Introduced for men and women from 2000, the triathlon is the most open of Olympic events. No nation has won more than one gold medal. Only Australia have won more than one silver and Switzerland more than one bronze.
The Swiss took first and third when the sport made its debut at Sydney, with gold medallist Brigitte McMahon and bronze-placed Magali Messmer separated by home favourite Michellie Jones.
Australia shone in subsequent events with silver for Loretta Harrop behind Austria's Kate Allen in 2004, followed by gold and bronze respectively for Emma Snowsill (pictured) - who has controversially not been selected for London 2012 - and Emma Moffatt in Beijing.
Two men have each won two Olympic medals for triathlon. Canada's Simon Whitfield struck gold in 2000 and silver in 2008, while Bevan Docherty finished second behind fellow New Zealander Hamish Carter in 2004 and returned to take the bronze in 2008.
The triathlon can be won and lost during the changeover — or transition — between each event as transition time is included in the overall time for the race.
EVENTS / FAVOURITES / FORMAT:
1 Alistair Brownlee (Great Britain)
2 Javier Gómez (Spain)
3 Jonathan Brownlee (Great Britain)
4 Alexander Bryukhankov (Russia)
5 Sven Riederer (Switzerland)
6 Jan Frodeno (Germany)
7 Steffen Justus (Germany)
8 Dmitry Polyanskiy (Russia)
1 Helen Jenkins (Great Britain)
2 Emma Moffatt (Australia)
3 Andrea Hewitt (New Zealand)
4 Nicola Spirig (Switzerland)
5 Paula Findlay (Canada)
6 Lisa Nordén (Sweden)
7 Emma Snowsill (Australia)
8 Bárbara Riveros (Chile)
In London the men's and women's competitions will take place in the usual format, each being settled on a single day in Hyde Park.
Competitors will complete a 1,500-metre swim in the Serpentine followed by a cycle ride around a seven-lap course taking in Buckingham Palace and the Wellington Arch to a total of 40km. They will conclude with a 10km run around the Serpentine.
ALL-TIME MEDAL TABLE: