Trail Gaulois is a Sunday trail race held in Rieux-Volvestre, offering two off-road distances: 22 km and 10 km. Both routes follow natural paths alongside the Garonne River, establishing it as a local trail event rather than a road race. The 22 km race, for adults, begins earlier, followed by the 10 km race, which is open to participants aged 16 and older. Bib collection takes place at the Salle du Marfaut. The races are semi-autonomous, requiring runners to carry their own cups for aid stations.
The course incorporates elements of local history, guiding participants through the Village Gaulois and utilizing historic trails such as the chemin des mules and chemin des contrebandiers. Sections of the route also trace an old Roman road and a path on the Compostela pilgrimage route. The event features scratch podiums and category rankings, online photo galleries, and two children's races (1500 m and 500 m) scheduled after the main races.