An abdominal exercise device includes a support structure, a track movable relative to the support structure, a body support member movable relative to the support structure and track, and an adjustable base secured to the support structure. A locking mechanism attaches to the track, and selectively secures the track at a fixed orientation relative to the support structure. In a first state, the locking mechanism restricts the track from rotating relative to the support structure. In a second state, the locking mechanism allows the track to rotate relative to the support structure. In using the exercise device, the user may obtain any of three motions. A first motion is provided by sliding the body support member along the track. A second motion is provided by rotating the track relative to the support structure. A third motion is a combined motion in which the body support slides along the track and the track rotates relative to the support structure. The resistance of each of the three motions may be varied by selectively varying the Sip Factor of the system.