# Reverse Crunch (Version 2) - Canonical: https://fitwill.app/exercise/8131/reverse-crunch-version-2/ - Media ID: 8131 - Primary muscle: Abs - Body part: Core - Equipment: Body Weight - Video: https://fitwill.app/videos/8131/reverse-crunch-version-2.mp4 ## Description The Reverse Crunch (Version 2) is a floor-based abdominal exercise performed lying on your back with your hands lightly supporting your head and your legs lifted off the floor. From there, you curl your hips up and in toward your ribcage, letting the knees travel up over the torso before lowering back under control. Unlike a standard crunch, where the shoulders move toward the hips, this version reverses the action: the pelvis rolls toward the chest while the upper body stays anchored to the floor. This exercise is especially useful for anyone who wants to emphasize the lower portion of the rectus abdominis, the section of the abdominal wall that often gets less direct work in sit-ups and forward crunches. Because the legs stay elevated throughout, it also demands continuous trunk control, which makes it a strong choice for people training core stability for lifting, running, or everyday movement. Gymnasts, martial artists, and overhead athletes frequently use it to build the hip-to-ribcage control needed for tucked and piked positions. Setup matters more here than in most floor ab exercises. Your lower back should stay pressed toward the mat at the start, your knees bent to roughly 90 degrees, and your hands placed behind your head for light support only. If the legs start too low or the back arches, the hip flexors and lower back take over and the abdominal curl loses its purpose. A stable, slightly tucked starting pelvis lets you roll through the spine instead of just swinging the legs. To execute it well, think of pulling your hip bones up toward your ribs rather than lifting your feet. The movement is short and focused: the hips peel off the floor a few inches, the knees draw up and over the chest, and the abs squeeze hard at the top before you lower slowly, one vertebra at a time. Momentum is the enemy here. A slow, deliberate tempo with a strong exhale on the curl produces far more tension than fast repetitions ever will. A common mistake is turning the reverse crunch into a leg raise by letting the hips stay pinned to the floor while the legs do all the moving. Another is yanking the head forward with the hands, which strains the neck without adding anything to the abdominal contraction. Keep the pull coming from the pelvis, keep the elbows wide, and let the range of motion be dictated by how much spinal curl you can genuinely control. Because it requires no equipment beyond a comfortable floor surface, the Reverse Crunch (Version 2) fits easily into home workouts, warm-up circuits, or the finisher slot at the end of a strength session. Start with sets of eight to twelve controlled repetitions and only progress the difficulty once your pelvis rolls smoothly without the lower back arching on the way down. ## Instructions 1. Lie flat on your back on an exercise mat with your legs raised so your knees are bent to about 90 degrees and your lower legs are roughly parallel to the floor. 2. Place your hands lightly behind your head with your elbows flared out to the sides, and let your head and shoulders rest on the mat without pulling on your neck. 3. Press your lower back gently into the floor and brace your abdomen so your pelvis is level before you begin the movement. 4. Exhale and curl your hips up off the mat, driving your knees up and over your chest so your pelvis rolls toward your ribcage. 5. Squeeze your abdomen hard at the top when your hips are fully curled and your knees are stacked above your torso. 6. Lower slowly and with control, letting your spine return one segment at a time until your hips touch back down and your knees return to the bent 90-degree start position. 7. Keep your lower back in contact with the floor for as long as possible during the lowering phase rather than letting it arch. 8. Inhale at the bottom of each repetition as you reset your brace, then exhale as you curl up again. 9. Maintain the same bent-knee leg position throughout the set instead of straightening or dropping the legs toward the floor. 10. Complete your repetitions with a steady tempo, resting briefly between sets when the curl speed starts to slow noticeably. ## Tips & Tricks - If your hips never actually leave the floor, you are doing a leg raise, not a reverse crunch. Focus on tilting the pelvis toward your ribs first, then let the knees follow. - Do not let the legs swing to generate momentum. If you need a bounce to lift your hips, reduce the range or slow the tempo until you can curl up under pure muscle control. - Keep your elbows wide and your hands unclasped so your fingers simply cradle the head. Pulling on the neck is the most common way people turn a good set into an uncomfortable one. - Exhale sharply as the hips curl up. Blowing the air out naturally helps the abdominal wall shorten and makes the top squeeze more pronounced. - If your lower back arches on the way down, stop lowering the moment you feel it lift and reverse from there. Range you can control beats range you can fake. - Keep the knees at a fixed bend angle throughout. Straightening the legs mid-rep shifts the effort toward the hip flexors and makes the movement harder to steer. - Pause for one full second at the top of each curl. The brief hold turns a momentum-driven rep into a genuine abdominal contraction. - Place a folded towel under your hips if the tailbone digs into the floor during the curl, especially on hard surfaces. ## Frequently Asked Questions ### Which muscles does the Reverse Crunch (Version 2) work? The primary muscle is the rectus abdominis, with the greatest emphasis on the lower section of the abdominal wall. The hip flexors assist by bringing the knees toward the chest, and the obliques help stabilize the trunk throughout the curl. ### How is the Reverse Crunch (Version 2) different from a regular crunch? In a regular crunch the shoulders and ribcage lift toward the hips, while in the Reverse Crunch (Version 2) the pelvis rolls up toward the ribcage and the upper body stays on the floor. This reverses which end of the abdominal muscle shortens first and shifts emphasis toward the lower abs. ### Why should my knees stay bent at 90 degrees during this exercise? The bent-knee position keeps the lever length manageable so the focus stays on curling the pelvis rather than controlling long, straight legs. It also reduces the tendency for the lower back to arch under the load of the legs. ### Is the Reverse Crunch (Version 2) suitable for beginners? Yes, provided the range of motion is scaled down. Beginners can start with a small pelvic tilt that barely lifts the hips and build up to a full curl as the abdominal control improves. ### How high should my hips rise at the top of the movement? The hips only need to lift a few inches off the floor, enough for the pelvis to curl toward the ribs and the knees to travel up over the chest. Lifting higher than your spinal curl allows means you are swinging the legs rather than crunching. ### What should I do if my neck hurts when my hands are behind my head? Keep your hands relaxed at the sides of your head with your elbows wide, and let your head rest heavily against your fingers rather than pushing into them. If discomfort persists, cross your arms over your chest instead and skip the head support entirely. ### Can I substitute the Reverse Crunch (Version 2) with hanging knee raises? Hanging knee raises are a reasonable progression, but they demand much more grip and shoulder endurance and make it harder to feel the pelvic curl. Master the floor version first, since it lets you isolate the same hip-to-ribcage curl without those extra demands. ### How many repetitions should I perform? Eight to twelve slow, controlled repetitions per set is a solid target for most people. If you can breeze past twenty, you are likely using momentum, so slow the lowering phase down instead of adding volume. ### Is it safe to do this exercise if I feel strain in my lower back? Mild muscular effort is normal, but sharp or pinching sensations are not. Stop at the point where your lower back would start to arch, reduce your range, and make sure your brace is set before each rep.