The Duathlon de Sainte Aldegonde is a run-bike-run race held in late March in La Longueville, Nord department, Hauts-de-France. The adult event follows the Duathlon S format: a 5 km run, a 20 km road cycling leg, and a 2.5 km final run. Youth races for children and juniors are also part of the programme.
The course is located in the Pays de Mormal, featuring rural roads and paths across the northern high plateaus, avoiding significant climbs. These consistent gradients are important, as participants must conserve energy for the second run following the cycling segment. The event is suitable for adults assessing their post-winter fitness, newcomers to competition, club athletes preparing for the early season, and families accompanying younger participants in the shorter races.