Updated January 11, 2025
Understanding what “core exercises to avoid” is by far one of the most common questions asked during pregnancy. So, this post will guide you through a simple rubric that can help you make more informed choices about what core exercises are right for you and reduce the fear that tends to accompany prenatal core work.
Read on to learn:
- The importance of having a strong core during pregnancy (and the #1 most effective core exercise)
- How pregnancy impacts your core
- Core exercises to avoid or modify (once you develop a belly)
- How to determine when it’s time for YOU to modify a certain exercise
The Importance of Having a Strong Core During Pregnancy
Before we get into what to avoid, we do want to emphasize the importance of building and maintaining a strong core that can withstand the stresses of pregnancy and childbirth, and recover more quickly afterward. A strong core can be the key to mitigating pains and injuries during pregnancy, facilitating an easier childbirth, helping you recover faster, and enabling you to more easily carry out the (very physical) demands of life with young children. To get you started, master the #1 most effective core exercise.
How Pregnancy Impacts Your Core
The two biggest contributors to your prenatal core changes are the increase in intra-abdominal pressure (IAP) and the shifts in your alignment. Let’s discuss each.
1. Intra-Abdominal Pressure (IAP) Increase
When a body gains weight during pregnancy, it is primarily centered in the abdominal cavity. This added mass increases the pressure in that cavity, or intra-abdominal pressure (IAP). The increased pressure pushes outward onto the abdominal wall, which makes the left and right sides of the rectus abdominis (or “6-pack” muscle) spread further apart. You can see this in the right image below.
This “widening” of the gap between the left and right sides of the rectus abdominis muscle is known as Diastasis Recti (DR). A certain amount of DR is a normal and necessary part of pregnancy in order to make space for a growing baby. However, it’s important to minimize activities that further elevate this pressure, as this could make DR become more difficult to heal in the postpartum period. So, that is where some of our core exercise modifications come in.
2. Alignment Shifts
The other factor impacting core exercise modifications is that the growing belly tends to tip one’s pelvis forward — as you can see in the image below — which compresses the tissues in the low back (ouch!) and stretches the abdominal tissues (which already have stress on them from the increase in IAP that we just discussed). This gets compounded as weight gain increases.
Core Exercises to Avoid and Modify (Once You Develop a Belly)
The stresses discussed above come as a result of a growing belly. Therefore, the core exercise modifications pretty much start once you develop a belly. The goal is to stay strong while being sensible about your exercise choices so as not to place additional stress on your core. Here are some general guidelines that can help you do so. Once you develop a belly, begin to avoid the types of movements listed below.
***IMPORTANT NOTE***
The guidance below is for “loaded” movements (strengthening exercises). Unloaded movements in these positions — like a cat-cow stretch, side-stretch, or twisting to crack your back — are perfectly fine.
Spinal flexion (crunching)
Sit-ups and crunches are obvious examples, as well as any other forward rounding that targets the abdominal muscles.
Lateral flexion (sideways bending)
Just as forward bending elevates pressure in the core, so too does loaded side-to-side bending.
Spinal extension (arching)
While this is not a “loaded movement,” deep stretches like a backbend or full upward dog stretch the linea alba tissue (between the left and right sides of the rectus abdominus muscle) too much and could further widen the gap.
Twisting
This means rotation with dissociation of hips and shoulders (hips move one way, shoulders move the opposite way). Rotation with your hips and shoulders in line – where your entire trunk moves as a unit — is perfectly safe to do throughout pregnancy. For further clarification, see Is Twisting Safe During Pregnancy?
Full center planks (modify)
Most people will likely need to begin modifying full planks once there is a medium size belly — especially center planks given the direct downward facing pressure on the belly (though many people will need to modify side planks as well at some point). There are two key signs that indicate a need to regress (or take it down a notch): 1) loss of neutral alignment (losing the straight line between ear-shoulder-hip-knee-ankle, as you see in the photo below) and 2) “coning” in the belly (see the next section below for details). You can modify planks by performing them on your knees or on an incline.
Advanced back-lying or incline core work
Many core exercises performed on your back or on an incline – like the “Pilates 100s” and V-sit shown below — do not involve any crunching, arching, bending, or twisting, yet they still create excess IAP because of the degree of stress they place on the abdominal muscles. Therefore, these intense core exercises will also likely need to be modified and eventually avoided.
How to Tell When it’s Time for YOU to Modify an Exercise
It is impossible to provide a list of black and white “rules” that apply to every single person. Therefore, we provide the best general guidance we can, but then it is up to you to make the best decisions for your body — based on your activity history, belly size, conditions, etc.
One very helpful tool to use is to watch for coning or a vertical torpedo-like protrusion down the center of your abdomen, as shown below. This is a sign that the movement being done exceeds the capacity of the core muscles at that time. If you see this — at any point (not just during pregnancy) – stop the movement, and regress (take it down a notch) until you no longer see the coning. This can be very helpful for determining when you need to start regressing exercises like planks.
Get the Complete Guide: Moves to Avoid by Trimester
For more details on core exercises — as well as comprehensive guidance on activities, behaviors, and other exercises to modify or avoid — grab our Moves to Avoid by Trimester Guide. You’ll not only learn what to avoid or modify, but you’ll also get evidence-based rationale as to why. Then, you’ll learn additional signs to look for that indicate it’s time to regress or stop a movement so that you can make the best decisions for YOUR body.
Want a Complete Workout Program?
Remove all the worry about what to avoid or modify, and get safe and highly effective workouts throughout your pregnancy journey with our Prenatal Workout Programs. Just select the program that’s right for you based on your stage when starting and you’ll be guided through a structured training program complete with three total body workouts per week, nutrition guidance, childbirth education, and more.
Are You a Health & Fitness Professional?
If you are a health & fitness professional interested in learning how to coach pre & postnatal clients, explore our Pre &Postnatal Education & Certification for courses, resources, and community to help you build your pre & postnatal fitness expertise.