The IAU 24 Hour World Championship is an annual international 24-hour run competition which succeeded the IAU World 24 Hours Track Championships.
The IAU 24 Hour World Championship is an annual international 24-hour run competition organised by the International Association of Ultrarunners (IAU). Preceded in 2001 by the IAU World 24 Hours Track Championships, as a track running event, this competition became the IAU World 24 Hours Challenge in 2003. 
