Abstract: The running board of the present invention provide the structural integrity to withstand the static and dynamic loads to which articles of this type are normally subjected. The design of the running board in terms of its configuration, the components making up the running board, namely, the blow molded exterior shell and the foam core, have specific structural characteristics. For example, the foam core has a density in the range of 100 kg/m.sup.3 to 150 kg/m.sup.3 and has sufficient resiliency to permit the part to return to substantially its original shape following removal of a load of predetermined magnitude.