As a mum to a boy with asthma and a former yoga teacher, breath isn’t a novelty to me—it’s a necessity. I’ve spend countless visits to the emergency rooms with Neil since he was 3 yo using oxygen masks, steroids and all sorts of in-patient treatments.
I’ve taught people how to “just breathe” before I truly understood what that even meant. Now, after years in the health and fitness industry, and with the obsession with the science of movement, I’ve come to see breath as the quiet backbone of everything we do.
I also like to keep things simple. And breath is not simple. It’s layered, complex, and deeply tied into everything from spinal mechanics to emotional regulation. But if we can learn to understand it—not over-control it or mystify it—we can make our teaching more effective and our practice more sustainable.
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Read more: Breathing: The Missing Link in MovementThe Diaphragm
Let’s start with the big player: the diaphragm. It’s a dome-shaped muscle that sits beneath your lungs and attaches to your spine, ribs, and sternum. When you inhale, it contracts and moves downward, creating negative pressure in the chest so the lungs can expand. This descent also puts gentle pressure on the abdominal contents, triggering a chain reaction through the abdominal wall and pelvic floor.
Here’s what’s often overlooked: this movement isn’t just about oxygen. It’s about pressure regulation and core control. The diaphragm plays a crucial role in stabilising the trunk and supporting the spine during movement. Research by Hodges and Gandevia (2000) shows a direct link between diaphragm activity and postural control. It’s not just a breathing muscle—it’s part of your deep core system.
The ribcage and the spine
Every time you breathe, your ribcage moves. It expands with inhalation and contracts with exhalation. But it doesn’t do that in isolation. The thoracic spine is closely tied to rib mobility.
Spinal extension allows the front ribs to open. Flexion compresses the front and opens the back. Rotation spirals the ribs around the spine’s axis, while lateral flexion allows for asymmetric movement—creating more space on one side and less on the other. When this spinal mobility is restricted, so is the diaphragm’s ability to descend fully.
A stiff thoracic spine, whether from long hours at a desk or general movement avoidance, leads to a locked ribcage. And when the ribs stop moving, the diaphragm stops moving well too. That’s when other muscles step in.
Accessory Breathing
Accessory breathing muscles are the backup crew. They step in when the diaphragm can’t do its job fully—during exertion, stress, or shallow breathing. Here’s who they are:
- Sternocleidomastoid (SCM): Lifts the sternum and clavicle – if you turn your neck you will see the thick line. This is the one.
- Scalenes: Elevate the first and second ribs.
- Pectoralis Minor: Helps elevate ribs if the scapula is fixed
- Upper Trapezius and Levator Scapulae: Often tense and overactive in neck breathers
- Serratus Anterior and Posterior: Contribute to forced respiration
- Latissimus Dorsi: Assists in forced exhalation, particularly when posture is compromised
These muscles are brilliant in a sprint or during high output. But when they dominate at rest, that’s a red flag. Chronic accessory breathing leads to elevated shoulders, tight necks, and tension headaches. You’ll see it in people with forward head posture, flared ribs, or who “suck in” their belly all day (talking to you Pilates instructors and practitioners!)
When Breath is Shallow, Tension Takes Over
If breath is shallow and high in the chest, it’s a cue that the diaphragm isn’t getting full range. So the accessory muscles pick up the slack. Over time, this leads to tension in the neck, shoulders, and upper back. The sternocleidomastoid, scalenes, levator scapulae, and traps all work overtime, creating discomfort, stiffness, and eventually dysfunctional movement patterns.
This also feeds into thoracic stiffness. The less your spine and ribs move, the more the breath stays small—and the more your body relies on tension instead of flow.
Research by Kolar et al. (2012) highlights how inefficient breathing patterns not only decrease respiratory function but also disrupt postural stability and motor control. So yes—your shallow breath might be the reason your upper traps are always tight.
Natural Doesn’t Mean Passive
The goal isn’t to micromanage every breath in your session. We’re not cueing dramatic belly rises or “inhale to open, exhale to squeeze” on repeat. What we want is awareness and optionality. Let the breath be natural—but not neglected. Encourage expansion through the ribs. Invite spinal movement. Let the diaphragm participate in the way it was designed to.
Breath is also a motor behaviour. It’s trainable. Like any skill, it adapts with feedback, experience, and conscious awareness. When we move well, we breathe better—and when we breathe better, we move more efficiently.
I usually start my classes with a bit more attention to the breath and then let it go. With time the practitioner becomes more and more aware of it and it becomes the part of the movement in the natural way.
The takeaway
If you’re a client: start noticing. Are you bracing during a plank? Holding your breath when things get hard? Are your shoulders doing more breathing than your ribs? These are little signs that your breath needs some room to move.
If you’re a movement professional: observe breath like you observe posture. Restore ribcage mobility, reintroduce rotation and lateral flexion, and create space for breath—not just lungs—to move.
Let the breath guide the movement
Good breath isn’t loud. It doesn’t demand attention. But it supports every lift, lunge, and reach. It stabilises the spine. It regulates pressure. It connects systems.
So whether you’re working with a new mum, a stressed office worker, or someone recovering from injury—don’t just ask them to engage their core. Ask them to breathe well first.