The secrets of a 12-year-old Chinese swimmer fascinate the world, but pose a dilemma.

No one has ever swum so fast so young. World Aquatics has had to create a new category for its world records titled "12 and Under," where Yu Zidi could occupy all the ranks because, as Chinese journalists in Singapore pointed out, "she can take seven events, like a buffet." In fact, if she breaks a junior world record, it could not be recognized. It's not allowed until the age of 14. Everything has been blown up.

To explain this phenomenon, we must understand her anthropomorphic qualities, which allow her to swim so well in all strokes with so little training. If Mireia Belmonte, in her prime, said she swam 90 kilometers a week, the difference in training between a 12-year-old girl and a 22-year-old swimmer is obvious. But in swimming, more is not better. "Her underwater movement and leg movement are very good. She aligns her body very well. She lowers her back to the bottom of the pool and then comes back up, which reduces the impact on the water. Her swimming frequency is very high," explains Andreu Roig, a biomechanical specialist at the CAR, who envisions a 200-meter butterfly stroke for Yu Zidi.

He aligns his body very well and his swimming frequency is very high.” Andreu Roig, Biomechanical Engineer at the CAR

“Maintaining this frequency in the 200m is demanding. He's been doing a lot of cardio,” he adds. He concludes: “His good alignment allows him to maintain the speed achieved with his kick and stroke.”

Yu Zidi, like other outstanding swimmers such as Summer McIntosh and David Popovici, has near-perfect fundamentals. They've managed to position their bodies in an aerodynamic position in the water: they move forward with fewer strokes, and they're efficient.

Added to this is the training of the Chinese school. The analysis was published by the New York Times based on documents from the Hebei Provincial Sports Bureau. They highlight that Yu Zidi swims 15 kilometers daily, that he has spent at least two hours a day in a hypoxia chamber simulating an altitude of 2,000 meters for two years, and that his hemoglobin is 16.2, higher than that of women. He has a lactate level of 14.3 mmol/l, and his recovery is 40% faster than that of adults.

"I've never seen anyone like this at 12 years old. She'll be a pillar for China," says Michael Bohl, now a coach in the Asian country and formerly an Australian swimming guru. He has trained and knows the secrets of Thorpe, Titmus, and Hackett. In one year, the Chinese woman has improved her average time by five seconds over her best events, has passed 27 drug tests in three years, and bone studies predict she'll be 1.81 meters tall. She will be a physical prodigy similar to Katie Ledecky or Kylie McKeown.

And that, although it may seem otherwise, isn't so good. "Your weight and strength will change, and the levers of support will be different. If anthropometric growth isn't accompanied by strength and agility work, it can be detrimental. The butterfly and breaststroke require special coordination," he adds.

Its weight and strength will change over time and the levers will be different.” Andreu Roig, Biomechanical Engineer at the CAR

At the London Games, 16-year-old Chinese Shiwen Ye won the 200 and 400 medleys. She was nicknamed "The Chinese Woman Who Swims Like a Man" for completing the last 50 meters as fast as Ryan Lochte. She never swam like that again. Her body changed.

Yu Zidi has broken all precocity. And that opens up other debates, moral ones. The Rize psychologist, Ana Merayo, cuts the slack. “She's building her self-esteem and her worldview. What she's experiencing doesn't fit with her evolutionary and socio-emotional stage. I'm only worth it if I win. For her, the game isn't a space for learning, which is what it should be at her age. For her, it's a profession,” she explains.

Yu Zidi, who is from Hebei, the same city as her idol Bijing Li, goes to school, but dedicates many hours to swimming at a high-performance center. In Spain, the closest 200m medley record is 2:19 by Nadia González, Hugo's sister, achieved at the age of 13. At that age, girls train about 12 hours a week and swim about 20 kilometers. "In China, they work by level, not by age," says one coach. "She's a Mozart, you can't stop her," responds another. On Monday, Yu Zidi broke Mireia Belmonte's Spanish record in that event by 0.024 seconds: she swam in 2:09.22.

Your life must be balanced, you must have horizontal relationships” Ana Merayo Psychologist at The Rize

"If children are not protected, situations such as premature abandonment, burnout, anxiety disorders arise... Their lives should be balanced, they should have horizontal relationships, and they should be a child," Merayo adds.

Zidi's "professional" life has only just begun. In Singapore, she still has the 200m butterfly and 400m medley, her favorite events. And, given what we've seen, a medal isn't out of the question. It would be one of the most astonishing situations in the sport, even if some red lines may have been crossed.

“I invite everyone to reflect; we have a responsibility,” Merayo explains. “I'm not a genius, I just put in the work and effort,” the swimmer said, smiling after her fourth-place finish. Living a premature dream.