These are the four moves a Pilates instructor does every week to build strong abs in her 40s

When you think about building core strength, what are the first exercises that come to mind? If it's sit-ups and crunches then stay with us.

These moves can help you build strength in your abdominal muscles. However, the core is made up of other muscles too—the pelvis, obliques and lower back, to name a few—but crunches and sit-ups isolate the abdominals, rather than working the core as a whole.

“I wouldn’t necessarily say that crunches are a bad core exercise—they have their place—but our core has a much bigger job than simply flexing the spine forwards,” explains Pilates instructor and strength coach Rebecca Daodun.

“In real life, our trunk needs to bend, rotate, resist movement, transfer force between our upper and lower body and keep us stable while our arms and legs are moving,” she continues.

Below, Daodun has shared four moves that she does each week to strengthen her entire core.

“I like including exercises that challenge the core in different planes and in different positions, rather than relying solely on crunches,” Daodun adds.

Four core exercises to try instead of crunches

1. Weighted side bend

“This challenges the core through lateral flexion [side bending] with the weight adding resistance,” explains Daodun. “The obliques are working to control both the movement down and, importantly, the return to upright.”

“I love this move because we tend to think of core training as everything happening at the front of the body, when actually our trunk needs to be strong in every direction,” she adds.

How to do it:

Reps: 8-12

• Stand tall with your feet about hip-width apart, holding a dumbbell in one hand by your side.
• Keep your ribs stacked over your pelvis and your shoulders relaxed.
• Bend your torso toward your side holding the weight.
• Pull yourself back to an upright position.

Trainer tip: Use your core muscles on the opposite side of your weight to move through your waist not your hips.

2. Standing cross-body knee drive

“This is a much more integrated core exercise,” says Daodun. “You’re balancing on one leg while bringing the opposite knee and arm towards each other, so the obliques are involved in the cross-body movement while the rest of the trunk and pelvis have to stabilize you.”

“It combines core strength with balance, coordination and hip control—all things we need outside the gym too,” she explains.

How to do it:

Reps: 8-12

• Stand tall with your feet hip-width apart, holding a dumbbell in your left arm.
• Raise the dumbbell overhead and hold your other arm out to the side for balance.
• Drive your right knee up and across your body while bringing your left elbow down and across your body toward it.
• Return to the starting position with control

Trainer tip: Keep your standing leg and pelvis stable to avoid wobbling or rotating excessively.

3. The Hundred

“This is a classical Pilates movement,” says Daodun. “Rather than repeatedly curling up and down as you would in a crunch, you maintain the abdominal curl while the arms pump and the legs are held away from the body.”

“That creates sustained abdominal work and asks the trunk to remain controlled while the limbs are moving,” she continues, adding: “The further the legs move away from you, the greater the demand, so it can also be modified very easily by bending the knees or bringing the legs closer.”

How to do it:

Sets: 2-3 Reps: 30 pumps

• Lie on your back with your knees bent, then raise your head and shoulders into a gentle abdominal curl.
• Extend your arms straight by your sides and raise your legs into tabletop position with your knees over your hips and your knees bent to a 90° angle.
• For an extra challenge, straighten your legs—the lower and straighter your legs, the more challenging this move will be.
• Begin pumping your arms up and down in small, controlled movements while keeping your abdominal curl.

Trainer tip: Breathe rhythmically throughout the movement, keeping your lower back against the floor and your neck relaxed.

4. Back extension

“I always include extensions when talking about a strong core because the core isn’t just your abs,” Daodun says.

“The muscles along the back of the trunk, including the spinal extensors, are part of the system that supports and controls the spine,” she continues.

“Back extensions strengthen the posterior side of the body and balance all the flexion we tend to focus on when we think about traditional ab exercises.”

How to do it:

Reps: 8-12

• Lie on your front with your legs extended behind you.
• Place your arms on the floor by your head with your elbows bent to 90° in line with your chest.
• Keep your neck long and your pelvis grounded.
• Gently raise your chest, upper torso and arms by engaging your back.
• Stretch your arms in front of you overhead and then return them to 90° by your sides.
• Lower your body and your arms and repeat.