Have you seen a pregnant woman do a move dubbed the belly pump? This technique calls for an expectant mom to engage her abdominal muscles and inhale very deeply, which in some cases make her bump nearly disappear until she exhales. Cue jaw drop.
Don’t call it a fun party trick. The belly pump is one of several foundational techniques designed to strengthen a woman’s core during pregnancy and after delivery. The moves were created by pre- and postnatal exercise specialist Brooke Cates of the Bloom Method in Boulder, Colorado, and images of women doing them are going viral.
The idea behind the Bloom Method is to combine deep, diaphragm-contracting belly breathing with core activation (meaning you exhale while still contracting your core abdominal muscles), says Cates. “It retrains the deep core muscles called the transverse abdominals to come in like a corset, and teaches the external muscles to lay flat,” she says.
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The benefits, according to Cates, include a reduced risk of abdominal separation (when the two bands of muscle that join at the abdomen separate, often because of pressure from a mom-to-be’s growing uterus), more strength for pushing during labor and delivery, and quicker healing after birth. The Bloom Method website also says it can reduce stretch marks and loose skin.
Yep, the images of a very pregnant woman inhaling and exhaling as her bump shrink and grows again are pretty bizarre. But is the technique safe, and does it live up to its claims?
“There’s no danger to doing it,” says Michael Cackovic, MD, director of the maternal cardiac disease in pregnancy program at The Ohio State University Wexner Medical Center. “The baby is extremely protected—there’s nothing you can do from the standpoint of using your abdominal wall that will hurt the baby,” he says.
While Dr. Cackovic isn’t aware of any research backing up the supposed benefits, he does support the overall concept. During the pushing stage of labor, doctors typically spend the first 15 to 20 minutes teaching women how to push, he explains. If you’ve strengthened your core muscles throughout pregnancy, you may be able to push more efficiently and not need those extra minutes learning how to do it.
Cates also says that the Bloom Method teaches clients to stay connected to their deep core muscles, something that helps a woman’s body bounce back faster after birth, she adds. The “muscle memory” learned from training your core will also help your muscles regain strength after birth faster, and that helps you return to your pre-baby shape.
“My moms send me photos two weeks after birth and sometimes their six-pack is showing,” says Cates.
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Whether this is indeed true for most women or not, Dr. Cackovic does agree that exercising and being more fit throughout pregnancy is predictive of how fast you recover. “Based on the fact that this focuses on core development, I think it would be more effective than other workouts whether you had a vaginal or C-section birth,” he says.
Ultimately, whether a woman practices a technique like the Bloom Method or another type of exercise may not matter as much as if she’s exercising at all. Research shows that women who work out when they’re pregnant for 35 to 90 minutes three to four times per week reduce their likelihood having a C-section, gestational diabetes, and high blood pressure—without upping their risk of complications.
This article originally appeared on Health.com