What are the different types of triathlons, and what distances do they cover?
There are five lengths of triathlons typically recognized. They are as follows:

1. Super-sprint-distance triathlon: 400m swim, 10km bike, 2.5km run
2. Sprint-distance triathlon: 750m swim, 20km bike, 5km run
3. Olympic-distance triathlon (aka "standard distance"): 1.5km swim, 40km bike, 10km run
4. Half-Ironman-distance triathlon (aka "middle distance"): 1.9km swim, 90km bike, 21.1km run
5. Full Ironman-distance triathlon: 3.8km swim, 180km bike, 42.2km run