Hook feet under foot brace and lie supine on incline board with hips bent. Hold plate on chest with both hands or use no weight.
Flex waist to raise upper torso from bench. Keep low back on bench and raise torso up as high as possible. Return until back of shoulders contact padded incline board. Repeat.
Exercise can be performed without added weight until more resistance is needed. Elevate incline to increase resistance. See Arm Position During Waist Exercises. If no knee support is built in to incline board, ball can be placed under legs as illustrated. Hip and knee flexors may be involved as stabilizers if incline is steep and no calf support is used. See advanced technique and Spot Reduction Myth.