IKMF competition rule. Marathon & Extended Formats category.
Extreme marathon events (2+ hours) are exhibition lifts/record attempts done in the context of an 'Extreme Kettlebell Marathon Festival'. The athlete must have CMS (marathon) rank at minimum. Athletes over 59 may not participate. Must obtain authorization from IKMF country representative and president. Kettlebell sizes start at 16kg men / 8kg women in 4kg increments.
See the interactive comparison on KETTLEBELL MONSTER™ for filterable views and more detail.