Le Défi de Kervallon is a road race in Brest, held in the Cavale Blanche neighborhood and organized by the Brest Goélopieurs association. It features two timed adult races: a 5 km starting at 10:15 and a 10 km starting at 11:00. The 5 km is open to participants aged 14 and up, and the 10 km is open to those aged 16 and up. Free children's races, with distances determined by age group, take place before the adult events. The race also benefits the SNSM Brest intervention and training center, adding a charitable aspect to the competition.
The adult course is a 5 km loop, run once for the 5 km race and twice for the 10 km race. This loop combines streets with natural areas around Cavale Blanche, and it is notably hilly, featuring a 1 km climb, numerous descents, and approximately 70 m of elevation gain per lap. The 10 km includes a separate climb competition with a podium for top climbers, and the Grand Défi classification recognizes individuals competing in both the 5 km and 10 km races. Music is provided along the course to support runners during challenging sections. Previous editions have attracted competitive club runners and local participants seeking a demanding, hilly race in Brest.