Reverse Crunch Exercise Guide
When you want to tone your abs, one of the best exercises you choose to do is a reverse crunch. The reverse crunch exercise strengthens your abdominal muscles while placing less strain on your back and neck than a regular crunch. In this version of the abdominal crunch, you move your legs rather than your torso. It is good for the lower abs as well as the rectus femoris and the hip flexors (iliopsoas) and is appropriate for many sports as a general conditioning exercise.
As the name implies, the reverse crunch is essentially the opposite of standard crunches. Instead of “crunching” your torso toward your legs, you crunch your legs toward your torso.
Proper Reverse Crunch Technique
1. Lie with your head, shoulders, and buttocks in contact with the surface of a stable bench. Grab the bench behind your head for support (stability), keeping your forearms against the sides of your head. Flex your hips and knees to a right angle (your hips and knees should form a 90-degree angle). In other words, your thighs are perpendicular to the floor.
2. Slowly lift your pelvis (buttocks) off the bench until your feet point to the ceiling. You want to bring your knees slowly toward your chest, lifting your hips and glutes off the floor. Use your abs to do this, rather than the momentum of your legs. Try to maintain the bend in your knees throughout the movement. Pause briefly at the top of the motion.
3. Contract your abs hard and lower your legs slowly to the start position; your buttocks should just make contact with the bench.

What Muscles Do Reverse Crunches Work?
Primary muscles: rectus abdominis (lower portion)
Secondary muscles involved: external and internal obliques, transverse abdominal, hip flexors (iliopsoas, rectus femoris)
Antagonists: spinal erectors
Exercise Tips & Tricks
- Put your hands behind your head and grasp the bench for support.
- In the start position, your thighs should be vertical and your lower legs parallel to the bench so that you have a 90-degree bend at your knees and hips. Keep your feet and legs together.
- Keep your upper torso in contact with the bench.
- Contract your lower abs to lift your pelvis up off the bench, raising your legs until toes point to the ceiling.
- Don’t use your momentum to swing your legs up. Try to keep the motion controlled by your abs.
- Lift your legs up and back to bring your knees toward your shoulders (chest) without changing the angle of your hips (i.e., without changing the distance between your thighs and your abdomen), otherwise the powerful hip flexors will take over almost all of the work. The key point of the reverse crunch is to maintain the bend in your knees throughout the movement. See this image.
Reverse Crunch Variations
- Exercise-Ball Reverse Crunch. Place an exercise ball (Swiss ball) next to an exercise machine or other apparatus that you can grab for stability. Follow the same instructions given above.

- Incline Bench Reverse Crunch (Incline Reverse Crunch).

Although there is little proof that the lower abs can be truly isolated, it certainly feels that way when performing this crunch variation. Without a doubt it does tax the entire abdominal muscle wall, and provided that your lower back is injury free, it is a great way to target your abs.