In his civil life, Lundberg studied medicine and sports. Along with his athletic career, Lundberg worked as a sports journalist, and he was the first sports editor at the Danish newspaper Dagbladet Information, a sports editor at the social democratic newspaper Aktuelt, editor of the annual Fodbold Jul are among his other editorial posts. After ending his sporting career, he, among other things, was a social democratic regional politician and a writer. The number of books written solely by Lundberg or teaming up with other writers adds up to more than 50 with themes ranging from health to sports and fiction. His writings included the four-volume Dansk Fodbold; a chronicle of Danish football from 1939 to 1989, published for the 100th anniversary of the Danish Football Association.