Krüger earned his BA (English major) from UCLA in 1967 and his PhD from the University of Cologne (Modern and Medieval History) in Germany in 1971.
He attended UCLA on a track scholarship, was 10 times German champion, and represented West Germany at the 1968 Summer Olympics in the 1500 metres run, where he reached the semi-final.
[1][2] He was one of the first Germans to be honored as All-American for being part of the UCLA Distance Medley Relay which ran faster than the World Record in 1965.
[7] In 2012 he received the Human Resources Award for innovative health management of the Deutsche Verband für Gesundheitssport und Sporttherapie and the Fraunhofer-Gesellschaft for their successful Core training programme of forest workers.
[8] He was honored by an international Festschrift at the occasion of his 65th birthday (2009) and received the prestigious Bernhard-Zimmermann-Medal for his merits for sport history in 2016.