Curl into a ball, hit every ab.
Move arms and legs in at the exact same time for a full upper and lower hit.
The cocoon crunch closes your body from both ends at once, torso curling up while your knees pull in, so the upper and lower regions of your abs shorten together against the leverage of your outstretched limbs. Extending arms and legs back out without letting them touch the floor keeps tension on for the entire set. It is a complete ab movement in a single rep, no equipment required.
The long lever. Reaching arms overhead and legs straight out puts your core under stretch with maximum leverage, then you fold everything in at once. The extension phase without touching the floor is where it really bites.
You are probably extending further than your core can control, letting your back arch off the floor. Shorten the extension, keep your lower back heavy, and lengthen the lever gradually over sessions.
Quality caps out fast, so 8 to 15 controlled reps per set beats 30 sloppy ones. When your arms and legs stop moving in sync, end the set.
