Conner Mantz's remarkable run has hit an unexpected hurdle. The Olympic marathoner and former BYU star, known for his incredible consistency, will be a notable absence at the starting line of the Boston Marathon. Mantz has built an almost unprecedented streak since 2022, finishing in the top seven in seven of his last eight marathons and setting an American record. In a sport where grueling training and the marathon distance itself breed injuries, maintaining such a level is a rare feat.

That streak, however, is now on pause. Mantz was forced to withdraw from Boston just three weeks before the race due to a sacral stress fracture. For an athlete of his caliber, missing a major event like Boston is a significant blow. "It’s tough when you’re the American record-holder and the Boston Marathon is wanting you and incentivizing you to run," said his longtime coach, Ed Eyestone. "It’s tempting even when training isn’t perfect, but we made the right call."

Eyestone emphasized the importance of protecting the athlete's long-term career and respecting the prestige of the race. "We didn’t want to go there at 80 percent. We need to protect the Mantz brand. We need to respect the event and the marathon and the distance and the competition. This is not the local fun run." This decision highlights the difficult balance elite runners must strike between ambition and physical preservation.

Mantz's rise has been spectacular. After dominating NCAA cross country at BYU, he turned professional and immediately made his mark on the marathon scene. He has been the top American finisher in seven of his eight professional marathons, consistently running under 2:09:00. His 2025 season was historic, featuring four American records on the road and a stunning 2:04:43 marathon in Chicago that shattered a 22-year-old national record. Coach Eyestone summed it up perfectly: "I don’t know if there’s been a better year for an American for a long time."

While Mantz watches from the sidelines, other former Cougars will carry the BYU banner in Boston. His training partner, fellow Olympian and NCAA champion Clayton Young, is still set to compete, though Eyestone notes his training build has had a few "hiccups." Young, who placed ninth at the world championships last September, has faced his own challenges staying healthy leading into this iconic race. Their shared journey from Provo to the world stage continues, even if their paths diverge on race day this time.