Reverse Crunch
Auto DetectedA bodyweight core isolation movement performed lying supine, which uses pelvic tilt and spinal flexion to target the rectus abdominis and hip flexors for stability and hypertrophy.
About Exercise
Equipment
Body Weight
Difficulty
2/5 • Beginner
Primary Muscle Groups
Abs, Hip Flexors
Secondary Muscles
Obliques
Popularity Score
7
Goals
Training Style
Setup Requirements
Requires Rack
No
Requires Bench
No
Requires Spotter
No
Space Needed
Small
Noise Level
Low
Muscle Breakdown
View Muscle MapAbs
9/10Rectus Abdominis, Transverse Abdominis
Hip Flexors
8/10Iliopsoas
Obliques
3/10External Obliques
Programming
Typical Rep Range
10-20 reps
Rest Between Sets
30-90 seconds • Shorter rest for endurance focus.
How to Perform
Lie supine on the floor or a mat with your arms flat beside your body for support. Bend your knees to 90 degrees, keeping your feet lifted slightly off the floor to begin the movement.
- Engage your abdominals to curl your pelvis off the floor, drawing your knees toward your chest or ceiling.
- Focus on spinal flexion (crunching the lower spine) rather than just pulling with your legs.
- Pause briefly at the peak contraction when your hips are fully lifted.
- Slowly lower your hips and legs back down, maintaining strict control.
- Stop the descent just before your feet or lower back touch the floor.
Coaching Tips
Form Cues
- Curl the pelvis up.
- Control the lowering.
- Knees to the ceiling.
- Maintain core tension.
Breathing
Exhale forcefully as you crunch your hips up toward your chest; inhale slowly as you return to the starting position.
Tempo
2-1-1
Range of Motion
The movement spans from the starting position with knees bent and feet lifted, until the hips curl off the ground and the knees approach the chest.
Safety
Safety Notes
- Perform slowly to maximize muscle engagement and protect the lower spine.
- If you feel strain in the lower back, reduce the range of motion.
- Do not allow your feet to fully touch the floor between repetitions.
Spotting
Not applicable; this is a bodyweight core movement.
Common Mistakes
- Swinging the legs to generate momentum.
- Allowing the lower back to arch.
- Dropping the legs too quickly on the eccentric.
When to Avoid
- Acute lower back pain or lumbar instability.
- Recent abdominal surgery.
Build Up First
- Basic control over supine pelvic tilt.
Also known as
Leg Pull-in Knee-ups, Laying Bent Leg Raise, Bent Knee Hip Raise, Knees to Chest
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