A loaded Russian twist that suspends your whole torso.
Brace hard and move from your core, not your arms, to keep the torso stable.
The torture twist earns its name by suspending your entire torso off the pad while your core steers a dumbbell through a wide arc. With your feet anchored and hips on the pad, the abs work overtime just to hold your body in line with your legs, and sweeping the weight down to one side and across to the other layers rotation on top of that hold, one direction at a time. It is advanced core training that punishes any attempt to let the arms do the steering.
A bench or setup that anchors your feet and supports your hips while your torso hangs free, plus a light dumbbell. A hyperextension or sit-up bench with foot rollers is the usual home for it.
Light, at least at first. Holding your torso suspended is already brutal, and the wide arc multiplies whatever is in your hands. If your arms bend or your torso wobbles, drop the weight.
Because circling the weight with your arms is easier than rotating from your trunk. Keep the arms long and locked, brace hard, and make your core drag the weight around the arc.
