Reverse Crunch: The Best Lower Ab Exercise at Home
How to do a reverse crunch properly: curl your pelvis, not your legs. Step-by-step form, mistakes, easier and harder variations and how it targets lower abs.
By Ayoub Farid · · 2 min read
If you can't feel your lower abs, the reverse crunch is your exercise. Instead of curling your ribs toward your hips (like a regular crunch), you curl your hips toward your ribs. That pelvic curl emphasizes the lower part of your abs.
How to do a reverse crunch
- Lie on your back, arms by your sides, palms down.
- Lift your legs so knees are bent at 90°, shins parallel to the floor.
- Exhale and curl your pelvis off the floor, bringing your knees toward your chest.
- Your hips should lift a few centimeters; your knees shouldn't just swing.
- Slowly lower your hips back down over two to three seconds.
Common mistakes
| Mistake | Fix |
|---|---|
| Swinging legs | Keep knee angle fixed, curl the pelvis |
| Using arms to push | Light palms only |
| Dropping fast | Slow lowering |
| No hip lift | Small curl is fine, but lift |
Variations
- Easier: smaller range, feet touch the floor between reps
- Standard: as above
- Harder: on a decline bench, straighter legs, pause at top
- Advanced: hanging knee raise with pelvic curl (guide)
Sets and reps
Two to three sets of 10–15. It's in our lower ab workout and ab workout at home.
Reverse crunch vs leg raise
Leg raises are mostly an isometric challenge for the abs while the hip flexors move the legs. Reverse crunches actively curl the pelvis, so many people feel their lower abs more. See leg raises.
Muscles worked
The reverse crunch trains the rectus abdominis with an emphasis on the lower portion, because the movement starts at the pelvis. The transverse abdominis and obliques stabilize, and the hip flexors help hold the knee position. Unlike leg raises, the hip flexors don't do most of the lifting, which is why many people finally feel their lower abs working.
Common setup fix: find the curl
If you're not sure you're curling the pelvis, try this: lie on your back with knees bent and feet on the floor. Without moving your legs, flatten your lower back into the floor by tilting your pelvis. That small tilt is the start of a reverse crunch. Now do the same with your knees lifted, and continue the tilt until your hips peel off the floor.
A 5-minute lower ab block
- Reverse crunch: 12 reps, 3-second lowering
- Dead bug: 8 per side
- Reverse crunch with pause at top: 8 reps
- Flutter kicks: 20 seconds
Rest 30 seconds, repeat once.
Progressing toward hanging work
The reverse crunch is the floor version of the hanging leg raise with pelvic curl. Once you can do 3 sets of 15 slow reverse crunches, try them on a decline bench, then move to hanging knee raises. The same pelvic curl skill carries over directly.
Frequently asked questions
Do reverse crunches burn lower belly fat?
They strengthen the lower abs. Fat loss is a separate process. See lower belly fat.
Are reverse crunches safe for the back?
Generally yes, because the lower back stays supported. Move slowly.
How many reverse crunches should I do?
Two or three sets of 10–15 controlled reps.
Why don't I feel them?
You're probably swinging. Slow down and focus on lifting the hips.