How Pregnancy Affects Your Core – and How to Train It Safely
By Sarah Percy, (Doctor of Physiotherapy, Bachelor of Exercise Science)
Women’s Health Physiotherapist & Director, Female Physio Co.
Abdominal separation - more formally known as diastasis recti abdominis muscle (DRAM) - is one of the most common physical changes experienced during pregnancy. Despite how widespread it is, there remains a significant amount of confusion, fear, and outdated advice surrounding it - especially when it comes to core and strength training during pregnancy.
Let’s make one thing clear: yes, you can and should train your core during pregnancy. When performed safely and with proper guidance, strength training is one of the most effective strategies for preventing and reducing excessive abdominal separation, while supporting your body through the demands of pregnancy and birth.
What Is Abdominal Separation?
As your uterus grows, increasing pressure is placed on your abdominal wall. To accommodate this, the linea alba - a central band of connective tissue between the two sides of the rectus abdominis (your "six-pack" muscle) - naturally stretches and thins. This stretch, not a tear, is what leads to the separation commonly referred to as diastasis recti.
What Is a Normal Amount of Diastasis?
A 2023 systematic review by Wang & Wang assessed abdominal separation in women who had not been pregnant. They found that the inter-recti distance (IRD) naturally ranges from 1.6mm to 11.7mm (just over 1 cm). This tells us two important things:
- Many women already have a baseline level of abdominal separation prior to pregnancy.
- We shouldn’t expect our postpartum bodies to match the anatomy of someone who has never experienced pregnancy. Abdominal separation is a normal, adaptive part of growing a baby - and our “new normal” postpartum doesn’t mean something is wrong.
Further supporting this, a study by Mota et al. found that women assessed at 6 months postpartum (after their first pregnancy) had IRD values two to three times greater than their pre-pregnancy measurements. For example, a woman with a 1 cm separation pre-pregnancy may measure 2–3 cm postpartum - and this can be completely normal.
Can I Do Core Exercises During Pregnancy?
Yes - and you absolutely should. Once upon a time, abdominal exercises were discouraged during pregnancy.
Fortunately, we now understand that functional, targeted core and strength training can:
- Minimise excessive abdominal separation
- Support spinal alignment and postural control
- Reduce common pregnancy-related aches and pains
- Improve labour outcomes (such as pushing efficiency)
- Enhance postnatal core recovery Recent research even shows that cued abdominal contraction - activating your abdominal muscles deliberately - can shorten the second stage of labour (pushing phase).
How to Train the Core Safely in Pregnancy
1. Train the Entire Core Unit
Your “core” is more than just your rectus abdominis.
It includes:
- Transversus abdominis (deep core stabiliser)
- Internal and external obliques
- Paraspinals (muscles along your spine)
- Pelvic floor (an essential player in core function)
- Diaphragm
An effective core program should activate and strengthen all of these muscle groups.
2. Manage Intra-Abdominal Pressure
The key to safe core training during pregnancy lies in breath coordination. Breath directly influences pressure within the abdominal cavity, and if unmanaged, that pressure can strain the linea alba or pelvic floor.
Here’s a basic rule:
- Exhale during the effort (the hardest part of the movement)
- Inhale on the return or relaxation phase
For example, during a crunch:
- Exhale as you lift your chest
- Inhale as you lower down
This breathing strategy ensures you’re engaging your core effectively, protecting the abdominal wall and pelvic floor from excessive strain.
Sample Core Exercises for Each Trimester
Before 20 Weeks
These movements can typically be performed on your back if you feel comfortable and symptom-free:
- Abdominal crunches
- Bicycle legs
- Planks and side planks
- Heel taps
- Mountain climbers
- Toe taps with core activation
- 4 Point Kneel Hover
After 20 Weeks
As your pregnancy progresses, modify positions and reduce time spent lying on your back:
- Modified planks (on knees or elevated surface)
- Bird-dog (on all fours)
- Pallof press (anti-rotation)
- Incline mountain climbers
- Kneeling hip hinge with a posterior pelvic tilt
- Wall sits with core and pelvic floor engagement
Each of these exercises strengthens the deep core unit while maintaining healthy pressure, alignment, and posture. They’re also excellent for supporting pelvic floor coordination and function.
What About ‘Doming’ or ‘Coning’?
Doming or coning refers to a visible bulge along the midline of your abdomen during core engagement. It often occurs when intra-abdominal pressure increases and is not properly managed. A small degree of doming may be unavoidable at times, but repetitive or excessive doming should be monitored closely. Always check in with a Women’s Health Physiotherapist if you notice excessive coning during your workouts - especially if you're unsure how to adjust the exercise or modify your technique.
Final Thoughts: You Are Not Fragile - You Are Adaptable
Pregnancy is not a time to avoid movement - it’s a time to train intentionally and confidently. With the right guidance and education, your body is capable of incredible adaptation and strength. If you’re unsure where to start, I highly recommend seeing a Women’s Health Physiotherapist. A tailored assessment of your abdominal wall and pelvic floor can help you build a core training plan that supports your goals during pregnancy and postpartum. Your body was made for this.
Let’s help you feel strong and supported - every step of the way.
Ready to start your journey? Join our Pregnancy Program today!
References:
Wang, Y., Wang, Y., 2023, Systematic review and meta-analysis of the inter-recti distance on ultrasound measurement in nulliparas, J Plast Surg Hand Surg, 57 (1-6):22-28.
Theodorsen, N.M., Bø, K., Fersum, K.V., Haukenes, I., Moe-Nilssen, R., 2024, Pregnant women may exercise both abdominal and pelvic floor muscles during pregnancy without increasing the diastasis recti abdominis: a randomised trial, J Physiother. 70(2):142-148.
Youssef, A., Montaguti, E., Dodaro, M.G., Kamel, R., Rizzo, N., Pilu, G.. 2019, Levator ani muscle coactivation at term is associated with longer second stage of labor in nulliparous women, Ultrasound in Obstetrics & Gynecology.53(5):686-92.
