‘I’m a Pilates Instructor, and This Is the Number One Core Workout Rule I Want You To Forget About’

If you’re used to flattening your back into the mat while doing core exercises during strength training or HIIT workouts, your first Pilates class can be a wake-up call. One of the primary things your instructor teaches you is the importance of maintaining a neutral spine—yes, even while doing core exercises that require lying on your back.

The problem with “imprinting,” or pressing your low back into the floor, is that it reduces the range of motion your core muscles can move through. And in exercises that require you to lift your legs into the air, it can also take some of the work out of your core and put it into your hip flexors, causing them to grip. “It’s not terrible if you feel your hip flexors, but we just want to feel abdominals primarily,” says Brian Spencer, an instructor at East River Pilates and a Well+Good Good Moves trainer.

So what exactly is neutral spine?

As the name implies, neutral spine is the position in which your back maintains its natural curvature without you over-flexing or extending it—so no tucking your tailbone under to flatten your low back into the mat, and no arching unnecessarily through your mid-back and ribcage.

Spencer says that, often, the issue people have is extension, meaning they arch and lift their low back off the floor to compensate for core muscles that aren’t quite able to manage the workload required of them. This is one reason strength and HIIT trainers often cue to flatten your low back into the mat, but that tweak takes the work out of your core and strains your low back muscles.

An example of this is during leg lifts when you try to lower your legs farther than your core can handle and your low back starts to come up higher to counterbalance the weight. Instead, “make sure you’re working in a range of motion that your abdominals and core stabilizers can support,” Spencer says.

How to find neutral spine

“Neutral spine is your pubic bone stacked right on top of your tailbone—it’s not trying to go in between the legs or toward the belly button,” Spencer says. Until you have a sense of what neutral spine feels like in your body, one of the ways instructors like to help students find the correct position is by having them perform pelvic tilts.

Spencer shows you how to do this in the video below:

Essentially, you alternate between tipping your pelvis away from you and then tilting it toward you while lying on your back with your legs bent and feet flat on the floor. Imagine you have a bowl of water sitting on your pelvis: You want to let your pelvis rock away from you, spilling water onto your thighs, then pull it toward you to pour water into your belly button.

“This is to help us really memorize our low backs and pelvises so that we can understand when we’re in too much extension or too much flexion,” Spencer says.

Neutral spine is in between these two extremes, but it’ll feel different for everybody. You may have more or less of a natural curve in your lumbar spine, so the space between your low back and the mat may be bigger or smaller than someone else’s. But as a general rule, you want to feel like you could place a blueberry in that pocket of air and not squish it while you’re working out. Or, as Spencer puts it: “Find a gentle space between your low back and the mat.”

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