Abstract: An adjustable seat assembly for exercising apparatus which may embody a hand-held weight frame, a movable weight supporting frame, a leg exercise unit or other exercise device. The seat assembly has an elongate seat mounted on a base for endwise adjustment relative to the base to accommodate the seat to various exercise devices. The seat has a seat portion, a back portion, and means including an arcuate support extending between the back portion and base and movable endwise relative to the base of pivotally adjusting the back portion relative to the seat portion to a range of angular positions between an upright position and a downwardly inclined position.