China's Fu Yuanhui starts in a women's 50m backstroke heat at the Aquatics World Championships in Kazan, Russia, August 5, 2015. [Photo/Agencies]

"I invested so much into this victory. Two years ago I took part in the world championships and I learned a lot there. Now I am training much harder than anybody else in the world. I am doing it to be the first," said the 19-year-old Fu, who finished fourth in the 100m back.