When it happens:
July 30 to Aug. 4
How it became a sport:
Swimming has been part of every modern Olympic Games, but the competitions weren't always held in a pool. The first few Games held swimming competitions in open water — at Paris' 1900 Games swimmers competed in the River Seine. In 1908 the rules were formalized, when the London Games organized the first Olympic Swimming competition to be held in a pool. Women’s events were added in 1912 at the Stockholm Games. At London Games all eyes are on Michael Phelps and Ryan Lochte who will compete head-to-head in up to six races.
What it takes:
Speed, strength and stamina are crucial in swimming. There are four types of swimming styles featured in the Olympic competition: Freestyle (front crawl), backstroke, breaststroke and butterfly. All four strokes are featured in the individual medley and medley relay events.
First, swimmers compete in heats determined by their seeding. (Higher seeded athletes get better placement—the center lanes are the most desirable and reserved for athletes with the best performances heading into each race.) For 50m, 100m and 200m events, the top 16 swimmers from the heats move on to the semi-finals, and the top eight from these compete in the final.
How you win:
For all events, getting a good start is vital. Events start differently, either by diving in or starting in the water. Good stroke technique can help win the event, as can making fast turns and a good finish. Swimmers should have all parts of their race technique down to perfection, including the changeovers in the relay events. A false start results in disqualification. Judges check to ensure that stroke and turning techniques are legal and that in the relay events each swimmer touches the end of the pool before his/her teammate leaves the starting blocks. Rule violations are reported to the chief referee, who decides on any penalty.
Long course – a 50m pool of the type used in Olympic competition, as opposed to a short course measuring 25m.
Medley – a combination event in which a swimmer or team swims separate legs of backstroke, breaststroke, butterfly and freestyle.
Negative split – when an athlete swims the second half of a race faster than the first half.
Open turn – a type of turn in which swimmers must touch the end of the pool with their hands.
Tumble turn – an underwater roll at the end of a lap, which allows swimmers to push off from the end of the pool with their feet.