By Daniel Takata on SwimSwam

This article originally appeared in the 2021 Year In Review edition of SwimSwam Magazine. Subscribe here.
Do you remember high-technology swimsuits? Since it’s been almost 12 years since they were banned from swimming, they are becoming a distant memory.
But they made a huge impact between 2008 and 2009, since they were used by almost every elite swimmer in that period and were instrumental in breaking several world records. Some of these records still stand today, such as Cesar Cielo’s 50 and 100 freestyle, Michael Phelps’ 400 IM, and Federica Pellegrini’s 200 freestyle.
The effect of the suits is undeniable. But what if the swimmers were still allowed to use them? How fast would their times be?
The legacy of the suits
In 2008, Speedo launched the LZR Racer suit, adding polyurethane panels to its existing design, and replacing the Teflon coating used in previous models. The more polyurethane the suits had, the less drag they created. The result was 55 world records were broken in that year in long course meters — 25 of those during the Beijing Olympics.
In 2009, other manufacturers like Jaked and Arena went further and made their suits entirely with polyurethane, allowing the swimmers to glide through water even faster. Sixty-seven world records were broken that year in long course meters — 43 at the World Championships in Rome — the most ever.
In the beginning of 2010, FINA banned those suits for good. Now, swimsuits have to be made with only textile material, no polyurethane.
It is true that, as of today, several of the fastest performances of all time were registered in that period. And some of them still seem ahead of our time, like the world records in the men’s 200 freestyle (Germany’s Paul Biedermann, 1:42.00); men’s 400 IM (America’s Michael Phelps, 4:03.84); and women’s 200 fly (China’s Liu Zige, 2:01.81).
But swimming has evolved, and most of the world records set in high-tech suits have already been surpassed. From the 34 individual events officially recognized by FINA, 25 have seen world records set from 2010 on.
In SwimSwam Magazine Issue 23, we brought the article “What if the super suits had never existed?” We tried to answer questions like: If the swimmers were not using technology suits in 2008-2009, what would their times be? How many world records from that period would still stand?
Now, we go in the opposite direction. What if the super suits had not been banned in 2010? How fast would active swimmers be? Certainly, we would have some very fast times. Using statistical analysis, we can have an idea of this hypothetical scenario. And, in fact, we would be witnessing some pretty amazing performances.
Statistical analysis
Let’s take a look at the evolution of the men’s 100 freestyle. The graph below shows the average time of the fastest 100 swimmers in each year since 1990.
Average Time of the Fastest 100 Swimmers in the Men’s 100 Freestyle Since 1990
The decreasing pattern is evident, as we would expect, but there is another interesting aspect.
Every four years, there was a dramatic drop in the average time. This is not coincidental, since it corresponds to the Olympic years. The only exception is the period 2008-2009: The times decrease from 2007 to 2008 and decrease even more from 2008 to 2009, which is unusual since 2009 was not an Olympic year. Of course, the super suits were the cause.
In a statistical perspective, we can estimate the decreasing trend over the years and the seasonal effect every four years using data from 1990-2007, and 2010 on, to estimate the time from the 2008-2009 period in “normal” conditions — in other words, without super suits.
For example, Cesar Cielo’s 100 free world record from 2009 is 46.91, but his estimated time without the suit is 47.78, because the average gain due to the suit is estimated as 0.87. This way, we can estimate the effects of the high-tech suits in each event.
The statistical model is called ARIMA (Autoregressive Integrated Moving Average), one of the most used models to adjust time series data.
Since the 2009 suits were faster than the 2008 suits, different effects were considered for each one of those years. In the men’s events, there were swimmers who preferred to use only the leg suit, and others used the full body suit. A very careful data analysis was conducted to estimate the percentage of swimmers who used each type of suit in each event, using data from the major competitions.
In this analysis, we consider that if the swimmers could use those super suits today, they would choose the fastest ones available — the full body suits from 2009, made entirely with polyurethane.
It is important to notice that we are only able to calculate the average effect of the suits. The suits’ effects could vary from swimmer to swimmer, and the individual effect is impossible to measure without a designed experiment.
The following tables show what the world records would be if the suits were allowed today.
