L'Alphonsine is a women-only 5.65 km run and walk in Chatou, west of Paris, held in October on the Île des Impressionnistes in the Parc des Impressionnistes. It is organized by the town’s Jeunesse et Sports service with the Croissy-Chatou athletics club. The event is part of France’s Octobre Rose campaign, and money raised supports Aidons la Recherche in its work for women with breast cancer.
The main distance can be completed as a run, a walk, or a mother-daughter duo, while the Alphonsinette offers girls aged 8 to 13 their own 2 km race. Recent editions have drawn several hundred participants, with walkers often outnumbering runners and dozens of young Alphonsinettes joining the morning. The program includes group warm-ups, stretching, a partner village, and a tombola, making the day feel more like a local health-and-solidarity gathering than a competitive race.