USOL'Swimrun is a family-oriented swimrun held at Lac du Ronzey in Yzeron, located approximately 30 minutes from Lyon in the Auvergne-Rhône-Alpes region. This event coincides with Mother's Day and is structured around the concept of mothers and children competing as pairs, positioning it as a welcoming introduction to the sport rather than a highly competitive specialist race. Swimrun involves alternating between open-water swimming and running without a complete change of gear; participants retain their swim cap, goggles, and running shoes throughout the entire event.
The event features four race formats, including options for youth and open S and XS categories. The shortest children's format, designed for ages 6 to 9, covers a total of 600 meters, comprising two 50-meter swims and 500 meters of running. Adult-distance options extend to 4 km and 7 km courses. The race route utilizes the local waters of Lac du Ronzey, with swimming segments in lakes and ponds, connected by running sections. The event targets families, novices, younger competitors, and individuals interested in trying swimrun in a relaxed environment.