Goodbye, Crunches and Sit-Ups—This Is the Move Pilates Instructors Use To Sculpt Deep Core Muscles

When it comes to ab exercises, a lot of people focus on the rectus abdominis, which is science speak for six-pack abs. While there’s no shame in wanting a toned stomach, true ab strength means having a strong deep core too. 

The “deep core” is located beneath the six-pack muscles and helps stabilize the body. If you struggle with maintaining good posture for an extended period of time, that’s a sign that you could benefit from strengthening your deep core. Having a strong deep core makes it easier to maintain good posture and can prevent or reduce lower back pain.

Related: Abs of Steel! Here Are 8 of the Best Core-Defining Workouts You Can Do at Home

“In Pilates, the deep core muscles are known as ‘the powerhouse.’ The powerhouse is more than just your abs. It is a coordinated system that includes your abdominals, back muscles, glutes and pelvic floor,” says Erica Walters, NCPT,a level-three certified Pilates instructor and the owner of Pilates Fit Studio in Kentucky. 

Walters explains that a strong deep core creates stability, which allows arms and legs to move with strength, control and grace. “Without a connected center, your arms and legs are working in isolation. With a connected center, every movement becomes more powerful and more efficient,” she tells Parade.

Lauren King, NCPT, a Pilates instructor at Strong Pilates Commack in Commack, New York, adds to this, saying that a well-functioning deep core supports posture, helps distribute load through the spine and allows the body to move with better control and coordination. “Its main role is stabilization. These muscles activate to control and support movement, which is how the core functions in everyday activities,” she says.

Want to strengthen your deep core? There’s a Pilates move that’s more effective than crunches.

Related: Here’s How Often You Actually Have to Work Out Your Abs To See Results—and the Best Moves to Try

Is Pilates a Good Workout for Strengthening the Deep Core?

If you want to strengthen your deep core, Walters and King both say that Pilates is a great workout to do regularly. “Rather than isolating the core, Pilates integrates it into full-body movement. This helps build strength that carries over into daily life,” King says.

She explains that Pilates focuses on control, alignment and breath, which helps engage the deeper stabilizing muscles, including the transverse abdominis and pelvic floor.

Classic Pilates was literally designed to strengthen the deep core. “The system uses your own bodyweight along with spring resistance on the apparatus to build deep, connected strength,” Walters shares.

Scientific research shows that practicing Pilates regularly can truly strengthen the deep core. In a 2025 scientific study published in the journal Medicina, one group of healthy adults did Pilates three times a week for six weeks. A second group did aerobic-based exercises three times a week for six weeks. At the end of the six weeks, the Pilates group had a significant improvement in core strength, which was measured through muscle thickness, contraction timing and contraction ratios.

A 2023 scientific review published in the journal Healthcare also found that doing Pilates regularly can strengthen the deep core and can help improve lower back pain too.

Related: Sit-Ups Are So Yesterday! These 6 Exercises Will Target and Flatten Your Lower Abs

The Best Pilates Move for a Stronger Deep Core, According to Instructors

Walters’ favorite move for strengthening the deep core is called “the hundred,” and it can be done using a mat—no reformer needed.

“’The hundred’ demands that your ‘powerhouse’ hold your entire body in position while your arms move independently. It is a masterclass in connected strength,” she says. Here’s how to do it:

The Hundred

1. Lie on your back and hug your knees to your chest.
2. Lift your head and shoulders, thinking only of moving the thoracic spine (the part of the spine spanning from the base of the neck to the bottom of the rib cage). This is important to avoid straining your neck. 
3. Extend your arms long by your sides, hovering just above the mat. Then, extend your legs to a 45-degree angle.
4. Begin pumping your arms vigorously up and down. Inhale for five counts, exhale for five counts. That is one set of 10. Repeat 10 times to reach 100.

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2 Other Expert-Backed Pilates Moves for Sculpting Your Deep Core

Another deep core-strengthening move that Walter recommends? It’s called “the teaser.” This move can also be done on a mat and does not require a reformer.

“‘The teaser’ asks the ‘powerhouse’ to control the entire body, folding and unfolding from the center. There is nowhere to hide,” she says. Here’s how to do it:

The Teaser

1. Start by lying on your back with your knees bent and your feet flat on the floor. 
2. Begin by working only the upper body: Roll up and down three times, articulating through the spine. 
3. Add the lower body by lifting one leg at a time, pressing into the standing leg for stability, and rolling up and down three times on each side.
4. From there, you can build on to the move to make it even more challenging. To do this, lie on your back with your legs extended at a 45-degree angle. Roll your upper body up to meet your legs in the V shape, then roll only your upper body back down while your legs stay in place. Repeat three times.

And one of King’s favorite Pilates moves for strengthening the deep core is the “dead bug.” This exercise move (which doesn’t require a reformer) strengthens the deep core without putting pressure on the spine or neck.

“The goal is to keep your spine stable throughout the movement. This trains the core to resist movement while the limbs are in motion, which is key for building stability and control,” King tells Parade.

Dead Bug

1. Lie on your back with your arms reaching toward the ceiling and your knees in a tabletop position.
2. Slowly extend one arm and the opposite leg away from the body, then return to center and alternate sides. Do 10 reps per side. 

To really benefit from these deep core moves, King recommends doing them three to four times a week. She says that in a few weeks, you’ll notice a difference in how you feel. For example, it will be easier to maintain good posture for a longer period of time.

Having a strong core is more than about looking good. It’s about being able to move easily and avoid pain as we age. Once you start integrating deep core strength into your workout routine, you’ll notice a difference in how you feel, making it well worth the effort.

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Sources:

• Chang, W. D., Lin, H. Y. and Lai, P. T. (2015). Core strength training for patients with chronic back pain. Journal of Physical Therapy Science. 27(3):619-622. 
• Erica Walters, NCPT, level-three certified Pilates instructor and the owner of Pilates Fit Studio in Kentucky
• Lauren King, NCPT, Pilates instructor at Strong Pilates Commack in Commack, New York.
• Lee, K. (2025). Effects of Core Stability Training on Deep Stabilizing Muscle Function and Neuromuscular Control.Medicina. 61(3):364. 
• Franks, J., Thwaites, C. and Morris, M. E. (2023). Pilates to Improve Core Muscle Activation in Chronic Low Back Pain: A Systematic Review.Healthcare. 11(10):1404.