Written by Dorothea Iatrou, certified Reformer and Mat Pilates instructor with a BSc in Physical Education and Sport Science, a background as a competitive track and field athlete, and wellness supervision experience at a five-star resort.
Ask most people where core strength comes from and they will point at their abs. Ask a Pilates teacher and the answer is almost always the same, and it surprises people every time: it starts with the breath. Learn to breathe the way Pilates teaches, and you train your deepest core muscles from the inside out, long before you do a single crunch. Here is why that works, and exactly how to do it.
The muscle most workouts ignore
Your deepest abdominal muscle is the transverse abdominis. It wraps around your midsection like a corset, and its job is to stabilise the spine and pelvis. Unlike the more visible "six-pack" muscles, the transverse abdominis does not move you through big, showy movements. It holds you steady so that everything else can move safely and powerfully. A strong, responsive transverse abdominis is what people really mean when they talk about a strong core.
Here is the key: the transverse abdominis works hand in hand with your diaphragm, the dome-shaped muscle that drives your breathing. When you exhale fully, that deep abdominal layer naturally draws in and engages. In other words, your breath has a direct line to your deepest core muscle. Train the breath and you train the core.
Why Pilates breathing is different
Many forms of movement teach belly breathing, where the abdomen expands on the inhale. That is wonderful for relaxation and calming the nervous system. But in Pilates we want the deep core to stay engaged while we breathe, so we use a different technique called lateral, or thoracic, breathing.
Lateral breathing means directing the breath into the sides and back of the ribcage rather than down into the belly. As you inhale, your ribs expand outward and your diaphragm descends; as you exhale, the ribs gently close and the deep core draws in. Because the belly is not ballooning outward, the transverse abdominis and pelvic floor can stay switched on, creating internal pressure that supports the spine from every angle. It is this "corset" of support that protects your lower back and lets your arms and legs move with power and precision.
Exhale on the effort
There is one more piece that ties breath to strength: timing. In Pilates we usually exhale on the hardest part of a movement, the effort. As you breathe out through the difficult phase, you naturally deepen the engagement of that corset of deep muscle exactly when your spine needs the most support. This is why a Pilates class can leave your abdominals genuinely tired even when the movements themselves look small and controlled. The work is happening on the inside.
How to practise lateral breathing
You can learn this right now, and five minutes of practice a day pays off quickly:
- Get into position. Lie on your back with your knees bent, or sit tall. Place your hands on the sides of your ribcage, fingers around the front and thumbs reaching toward the back.
- Inhale into your hands. Breathe in through your nose and aim the breath sideways into your hands. Feel your ribs widen outward and toward the back. Your belly should stay relatively quiet.
- Exhale and draw in. Breathe out fully through softly pursed lips. Feel the ribs close back in and imagine gently zipping up from the pelvic floor toward your navel, keeping the core lightly engaged.
- Repeat with attention. Five to ten slow, deliberate breaths, feeling the rhythm of expansion and engagement.
The most common mistake
By far the most common error is letting the belly rise and fall, slipping back into diaphragmatic breathing. A simple check: place one hand on your chest and one on your belly. Neither should move dramatically. The real movement happens in the sides and back of your ribs. If your belly is doing all the work, soften the breath, place your hands back on your ribcage, and aim the air sideways again.
Benefits that reach beyond the core
Breath-led core work does more than build a strong midsection. Because the breath and the nervous system are so closely linked, this kind of focused breathing lowers tension and leaves most people feeling calmer and more present after a session. It improves posture, since a supported spine naturally stacks taller. And it teaches a skill you carry everywhere: the same quiet engagement that stabilises you in class is exactly what protects your back when you lift a child, carry shopping, or twist to reach the back seat of the car.
Frequently asked questions
Should I breathe through my nose or mouth in Pilates?
A common approach is to inhale through the nose and exhale through the mouth with softly pursed lips, which helps you control and fully empty the breath. The most important thing is breathing fully and timing the exhale with effort, not a strict rule about nose versus mouth.
Why do I feel my abs working just from breathing?
Because the transverse abdominis engages naturally as you exhale. Lateral breathing keeps that deep muscle switched on throughout, so even gentle breathing becomes meaningful core work.
Is lateral breathing useful outside of Pilates?
Very. The same breathing supports your spine during lifting, improves posture, and helps manage stress. Many people find it becomes a habit they use throughout the day.
How long until breathing improves my core strength?
Most people feel a difference in how connected and supported their core is within a few weeks of consistent practice, especially when they pair daily breathing drills with two Pilates sessions a week.
The anatomy, in plain terms
It helps to picture what is actually happening. Imagine a cylinder in the middle of your body. The diaphragm is the lid on top, the pelvic floor is the base, and the transverse abdominis wraps around the sides like the walls. When these work together, the cylinder pressurises gently as you breathe and move, and that internal pressure is what stabilises your spine. Pilates breathing is simply the skill of coordinating that cylinder on purpose, rather than leaving it to chance.
A simple three-part sequence to try
Once lateral breathing feels familiar, link it to gentle movement:
- Breathe and connect. Lying on your back, knees bent, take five lateral breaths, feeling the ribs widen on the inhale and the core draw in on the exhale.
- Add a heel slide. As you exhale and engage, slowly slide one heel away along the floor, keeping your pelvis perfectly still. Inhale to return. The breath does the stabilising; the leg simply moves.
- Add a small curl. Exhale, draw the core in, and float your head and shoulders a few centimetres off the mat. Inhale to lower. Notice how the exhale, not brute force, is what powers the lift.
Three or four rounds is plenty. The aim is not exhaustion; it is the connection between breath and deep core that you will carry into every other exercise.
How breath connects everything else
Breath is the first of the six classical principles of Pilates for good reason: it makes the others possible. It fuels concentration by giving your mind a rhythm to focus on, it powers centring by engaging the deep core, and it sets the tempo for flow. If you would like to see how the full set fits together, our guide to the six principles of Pilates walks through each one.
Breath, calm and the nervous system
There is a reason you often feel steadier after a Pilates session, not just stronger. Slow, deliberate breathing gently shifts the nervous system away from its stressed, fight-or-flight state and toward rest and recovery. The long, controlled exhale we use in Pilates is especially calming. So while the primary aim of lateral breathing is core stability, a welcome side effect is a clearer, calmer mind, which is part of why so many people describe their practice as the most grounding part of their week.
When to use which breath
Lateral breathing is the working breath of Pilates, the one that keeps your core engaged while you move. But it does not have to be the only breath you ever use. Softer, fuller diaphragmatic breathing is a beautiful tool for winding down, for relaxation, or for the quiet moments at the end of a session. Learning both, and knowing when each is useful, gives you a breath for effort and a breath for rest.
Train with Dodo Fit
Want to learn this with hands-on guidance? Book a session with Dorothea and we will find the right starting point for your body and your goals. Browse the class options, check the weekly schedule, or get in touch with any questions.
