Can You Do Crunches With Diastasis Recti?

The Advice You’ve Probably Heard

If you have diastasis recti, you have almost certainly been told some version of this: Don’t do crunches. Don’t do sit-ups. Don’t do planks. Only do transverse abdominis work. Avoid anything that makes your belly dome.

This advice is everywhere — on Instagram, in mom groups, on popular postpartum fitness programs. It sounds careful and protective. And for years, it was the standard recommendation from physical therapists too.

But the research has moved on. And what it shows might surprise you.

What the Current Research Actually Says About Crunches

Here is the part that contradicts most of what you will read online: crunches can actually help bring the rectus abdominis halves closer together.

The mechanism is straightforward. When you do a crunch, your rectus abdominis muscles contract — they shorten. A shorter muscle is physically narrower. That narrowing pulls the two halves of the muscle closer to the midline. The muscle is literally getting smaller in width as it shortens in length.

This is not speculation. Research measuring inter-recti distance during exercise has shown that the gap between the muscle halves can decrease during a crunch compared to a resting position.

“But Crunches Create So Much Pressure!”

This is the other piece of the old advice that does not hold up: the idea that crunches create dangerous intra-abdominal pressure that pushes the organs against the weakened midline.

When researchers actually measured intra-abdominal pressure during different exercises, here is what they found: the pressure during a crunch is lower than during an overhead press. It is lower than during a sneeze. It is lower than when you pick up a toddler from the floor.

If the concern is pressure on the linea alba, then we should be telling women to avoid sneezing and picking up their children — not crunches. Obviously, that makes no sense.

The pressure argument was based on reasonable-sounding theory, not actual measurement. When the measurements were done, crunches turned out to be a relatively low-pressure exercise.

What Happens When You Avoid Ab Exercises

Here is what nobody talks about: not exercising your abs can make diastasis worse.

Muscles that are not loaded become weaker, thinner, and less capable of generating tension. If your rectus abdominis is already separated and stretched, and then you stop using it entirely out of fear, you are removing the stimulus it needs to rebuild.

Dr. Danaya sees this regularly in her practice. Women come in having avoided all abdominal exercise for months or years — often because a well-meaning Instagram post terrified them — and their separation has not improved at all. In some cases, the avoidance has made things worse because the muscles have gotten weaker from disuse.

Your rectus abdominis needs progressive loading to recover. Not reckless loading, not maximum-effort sit-ups on day one postpartum — but thoughtful, progressive exercise that challenges the muscle and gives it a reason to rebuild.

The “Transverse Abdominis Only” Myth

For a long time, the standard protocol for diastasis recti was exclusively transverse abdominis (TA) work — gentle bracing exercises, drawing-in maneuvers, and strict avoidance of all rectus abdominis activation.

The idea was that the TA wraps around the torso like a corset, and strengthening it would pull everything back together. And the TA is important — it plays a real role in core stability and midline support.

But the TA is not the only muscle that matters. Current research supports a combined approach: training the transverse abdominis, the rectus abdominis, the obliques, and the deep back muscles together. Your core is a system, and treating one muscle in isolation while ignoring the others produces limited results.

Dr. Danaya’s approach reflects this updated evidence. She assesses how the whole core system is functioning — not just the TA — and builds a rehabilitation program that loads all the muscles appropriately. Because pelvic floor weakness and core dysfunction are connected, her assessment looks at the complete picture.

So Why Is the Old Advice Still Everywhere?

Because the internet moves slowly and fear spreads faster than research.

The “avoid crunches” advice became so widespread and so deeply embedded in postpartum fitness culture that it developed a life of its own. Fitness influencers share it. Well-meaning friends repeat it. Some PTs who have not updated their continuing education still teach it.

And there is an emotional component: telling a postpartum woman to “be careful” and “avoid dangerous exercises” feels protective. It feels safe. Telling her that she can and should load her abs — that feels risky, even when the evidence supports it.

But protective advice that keeps women from exercising is not actually protecting them. It is limiting their recovery.

What You Should Actually Watch For

None of this means “go do 200 crunches tonight.” The research supports crunches as part of a progressive rehabilitation program, not as a reckless free-for-all.

The thing many women are told to watch for is doming or coning — when the tissue along your midline pushes outward during an exercise, creating a visible ridge or tent shape. You may have heard this means you should stop immediately.

Here’s what the research actually says: a 2023 study by Vesting et al. found that linea alba bulging and distortion are not associated with dysfunction. Doming does not mean you are injuring yourself, and it does not predict worse outcomes. It is simply what happens when load exceeds your current capacity at the midline — not a sign of damage.

That said, doming can be a useful signal to guide your programming:

• Reduce the intensity or range of motion if it feels like too much
• Try exhaling through the effort to better engage your deep core
• Consider whether you need a different progression step before this exercise
• Watch for leaking as another sign the load may be too much for your current capacity
• Work with a pelvic floor PT who understands diastasis to find the right modifications

Doming is a signal to modify your approach, not a reason to stop all ab work forever. And it is definitely not a sign that you are making your diastasis worse.

What a Good Diastasis Recti Assessment Actually Looks Like

One of the most common things Dr. Danaya sees is women who have been living in fear of their diastasis — avoiding exercises, wearing splints, feeling broken — and when she actually assesses them, their separation is within a normal range and their core is functioning well.

A proper assessment measures more than just the gap width. It looks at:

• Gap width above, at, and below the belly button
• Tissue tension — how much resistance the linea alba generates (this matters as much as width)
• Core function — can you generate tension, transfer force, and control your trunk during movement?
• Whole-body patterns — how your breathing, posture, hips, and back affect your core function

Many women leave their first session feeling relieved — not because their diastasis magically disappeared, but because they finally have accurate information instead of internet-fueled fear. As Dr. Danaya puts it: some patients come in terrified by what they read online, convinced something is seriously wrong, and within a few visits they understand what is actually happening in their body and feel confident exercising again.

The Bottom Line

The old advice — avoid crunches, only do transverse abdominis work, treat your core like it is made of glass — was well-intentioned but is not supported by current evidence.

Crunches can help close diastasis recti. Avoiding exercise can make it worse. Your core is a system that needs whole-system training, not single-muscle isolation.

If you have been avoiding ab exercises out of fear, you are not behind and you are not broken. But you may be missing out on the thing that would actually help your recovery: progressive, evidence-based loading of the muscles that need it.