Results/Photos

Date: Sept. 27, 2026 Participant: Carlos Castillo #31219 Race: 2026 Boulderthon 10K Distance: 6.2 miles

Strong Opening Mile Anchors Steady 10K Finish Carlos Castillo completed the 2026 Boulderthon 10K in 58:17, finishing 27th in the men's 40-44 division at over 5,000 feet of elevation in downtown Boulder. Castillo opened with his fastest mile of the race, clocking 8:25 for the first mile, then eased through a gradual build over the next four miles, with cumulative pace settling near 9:00 per mile by mile five. The final mile slowed the overall average slightly, but Castillo's early pace set a solid foundation for the race. Runners looking to negative-split a similar course might consider holding a touch more in reserve through those middle miles.