Shizo Kanakuri was a Japanese marathon runner who was an Olympic athlete in the early part of the 20th century, and he ran one of the more memorable marathons in history at the 1912 Stockholm Olympics. According to Wikipedia,
However, Kanakuri is best known for disappearing during the marathon race in the 1912 Stockholm Olympics. The race was held in Sollentuna Municipality, in Sweden, in unexpected 40? C (104? F) heat, and over half of the runners in the event suffered from hyperthermia. Kanakuri, weakened by the long journey from Japan, and suffering from problems with the local food, lost consciousness midway through the race, and was cared for by a farming family. He returned to Japan without notifying race officials. Swedish authorities considered him missing for 50 years before discovering that he was living in Japan and had competed in intervening Olympic marathons. In 1966, he was contacted by Swedish Television and offered the opportunity to complete his run. He accepted and completed the marathon in 54 years, 8 months, 6 days, 5 hours, 32 minutes and 20.379 seconds, remarking, “It was a long trip. Along the way, I got married, had six children and 10 grandchildren.”