Reverse Crunch

How to do the Reverse Crunch

1. 1Lie flat on your back on a mat with your arms at your sides, palms pressed down for support.
2. 2Lift your legs so your hips are bent to 90° and your knees are also bent at 90°, shins parallel to the floor.
3. 3Brace your core and press your lower back firmly into the mat to establish a neutral spine position.
4. 4Exhale and draw your knees toward your chest while simultaneously curling your pelvis up and off the floor — think of shortening the distance between your belly button and your knees.
5. 5Continue the curl until your hips are lifted and your tailbone points toward the ceiling, pausing at the top to squeeze the lower abs.
6. 6Inhale and slowly reverse the movement, lowering your hips back to the mat with control.
7. 7Stop just before your feet touch the floor and your lower back loses contact with the mat to keep tension on the abs.
8. 8Complete all reps, then lower your feet to the floor.

Form tips

• Initiate every rep from the abs, not the legs — think of pulling your pelvis toward your ribcage rather than swinging your knees upward.
• Keep the movement small and deliberate; a two-inch pelvic curl with full ab engagement is more effective than a large, momentum-driven swing.
• Press your palms or fingertips into the floor to anchor your upper body and prevent your torso from rocking.
• Exhale fully at the top of each rep to deepen the abdominal contraction and improve range of motion.
• Lower in twice the time it takes to curl up — a slow eccentric phase builds more tension in the rectus abdominis.

Common mistakes

• Using momentum to swing the legs rather than curling the pelvis — this transfers the work from the abs to the hip flexors and reduces the training stimulus.
• Letting the lower back arch off the mat at the bottom of the rep, which loses core bracing and places unnecessary stress on the lumbar spine.
• Pulling with the neck or lifting the shoulders during the curl, which adds tension to the cervical spine and indicates the abs are not doing the work.
• Allowing the feet to drop all the way to the floor between reps, which releases abdominal tension and turns each rep into a fresh momentum swing instead of a controlled contraction.
• Tucking the heels back toward the glutes instead of holding the shins parallel to the floor, which shortens the lever so much that the abs barely have to work to lift the pelvis.

Frequently asked questions