An exercise device for use in a doorway including resistance bands extending from slidable carriages is provided. The exercise device includes a pair of vertical rail members attachable to sides of a doorway. The vertical rail members are engageable with carriages such that the carriages are capable of being slid longitudinally along the vertical rail members. Resistance bands extend along the vertical rail members and extend out from the carriages. The tension in the resistance bands may be altered by manipulating the distance between the carriages. The resistance bands extending from the carriages are attachable at each end to an athletic accessory such as a hand grip, belt, or crossbar. A pull-up bar may also be attached to the exercise device, the pull-up bar capable of vibration for enhanced performance.