Emil Zátopek
3x gold medals in 1952 olympics
5k
10k
marathon
it was the first marathon he had ever ran.
or
Jim Ryun
mile records:
sophomore high school : 4:06
junior: 3:59 (still stands as the junior mile record for 59 years)
senior: 3:55.3 (beat olympic and world champion when he was still in high school)
was voted the best high school athlete of all time by espn (ahead of tiger and lebron etc...)