Synchronized swimming
In an event for women only, swimmers have to be artistic and graceful making complicated athletic moves look easy. Only figure skating requires quite this combination of athleticism and performance - all while keeping a smile on their faces.

The duet event returns to the Olympic Games with 24 pairs participating. Unlike the teams, duets have preliminaries with a technical and free routine. The top 12 advance to the finals where they only perform their free program again.

Competition for both events consists of a technical routine and a free routine, each performed to music within a time limit. They also look at execution of patterns as well as the overall performance. Two sets of marks are given for artistic performance as well as technical.

Swimmers have to hold their breaths for long periods, with up to 60 percent of their routine performed underwater. They aren't allowed to touch the bottom of the pool during their performance.

They talk about rockets and thrusts but they're not with NASA. These are just a few of the move made in synchronized swimming. Others are called twists and twirls. In order to make their performance easier, swimmers use nose plugs to keep out water and gel their hair back.