It wasn’t long after I became pregnant that I discovered the previously unknown-to-me world of diastasis recti exercises, which aim to prevent the separation of your front ab muscles that can occur during pregnancy. Beforehand, I never really thought about what exercises I should and shouldn’t do during my pregnancy. I knew it was crucial to listen to my body when exercising while pregnant; after all, pregnancy is full of bodily surprises, some due to relaxin, a hormone that increases during pregnancy that helps loosen joints to prepare your body (especially your pelvis) for delivery. But to me that meant going to my regular HIIT classes and sitting out the exercises that I didn’t feel comfortable performing—until I kept hearing one piece of advice from multiple trainers who specialize in prenatal workouts: If you’re pregnant, you should avoid doing crunches.
“Crunches are the worst thing possible” for pregnant women, explains Clarissa Smirnov, a certified prenatal Pilates instructor at Pilates ProWorks in San Francisco. Smirnov says she sees lots of clients ramping up their ab work during the first trimester, hoping they can build a strong core before their belly grows—but some exercises may lead to more separation, instead of less, and a tougher recovery.
Ali Handley, founder of BodyLove Pilates, agrees. “Major changes [that happen during pregnancy] mean that most traditional abdominal exercises that engage the six-pack are a big no-no as they only make ab separation bigger and harder to heal after you’ve had a baby,” she explains. Handley tells her clients to avoid crunches as well as planks and other prone-position moves if they aren’t strong enough to do them without keeping their belly buttons pulled in.
Why are crunches supposedly so bad during pregnancy?
As your uterus grows, your left and right rectus abdominus muscles (better known as the six-pack muscles) separate to make room for your expanding belly, a condition known as diastasis recti. While diastasis recti can occur in anyone, it’s a common side effect of pregnancy, and why many trainers believe that overworking your abs during pregnancy can worsen the separation. Diastasis recti feels like a gap between your muscles and can look like a bulge of skin or soft space in between your abs that you notice after delivery. Although not associated with pain, some studies have shown that it can be related to pelvic bone instability as well as weak pelvic floor muscles. Diastasis recti can repair itself after delivery, or you can seek out physical therapists or trainers that specialize in diastasis recti exercises that may help coax your abs back together (more on that below).
While most women will experience some degree of ab separation during pregnancy, some experts say modifying the way you exercise can help decrease the severity of your case. One study, for example, found that pregnant women who performed heavy lifting 20 times or more every week were more likely to experience ab separation than those who didn’t (the study didn’t define what researchers considered “heavy lifting”). Many trainers and physical therapists also recommend avoiding “conventional” ab exercises that may overwork the rectus abdominus abs—like crunches—in order to limit the amount of ab separation you experience during pregnancy.
The risks of crunches during pregnancy is still up for debate, however.
It’s important to note that what works for some women may not be the best for you; in fact, while there’s a fervent “no-crunches” camp, how to prevent or reduce diastasis recti is still up for debate. One study, for example, found that doing crunches in the late third trimester up to 14 weeks postpartum could actually be beneficial for narrowing the separation gap. “The reason crunches helped reduce [ab separation] may be related to the fact that [the move] is very specific for the rectus abdominis,” challenging those muscles more effectively than other ab exercises, explains study author Patrícia Mota, Ph.D., to SELF. And a recent review of studies on diastasis recti found that there’s currently not enough evidence to make a case for one method of exercise over another to prevent diastasis recti, although the authors did find that general exercise after pregnancy was beneficial for reducing any ab separation.
Want to avoid crunches anyway? Here are two exercises you can do to help prevent diastasis recti.
Having a strong core during pregnancy has many benefits: Not only can having strong abs and pelvic floor aid in labor and delivery, but it can also help you recover faster and help avoid posture problems once you’ve given birth. So, if you’re trying to build a strong core during your pregnancy and don’t want to do crunches, what should you do instead? Smirnov advises her prenatal clients to do diastasis recti exercises that target obliques (the muscles on the side of your torso) and transverse abs (the innermost layer of ab muscles located underneath the rectus abdominus “six-pack” muscles). Smirnov’s favorites include side planks as well as “anything that challenges your core in a functional way, putting your core in a stable position—then you can move your limbs around.” If you’re new to working out, Smirnov recommends the single-leg stretch; more advanced exercisers can benefit from planks or exercises where you’re on all fours, like the bird dog.
1. Side plank
Photo by Whitney Thielman
This exercise focuses on your obliques. Here’s how to do a side plank:
- Start on your left side with your left elbow below your left shoulder and your feet stacked.
- Lift your hips into the air. Keep your right foot on the floor for balance if needed.
- Continue to press hips up while keeping your core tight. Don’t forget to do both sides.
2. Bird dog
Photo by Whitney Thielman
Smirnov favors prenatal exercises that keep your torso stable while your limbs move. Handley also encourages her prenatal clients to do this move. “The goal is for your spine to stay the same as you move the limbs,” she says. Here’s how to do the bird dog:
- Start on your hands and knees in tabletop position with your wrists above your shoulders and your knees below your hips.
- Inhale and extend your right arm forward and left leg back, maintaining a flat back and square hips.
- Squeeze your abs and exhale as you draw your right elbow to your left knee.
- Extend back out to start. Don’t forget to do both sides.
Don’t feel the need to avoid crunches during your pregnancy? Take this advice from Mota, who says precise movement could be the key to ensuring crunches heal rather than increase ab separation: Your crunch should be a controlled movement rather than a full sit-up move. “Inhale and exhale. Lift your head and slide your hands along the front of your thighs to touch your knees with the fingertips, until you feel your shoulder blades off the table. Hold there for three seconds,” she advises.
No matter what, do what works for you.
Exercise throughout pregnancy has been proven to help you have a healthier nine months overall. Bottom line: If you’re pregnant and your doctor says it’s OK, exercise is always a good choice, but it helps to weigh the pros and cons until you find a fit for you. “Although today a lot of information is available about pregnancy and postpartum exercise programs, I don’t believe in ‘miracle solutions’ for the general population,” says Mota. “Pregnant women should be evaluated individually to understand which exercise better suits their condition.” This is where listening to your body becomes especially important. “My rule of thumb with all prenatal clients—if something doesn’t feel good, don’t do it,” advises Handley. “You should never work through pain.” For me, that meant signing up for prenatal Pilates classes and heeding Smirnov’s advice to work on my transverse abs—and saying a temporary goodbye to my favorite six-pack-focused boot camp classes.