In a stunning debut over the 100-mile distance, Ireland’s Caitriona Jennings set a new women’s world record at the 2025 Tunnel Hill 100 Mile, crossing the finish line in an extraordinary time of 12:37:04.

Jennings’ performance eclipsed the previous record of 12:42:40, set by Camille Herron at the same event in 2017. Her pacing was remarkably consistent, averaging 7:34 per mile (4:42/km) across the full 160.9 kilometers. Despite warming conditions after the cool 7 a.m. CST start on November 8, Jennings maintained her rhythm with unwavering focus and endurance.

While this was her first official 100-mile race, Jennings is no stranger to ultra-distance excellence. Earlier this year, she set the Irish 50k record at the Donadea 50k National Championships with a time of 3:16:33, and she also holds the Irish 100k record of 7:43:01, set in 2021. Her accolades include a victory at the 2022 IAU 50k European Championships and multiple top-10 finishes at the prestigious Comrades Marathon.

Perhaps most impressive was Jennings’ metronomic pacing: for nearly 80 miles, her splits hovered within seconds of 7:26 per mile, only slightly slowing in the final stretch. Her ability to stay ahead of world-record pace throughout the race speaks volumes about her preparation, resilience, and elite-level endurance.

📸 Caitriona Jennings celebrates her record-breaking run at Tunnel Hill.
Photo: Micki Colson/Colson Photography