Abstract: An aerobic step device comprising a platform and a detachable leg assemblies for maintaining the platform at selected heights above a support surface. The platform has a skirt depending from the edges of a top, flat rectangular surface. Each leg assembly includes a pair of laterally extending arms, each of which have a protrusion which engages a selected one of at least a pair of slots that are provided on the inner surface of opposed sides of the skirt, the slots being longitudinally and vertically offset from each other. The height of the platform depends into which slot the protrusion is received into. Ribs and locking tabs depend from the underside of the top surface of the platform to engage respective channels and openings in the leg assemblies in order to stabilize the device in its operative positions.

Abstract: An adjustable stepping structure for aerobic exercises comprising a platform upon which the participant places his or her feet, the platform being elevated above a support surface by means of one or more support elements which are capable of being detachably stacked upon each other until the platform is maintained at a selected distance above the support surface, depending upon the skill and physical characteristics of the participant.