Triathlon is an Olympic sport that consists of 3 sports, swimming, cycling and running, which are performed in order and without interruption between one event and the next. The time it takes for the triathlete to switch from one discipline to the next is called the transition. The transition from swimming to cycling is known as T1 and from cycling to running is known as T2.
Swimming takes place in open water (swamps, open sea, lakes...), on a course that must be clearly marked out by buoys. In the Olympic triathlon, a distance of 1,500 metres is completed.
Cycling must be done on a paved surface, with a distance to be covered of 40 kilometers (Olympic triathlon). This is precisely the most controversial segment at present due to drafting (going by wheel); in the past this was not allowed because it altered the individuality of the race and gave an advantage to the larger groups.
Finally, the foot race consists of ten kilometers. This is the easiest part to prepare, because it is cheaper than cycling and more accessible than swimming in open water, and at the same time safer.