Abstract: This invention relates to an improved adjustable exercise device for use in step benching which utilizes a combination of a two-piece bench step providing both a lower riser step as well as a higher riser step, the two units having an interlocking feature and lightweightness for a stable broad non-slip load-supporting surface which may be approached from any direction and may be readily assembled and disassembled as desired. The step heights may be varied between the 4 inch and 6 inch step heights which are preferred for the several most desirable levels of step benching. In a modified embodiment another base member is innerlocked with the two-piece bench to increase the vertical height of the top support surface.