Muscles worked
What the reverse crunch trains
Tap a muscle to see just that one and what it does in the lift.
Before the first rep
How to set up
- 01
Lie on a mat. Lie flat on your back on a mat with your arms by your sides, palms pressing lightly into the floor.
- 02
Knees over hips. Lift your legs so your thighs point straight up and your knees are bent to about 90 degrees, shins roughly level with the floor.
- 03
Ribs down. Breathe out and let your ribs drop toward your hips so your lower back rests flat on the mat before the first rep.
- 04
Head down. Keep the back of your head and your shoulders relaxed on the floor. Nothing above your shoulder blades moves during the set.
Step by step
How to do the reverse crunch
- 01
Curl the hips up. Breathe out and use your abs to roll your hips off the floor, bringing your knees toward your chest. Your tailbone lifts first, then your lower back peels off the mat.
- 02
Keep the knee angle. Hold the same bend in your knees the whole time. The movement comes from your pelvis curling, not from swinging your legs in.
- 03
Pause at the top. Stop when your hips are a few inches off the floor and your knees are over your chest. Hold for a moment and squeeze your abs.
- 04
Lower slowly. Roll your back down one section at a time over two to three seconds until your hips touch the mat and your knees are back over your hips.
- 05
Reset and repeat. Let your hips settle without your legs dropping toward the floor, then start the next rep from a still position.
Cues to say in your head
- Ribs to hips
- Curl, don't swing
- Tailbone off the floor
- Knees stay bent
- Roll down slowly
- Breathe out going up
Fix these first
Common mistakes
Swinging the legs to get the hips up
Start each rep from a still position and keep the knee bend fixed. If you need a swing, the reps are too fast or you need a smaller range.
Letting the legs drop between reps
Stop when your knees return over your hips. Lowering the legs toward the floor turns it into a leg raise and tends to pull your lower back off the mat.
Dropping the hips fast
Lower over two to three seconds. The slow way down is part of the work for your abs, not a rest.
Pushing hard through the hands
Keep your palms light on the floor for balance. Shoving down with your arms lifts your hips for you.
Lifting the head and shoulders
Keep your head and shoulders on the mat so the curl comes from the bottom up.
Stay safe
Work on a mat and keep the range small and controlled at first, since the reverse crunch rounds your lower back on purpose. A muscle burn in your abs is normal; stop if you feel sharp pain or pinching in your lower back or hips, or if you can only finish reps by swinging. If you have a back injury, or are pregnant or recently postpartum, check with a doctor or physical therapist before doing this exercise.
Programming
Sets, reps and how much weight
| Goal | Sets | Reps | Load | Rest |
|---|---|---|---|---|
| Muscle | 3 to 4 | 10 to 15 | 60–70% 1RM | 45 to 90 sec |
| Endurance | 2 to 3 | 15 to 25 | 50–60% 1RM | 30 to 60 sec |
| Technique | 2 to 3 | 8 to 12 | 50–60% 1RM | 45 to 60 sec |
Plan your next session
Put in a recent set. You get working weights for your goal, a warm-up and the plates to load.
Estimated 1RM 216 lb
Endurance sets
108–129lb
2 to 3 sets of 15 to 25 reps, 30 to 60 sec rest. Good as a finisher or in a core circuit. Stop the set when you start to swing.
Estimates use the Epley formula and work best from sets of 3 to 8 reps. Treat them as a starting point and adjust by how the first working set moves.
Questions
Reverse Crunch questions
Does the reverse crunch work the lower abs?
It works the whole rectus abdominis, which is one long muscle, so no exercise can fully isolate the lower abs. Because the movement curls your pelvis up from the bottom, many people feel it more in the lower part of the abs than in a regular crunch.
What muscles does the reverse crunch work?
Mainly the abs (rectus abdominis), with the obliques helping. Your hip flexors hold your legs in place, but the goal is to let your abs do the lifting.
How many reverse crunches should I do?
Start with 2 to 3 sets of 10 to 15 slow, controlled reps, two or three times a week. Add reps, a pause at the top or a slower lowering before you add weight.
Why do I feel reverse crunches in my hip flexors?
Your hip flexors work to hold your legs up, so some feeling there is normal. If they take over, the legs are usually swinging or the knee bend is changing instead of the pelvis curling, so keep the knee bend fixed, slow down and think about rolling your tailbone up.
How do I make reverse crunches harder?
Slow the lowering to three or four seconds, hold a light dumbbell between your knees, or do them on a decline bench with your head at the high end, holding the bench behind your head. After that, a hanging version on a bar is the next step.
Train in Protocol
Log your reverse crunch by voice. Protocol tracks the rest.
Your last session shows up before every set, warm-ups and plates are worked out for you, and your coach sees every lift next to your sleep and recovery.