Pan Zhanle’s new swimming world-record at Olympics makes no sense, and that’s the problem

One swimmer, a slow pool, and the biggest world record jump in 25 years.

Pan Zhanle did the unthinkable on Wednesday in the men’s 100 meter freestyle. The 19-year-old didn’t just break the most difficult world record in swimming, but he smashed it by 0.4 seconds — and beat second place by 1.08 seconds, a full body length. What has ensued from that moment is, in a word, ugly. There have been allegations of doping from one side, claims of racism from the other, and in the middle the inescapable reality that what ensued simply doesn’t make sense.

Australia’s Kyle Chalmers and Romania’s David Popovici finished 2nd and 3rd, and as soon as they saw the world record had been broken there were words. It appeared that Chalmers looked across Pan’s lane to Popovici, nodded, and said “doping.”

This followed Pan alleging that he’s gotten a cold shoulder from Chalmers since arriving in Paris, saying the Australian ignored him when he tried to say hello at the opening of the games — as well as saying that that Jack Alexy of the USA splashed water on his coach.

“We cleaned our past shame. On day 1 I tried to say hello to Kyle Chalmers and he ignored me. And the USA’s Jack Alexy splashed water on our coach. I felt they looked down on us. Can I say this on TV? I finally beat them all today!”

There has been a history of doping inside the Chinese swimming team. From 1990 to 1998 a total of 28 swimmers tested positive for performance-enhancing drugs. A story in April of 2024 by the New York Times reported that 23 swimmers from China tested positive for the banned heart medication trimetazidine at the Chinese Swimming Championships in 2021, only to have 13 of them compete in the Tokyo Olympics. It’s raised huge questions about the World Anti Doping Agency (WADA), and whether the body has deference to China in terms of pushing their athletes.

In June of 2024 Michael Phelps spoke to congress about his concerns regarding the Chinese swimming team and WADA, saying “any attempts of reform at WADA have fallen short, and there are still deeply rooted, systemic problems that prove detrimental to the integrity of international sports.”

Pan Zhanle was not cited in any report about Chinese doping. At this time there’s no evidence he has used performance enhancing drugs. Still, it’s raised a lot of questions about the nature of the record-breaking swim.

One thing is certain: We witnessed the most stunning achievement in swimming history.

The lingering question is: How?

To understand why this was such a momentous achievement is to understand the men’s 100m freestyle as an event. It’s the marquee race in terms of speed swimming, and has been since the inception of the Olympic games. Unlike the blazing anarchy of the 50m, the 100m requires a perfect formula of speed, stamina and technique to race as quickly as possible for a lap, execute an ideal turn, and ensure the right number of strokes are taken on the return lap to reach the wall outstretched.

The race reached a whole other level of popularity in 1922, when USA’s Johnny Weissmuller became the first person in recorded history to swim the 100m quicker than one minute, finishing in 58.6 seconds. From that moment on the 100m free became the event when it came to record progression, and the whole world wanted the honor of holding it.

Records fell and speeds increased, as is the case in all sport — but the 100m was different because of how narrow these margins were. It wasn’t until 1976, over 50 years since Weissmuller broke a minute, that Jim Montgomery managed to reduce the record to under 50 seconds with 49.99.

The 1980s came and went, with the record progression only managing to drop 1.57 seconds in over a decade. Swimmers were pushing themselves to the absolute limit, and it felt like we were reaching the boundaries of what the human body was capable of. The record kept falling, but margins were now within a 10th of a second each time it fell. It wasn’t until the 2000 Olympics in Sydney that the men’s 100 free dropped below 48 seconds to Pieter van den Hoogenband of the Netherlands, and that record carried controversy with it. The 2000 games were legendarily when technology led to swimmers wearing full body drag-reduction suits, which resulted in dozens of swimming world records falling, and governing bodies to ban the suits as a result.

From 2000 to 2024 the record progression clawed forward at a snail’s pace. The record was broken eight times, but in the span of 24 years the men’s 100 free only went from 47.84 seconds, to 46.86 seconds. Over two decades of development, training, sports science, and excellence could only push the record down by 0.98 seconds.

Then Pan Zhanle arrived.

A professional swimmer since the age of 15, it was clear that Pan was destined to be a truly great swimmer for China. Beginning as a 1500m specialist, over time he began tackling shorter distances and eventually made the 100m his marquee event. In 2021 he made his international swimming debut, finishing 11th in the semifinals of the 100m at the FINA World Championships, but turning heads as the 16-year-old was still developing and setting solid times.

It’s here things start to get a little murky. While there’s absolutely no question swimmers improve with age from being teenagers, the explosion Pan had in a short period of time was unreal. At the 2022 Asian Games (held in August of 2023 due to Covid restrictions) he posted a time of 46.97 in the 100m. A truly incredible time which would have won silver at the European championships a year earlier.

When the World Championships in Doha rolled around in February of 2024, Pan was on an entirely other level. He broke the world record with a time of 46.80 seconds, going quicker than he ever had before. That wasn’t necessarily stunning, and while impressive, it didn’t garner any controversy. Breaking the world record in 100m free by 0.06 seconds represents that snail’s pace of progression I mentioned earlier. By all appearances Pan was simply getting better, and now had claim to being the best 100m freestyle swimmer in the world.

However, what he did at Paris doesn’t make sense. It’s impossible to really understand how he managed to pull off breaking his own world record by 0.4 seconds in that pool.

The core issue is that the Paris pool is slow. Really slow. It was speculated before the games that records were unlikely to fall at the 2024 games because the Olympic pool only has a depth of 2.15 meters, which exceeds the 2.0 meter requirement for the games — but falls well short of the 3.0 meters recommended by World Aquatics. A deeper pool is a faster pool, because it ensures that the downward force on the water swimmers generate doesn’t rebound off the bottom of the pool and return to the surface to create chop or rough water.

Swimmers in Paris have already been saying the swimming was slow because of chop, with the shallow pool being the No. 1 culprit. As a result we’ve seen times well off personal bests. No world records have fallen outside of Pan, with the only Olympic records coming in races of 200m or longer, where slower stroke speed means there’s less of an impact from buffeting as in shorter races.

It was widely believed the men’s and women’s 100m freestyle races would be most impacted by the shallow pool, because chop from the opening lap would reach the surface as they made the turn into the second. This was largely true, with the women’s 100m freestyle being 0.3 off the pace of the world record, while in the men’s event Kyle Chalmers and David Popovici (who finished 2nd and 3rd) were also roughly 0.8 seconds slower than their personal bests in the Paris pool.

Then there’s Pan Zhanle, an outlier, whose performance makes no sense in the context of every other swimmer at the Olympic games. It’s not simply a matter of him winning the race, or going the quickest — but it is fundamentally bizarre that he was able to smash the most difficult record in swimming by 0.4 seconds, the largest margin in 25 years, and did it in a slow pool where competitors aren’t able to touch their own personal bests.

To be clear: This absolutely does not mean that Pan cheated or doped his way to gold. By all accounts he has passed every pre-Olympics drug test ahead of the 100m final, and the results of the post-race tests have yet to be released. That said, the nature of the swim is very unusual. If he were to just best his own record it would have been one thing, but it’s how abnormal Pan’s record is when compared to every other race in Paris that makes this odd — and we have no answers for that.