The Core "Canister": Why 360° breathing is the secret to postnatal strength
If you’ve spent any time in the postnatal fitness world, you’ve likely heard the terms "TVA," "pelvic floor," and maybe the dreaded "doming." But often, we treat these like separate parts of a puzzle. In reality, your core is a pressurised system—a canister—where everything from your throat to your pelvic floor needs to work in harmony.
The anatomy of the canister
Think of your torso as a cylinder. The diaphragm is the lid, the pelvic floor is the base, and the TVA (transversus abdominis) is the corset wrapping around the middle.
In a functional system, these three parts move together. As you inhale, the diaphragm drops down, the pelvic floor softens, and the abdominal wall expands. As you exhale, they all lift and contract together. This is 360° breathing.
The doming effect
During pregnancy, this canister undergoes massive change. The TVA is stretched, the diaphragm is pushed upwards by the baby, and the pelvic floor carries significantly more load.
Post-birth, many women find that when they try to "engage" their core, they see a ridge or a bulge popping up down the center of their stomach. This is doming (or coning).
Why does it happen? It’s usually a sign of mismanaged pressure. Instead of the pressure being distributed evenly throughout the canister (360°), it’s being pushed forward against the linea alba (the connective tissue between your abs) or downward onto the pelvic floor.
The Result: A core that feels "disconnected," potential worsening of Diastasis Recti, and a pelvic floor that feels heavy or unstable.
Moving from "sucking in" to "engagement"
The old-school advice was often to "suck your belly button to your spine." But if you look at the Incorrect Engagement side of the illustration, you can see why that’s counterproductive. Sucking in creates a "waist" but often shoves pressure both up and down, leading to that centralized bulge and downward strain.
Correct 360° Engagement looks different:
The Inhale: Your ribs expand wide to the sides and into your back (not just your belly!).
The Exhale: You gently lift the pelvic floor and feel the TVA "wrap" around your middle like a supportive hug.
This creates Optimal Distributed Pressure. The midline stays flat, the pelvic floor is supported from below, and the diaphragm moves freely.
Whether you are six weeks or six years postnatal, mastering this breath is the foundation of everything else. It’s the difference between a workout that strains your body and a workout that builds it back up.
When we work together 1:1, this is where we start. We don't just do the exercises; we look at the mechanics behind them. Because once you understand how to manage the pressure in your "canister," you can return to lifting, running, and moving with total confidence.
