor and the diaphragm are supposed to work together as a piston. When you inhale, the diaphragm descends and the pelvic floor lengthens. When you exhale, both rise. Chronic abdominal bracing disrupts this coordination. The pelvic floor gets locked along with everything else.
And perhaps most importantly, chronic bracing replaces responsiveness with rigidity. The core can’t do its real job, anticipating and responding to variable demands, because it’s stuck at one volume level. It’s like a speaker that’s always at maximum. You lose all nuance.
The People Who Do 100 Planks and Still Hurt
Here’s a pattern I see regularly. Someone who can hold a plank for three minutes. Three minutes. Their abs are objectively strong. Core endurance, by any standard measure, excellent.
And they’ve been dealing with low back pain for years.
When I assess people like this, here’s what I typically find. The superficial abdominals, rectus abdominis and external obliques, are hyperactive. They’re on all the time. The deep stabilizers, transverse abdominis and multifidus, are barely participating.
The body has developed a strategy that looks like core strength from the outside but is actually core dysfunction from the inside. The big, outer muscles are doing the stabilizing job that the small, deep muscles should be doing. It works, sort of. But the cost is a rigid trunk, restricted breathing, and a lumbar spine that can’t move segmentally.
More planks aren’t going to fix this. More planks are going to reinforce the exact pattern causing the pain.
What these clients need is to learn to let go of the outer muscles and find the inner ones. To discover that stability doesn’t come from clenching. It comes from intelligent, calibrated, responsive engagement of the right muscles at the right time.
What Genuine Core Function Looks Like
When the core is working well, you don’t feel it. Let me say that again because it’s counterintuitive. When your core is doing its job well, you’re not aware of it.
You don’t walk around “engaging your core.” You walk around, and your core engages appropriately and automatically based on what you’re doing. It turns on before you reach. It adjusts when you shift weight. It responds proportionally to the demand, more activation for heavy lifting, less for walking, even less for sitting.
This responsiveness requires several things.
Freedom in the tissues. The fascia and connective tissue around the trunk need to be mobile enough to allow the core muscles to do their job. If the thoracolumbar fascia is adhered, if the rib cage is restricted, if the hip flexors are pulling the pelvis into a tilt, the deep core muscles can’t function well. This is where structural integration comes in. Releasing fascial restrictions creates the conditions for genuine core function.
Good breathing. The diaphragm is the roof of the core. If it’s not moving well, the whole system is compromised. I address breathing in every session because it’s that foundational. A core without a functioning diaphragm is like a house without a roof.
Proprioceptive awareness. You need to be able to feel your deep core muscles. Most people can feel their rectus abdominis. Very few can feel their transverse abdominis or multifidus. You can’t control what you can’t feel. Movement education develops this awareness through specific, low-load exercises that demand deep muscle participation.
Motor control, not motor strength. The limiting factor is almost never how much force the core can produce. It’s the timing, sequencing, and proportionality of the core’s response. This is a coordination problem, not a strength problem. And coordination improves with practice, feedback, and attention, not with fatigue and overload.
How I Work with the Core
When a client comes in with core-related complaints, usually back pain, pelvic instability, or a general sense that their “core is weak,” here’s the general approach.
First, we look at their breathing. Almost always, there’s a breathing restriction. The diaphragm isn’t moving fully. The ribs aren’t expanding laterally. The exhale is active rather than passive. Until breathing is addressed, nothing downstream works properly.
Second, we assess their resting tone. Are they gripping? Is the abdomen held? Can they fully relax their abdominal wall on an exhale? Many people can’t. The muscles have been told to stay on, and they’ve forgotten how to turn off. Before we can train appropriate activation, we need to restore the ability to deactivate.
Third, we work on deep muscle awareness. This often starts with the most basic possible movements. Lying on the back, knees bent, feeling the gentle engagement of the deep core during a slow exhale. No crunching. No bracing. Just finding the subtle support that lives underneath the gripping.
Fourth, we build complexity gradually. From lying to sitting to standing to moving. Each progression adds demand, and at each stage, we’re checking: is the deep core responding appropriately, or is the old bracing pattern coming back?
Fifth, once the core’s responsiveness is restored, then we can add load. And when we do, the load is managed differently. Better distributed. Less reliant on any single structure. More resilient.
The Fascia Connection
I want to add one more layer to this, because it’s important in my practice.
The core muscles don’t function in isolation. They’re embedded in a web of fascia that connects them to everything above and below. The thoracolumbar fascia, a diamond-shaped sheet of connective tissue in the low back, is where the transverse abdominis, the latissimus dorsi, and the gluteus maximus all converge.
When this fascia is healthy and mobile, it transmits force beautifully. Your core, your back, and your hips work as an integrated unit. When this fascia is restricted, adhered, or dehydrated from years of sitting and limited movement, that integration breaks down. The muscles can be strong individually, but they can’t coordinate through the fascial web.
This is why structural integration work on the trunk can produce dramatic improvements in core function without any core exercises at all. Release the fascial restrictions, and the muscles suddenly have the conditions they need to coordinate properly. The “weakness” wasn’t in the muscles. It was in the connective tissue environment they were trying to work in.
Letting Go of the Myth
I know this is a lot to take in, especially if you’ve been doing core work diligently and being told it’s the answer to your back pain.
I’m not saying core exercises are useless. Some of them are excellent movement education tools. A well-taught dead bug can help someone find their deep stabilizers. A side plank can develop lateral stability. A Pallof press can teach anti-rotation.
But the framework matters. If you’re doing these exercises to “strengthen a weak core,” you’re likely reinforcing bracing patterns that are part of the problem. If you’re doing them to develop awareness, responsiveness, and coordination of your deep stabilizing system, that’s a different thing entirely.
The goal isn’t a stronger core. The goal is a smarter core. One that knows when to turn on, how much to turn on, and equally important, when to turn off.
If your back still hurts despite years of core work, the core isn’t the problem. The strategy is. And changing strategy is exactly what movement education is designed to do.
In the next post, I’m going to go deeper into the breathing piece, because it’s the foundation under all of this. Breathing affects core function, posture, pain, stress, and the ability to move well at any age. And almost everyone I see has a breathing pattern that’s limiting them.
If you’re doing everything right and your back still hurts, let me take a look. I won’t give you more planks. I’ll help you figure out what your core actually needs, which is probably not what you think.