Decline Sit Ups

The Sit-Up is primarily used for developing the rectus abdominus (six pack muscles) and the psoas group (the hip flexors). While the motion is pretty self explanatory, I will mention that people with lower back pain should buffer how far they go back on the lowering phase, and I typically encourage clients to bring their elbows past their knees each rep to stretch the low back at the top of the motion. Variations can include twisting at the top to activate the oblique muscles and holding a dumbbell to add resistance.