The event series is owned by The Ironman Group, which is owned by Advance Publications, following the acquisition from the Wanda Sports Group in August 2020. Such races include The Challenge Family series' Challenge Roth and the Norseman Triathlon. Other races exist that are of the same distance as an Ironman triathlon but are not produced, owned, or licensed by the World Triathlon Corporation. The Ironman World Championship has become known for its grueling length, harsh race conditions, and television coverage. Originally taking place in Oahu, the race moved to Kailua-Kona in 1981, where it continues today. Held in Kailua-Kona, the world championship has been held annually in Hawaii since 1978 (with an additional race in 1982). The name "Ironman Triathlon" is also associated with the original Ironman triathlon which is now the Ironman World Championship. Any participant who completes the triathlon within these time constraints is designated an Ironman. Many races will also have intermediate bike, run, and transition cut off times specific to each race venue.
The mandatory run cut off varies between 16 and 17 hours from when athlete began their swim. The mandatory bike cut off time for when an athlete must have completed their swim, transition and bike varies generally between 10 hours and 10 hours 30 minutes from when an athlete began their swim. The mandatory cut off time to complete the 2.4-mile (3.86 km) swim is 2 hours 20 minutes. Most Ironman events have a limited time of 16 or 17 hours to complete the race, course dependent, with the race typically starting at 7:00am. It is widely considered one of the most difficult one-day sporting events in the world. An Ironman Triathlon is one of a series of long-distance triathlon races organized by the World Triathlon Corporation (WTC), consisting of a 2.4-mile (3.86 km) swim, a 112-mile (180.25 km) bicycle ride and a marathon 26.22-mile (42.20 km) run, raced in that order.