What is omitted from a typical triathlon to create a duathlon?
Cycling
Running
Swimming
Duathlons are very similar to triathlons in the fact that competitors must complete three legs on a race. While triathletes compete in swimming, cycling, and running, duathletes start with a short run, then bike, and finish the race with a run again. As a result, a duathlon is a run-bike-run combination. So if swimming is not your thing, a duathlon gives you the opportunity to participate in a multisport competition. A duathlon is sometimes confused with biathlon, which is the official term for the Olympic sport of skiing and shooting.
The correct answer is Swimming.