Kathleen Hersey (USA) reacts after winning a womens 200m butterfly heat during the London 2012 Olympic Games at Aquatics Centre. Kirby Lee-USA TODAY Sports)
LONDON -- After so many rehearsals, Kathleen Hersey was ready for this Olympic stage. She's been an Olympian before, and she has peaked twice before.
The 22-year-old Atlantan emphatically debuted in London by posting Tuesday's fastest preliminary of the 200-meter butterfly before notching an even better time during the semifinals.
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Her time of 2 minutes, 6.41 seconds was 0.74 faster than China's Jiao Liuyang. Hersey also bettered her previous best of 2:06.44, set in 2009 before high-tech bodysuits were banned.
"I've had a lot of experience in this race, which I'm so grateful for," Hersey said. "When I got here, this pool . . . everyone has been so accommodating.
Later in the day Tuesday, Hersey bettered that time by posting a 2:05.90 in the semifinals.
"It was comfortable. To be in a race environment that you makes comfortable is half the battle."
It has been an emotional year for Hersey, whose adoptive mother, Regina, died in January. Hersey has said she has felt her mother's presence.
She is coached by Eddie Reese, the men's coach at the University of Texas. Preparing for the Olympics so soon after peaking for the U.S. trials is something she said Reese knows how to manage. The timetable resembles what the Longhorns do for the Big 12 Championships, followed by NCAAs.
"Our program, and college swimming, teaches you to kind of be prepared twice in a row," Hersey said. "I'm so grateful to be part of that NCAA environment and have that experience because it makes it easier coming here and doing it on a bigger stage."
Hersey finished eighth at the 2008 Olympics but missed finals at the 2009 and 2011 World Championships, placing ninth in semifinals each year. Her lone international medals are a bronze from the 2010 Pan Pacific meet and four golds from the 2007 Pan American Games.
Until Tuesday, she had been a spectator on a U.S. team that has already won 12 medals.
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"It's been good to watch," Hersey said. "And now it's my turn."
The other American entry, U.S. trials winner Cammile Adams, was eighth in qualifying in 2:08.18.
Hersey called her race "a sold morning swim" and said she was excited for Tuesday night's semifinals. She said she never had to shift to her fastest gear.
Hersey was born in Athens, Ga. and graduated from Marist School.
(David Woods, The Indianapolis Star/USA Today)