Dušan Mravlje was a successful engineer in a factory making industrial seals, but he decided to quit his career to pursue his greatest passion – and became one of the best long-distance runners the world has ever known.

Mravlje, who was born in 1953 in the northern Slovenian town of Tržič, caught the running bug when he was serving in the military; running gave him a break from the monotony of army life. He began to run longer and longer marathons until he quit his factory job and made running his career.

In the 1970s, he began to specialize in 100-kilometer runs. After completing the first one, he was so exhausted that he spent three days in bed, but he was persistent, and soon he was not just participating in 100-mter runs across Europe, but also winning them. All the while, he got by on just four hours of sleep and plenty of mental discipline.

In 1982, Mravlje won his first 24-hour run in Vienna. But even bigger achievements lay in store: In 1986, he came first in the grueling Sydney to Melbourne race in Australia. Nine years later, he won the Transamerica Foot Race, a 22-day run across the United States.

In total, he took home no fewer than 60 long-distance runs around the world. Among his proudest achievements is a non-stop run through Death Valley, California, and a cross-European run from Lisbon to Moscow. He became the first person to run across three different continents.

Over the course of his career, Mravlje ran some 300,000 kilometers – about three quarters of the distance from the Earth to the Moon.

Now retired from running, he remains well-known in Slovenia as the man whose drive and determination lead him to conquer some of the world’s most intimidating distances – while remaining humble and grounded in his personal life.