Abstract: A lightweight construction core having a cellular structure, whereby the cells are enclosed by walls formed from impregnated paper-like material. The core has the form of a plate with cavities or spaces provided therein and is inserted into a component in such a way that the loading of the component acts as pressure upon the edges of the walls. When the lightweight construction core is used as a support core for a ski, more particularly for a long-distance ski, the core is covered by a covering layer on its sliding surface and on its upper surface. These covering layers may be adhered to lateral edges of the ski. The cells are formed by sandwiching or layering corrugated strips with support layers disposed therebetween, said support layers also being formed from layers to which the corrugated strips are adhered.