Abstract: An exercise device designed to work the abdominal and oblique muscle groups. The abdominal exerciser comprises a carriage connected to a frame by a swing-arm that allows the carriage to swing along an arcuate path. In some embodiments, the carriage is connected to the frame by non-parallel first and second swing-arms. The carriage is adjustable so as to accommodate users of different sizes and to isolate different abdominal muscle groups. The abdominal exerciser device is designed to simulate an abdominal exercise “crunch” motion when the knees are brought within proximity of an upper body support.