The sit-up is performed from a prone position. Laying on the floor the subject bends their knees so that the bottom of the feet are flat against the floor. Arms can be crossed across the chest or held with elbows bent and fingers at rest behind the head [DO NOT pull against the head with the fingers during the motion, all of the work should be done by the abdominal muscles, never by lifting your head].

Slowly tighten the abdominal muscles to lift your upper torso from the floor, making a slow curl of the upper body off the floor. Hold for a moment. Slowly curl back down, again using the abdominal muscles to do the work.