A backrest assembly for an exercise bench includes a mounting bar, a first carriage member, a headrest, and a backrest. The first carriage member is configured for slidable insertion within a hollow cavity in the mounting bar. A back surface of the headrest is coupled to the first carriage member. The backrest segment is configured for upward and downward movement along the mounting bar. In one embodiment, the backrest assembly has at least two segments, such as an adjustable first backrest segment, and an adjustable second backrest segment.