With three grueling events combined into one energy-draining test of endurance, an Ironman triathlon pushes some of the top swimmers, runners, and bicyclists to their physical limits. This title introduces readers to a series of races that grew from a humble beginning in Hawaii in the 1970s to a global race series that captures the imagination of fans worldwide. The title features informative sidebars, exciting photos, a map, a glossary, and an index. SportsZone is an imprint of Abdo Publishing, a division of ABDO.