During his college years, Jurek continued to compete in the 50-mile Minnesota Voyageur, finishing second in 1994 and 1995 and winning the race in 1996, 1997, and 1998, when he set the current course record of 6:41:16.

[13] In 1999, Jurek won the 100-mile Western States Endurance Run on his first attempt, defeating five-time champion Tim Twietmeyer and becoming only the second non-Californian to win the race.

In 2004, he completed the "Ultra Running Grand Slam" by finishing Western States, the Leadville 100 (in which he was runner-up), the Vermont 100, and the Wasatch Front 100.

[13] In 2005, just a few weeks after winning Western States, Jurek set a new course record in the Badwater Ultramarathon, widely considered one of the world's most difficult races.

[13] In 2006, Jurek traveled to Mexico's Copper Canyon with a group of runners including Christopher McDougall and Jenn Shelton to participate in a race against the Tarahumara organized by Micah True, also known as "Caballo Blanco".

[6] On May 14, 2010, in Brive-la-Gaillarde, France, Jurek broke the USATF all-surface record for distance run by an American in 24 hours with 165.7 miles (266.6 km).

Chris McDougall tweeted: "Caballo had the only funeral he would have wanted: his friends spent days running in the wilderness in his honor.

"[21] On April 14, 2014, Jurek and Rickey Gates became the first North Americans to complete the Bob Graham Round in the UK's rugged Lake District under 24 hours.

In May 2015, Jurek began an attempt to break the supported Appalachian Trail thru-hike speed record, which was 46 days, 11 hours, and 20 minutes to complete the 2,168-mile route.

[24] Jurek is an advocate of plant-based eating for health and ethical/environmental reasons, and he cites his diet as the key to his athletic performance and recovery.

He gave up eating meat in 1997 and became totally plant based in 1999, motivated by the belief that poor nutrition was responsible for the chronic illnesses he saw in his family and in his physical therapy patients.