An aerobic step includes a body having a middle exercise area and four sides. A maximum height of the body is positioned in the middle exercise area. The middle exercise area has a domed shape and curves downwardly to the four sides. The four sides define two longitudinal sides and two transverse sides. The middle exercise area includes a layer of material co-molded with and supported by a main body portion which promotes gripping and non-slippage. The layer of material includes a pattern of grooves. Two handles are defined along a lower portion of the body in the form of cutouts. An edge material is co-molded with and positioned on the lower edge of the body for contacting the ground. The body has a convex upper surface, and a concave lower surface which promotes stacking for storage, or for adding additional height by nesting two or more steps together.