Javier Gomez and Alistair Brownlee (centre) show the three triathlon elements.
Triathlon is the only Olympic sport where the ability to get undressed quickly can be the difference between winning gold or not.
Unlike in other multi-event competitions at the Games - such as the heptathlon and decathlon in athletics as well as the Modern Pentathlon, which all have breaks between each event - triathlon competitors go straight from one element to another.
After starting with a 1.5 kilometre swim in open water, athletes then run to the transition zone, removing their wetsuit and putting on their helmet before mounting their bicycle for a 40km ride.
Competitors return to the transition zone for a second time to swap their bikes for running shoes before setting off on a 10km run.
The winner is the athlete who crosses the finish line first following the three different disciplines.
With the top athletes in the world often separated by only a few seconds after almost two hours of racing, the ability to be able to move smoothly between events in the transition zone is vital.
Technique plays a key role, but athletes must also possess high levels of stamina and endurance in what is one of the most physical sports.
The biggest names in the world - such as Spain's Javier Gomez and Britain's brothers Alistair and Jonny Brownlee - are adaptable at all three different elements, producing strong performances in each of the swimming, running and cycling.
Invented at San Diego University in the USA in 1974, the first triathlon event was held on Fiesta Island in California.
The first World Championships were held in 1989 in France following the creation of the International Triathlon Union (ITU), and the sport has since gone from strength to strength - making its Olympic debut at Sydney 2000.
Many events are held worldwide each year and over 120 affiliated national federations are now in existence.