Aquathlon de Rillieux takes place in Rillieux-la-Pape, in the Rhône department of France, typically in late winter. The primary open Format S includes a 1,000 m swim and a 5,000 m run. The shorter Format XS consists of a 400 m swim and a 2,000 m run. Rillieux Triathlon organizes the event, focusing on aquathlon without a cycling segment.
The event offers multiple options for participants. Adults can select the S or XS formats. Pairs can compete in the Super Relais, where each participant swims 200 m and runs 1,000 m. Younger athletes have dedicated shorter distances: Benjamins swim 200 m and run 2,000 m; Pupilles swim 100 m and run 800 m; Poussins swim 50 m and run 400 m. The Aquafamilly format is available for one adult and one child under 12, with distances adjusted for ages 6-8 and 9-11.