Badenski was born in Warsaw and represented the club Legia Warszawa. At the 1962 European Championships he finished sixth in the 400 metres. He did however win few international accolades before winning the bronze medal in the 400 metres at the 1964 Olympic Games. At the same Olympics he finished sixth in the 4×400 metres relay together with the Polish team. At the 1966 European Championships he won a silver medal in the 400 metres, only behind Stanislaw Gredzinski, and won the 4×400 metres relay together with Jan Werner, Edmund Borowski and Stanislaw Gredzinski.