Strengthening core muscles is about so much more than what meets the eye. Actually, the reason we have core muscles has nothing to do with what meets the eye: It has to do with the body’s balance and stability. And, improving core strength can increase both. Having a strong core can also help with posture and, as a result, help diminish back and even neck pain. Although traditional ab workouts — such as bicycle crunches and planks — can help strengthen and tone the core area, core strength has a secret sauce and it’s called inversions.

Inversions 101

When we think of inversions, we might first think about being upside down. And, while that is technically what an inversion is, there are a few more things to it in the name of fitness. “Inversions may make you think of a full headstand in an advanced yoga class, [but] the actual definition is much broader,” says Shari Castelli, a fitness instructor, certified nutritionist, and director of Industry Development at ClassPass. In exercise, inversions can mean going upside down, but they can also simply consist of movements that put you in the opposite position. “An inversion is any posture (or move) where your hips and head are above your heart, meaning that your body is ‘inverted’ as compared to normal,” says Castelli.

Examples of inversions range from more advanced movements such as hanging upside down in an aerial class or CrossFit training, and simple poses like a child’s pose or downward-facing dog in a yoga class.

How Inversions Strengthen the Core

“Inversions help with core strength and alignment by leveraging gravity to reduce muscle tension and bring your body back into balance,” Castelli explains. “Maintaining balance and alignment in an inverted position can help train key groups of muscles to work — and strengthen — together, including your pelvis, hips, abs, and lower back,” Castelli adds, noting how all of these muscles working synergistically together is “what truly makes up a strong core.”

Another reason why inversions can be so beneficial to core strength is because of the impact it has on the pelvic floor, aka the deep core. “When people refer to the pelvic floor, they are talking about a group of muscles that make up your ‘deep core’ and support the internal organs above your pelvis,” says Caselli, adding that inversions are a great way to strengthen the deep core. “In a full inversion, the weight of gravity is removed from your pelvic floor muscles, allowing you to relax the area while also improving your blood circulation,” Castelli notes. “You can also do a more subtle inversion in the form of exercises, like a glute bridge, for example, which strengthens your pelvic floor muscles without turning yourself totally upside down.”

The reason why the pelvic floor is so important — and how inversions can be the key to a stronger core — is because “your pelvic floor makes up the base of your core,” says Castelli. The job of the pelvic floor is to “work with your deep abs, back muscles, and even your diaphragm to help you move well and stay in alignment,” she adds, noting that a healthy pelvic floor is strong and flexible, making it all the more resilient. And, having a resilient deep core can “help you connect with and activate more of your abdominal muscles while also maintaining good form” when working out.

By going upside down or practicing movements that get your hips above your heart, you can further improve the efficacy of the more traditional core workouts, such as planks and crunches. And, as a result, the core can become even stronger.