A half Ironman consists of a 1.2-mile/1.9km swim, 56-mile/90km cycle and a 13.1-mile/21.1km run. It typically takes somewhere between five and eight hours for amateurs to complete a half Ironman, though this will vary significantly based on the course and conditions. It’s a significant step up from an Olympic triathlon, which typically takes amateurs around three hours to complete.