How many reps of the reverse crunch should a beginner do?

Two to three sets of 12 to 15 reps is a reasonable start, focusing on rolling the pelvis rather than counting fast reps. Add reps toward 20 before you look at slower tempos or an incline to make it harder.

How do I make the reverse crunch easier or harder?

Bend the knees in tighter to your chest and keep the movement small to make it easier while you learn the pelvic curl. To make it harder, straighten the legs more toward the ceiling to lengthen the lever, or slow the lowering phase to a three-second count.

What is the reverse crunch good for?

It trains the lower rectus abdominis through a posterior pelvic tilt while keeping the hip flexors relatively quiet, which makes it a joint-friendly way to hit an often-neglected part of the abs. It is a poor choice for someone who cannot lower the hips without the lower back arching off the floor, since that usually means the hip flexors are already taking over.

Beginner

Reverse Crunch

The reverse crunch flips the standard crunch: instead of lifting the ribs toward the hips, you curl the pelvis toward the ribs. That posterior pelvic tilt targets the lower portion of the rectus abdominis while keeping the hip flexors relatively quiet. It is a joint-friendly way to train the often-neglected lower abs.

Equipment: Body Weight
Body part: Abs
Type: Strength
Browse by muscle: Lower Rectus Abdominals
Browse by movement: Spinal Flexion

How to do it

1
Lie on your back with hands by your sides or gripping something behind your head.
2
Lift your knees so your hips and knees are both bent to about ninety degrees.
3
Exhale and curl your pelvis up and in, lifting your hips off the floor.
4
Bring your knees toward your chest at the top of the curl.
5
Inhale and lower your hips back down with control.
6
Keep the motion driven by your abs, not by swinging your legs.

Tips

Focus on rolling your pelvis upward rather than just kicking your knees.
Keep the range short and controlled; momentum defeats the purpose.
Flatten your low back into the floor before each curl, then let it peel up gradually as the hips lift so the lower abs do the rolling.

Variations

Common mistakes

The hands press down into the floor for extra lift, which quietly does the work the pelvis curl is supposed to do on its own.
Legs swinging down fast between reps whips the pelvis back into extension instead of lowering it under control.
The knees splay out to the sides as they come toward the chest instead of staying stacked over the hips, spreading the effort away from the lower abs.
Holding the breath through the curl instead of exhaling on the way up leaves the trunk stiff rather than actively contracting.

Frequently asked

How many reps of the reverse crunch should a beginner do?: Two to three sets of 12 to 15 reps is a reasonable start, focusing on rolling the pelvis rather than counting fast reps. Add reps toward 20 before you look at slower tempos or an incline to make it harder.
How do I make the reverse crunch easier or harder?: Bend the knees in tighter to your chest and keep the movement small to make it easier while you learn the pelvic curl. To make it harder, straighten the legs more toward the ceiling to lengthen the lever, or slow the lowering phase to a three-second count.
What is the reverse crunch good for?: It trains the lower rectus abdominis through a posterior pelvic tilt while keeping the hip flexors relatively quiet, which makes it a joint-friendly way to hit an often-neglected part of the abs. It is a poor choice for someone who cannot lower the hips without the lower back arching off the floor, since that usually means the hip flexors are already taking over.

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