arena Swim of the Week: Zhang Zhanshuo Becomes Fastest 16&U 400 IMer In History

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Disclaimer: Swim of the Week is not meant to be a conclusive selection of the best overall swim of the week, but rather one Featured Swim to be explored in deeper detail. The Swim of the Week is an opportunity to take a closer look at the context of one of the many fast swims this week, perhaps a swim that slipped through the cracks as others grabbed the headlines, or a race we didn’t get to examine as closely in the flood of weekly meets.

The ability to close has long been a hallmark of great 400 IMers, and we appear to have a new one on the rise in Zhang Zhanshuo, who unleashed a remarkable performance in the final of the event on Friday at the World Junior Swimming Championships.

Zhang, who only turned 16 in May, came into the championships as a relative unknown, having never represented China on the international stage with the nation not fielding a team at either the World Juniors or Junior Pan Pacs last year.

After setting a personal best of 4:17.68 at the Chinese National Championships in May, done while he was still 15, Zhang came in as the 3rd seed in the boys’ 400 IM at World Juniors.

He was certainly riding some momentum after winning bronze earlier in the meet in the 800 free (7:50.03), but he’d also taken on a busy schedule that included additional swims in the 400 free, 200 IM, and the boys’ 400 and 800 free relays.

After cruising through the prelims with a time of 4:20.45, qualifying 5th overall, Zhang had a monumental swim in the final.

After turning 6th after the butterfly leg, 5th after backstroke and 4th after the breaststroke, Zhang dropped the hammer on freestyle, closing with a blistering 27.38 final 50 to move into the silver medal position in a time of 4:12.44.

Not only does the time mark a five-second personal best, but it also makes Zhang the fastest 16-and-under swimmer in history, dipping under the previous standard held by his countryman Huang Chaosheng, who clocked 4:12.53 at the 2009 Chinese National Games.

The U.S. National Age Group Record for 15-16 boys stands at 4:14.73 from Carson Foster, while Michael Phelps‘ fastest-ever time before his 17th birthday was 4:15.20.

All-Time 16 & Under Performers, Boys’ 400 IM (LCM)

1. Zhang Zhanshuo (CHN), 4:12.44 – 2023 World Junior Championships
2. Huang Chaosheng (CHN), 4:12.53 – 2009 Asian Games
3. Ilya Borodin (RUS), 4:12.95 – 2019 World Junior Championships
4. Yousuke Mori (JPN), 4:13.31 – 2009 Japan Open
5. Daiya Seto (JPN), 4:13.42 – 2011 Japan Open
6. Kosuke Hagino (JPN), 4:14.58 – 2011 Japan Open
7. Johannes Hintze (GER), 4:14.72 – 2016 German Championships
8. Carson Foster (USA), 4:14.73 – 2018 Junior Pan Pacific Championships
9. Michael Phelps (USA), 4:15.20 – 2001 U.S. Spring Nationals
10. Sean Grieshop (USA), 4:15.67 – 2015 World Junior Championships

Although splits aren’t available for Huang’s swim from 2009 or Zhang’s previous personal best, we can take a look at how he split the race relative to Russian Ilya Borodin, the 2019 World Junior champion who joins Zhang and Huang as the only 16-year-olds to have broken 4:13 in the event.

Borodin was a second and a half faster on back and slightly quicker than Zhang on fly and breast, but Zhang erased all of that and more with his freestyle, where he out-split the Russian by more than three and a half seconds.

Split Comparison

In the race itself, Zhang was the runner-up to Japan’s Tomoyuki Matsushita, an 18-year-old who also used an impressive freestyle leg to run away with the win in a new Championship Record of 4:10.97.

Lorne Wigginton, 17, set a Canadian age group record to place 3rd (4:12.81), while early leader Riku Yamaguchi of Japan slid to 4th (4:13.18). Yamaguchi’s time for 4th place was notably 1.7 seconds faster than he went to win the gold medal last year.

Zhang will finish off his busy schedule with the boys’ 1500 free on Saturday, where he comes in as the 4th seed with a best time of 15:11.34.

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