“She hasn’t become that fast for no reason,” said teammate Ke Wenxi, who Yu beat in the 400m individual medley final to complete her golden hat-trick.
“I’ve seen how hard she works in training. During this national team training camp, I saw her working really hard every day.”
Yu also won the 200m butterfly and 200m individual medley races this week in Tokyo.
Her times were among the fastest in the world this year, and her 200m medley swim was just 0.4 seconds off the world record.
That mark is held by Canada’s Summer McIntosh, who is likely to be Yu’s biggest rival at the LA Games.
Yu would not be drawn on her ambitions for the Olympics, saying only that she intended to “keep working hard.”
It hinted at a mature attitude and a desire not to be shaken off in her pursuit of success.
“I gained a lot from these Asian Games, but there were also some regrets,” she said.
“I’ll go back and keep reviewing what I didn’t do well, and I hope I can do better next time.”