A foam core (12) for a cushion (8, 9) of a seat part (2) or a reclining part or a back rest (3) of a piece of upholstered furniture (1) or a motor vehicle seat (11) or for a mattress or support surface of a piece of reclining furniture, with a core base (13) of foam material, in particular of cold foam, visco foam, latex foam or molded foam, there being in the core base (13) a plurality of spring strips (14) which run preferably at least essentially parallel to one another. It is provided that at least one spring strip (14) has an in particular pultruded fiber core (20) which has preferably glass fibers, and a mantle (21) of a thermoplastic material, in particular of polypropylene, which surrounds the fiber core (20).