Swimsuit ban will affect world record progression

FINA changed the rules on swimsuits on 1st January 2010.  This effectively banned full body polyurethane swimsuits which had been blamed for the overwhelming number of world records in the 2008 Beijing Olympics and the 2009 Rome World Championships.  Nunzio Lanotte wrote a guest blog on this very subject and concluded that perhaps we shouldn’t worry since overall performances seemed to be continuing anyway.  One thing that is only just becoming evident, however, is that records made during the swimsuit era may be difficult to break.

The great thing about a pan-sport rule change relating to technology is that it can give a good idea of the effect that particular technology. Figure 1 shows times in the men’s 100 m freestyle since 1990 using the top times in each year, and the mean of the top 25 times in each year (each time used is for a different athlete so only the top time for any one athlete is used).   So what does it show?  The top time, as expected, is a little more erratic than the top 25 mean but a relatively clear trend is shown; on average times drop over time with a distinct drop in 2008 and 2009.  After the ban in 2010 times increased again and seemed to continue their downward trend in 2011.

Figure 1. Times in the men's 100 m freestyle. The average of the top 25 uses each athlete only once.

The swimsuit effect

The effect of the swimsuit is certainly visible in the data – the rule change in 2010 increased mean times in the men’s 100 m freestyle by around 0.75 s.  What is even more clear is that the top time in 2009 is over half a second faster than in 2011.  One question we might want to ask is, how long might it take for records set in 2009 to be broken.  Table 1 below shows the margins between 2009 and 2011 for all distances in the men’s and women’s freestyle and the approximate period of time it might take to beat the 2009 times.

50m 100m 200m 400m 800m 1500m
Difference (s)2011-2009 Men














Estimated years to new world record? Men














Table 1.  Margins between 2009 and 2011 times for men’s and women’s freestyle, and approximate times to for the margin to be made up.

FINA’s choices

Whether FINA or the general public will be happy with this state of affairs is not clear but people in general like to see world records broken in their sport – just not too many all at once.  So, FINA may go for the status quo i.e. leave it and see how things go.  They could lift the ban and let all swimsuits be used again, but this  would be confusing and would certainly not do anything for their credentials for good governance.  A third way might be to set a ‘new rules world record’ from 1st January 2010 reflecting the fact that records pre- and post-2010 are judged differently.

Whatever happens, not many records will be broken in London 2012.

For an overview of FINA’s process see the excellent overview by Jan Anders Manson and team here.

About stevehaake

Steve is Professor of Sports Engineering at Sheffield Hallam University. He has a degree in Physics from the University of Leeds and a PhD from Aston University on the mechanics of golf balls on golf greens. He has over 200 publications, including his first book "Advantage Play: Technologies that changed Sporting History" due out in October 2018.

4 Responses

  1. theclownshoes

    Nice blog Steve. Have you considered that other ‘behind the scenes technologies’, such as improved training tools, might change the historic trend in the data leading to the records being broken sooner that predicted?

  2. Good one, Steve. I actually think that world record in freestyle sprint will be the hardest to beat. But we shouldn’t underestimate the human factor either. Take the 400m FS, for instance. The current record is 3’40″07, established by Biedermann in Rome 2009 with a supersuit, but the previous one was 3’40″08, set by Ian Thorpe in 2002. Apparently the stratospheric talent of the Thorpedo had taken swimming ten years and a supersuit ahead! As long as the likes of Thorpe, Phelps and Pellegrini will be around, no record will be safe.

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