La Gelasienne is a semi-trail race held in December in Saint-Gelais, a village near Niort in western France. Participants can select either a 6 km or 10 km route, both commencing at 10:00. The event also offers a 6.5 km walk for those seeking a local outing without the competitive aspect.
The courses are not flat, featuring sufficient elevation changes to distinguish them from a standard road race. Vivons Saint-Gelais organizes the event, with backing from the municipality and the Foyer Gelasien. A recent edition saw 331 participants start the running races, contributing to its atmosphere as a well-attended local event rather than a large-scale competition.