Why Ab Separation Happens—And How to Fix It

In many cases, the linea alba naturally regains tension after pregnancy and the gap separating the two rectus muscles closes on its own. But commonly, women will find that there remains a gully running down their midsection. Concern arises when this separation is more than two finger widths and a woman is unable to generate tension in her core to bring the two halves together, Haag said.

“When you have diastasis recti, you’re not fully supported in your middle, so your core is not able to function as effectively as it should,” Haag said. In running, this may translate to symptoms such as hip or low back pain, leaking urine, or a decline in performance. “If you have a diastasis, you may notice notice deficits in your running until you are able to generate tension through your core again,” Haag said.

There is a lot we still don’t know about why some women are affected by diastasis recti and others are not. And unfortunately, there is no surefire way to avoid having a significant gap or ensuring that it a diastasis will close naturally postpartum, Haag said. However, we do know some things that can help women guide how they take care of their bodies during pregnancy and afterward.

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Diastasis recti is caused by an increase in pressure against the intra-abdominal wall. While much of this is due to the baby pressing up against a woman’s belly, other forces can contribute to this pressure as well, including holding your breath during exercise and gripping your abs (holding your tummy tight). When you do any of these things, your deep core muscles (pelvic floor, transverse abdominus, and diaphragm) can’t work effectively as a system and pressure increases. “One of the best things women can do is to keep this system working as best as possible,” Haag said. (Click here for more information.)

It’s important for new moms to know if they have diastasis recti before returning to running or starting any workout routine. Many physicians and midwives don’t check for diastasis at a six-week postpartum visit, but you can perform the self-test here (see below) to determine if you have it.

If you do have a gap that’s cause for concern, Haag recommends seeing a women’s health or pelvic-floor physical therapist who can give you specific exercises to help with the healing process.

“A good physical therapist will break down the activity that you hope to do and integrate the components of the activity with the cause for concern,” Haag said. For patients hoping to return to running, Haag often starts by having them learn to breathe properly and generate tension through their core while on hands and knees, then incorporates movement of the extremities (such as in the bird-dog exercise), then progresses to single-leg balance work.  All of the exercises focus on finding the optimal position for their core to function with the pelvic floor and breathing, but this will vary from person to person.

“Treating diastasis recti is not about bracing the abs, it’s about helping a patient learn how to create tension and move the way they want to move,” she said.

You’ll also want to avoid any core work that causes your belly to “pooch” out, which for people with diastasis, commonly occurs during moves like sit-ups and crunches. “What you want to feel while doing ab work is that your stomach flattens out,” Haag said.

Before returning to running, Haag recommends first walking to see if you experience any leaking, heaviness in your pelvis, or low back or hip pain. If you don’t experience any issues with walking, then you can feel more confident returning to running, she said. Depending on your activity levels before and during pregnancy, you can gradually increase your distance and speed. “Please remember that as you progress, if you develop any pain or urinary leakage, talk to your physician and ask for a referral to physical therapy to make sure you’re doing all you can do to get back into the routine you love.”

“It’s important to know that if you have diastasis recti, it’s not your fault,” Haag said. “Have trust in your body. It’s going to heal and there are people who can help.”

How to Check For Diastasis Recti

1. Lie down on your back with knees bent at 90 degrees and feet flat on the floor. Place one finger (pointing downward) just below your ribcage.
2. Exhale and engage your pelvic floor (imagine you’re stopping the flow of urine), then lift your head and shoulders a few inches off the ground.
3. From this position, feel for the muscles on each side of your finger. You may feel that there is hardly any space at all, or there may be room to fit, two, three or more fingers between them. Note the distance (measured in finger-widths) between the muscles, as well as how deep you can put your fingers in the gap.
4. Lie your head down and rest.
5. Then repeat the test again, this time checking the area just above the navel. Continue checking for separation all the way down to your pubic bone.
6. If at any point, you feel a separation of more than two finger widths, this is considered a diastasis. The larger the gap and the deeper and more squishy the tissue between your abs, the more work you will need to do to restore function.