An Olympic champion in the 400-metre freestyle at the 2012 London Games, Camille Muffat of France is retiring from competition at the age of 24.
Muffat was also a runner-up in the 200-meter freestyle and won a bronze medal in the 4x200 freestyle relay two years ago.
She intended to compete in the 2016 Rio Games, but said in the Saturday edition of French daily L'Equipe that "I knew becoming an Olympic champion in 2016 would be 100 times more complicated."
Muffat was the star of French swimming with Yannick Agnel. She said it was a carefully thought-out decision to retire but did not rule out a comeback.
She said: "It's maybe a mistake. But I don't think I'll regret it."