Lie on your back with your feet on the ground and your knees bent at a 90° angle. Put your hands behind your head so that your elbows are just outside your field of vision.
Tilt your hips up towards your head so that your tailbone comes up off the ground and your lower back presses firmly down on the mat.
Slowly pull your head and shoulders off of the ground towards your thighs without letting your lower back lift up from the mat.
Slowly drop your shoulders back to the mat; do not let your head rest on the ground until all repetitions are complete.
This is a basic abdominal move that is simple in nature but is often preformed incorrectly, which lowers its overall effectiveness and results. When done properly, however, this situp is extremely effective for toning and strengthening the abdominal muscles. At first your range of motion may be small but increasing your abdominal strength will increase your range of motion over time.