Reverse crunch: how to perform it.
The reverse crunch flips the logic of the crunch: instead of bringing the ribs toward the pelvis, you bring the pelvis toward the ribs, curling it up while lying down with your legs tucked. It's the movement that targets the lower portion of the rectus abdominis, the part that regular crunches barely touch.
Starting position
- Lie on your back, arms at your sides with palms flat on the floor (or hands under your pelvis to start).
- Legs raised, hips and knees at 90°: this is your starting position.
- Lower back in contact with the floor, neck relaxed.
Proper form
- Exhale and CURL your pelvis toward your ribs: your hips lift off the floor.
- Your knees move toward your chest as a CONSEQUENCE, not as the driver: the movement originates from the lower abdomen.
- Hold with your pelvis curled and your abs fully contracted: it's 4-6 inches of range, not a somersault.
- Uncurl over 2-3 seconds, one vertebra at a time, until your hips settle back down.
- Return to the 90° position without letting your legs drop, then go again.
When to inhale, when to exhale
Exhale completely as you curl (the air leaving helps engage the lower abdomen), inhale as you uncurl. Breathing here is half the exercise.
Mistakes to avoid
Kicking your knees toward your chest to generate momentum uses your hip flexors and inertia instead. The legs are dead weight locked at 90°: the only movement is the pelvis curling.
Leveraging your palms to lift your pelvis is a cheat that guts the exercise. Your arms stabilize: if you can't lift without pushing, shorten the range and build from there.
As you uncurl, your lower back must return to contact with the floor BEFORE your legs come down. If it arches, your hip flexors are taking over: tuck your knees in more.
DAWT tip. You can intensify the reverse crunch without adding load: slow the descent to 4 seconds, or perform it on a decline bench with your head up. Ab progression comes from control, not plates.
Variations and alternatives
Quick answers
Do "lower abs" actually exist?
The rectus abdominis is a single muscle, but research shows the portion below the navel activates more in movements where the pelvis does the moving, like the reverse crunch. So: a real nuance, not a myth.
Is the reverse crunch bad for your back?
With your lower back returning to contact the floor on every rep, it's one of the safer flexion exercises out there. It only becomes an issue if you swing your legs or let your back arch on the way down.
Related exercises
How much should you load on this exercise?
DAWT's AI coach tells you, set by set: it builds your plan around your goals, auto-regulates the load from your real effort and corrects you while you train. Download the app and start free.
