Lespagnard competed for his country at the 1968 Summer Olympics in Mexico City, Mexico, where he finished in seventeenth position in the decathlon event. He returned to both Munich and Montreal in the 1972 and 1976 Olympics, finishing fourteenth and nineteenth respectively.
He also led a political career, having been member of the Federal House of Representatives (1994-1999) and was the former mayor of Fleron, up until 2018.
