Cinematographer Curt Courant's last picture.
Bob Mathias (who plays US team track coach John Graham) was a double gold medal winner in the decathlon for the London 1948 and Helsinki 1952 Summer Olympic Games. He then had a brief fling as a film actor (1954-1960, three US-made films, including this one; and an Italian spear-and-sandals epic). He became a US Congressman for the 18th District of California (the Tulare/San Joaquin Valley area) for eight years (1967-1975).
Foot-race scenes were shot over much of the actual marathon race course used in the 1896 Olympic Games (where it was still feasible to be authentic to the period) and was pretty much the same course of the M&F marathon races when the Modern Era Olympic Games returned to Greece in 2004.
When Juliet Prowse dropped out of the film it was assigned to Jayne Mansfield.
Mickey Hargitay Jr.: "Miklos", Jayne Mansfield's 23-month-old son, at the beginning of the film as the little boy who throws food across the table.