The Course Nature de La Choinette is a winter forest race held in Chasne-sur-Illet, north of Rennes in Ille-et-Vilaine. Participants can select between 8 km or 16 km distances, while walkers may participate in the 8 km route with a slightly later start. The race begins in the village but primarily utilizes the adjacent Rennes forest and the surrounding countryside, positioning it as a local trail event rather than a road race.
The organizers, from the Oxygene section of the Association sportive chasneenne, focus on a course situated entirely within the forest, where the terrain varies significantly based on recent rainfall and weather conditions. Approximately fifty volunteers mark the circuit. An aid station is available at the 8 km point, with another at the finish line. This event is a new iteration of the older Saint-Valentin race. Its inaugural edition attracted 360 participants. The race supports a local cause by donating one euro from each entry fee to the Mouaze Telethon association. Every participant also receives a non-monetary prize.