When someone tells you they're doing a triathlon, the first thing that pops into your head is probably the hard-bodied athletes who spend what seems like every waking hour training to compete in Ironman events. But that's just one distance of triathlon, and the longest one, at that.
In fact, the triathlon was first conceived as a much shorter event. The first time (on record, anyway) that a competition featuring the triathlon events of swim-run-bike was held—back in 1920, in France—it featured a 3-kilometer run, a 12-kilometer bike and a swim across the Marne. It wasn't until 1977 that the modern Ironman—a 140.6-mile slog around the entire Hawaiian island of Oahu—was created to settle a debate about whether runners, swimmers or cyclists were the fittest athletes.
Lucky for most of us, there are many shorter, more common distances out there available for the Average Joe or Jane to compete in. Here's a breakdown of the four most common triathlon distances available:
Sprint Triathlon—750 meter (0.465 mile) swim / 20 kilometer (12.5 mi) bike / 5 km (3.1 mi) run
Standard or Olympic Triathlon—1.5 kilometer (0.93 mile) swim / 40km (25 mi) bike / 10 km (6.2 mi) run
Half-Ironman or 70.3 Triathlon—1.9 kilometer (1.2 mile) swim / 90 km (56 mi) bike / 21.1 km (13.1 mi) run
Ironman Triathlon—3.8 kilometer (2.4 mile) swim / 180.2 km (112 mi) bike / 42.2 km (26.2 mi) run