Legs up, reach for your toes, crunch the abs tight.
Lift from your upper abs, peel your shoulder blades off the floor without yanking your neck.
Holding your legs up while you crunch towards your toes turns your abs into the only lift in the room, the fixed vertical legs give them a stable target and the short reach keeps tension exactly where the upper abs contract. Peeling the shoulder blades off the floor and lowering under control is the whole rep, no swinging, no momentum. It earns its place in ab sessions as a simple, joint-friendly crunch progression that needs nothing but floor space.
Leg position. With legs vertical, the range is stricter, the hip flexors contribute less, and every centimetre of reach has to come from the abs contracting. Same family as the crunch, tighter quality control.
Chase quality sets of 12 to 20 where the last reps still peel the shoulder blades up cleanly. When that gets comfortable, slow the lowering phase or add a pause at the top rather than piling on sloppy reps.
Yes. With legs up and abs braced, your lower back should stay pressed into the ground the entire set. If it arches off the floor, reset your brace and shorten the reach until you can keep it down.
