An energy chain with skids which are each fastened to a cross bar by means of a holding device and which each reach over a narrow side of a side plate, as well as to a retrofittable skid per se. At both of its ends the cross bar has in each case a widening towards the side plate. The holding device has two opposing holding elements, which are spaced apart in the longitudinal direction and with which it can be fitted onto the cross bar between the widenings and can be displaced laterally outwards into an engagement with one of the widenings, in which engagement the opposing holding elements engage in a positive-locking and/or force-locking manner in or behind an area of this widening to fasten the skid in the operative position.