 In addition to his political career, Wilwertz was heavily involved in sport administration.He was President of the Luxembourgian Cycling Federation before the Nazi occupation, and again from 1945 until 1967, during which time he was also a Vice President of the Union Cycliste Internationale.Between 1950 and 1970, Wilwertz served as the President of the Luxembourgian Olympic and Sporting Committee (COSL).