Les Foulées Siffait is an October trail-running event held in Le Cellier, Loire-Atlantique, starting and finishing at the sports complex on rue de Langförden. La Grande Vadrouille organizes this event as part of Pink October, with each adult registration prompting a donation to breast cancer awareness and research. The event features three primary distances: a race under 10 km, a race of approximately 15 km, and a 30 km format.
The route incorporates viewpoints along the Loire River, passes by historic monuments, includes single-track trail sections, and features climbs, positioning it as a local trail day rather than a flat road race. The 30 km course is divided into three distinct loops, with time cutoffs and final rankings determined solely on the last loop. Bib numbers are capped, and two children's races are available for ages 7 to 12, with all proceeds from children's entries donated to the League Against Cancer.