Besides the length of Charles Grethen's primary race event, which two race lengths are standard in middle-distance running?
Charles Grethen Charles Grethen (born 2 June 1992 in Tuntange) is a Luxembourgian middle-distance runner competing primarily in the 800 metres. He represented his country at three consecutive European Championships.
Vincent O'Brien National Stakes The Vincent O'Brien National Stakes is a Group 1 flat horse race in Ireland open to two-year-old thoroughbred colts and fillies. It is run at the Curragh over a distance of 7 furlongs , and it is scheduled to take place each year in September.