Women’s Events
Event | Swimmer | Adjusted WR | Year |
50 freestyle | Sarah Sjostrom (SWE) | 23.24 | 2017 |
100 freestyle | Sarah Sjostrom (SWE) | 50.91 | 2017 |
200 freestyle | Ariarne Titmus (AUS) | 1:51.82 | 2021 |
400 freestyle | Katie Ledecky (USA) | 3:54.33 | 2016 |
800 freestyle | Katie Ledecky (USA) | 8:01.33 | 2016 |
1500 freestyle | Katie Ledecky (USA) | 15:15.27 | 2018 |
50 backstroke | Liu Xiang (CHN) | 26.49 | 2018 |
100 backstroke | Kaylee McKeown (AUS) | 56.47 | 2021 |
200 backstroke | Regan Smith (USA) | 2:01.72 | 2019 |
50 breaststroke | Benedetta Pilato (ITA) | 28.57 | 2021 |
100 breaststroke | Lilly King (USA) | 1:02.67 | 2017 |
200 breaststroke | Tatjana Schoenmaker (RSA) | 2:16.36 | 2021 |
50 butterfly | Sarah Sjostrom (SWE) | 23.95 | 2014 |
100 butterfly | Sarah Sjostrom (SWE) | 54.52 | 2016 |
200 butterfly | Liu Zige (CHN) | 2:01.81 | 2009 |
200 IM | Katinka Hosszu (HUN) | 2:03.89 | 2015 |
400 IM | Katinka Hosszu (HUN) | 4:23.95 | 2016 |
Men’s Events
Event | Swimmer | Adjusted WR | Year |
50 freestyle | Caeleb Dressel (USA) | 20.49 | 2019 |
100 freestyle | Caeleb Dressel (USA) | 46.09 | 2019 |
200 freestyle | Yannick Agnel (FRA) | 1:41.73 | 2012 |
400 freestyle | Ian Thorpe (AUS) | 3:37.97 | 2002 |
800 freestyle | Zhang Lin (CHN) | 7:32.12 | 2009 |
1500 freestyle | Sun Yang (CHN) | 14:26.17 | 2011 |
50 backstroke | Kliment Kolesnikov (RUS) | 23.26 | 2021 |
100 backstroke | Ryan Murphy (USA) | 50.77 | 2016 |
200 backstroke | Ryan Lochte (USA) | 1:50.88 | 2011 |
50 breaststroke | Adam Peaty (GBR) | 25.31 | 2017 |
100 breaststroke | Adam Peaty (GBR) | 55.61 | 2019 |
200 breaststroke | Anton Chupkov (RUS) | 2:03.48 | 2019 |
50 butterfly | Andriy Govorov (UKR) | 21.72 | 2018 |
100 butterfly | Caeleb Dressel (USA) | 48.35 | 2021 |
200 butterfly | Kristof Milak (HUN) | 1:48.80 | 2019 |
200 IM | Ryan Lochte (USA) | 1:51.54 | 2011 |
400 IM | Michael Phelps (USA) | 4:00.31 | 2008 |
Some of the “new” world records would be unbelievable. Katie Ledecky would be close to breaking the eight-minute barrier in the women’s 800 freestyle. Sarah Sjostrom would be cracking magical barriers: 51 seconds in the women’s 100 freestyle and 24 seconds in the 50 butterfly, as well as Adam Peaty in the men’s 100 breast, in under 56 seconds.
Interestingly, two of the world records by Chinese swimmers set in 2009 would stand today (men’s 800 freestyle by Zhang Lin and women’s 200 butterfly by Liu Zige), as no one after that has come close enough to hypothetically swim faster than those times even when wearing the super suits.
And then there is Michael Phelps’ case. In 2008, he set the men’s 400 IM record wearing a Speedo LZR leg suit. If he wore the full polyurethane suits available in 2009, he could conceivably break the 4-minute barrier.
As long as those “new” world records seem too fast to be real even in a super suit, remember that back in 2009, the swimmers set astonishing performances that were way ahead of their time. The effects of the suits were huge.
Read the full story on SwimSwam: What If The Super Suits Had Not Been Banned In 2010?