La Boucle Infernale is an endurance race in Saint-Paul on Réunion, organized by Ouest Trail Réunion. Its Backyard edition uses a 6 km loop with 170 m of climbing, so runners face the same short course repeatedly instead of one long point-to-point route.
The format originates from the backyard ultra concept created by Lazarus Lake, often called Last Man Standing: runners return to the loop until only one person remains. This is still a young event, with its third edition. The appeal is straightforward: the distance seems manageable initially, but the repeated climbs and restarts make it a test of patience, pacing, and stubbornness.