“Not Twice” follows 21-year-old runner Mason Matherly, a Denver native, student and aspiring endurance athlete, as he competes in the Leadville 100 Ultramarathon in Leadville, Colorado.

Filmed over 30 hours from August 22-23, 2026, the short documentary captures Matherly’s attempt to complete the 100-mile race, one of the world’s most challenging ultramarathons,
while confronting the physical and mental demands of endurance running.

Through race footage, audio and post-race interviews, the film documents his experiences from the starting line to the finish, highlighting moments of pain, doubt, perseverance and self-reflect

Matherly, who actively pursues a life of mountaineering, running and other endurance goals, views the race as another step toward completing the Seven Summits, the highest peaks on each of the seven continents, and qualifying for the UTMB Mont-Blanc ultramarathon.

“Not Twice” explores how determination, discipline and personal accountability shape Matherly’s pursuit of ambitious athletic goals and his commitment to giving his best effort in every challenge.