Core training after pregnancy – When to start, what to do, and why it matters

In this article, we break down the difference between your deep core – the stabilizers that protect your spine and pelvis – and your superficial core – the muscles that move you. You’ll learn how to activate the right muscles in the right order, so you can rebuild your strength safely and effectively.

The deep vs. superficial core

Think of your core as having two layers: deep and superficial.

Deep core muscles are your stabilizers:

• They work behind the scenes to keep your spine, pelvis, and organs supported.
• These include the transverse abdominis (a deep stomach muscle), pelvic floor, diaphragm (your main breathing muscle), and multifidus (small muscles along your spine).
• They help with posture, breathing, and controlling the flow of urine and feces (poop).

Superficial core muscles are your movers:

• They’re the ones you feel working when you do crunches or twists.
• These include the rectus abdominis (your six-pack muscles), obliques (side muscles), and erector spinae (muscles along your back).
• They help with bending, twisting, and generating power.

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When can I start core strengthening?

Most women can start gentle exercises for their deep core – the pelvic floor and transverse abdominis – within the first six weeks after giving birth. That said, it’s always best to check with your doctor or a pelvic health physical therapist before starting.

More traditional or stronger core training exercises (like crunches) are usually best left until at least 12 weeks postpartum – and then it’s important to ease into them slowly.

Strong core exercises (like full planks or sit-ups) should only be added once you’ve gained good strength and control with the easier ones.

If you’ve had a caesarean, you may need to progress even more gradually. Research shows that abdominal fascia – the thick, sinewy tissue that knits your stomach muscles together – has only regained about 51–59% of its original strength by six weeks post caesarean section and 73–93% by six months. Core exercises are very important after a caesarean, but you risk developing diastasis recti if you train too hard too soon.

Step 1: Learn to activate your pelvic floor

What do the pelvic floor muscles do?

Your pelvic floor muscles are the ones between your legs, stretching between your tailbone and pubic bone. They surround your vagina and the openings where you pee and poop.

These muscles:

• Help control bladder and bowel function – they stop leaks and help you hold in pee and poop.
• Provide support for your pelvic organs, including your bladder, uterus, and bowel. Without this support, these organs can move down too much (a condition called prolapse).
• Play a role in sexual function.
• Are important for core stability.

During pregnancy, the pelvic floor stretches, and it can also tear during a vaginal birth.

Why train them first?

All movements create pressure inside your abdomen. If your pelvic floor isn’t strong enough to handle this pressure, you may experience:

• Incontinence (leaking pee, poop, or wind)
• Prolapse (pain or a heavy, dragging feeling in your vagina from organs shifting downward)

That’s why learning to control your pelvic floor is step one before moving on to other exercises.

How to activate your pelvic floor

The easiest way to engage these muscles is by:

• Imagining you’re holding in a big pee – squeeze the muscles around your front passage.
• Imagining you’re holding in wind (a fart) – squeeze the muscles around your back passage (bum hole).

Pelvic floor muscles need to be both strong and responsive – they should be able to hold contractions for several seconds (for endurance) and react quickly (for things like sneezing or coughing).

The Core workouts in the Postpartum Training Plan of the Exakt app include exercises to train both endurance and quick contractions. You can also practice them 2–3 times a day in addition to the structured workouts.

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Instead, train them only a few times a day and focus on engaging them when needed – like when lifting something or bracing before a sneeze. Over time, they will start firing naturally when needed.

Step 2: Learn to activate the transverse abdominis

What does the transverse abdominis do?

Your transverse abdominis is like your body's built-in corset. It’s the deepest layer of your abdominal muscles, wrapping around your waist like a belt.

Its job? To protect your spine, support your organs, and control abdominal pressure.

For postpartum moms, the transverse abdominis is key for healing diastasis recti and regaining core strength.

If this muscle is weak, other muscles (like your six-pack or lower back) take over, which can lead to pain and poor posture.

How to activate it

• When you contract your pelvic floor, your transverse abdominis also kicks in automatically.
• You can increase this activation by gently drawing your belly button in and down (not sucking in, just a light tension).

The early Core workouts in the Postpartum Running Plan in the Exakt app teach this movement. Once you can activate your transverse abdominis, you’ll strengthen it further by adding the contractions to your other exercises.

Step 3: Don’t hold your breath

What does the diaphragm do?

Your diaphragm forms the top of your deep core. It’s your main breathing muscle and moves up and down as you breathe.

If you hold your breath during exercise, your diaphragm can’t work properly, which affects the rest of your core function.

How to train it

You can train your diaphragm by focusing on breathing into your belly. If you find this difficult, try the following:

• Place one hand on your chest and the other on your abdomen.
• Relax your shoulders and slowly breathe in, aiming to push the hand on your belly upward as you inhale.
• The hand on your chest will also rise slightly, but the one on your belly should move first and a bit more.
• Check that your neck and shoulders stay relaxed, then breathe out slowly.
• It’s often easiest to start this exercise while lying on your back, but you should eventually be able to do it comfortably in any position.

One can get really technical about when to breathe in and out during exercise, but we find that often just confuses and frustrates people, causing them to give up.

If you find yourself bracing and holding your breath, you’re likely using your superficial core rather than your deep core. This tends to happen when the exercise you’re attempting is too challenging for your current strength.

What does "Activate your core" mean?

You’ll often see instructions in the Exakt app (or online) telling you to "activate your core" during an exercise. But what does that actually mean?

Are you supposed to brace as hard as you can? No.

It simply means gently tensing your deep core (pelvic floor + transverse abdominis) before starting the movement.

This helps with control, stability, and proper movement patterns.

If you want to start running or ease back into it safely after giving birth, the Exakt Postpartum Running Plan is a great place to start. It’s a holistic program that combines strength, mobility, and running workouts designed specifically for postpartum women – helping you rebuild your core strength and fitness feeling strong, confident, and supported.

Research-based strength, mobility, and run training for postpartum women

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