In the women's 200m butterfly final at the World Swimming Championships 2025 in Singapore, Yu Zidi finished fourth. Photo: VCG

"What were you doing over the summer break when you were 12?" This was the question that many swimmers found themselves asking after witnessing the wonder of Yu?Zidi, the 12 year old Chinese prodigy who surprised the world at the World Aquatics Championships in Singapore. 

The tween qualified for two individual finals in the span of 24 hours in the 200?m individual medley and the 200?m butterfly, on top of being the youngest medalist at the World Championships in 89 years, after the Chinese women's 4×200?meters freestyle relay team won a bronze medal.

"When I was 12, I was still running around the park, catching bugs and having a good time," recalled Romanian swimmer David Popovici, the reigning world champion in 100 and 200-meter freestyle.

"Her 12-year-old times are much faster than mine at that age. When I was 12, I set the national record in the 200m medley, but I was still seven seconds slower than her. She's really fast."

Yu Zidi after the race Photo: VCG

Razor-thin margin

Yu's relay bronze was historic not just in its result, but also in its significance: In 1936, Inge Sorensen, a 12 year old Danish swimmer won Olympic bronze -- but no athlete of Yu's age had ever reached as many finals or swum as fast since then. 

"This was my first time competing in a team relay, which was even more exciting than individual events. This relay bronze motivates me to keep working hard," Yu told Xinhua News Agency. "Right after the race, I talked to my family. I want to bring back the medal and mascot to share the joy with them."  

Not only did Yu, who will turn 13 in October, become the youngest medalist ever at a global championship, but she also placed 4th in both the 200?m IM and 200?m butterfly, missing podium finishes by razor thin margins.

In the 200?m individual medley, Yu posted a personal best and missed bronze by only 0.06 seconds, with a closing freestyle split of 30.17 seconds, just 0.01?seconds slower than champion Summer McIntosh's 30.16?seconds peak. In the 200?m butterfly, she was only 0.31?seconds from third place. 

However, Yu's achievements are not eligible to be recognized as a new world junior record, as current regulations under the world swimming governing body require that an athlete must be aged between 14 and 18. 

Despite being the youngest competitor in the pool, Yu carried herself with a composure that belied her age. When asked how she managed to stay calm amid the pressure, Yu responded with surprising clarity.

"The world championships are much more intense than I'd imagined, and the atmosphere is great. During warm-up, the pool was very crowded and lively, but I adapted well," she said, before describing how she mentally prepared for the race day.

Participating in her last individual event at this World Championships of the women's 400-meter individual medley, Yu finished the women's 400 meters individual with 4:33.76, 0.5 seconds behind the bronze medalist.

"I really like the 200m individual medley, 400m individual medley, and 200m butterfly," Yu was quoted as saying. "However, among the four strokes in individual medley, my breaststroke still needs improvement."

Start from water park

Born in October 2012 in Baoding, Hebei Province, Yu's love affair with swimming began unexpectedly at age 6 during a wet?and?wild heat wave escape to a water park. 

Fast?forward four years and she had already shattered age?group bests across China, earning a place at the Hebei Taihua Jinye Swimming Club and finding herself pacing beside stars like Li Bingjie, a Tokyo Olympic champion and women's distance freestyle swimming specialist. 

According to a story published on the website of the Hebei Sports Bureau , which oversees Yu's development, Yu was once close to calling it quits at 11 due to external pressure, but was inspired to come back after watching Ye Shiwen, who won two Olympic gold medals in 2012 when aged 16. 

Now, Yu has grown transformed into one of the hot topics in the world swimming circle, attracting international and local media attention. 

The World Championships in Singapore is just a starting point, and the tween has already begun to look forward to the World Championships in Budapest two years from now.

"I still want to participate in the next World Championships, compete well against the world's top swimmers again, and strive to stand on the podium," Yu said.

Experts caution that nurturing precocious talent without burning out athletes before their true prime time is a delicate art. 

"Yu's presence at the world championships underscores China's talent cultivation depth in swimming," Zhang Bin, a Beijing-based sports commentator, told Global Times. "Professionally administered programs, gradual progression and attention to mental health are key ingredients for success that lasts."

With efforts from Yu's many older teammates in competitive swimming, diving and artistic swimming, the Chinese delegation scooped a total of 15 gold, 12 silver, and 10 bronze medals to culminate the World Aquatics Championships at the top of the medal table.