Summary from Wikipedia

Born into a working-class family, Nurmi left school at the age of 12 to provide for his family. In 1912, he was inspired by the Olympic feats of Hannes Kolehmainen and began developing a strict training program. Nurmi started to flourish during his military service, setting Finnish records in athletics en route to his international debut at the 1920 Summer Olympics. After winning a silver medal in the 5,000 m, he won gold in the 10,000 m and the cross country events. In 1923, Nurmi became the first runner to hold simultaneous world records in the mile, the 5,000 m and the 10,000 m races, a fea ...