Rebuilding the Core After Birth, Without the Crunches

When people hear "core," they usually picture a six-pack or a plank challenge. That picture is part of why so many postpartum women end up doing the wrong work at the wrong time, sometimes before their body is ready for it at all.

The Core Is a Pressure System, Not a Muscle

The core is not just the visible abdominal muscles. It is a pressure system that includes the diaphragm at the top, the pelvic floor at the bottom, and the deep abdominal and back muscles wrapping around the middle. During pregnancy, that whole system stretches, shifts, and adapts to a growing baby. After birth, it does not just snap back into its old coordination pattern. It has to relearn how to work together.

Why Not Crunches

This is why I rarely start a new client on anything resembling a crunch. A crunch asks the front abdominal wall to shorten and flex, which can push pressure outward against a midline that may not yet be able to manage that load. What I look for first is much quieter work: can this person breathe in a way that lets the ribcage expand without the belly ballooning forward, can they gently draw the deep abdominals in without holding their breath, can they feel their pelvic floor respond along with that breath rather than working against it.

None of this looks impressive from the outside. Someone watching a session might see a woman lying on her back breathing slowly and wonder when the actual workout starts. But this is the actual workout, at least at the beginning, because without that foundation of breath and pressure management, any strength built on top of it tends to be built on shaky ground.

What the Research Says About Which Exercise

I should be fair about crunches. The research does not show that one type of exercise is the winner. A 2026 review of nine trials found that structured exercise programmes narrowed the gap overall, with no clear difference between types.¹ A bigger analysis of 27 trials and 1,340 women found that programmes training the deep and the outer abdominal muscles together, ideally with breathing work, did better than isolated or passive approaches, though the authors warn that confidence in some of that evidence is low.²

So my reason for not starting with crunches is not that a crunch is forbidden. It is sequence. Until breath and pressure are working together, I would rather build the system first and add harder work on top. That system view is not only a metaphor either. In a lab study, the pelvic floor muscles switched on before an arm moved and followed the rhythm of the breath.³

A Simple Breath-First Start

Lie on your back with your knees bent and your feet flat. Rest your hands on the sides of your lower ribs. Breathe in through your nose and try to widen the ribs sideways under your hands, letting the belly rise only a little. Breathe out slowly and feel the ribs settle. That is all. Five slow breaths, once or twice a day.

If you see doming or a ridge down the middle of your belly, feel pain, or notice pressure or leaking, stop and check with your doctor or physiotherapist.

Rebuilding, Not Returning

Rebuilding is not the same as returning, and I say that deliberately. We are not trying to recreate exactly what existed before pregnancy. We are building a system that can manage the demands of this new life, which usually includes carrying a car seat on one hip, bending over a crib dozens of times a day, and getting up off the floor more often than most exercise programs ever account for.

Progress happens in layers. Breath and pressure work first, then gentle activation of the deep core, then integrating that activation into simple movement, then gradually adding load. I am not a physiotherapist, and if someone has significant pain, a large separation, or symptoms like pressure or leaking, I want them assessed clinically before or alongside anything I do. But for the general work of rebuilding, the sequence matters more than the intensity.

What I have noticed, working this way with client after client, is that the strength that comes from this slower approach tends to hold up. Not because it is dramatic, but because it is built on a system that actually understands how to distribute load, rather than a surface layer of muscle asked to do a job the rest of the body was never prepared to support. This sequence, breath first, is the same one behind every postpartum recovery program I build.