Diastasis Recti: Why Ab Separation Happens (And What To Do About It)

July 25, 2021 - 10 minutes read

What is diastasis recti?

Diastasis = separation; recti = rectus abdominis

Diastasis recti occurs when the left and right sides of the “six pack” muscle (the rectus abdominis) begin to pull away from each other along the midline of the core. This creates a separation that runs vertically along the abdomen, and can be seen as a bulge down the middle of the stomach when you increase the pressure in your core (such as during a sit-up).

This condition is very common both during and following pregnancy, but can also affect newborn babies, older women, and men.

What happens if you have abdominal separation?

While diastasis recti isn’t usually a major cause for concern, it can contribute towards a number of common problems you may experience in your day-to-day life. These can include:

1. Stomach bulging

When the front of the core muscles pull apart, your abdomen loses some of it’s tension and it becomes tough for your muscles to support the pressure of your organs. This can therefore result in a “bulging” appearance in your midsection and may contribute to the look and feel of a more pronounced belly.

2. Strength and stability issues

A well-functioning core is an important part of helping you stay strong in your day-to-day movements. When diastasis is present, however, it becomes challenging to fire your ab muscles correctly, and you can begin to lose stability. This often results in lower balance, reduced overall strength, pelvic floor dysfunction, and even injury when lifting heavy objects.

3. Poor posture

Not only can diastasis affect your strength, it can also affect your posture. When you aren’t able to stabilize the front of your core, the pelvis will often dip downward into what we call an “anterior pelvic tilt”. This can result in an exaggerated arch through the low back and lead to a number of other compensations through the rest of the spine.

4. Low back or pelvic pain

Without a strong core to stabilize the midsection – and with the increased pressure that comes with poor posture – the low back has to take on a lot more strain throughout the day. This increased load causes these muscles to become overactive and can lead to joint irritation, pelvic discomfort and the all-too-common experience of low back pain.

Why does diastasis recti occur?

In order to fully grasp how diastasis recti happens, it’s helpful to understand how your abdominal muscles function.

Unpacking the core

Strategically placed in layers, the abdominals are made up of four muscles:

  • the transverse abdominis
  • the internal obliques
  • the external obliques
  • the rectus abdominis

Working together, these muscles help to stabilize the spine, crunch the trunk forward, bend the trunk to the side, and rotate the torso left and right. And this allows us perform everything from simple tasks, like getting up from a chair, to more complex movements, like throwing a baseball.

Separation of the rectus abdominis

The main area affected by diastasis recti is the front-most core muscle, the rectus abdominis (your “six-pack” muscle).

Running vertically down the centre of the abdomen, the rectus abdominis is made up of two parallel muscles that are separated down the middle by a band of connective tissue called the linea alba.

The linea alba is responsible for binding and supporting the front of the core. But when excessive pressure is present in the abdomen for a prolonged period of time (such as from an expanding uterus during pregnancy, intense pushing during child-birth, or repetitive lifting or exercising without proper recruitment of the deep core muscles), there comes a point where the linea alba is no longer able to resist that force. And, as a result, it begins to stretch apart and thin.

This is what drives the separation between the two sides of the six-pack muscle and eventually leads to the development of diastasis recti.

Who is at risk for ab separation?

Those who are most at risk for developing diastasis recti include:

  • Pregnant or postpartum women
  • People with weak core musculature
  • People with lumbar lordosis posture (excessive arching through the low back)

It’s perfectly normal for women who are pregnant to develop diastasis, but the severity of the split, and how long it lasts postpartum, often depends on a number of conditions, including:

  • Your height (taller people tend to split less)
  • The number of babies you’ve given birth to in the past (more pregnancies = high chance of separation)
  • The size or number of babies you’re carrying (multiple and/or larger babies tend to cause larger splits)
  • The amount of room you have in your abdominal cavity (the smaller the space, the more it has to split)

How to test for diastasis recti

If you’re curious as to whether you have diastasis recti, you can easily test for it at home using the following guide:

  1. Lie flat on your back with your knees bent
  2. Place the fingers of one hand just above your belly button
  3. Place the other hand on your upper thigh
  4. As you exhale, lift your head and shoulders off the floor and slide your hand down your thigh toward your knee (this will make your abdominal muscles tighten)
  5. Use your other fingers to feel the width of gap along the midline of your core

Then use these ranges to determine your level of diastasis:

< 2 fingers wide: No diastasis is present
2 to 3 fingers wide: Diastasis is present
> 4 to 5 fingers wide: Severe diastasis that might require specialized physical therapy

How to fix diastatis recti

While the linea alba itself can’t be strengthened through exercise, the muscles of the abdominal wall can, and this is often helpful in reducing the distance between the separated abdominals.

Disclaimer: if you have severe diastasis recti, be sure to check with your doctor or physical therapist prior to starting an abdominal rehabilitation program. 

Learn to activate your transverse abdominals

The transverse abdominis (TVA) is the deepest muscle of your core and one of the most important players in reducing diastasis recti. The TVA runs horizontally across the midsection and works to stabilize the core, meaning it basically acts like a muscular corset. Learning to activate and build strength in the transverse abdominis is basically like learning to tighten the corset, putting pressure back on the abdominal organs to reduce the strain against the linea alba.

Develop a connection to your pelvic floor

Much like the TVA, the pelvic floor is another often-overlooked set of muscles that are integral in helping you reduce abdominal separation. Positioned along the base of your pelvis, these muscles are responsible for supporting the pelvic organs from below, and learning to engage your pelvic floor allows you to reduce the level of pressure on the rest of your core.

Avoid movements that make it worse

While there are lots of exercises that can help reduce the strain on your rectus abdominis, there are others still that can exasperate the condition. In general, avoid exercises that significantly increase pressure in the abdomen or that encourage the coning of your core, such as crunches and sit-ups. Some recommendations also include refraining from working the oblique muscles as you would in a twist or “bicycle” abs exercise. Instead, opt for functional abdominal work, like squats while cueing to engage the TVA and pelvic floor.


If you think you may be at risk for diastasis recti, or have recently been diagnosed, consult your doctor on the appropriate treatment. If a conservative approach is recommended for you, exercise is a great way to start improving the strength of the abdominal musculature to help compensate for the looser linea alba.

Related: 6 Simple Exercises To Help Rebuild Your Core After Pregnancy