Conner Mantz's American Record Comeback from Injury

American marathon record holder Conner Mantz is rebuilding his fitness after a sacral stress fracture sidelined him for 12 weeks. The 29-year-old broke Khalid Khannouchi's 23-year-old American record with a 2:04:43 finish at the Chicago Marathon last October.

Mantz admits he felt a tinge of disappointment after his record run. "I just felt like I had more in me," he told Runner's World. He was kicking himself, as his real goal is a spot on an Olympic podium, preferably at the very top.

The Injury Setback

The record was followed by the biggest injury of his career. Mantz confesses he got too excited after Chicago, where he felt less sore than ever, and jumped back into training too quickly. He was eyeing a medal at the 2026 World Athletics Cross Country Championships and wasn't listening to his coach. The result was a sacral stress fracture that left him unable to run for 12 long weeks.

During that time, he was lapping the pool, doing physical therapy, and scrolling enviously through his running friends' social media feeds. "I get the record, and then I get injured? It humbles you," Mantz said. "It's like: Just in case you think you're the man, now you're not even walking."

The Long Road Back

When he started running outside again just two weeks prior to the interview, the sensation was jarring. "That first time, I felt like I weighed a million pounds," Mantz said. "My legs just sank into the ground." On one winter morning, he managed a 20-mile run along the Provo River Parkway Trail, averaging a 5:45 per mile pace at 4,500 feet of elevation. He posted the effort to Strava, where he has over 60,000 followers.

The effort was a struggle. "My couch was calling," he admitted, noting he was too tired to drive himself to a subsequent interview. He trains under legendary coach Ed Eyestone at Brigham Young University, his alma mater, where he won two NCAA Division I Cross-Country Championships.

Life and Faith in Utah

Mantz lives with his wife, Kylie, in Mapleton, Utah. Kylie, whom he met in a religion class at BYU, ran a 2:43:49 in her first-ever marathon last year with her husband at her side. Their life is rooted in their faith as members of The Church of Jesus Christ of Latter-day Saints, which influences their daily routines and community.

Before his collegiate and professional running career, Mantz served a two-year LDS mission in Ghana after graduating high school in 2015. He gained 30 pounds in his first eight months there, citing stress and a complete halt to his running routine as factors. His missionary companion would not run, which meant Mantz could not either.

He described the mission as a grind but also freeing, with a simple, repetitive routine focused on a singular goal. Returning to America and to running after two years was a major culture shock. He had to reclaim his body and resume a life that, as a world-class distance runner, is no less rigid and focused. Mantz is now channeling that focus into his comeback, with the 2028 Los Angeles Olympic marathon as his ultimate target.