Targets of crunches are the abdominal muscles, which are commonly referred to as the ABS. The abdominal muscles are a group of muscles located in the front and sides of the abdomen. These muscles are important for providing stability and support to the spine and trunk, and they are also used in many exercises such as sit-ups and crunches. Crunches are a type of exercise that involve contracting the abdominal muscles to lift the upper body off the floor. This exercise is often used to strengthen and tone the abdominal muscles.