The Cormaris Trail is a February trail-running series held in Cordemais, utilizing the hiking paths of the Sillon de Bretagne. Organized by ASC Cormaris Triathlon Athlétisme, a component of the town’s sports association, it operates under French athletics federation rules. The series features multiple distances instead of a single main event: a 15 km race on Saturday evening, 1 km and 3 km youth races on Sunday morning, and adult trail races of 13 km, 20 km, and 30 km.
The courses traverse hilly terrain, offering a blend of technical sections and faster running, distinguishing it from a simple winter run. February weather conditions can lead to wetter, colder trails with reduced visibility underfoot. Entry numbers are limited, with adult races typically capped at a few hundred participants. Le Defi des Tontons presents a more challenging option by combining the 15 km and 30 km races. Participants require either a valid FFA or Ufolep license, or an electronic PPS health attestation from the French federation.