MDS Crazy Loops Courmayeur is a mountain loop race in Courmayeur, Italy, located in the Aosta Valley. Participants select a 3, 6, 9, 12, or 24-hour duration, then complete short loops of approximately 3 to 5 km repeatedly for as long as they are able or wish. This format resembles a backyard ultra but is more flexible, as participants are not required to begin each loop at a set hourly interval. The organizers describe it as Marathon des Sables-style endurance adapted for the Alps, focusing on altitude, repetition, and self-directed pacing.
The course is situated beneath Mont Blanc and features terrain characteristic of Courmayeur's trail-running reputation, such as ridges, alpine meadows, and mountain vistas. Courmayeur is also a key location on the UTMB route, lending the setting significant trail-running relevance. The race structure allows for running intensely, walking certain segments, taking breaks to admire Mont Blanc, and then continuing for another loop. of the event is its welcoming nature: participants share the course with Handisport teams, and runners have the option to assist or accompany them.