Double Olympic champion Rebecca Adlington announced Tuesday her retirement from competitive swimming at the age of 23.
The popular Briton won two gold medals at the Beijing Games in 2008 but could only muster two bronze medals at London 2012 as the host nation's swimmers managed a disappointing three medals between them in the pool.
She said now was the right time to quit as she could no longer keep pace with a younger generation of swimmers.
"I hate the word retire," Adlington said. "I love swimming but as a competitive element and elite athlete I won't compete any more.
"I'll always be swimming even when I am 90 years old."
However, Adlington added: "I certainly can't compete with that (younger swimmers). I can't do the same level of work, I need far more time for recovery.
"It's time. Beijing changed my entire life, everyone wanted to learn about me. It was the best moment of my entire career," insisted Adlington, who in 2008 won Olympic gold in both the 400 metres and 800m freestyle.
Adlington, from Mansfield, central England, also thanked her family and her coach Bill Furniss, who on Monday was appointed as the new head coach of British Swimming.
"I couldn't have done it without my family. Even my sisters, they helped me with my homework.
"Bill is the biggest thing....he has helped me as an athlete as much as a person."
Furniss paid tribute to Adlington on Tuesday via Twitter, saying: "Proud to have been Rebecca's coach the same qualities that made her the best ever will ensure success in everything she does."
Meanwhile British Olympic Association chairman and London 2012 chief Sebastian Coe backed Adlington to help spread the appeal of swimming even though she was no longer an elite competitor.
"Becky Adlington's unforgettable success in Beijing inspired a generation to get in the pool and swim," Coe said.
"Her down-to-earth personality and remarkable career achievements have made her a national treasure," added the British athletics great, who won 1500m gold on the track at both the 1980 and 1984 Olympics.
"Becky's vision for the future of grass-roots swimming in this country will create a wonderful legacy from one of our greatest Olympians.
Adlington first came to international attention by taking silver in the 800m freestyle at the 2006 European Championships.
Since then, she has won Olympic, world, European and Commonwealth titles.
In Beijing, she became Britain's first female double gold medallist in swimming and took the 800m freestyle in a world record time of 8 minutes 14.10 seconds, a mark that still stands.
But there have been low points as well with Adlington, following the euphoria and publicity that greeted her unexpected triumph in China, only finishing fourth in the 800m a year later at the 2009 World Championships in Rome.
And in London a clearly emotional Adlington felt she had let her country down after failing to defend either of her Olympic titles and having to settle for two bronze medals instead.
However, the podium ceremony at the 800m saw an enthusiastic crowd chant her name, a reception that moved Adlington to tears.