Your belly is a fizzy bottle. Pressure is what you shake.
The one concept that explains coning, leaking and why some exercises feel wrong after birth.
Quick answer
Intra-abdominal pressure is the pressure inside your abdomen, created when your diaphragm, deep abdominal muscles and pelvic floor squeeze the space between them. Every time you cough, lift the pram or hold your breath to sit up, that pressure spikes.
After birth the walls holding that pressure in are softer, so the force looks for the weakest exit. It pushes forward through the midline (coning or doming) or down onto the pelvic floor (heaviness or leaking). Managing pressure means exhaling on the effort, keeping your ribs stacked over your pelvis, and adding load gradually rather than avoiding movement altogether.
What intra-abdominal pressure actually is
Picture your torso as a soft container. The roof is your diaphragm, the floor is your pelvic floor, the front and sides are your abdominal muscles, and your spine is the back. When you exert yourself, all four coordinate and the pressure inside rises. That is normal and necessary. Pressure is how your trunk stiffens so you can lift, push, cough and sneeze without collapsing.
The problem is not pressure itself. It is pressure that has nowhere good to go. Pregnancy stretches the connective tissue down the front of your abdomen and loads the pelvic floor for months. Afterwards, those tissues need time and graded work to stiffen up again. Until they do, a pressure spike that your pre-baby body absorbed easily can bulge outward or press downward instead.
structures share the job: diaphragm above, deep abdominals around, pelvic floor below
of women still had abdominal separation at 6 months postpartum (Sperstad et al., 2016)
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Why it matters more after a baby
Abdominal separation is widespread, so this is not a niche concern. Sperstad et al. (British Journal of Sports Medicine, 2016) found separation in 60% of women at 6 weeks postpartum, 45.5% at 6 months and 32.6% at 12 months. A softer midline means a wider, thinner strip of connective tissue between the two halves of your six-pack muscle, and that strip is exactly where forward pressure shows up as a ridge or a dome.
The same spike travels downward. That is why leaking, urgency and a dragging or heavy sensation often appear alongside a stubborn belly rather than separately. If that pairing sounds familiar, we cover it in more detail in how your pelvic floor and abdominal separation are linked.
What raises pressure and what manages it
| Raises pressure sharply | Helps manage pressure |
|---|---|
| Holding your breath through effort | Exhaling as the effort begins |
| Crunches, sit-ups and full planks too early | Deep core breathing and side-lying work |
| Ribs flared, back arched, chest lifted | Ribs stacked over the pelvis, neutral spine |
| Bracing hard and bearing down | A gentle lift and wrap, then breathe |
| Constipation and straining on the toilet | Fibre, fluids and no pushing |
| Jumping straight back to heavy lifting | Adding load in small, weekly steps |
Notice that nothing on the left is banned forever. Crunches are not evil, they are simply badly timed for a midline that is still remodelling, which is the argument we lay out in why crunches often make the pooch look worse.
Step 1: Learn what a neutral rib position feels like
Stand side-on to a mirror. If your lower ribs flare forward and your lower back arches, the top of your pressure container is tipped and the deep abdominals cannot work well. Soften the ribs down so they sit over your pelvis, without tucking your bottom or gripping. This position alone changes how force is distributed.
Step 2: Exhale on the effort
This is the single highest-value habit. Breathe out as you begin the hard part: standing up with the baby, lifting the car seat, pushing the pram up a kerb. The exhale lets your diaphragm rise and your deep core respond, instead of trapping air and forcing pressure outward or downward. Our walkthrough of deep core breathing as your first postpartum exercise takes you through the timing.
Step 3: Connect the deep abdominal wall before you load it
The transverse abdominis is the deep corset layer that wraps your waist and tensions the midline. Before a lift, exhale and gently draw the area between your hip bones back and up, as if closing a zip. It should feel subtle, not like a hard brace. If you are not sure what you are contracting, start with this plain-English explanation of the transverse abdominis.
Step 4: Watch your midline while you move
Lie on your back, knees bent, and lift your head. If a ridge rises down the centre of your belly, that is coning, and it is a live signal that pressure is escaping forward. Modify the movement or reduce the range until the ridge disappears rather than pushing through it. The difference between a narrow ridge and a broad bulge is worth knowing, and we untangle the terms in coning versus doming explained.
Step 5: Add load in small steps
Tissue adapts to gradual, repeated demand. That means progressing from breathing and side-lying work to bridges, to loaded carries, to heavier lifting over weeks, checking your midline and your symptoms at each stage. If a step brings back coning, heaviness or leaking, drop back one level and rebuild. Progress is rarely a straight line, and results vary from mum to mum.
Want this laid out as a plan?
Core Reconnect walks you through pressure-aware core rebuilding step by step, in short sessions you can do at home. One payment, no subscription, yours to keep. Use code GLOW20 for 20% off.
The takeaway
You do not need to fear pressure or avoid effort. You need to give pressure somewhere sensible to go: exhale on exertion, keep your ribs over your pelvis, wake the deep abdominal wall before you load it, and build up gradually. If coning, heaviness or leaking persists despite doing that, book a women's health physiotherapist rather than pushing harder.
Frequently asked questions
Is high intra-abdominal pressure dangerous?
Everyday pressure rises are normal and healthy. The concern postpartum is repeated, unmanaged spikes against tissue that is still recovering, which can show up as coning or pelvic floor symptoms. Managing the spike matters more than avoiding effort.
Does holding my breath when I lift make it worse?
Breath-holding traps pressure inside the abdomen with nowhere to release. Exhaling as the effort starts allows the diaphragm and deep core to share the load, which usually feels easier straight away.
Should I wear a belly binder to control pressure?
Some mums find short-term support comfortable in the early weeks, particularly after a caesarean. Support garments do not replace rebuilding the muscles, and wearing one very tightly can push pressure downward onto the pelvic floor. Ask your midwife, GP or physiotherapist about your situation.
Why do I leak when I sneeze but not when I exercise?
A sneeze is a very fast, very large pressure spike with almost no time to prepare. Slower exercise gives you time to exhale and engage. Leaking is common after birth but it is not something you have to accept permanently, and the NHS and ACOG both recommend seeking help for it.
How long does it take to feel more in control?
Many mums notice better coordination within a few weeks of consistent breathing and deep core work, while tissue changes take considerably longer. Give it eight to twelve weeks before judging progress. Results vary from mum to mum.
Sources: Sperstad JB et al., "Diastasis recti abdominis during pregnancy and 12 months after childbirth", British Journal of Sports Medicine, 2016. General guidance on postnatal recovery, pelvic floor symptoms and returning to exercise from the NHS, the American College of Obstetricians and Gynecologists (ACOG) and Cleveland Clinic.
This article is general education, not medical advice, and it is not affiliated with any program or clinic named elsewhere on this site. Results vary from mum to mum. Speak to your GP, midwife or a women's health physiotherapist before starting or changing postnatal exercise, and seek review if you have pain, a heavy or dragging sensation, leaking, or a midline gap that is not changing.