The 24 Hours of Isère in Tullins guides participants along a road circuit within Tullins, located in Isère, at the base of the Vercors foothills and amidst Dauphiné walnut orchards. This April ultra-running event focuses on time duration over distance: the primary event lasts 24 hours, commencing at 9:00 AM, with participants aiming to complete maximum distance before the time limit expires.
The event accommodates both solo runners and teams of six in a relay format, extending beyond a purely individual endurance challenge. A 6-hour race is also offered, beginning at 10:00 AM, featuring a shorter 1 km option for that category. CMI, Coureurs du Monde en Isère, is the organizing body, and the race holds an FFA label from the French athletics federation. The event relies on local volunteers, contributing to its atmosphere as a community-based French club race with significant ultra-running standing.