Triathlon was invented in the early 1970s in the United States of America and has since become a popular recreational fitness activity, but breaks new ground at Tokyo 2020.
Comprising three separate elements of swimming, road cycling and distance running, the event was introduced into the Olympics program for Sydney 2000.
The triathlon schedule has been tweaked for the first time since being introduced to the Olympics with the creation of a third medal event: the mixed relay.
Great Britain took home three medals in triathlon at the Olympics in Rio de Janeiro in 2016 and could contend in all three events.
Here is everything you need to know about triathlon ahead of Tokyo 2020:
How long is an Olympic triathlon?
The men’s and women’s individual competitions will be comprised of the standard Olympic distances in each of the three component parts: a 1.5 km swim, a 40km cycle and 10km run.
The mixed relay will feature teams of four (two men and two women) each performing a shorter triathlon comprised of a 300m swim, 6.8km cycle and 2 km run, in the order of woman-man-woman-man.
What is the mixed relay?
The mixed relay is new to the Olympics and will mark the first time that men and women have competed alongside one another in triathlon at the Olympics.
The event has been held twice at the Commonwealth Games, with England taking a gold in 2014 in Glasgow and a silver on the Gold Coast four years later.
Swimming and athletics have also introduced mixed relays to its schedule for Tokyo 2020.
What does the course look like?
All three competitions will be held at the Odaiba Marine Park, with the swim component held in Tokyo Bay. In the individual events, competitors will then complete eight laps of a 5km bike circuit and then four laps of a 2.5km running route.
The mixed relay’s laps are shorter: 3.4km to be covered on the bike and a 1km loop on foot. Each competitor will complete two laps in each discipline.
The course is flat with few undulations.
What is a ‘transition area’?
While the three core skills of triathlon will ultimately decide the medallists, transitions are also key.
Competitors will enter the transition area at the end of the swim and cycle elements to change clothes, shoes and prepare for the next segment, with a slow transition potentially losing an athlete crucial seconds.
There are clear rules about what is allowed in the transition zone, including lines to mark where bikes must be mounted or dismounted.
Is drafting allowed?
Drafting refers to the practice of following closely behind the rider in front of you during the cycling portion in order to receive a wind break, reducing resistance and retaining
The technique is usually outlawed in non-elite triathlons for reasons of safety and fairness.
It is, however, permitted at elite level on the Triathlon World Cup circuit and at the Olympics.
Who are the favourites to medal?
Jonny Brownlee of Great Britain will be looking to complete his set of medals from the Olympics as he competes in the men’s event at a third Games in Tokyo.
Brownlee took silver in Rio to follow bronze at London 2012, each achieved behind back-to-back gold medal winner and older brother Alistair.
The elder Brownlee failed to qualify for Tokyo 2020, however, after being disqualified for pushing a rival under the water at a World Triathlon Championship race in Leeds earlier this year.
The winner of that event in Leeds was Alex Yee, who has taken Great Britain’s second qualification spot and is tipped to contend for a medal.
Supreme Frenchman Vincent Luis is the favourite for gold, while Mario Mola of Spain has been in fine form during the first half of 2021.
Dutch triathlete Maya Kingma is among the contenders for women’s gold, while Vicky Holland (bronze medallist in Rio), Jess Learmonth and Georgia Taylor-Brown will all harbour hopes of challenging for Great Britain.
Commonwealth Games gold medallist Flora Duffy could make history – the 33-year-old is the only woman at the Olympics from the British Overseas Territory, which has never won an Olympic gold medal.
France’s mixed relay squad has proved dominant in recent years and their quartet took victory in the Olympic test event two years ago, but Great Britain, Australia and the United States could all be in the mix in what could be a competitive debut running.
When is it?
The Men’s Individual is scheduled for 26 July, before the Women’s Individual a day later. The inaugural Mixed Relay is due to be held on 31 July.