High Quality Content by WIKIPEDIA articles! Udarnik (Russian: Ударник) is a Russian, Bosnian, Croatian and Serbian term for a superproductive worker in the Soviet Union and ex-Yugoslavia. The term is derived from the expression "udarny trud" for "superproductive, enthusiastic labour", which is often translated as strike labour (udar "shock, strike, blow"), and udarnik as strike worker, respectively.