Olympic swimming gold: The suit or the swimmer in the suit?

Olympic swimming gold: The suit or the swimmer in the suit? Mark Spitz won seven gold medals wearing briefs. Michael Phelps won 14 gold medals in Athens and Beijing in a high-tech all-over bodysuit. In 2010 high-technology swimsuits were banned from competition, as significantly improving performance. But do they really make a difference? Ray Stefani evaluates them, beginning with an evocative photo from the 1924 Olympics. The beginning: less is more The photograph is grainy but evocative. It was taken at the medal ceremony for the 400 metres men s swim at the 1924 Paris Olympics and speaks a proverbial thousand words about our topic. It shows three champion swimmers; but was it the swimmers or the suits they wore that brought them success? From left to right are Andrew Boy Charlton (Australia) who won the bronze medal; Johnny Weissmuller (USA), the gold medal winner; and seemingly about to step off the platform, Arne Borg (Sweden), the silver medal winner. (Before the Second World War, silver and bronze medal winners stood in opposite orientation to today.) Charlton became known as Boy after he had beaten an Olympian in a match race at the age of 14. He was 16 at the time of the photograph. Notice that Charlton and Weissmuller wore nearly identical form-fitting, upper-body covering suits with a tight weave that is remarkably similar to men s suits used in recent Olympic competition, except for lack of thigh coverage. Borg s suit Medal ceremony for the men s 400 m swim at the 1924 Paris Olympics. Boy Charleton (Australia), Johnny Weissmuller (USA), and, in a lower-cut suit, Arne Borg of Sweden. Photo: Official Report of the Paris Organizing Committee, with permission of the IOC 2012 The Royal Statistical Society 13

Speedo s LZR Racer Michael Phelps poses surreally underwater in his LZR Racer suit. Photo: Speedo is clearly skimpier than the other suits, for a reason that will become apparent. About six months before that photo was taken Borg had left frozen Sweden in January 1924, for a trip that must have been challenging in that age. He showed up in Charlton s home town of Sydney to compete against him in the New South Wales Championships to be held in what were then called the Domain Baths. Charlton and Borg had already caught the public eye, as between them they held world records at 400 m, 800 m and 1500 m, each keen on breaking the other s records. Imagine Mark Spitz and Michael Phelps competing as contemporaries and you might get an idea of the attraction. On the day of the 440 yard showdown the line of potential spectators stretched about ½ mile 1. About 6000 spectators entered before police shut the gates. Since this was Australia, of course odds were offered: 2 to 3 for Borg as favourite, while Charlton was considered the best of the underdogs at 5 to 4. Borg led until the 300 yard mark. Charlton drew even and won by 20 yards in a time of 5:11.8, equalling Borg s 400 m world record. Borg towed Charlton across the pool in a small boat to acknowledge the winner. Later in that meet Charlton set the The LZR Racer swimsuit was launched on 13 February 2008 as the focus of Speedo s campaign for the Beijing Olympics. It was marketed as the world s fastest swimsuit. A holographic video of Michael Phelps wearing the suit was displayed in London, Sydney, New York and Tokyo, with Phelps exclaiming: When I hit the water [in the LZR swimsuit], I feel like a rocket. Among other effects, it compresses the body into a more hydrodynamic shape, traps air to increase buoyancy, and the fabric and its ultrasonically welded seams reduce drag. A slight disadvantage is that it can take 20 minutes or more to put on. Within a week of its launch three world records had been broken by swimmers wearing the suit. It led a Japanese coach to say: If swimmers don t wear the LZR Racer, they won t be able to compete in Beijing Olympics. At those Olympics 94% of all swimming races were won by wearers of the LZR Racer. world record at 800 m (880 yards). The day belonged to Charlton. After his death in 1968, the Domain Baths were renamed after him. Located not at all coincidentally in Sydney was a company called MacRae Knitting Mills, founded in 1914 2 as MacRae and Company Hosiery. Its name had been changed when the hosiery maker began to make swimwear and other clothing. Borg s suit in the photo was most likely made by MacRae. We can deduce that from events that were about to happen over the following four years. The 400 m swim shown in our Olympic photograph provided some revenge for Borg, in that he was second to Charlton s third about six months after the Sydney competition. Borg had also beaten Charlton s 800 m world record before the Games and set the 1500 m world record at 21:11.4 in a qualifying heat. Charlton won the 1500 m gold medal in a time of 20:06.6, taking about 5% off Borg s world record and 10.2% off the Olympic winning time in 1924 which is still the highest percentage improvement in swimming in a four-year period between Olympiads. In short, Weissmuller and Charlton carried the day in Olympic swimming. Over the next four years before the 1928 Olympics, Borg regained the world record at 1500 m. Also ahead of the 1928 Games, the MacRae Knitting Mills changed its name yet again. It held a contest 2 to find a more saleable name and a slogan. The winning name was Speedo Knitting Mills and the winning slogan was Speed on in your Speedos. Wearing the newly named Speedo Racer-back, Borg won the gold medal in the 1500 m swim. The Speedo website 2 identifies Borg as the first Olympic champion to wear a Speedo. Speedo touted the more open back and more open shoulder as providing fewer encumbrances for male swimmers. The suit Borg wore in the 1924 photo was probably the Racer-back prototype. Had Borg beaten Charlton in MacRae s home town of Sydney in 1924 and then over 1500 m in the 1924 Olympics, might the Speedo brand name have been four years older? As social standards became more permissive, swimsuits covered less and less flesh. Speedo touted the mantra that less is more in terms of speed for male swimmers, while a line for female swimmers also became popular. In fact, the term Speedo became synonymous with any skimpy swimsuit. Suits shrank and records fell for 50 years. Mark Spitz won his seven gold medals in 1972, in the briefest of briefs. But in the 1980s, things changed. The middle: more is less Speedo and other manufacturers such as TYR then changed direction and touted more is less in terms of elapsed time. The high-tech bodysuit appeared, and became ever more sophisticated. There were new synthetic fabrics; textured surfaces were said to reduce turbulence and drag; and, most noticeably for male swimmers, more and more of the body was again covered in fabric, again to claim a reduction in drag 2,3. Certainly records continued to fall and Olympic winning times dropped, but was that due to the suits or the swimmers? To what extent did the suits deliver on the implied promise of more speed? For the 1992 Games, Speedo 2 developed the S2000 suit, said to have 15% less drag than conventional swimwear fabric ; its wearers won 53% of the swimming medals. For the 1996 Games they launched the AQUA- BLADE with 8% lower surface resistance than S2000, winning 77% of the medals. Their FASTSKIN sharkskin-based design was there for the 2000 Games and for 83% of the medals, with up to 7.5% drag reduction, and 14

for 2004 Speedo produced FASTSKIN FSII which reduces passive drag by up to 4%. Also for 2004, TYR indicated that the TYR Aqua Shift reduces drag by 10% over FAST- SKIN II. For 2008 there was Speedo s LZR Racer, the most technologically advanced swimsuit in the world. If all those reductions in drag are to be believed, the TYR Aqua Shift of 2004 should have 38% less drag that the conventional suits worn before 1992. It is an implausible figure. Evaluating claimed drag reduction Putting the hyperbole aside, there are five questions to consider if we want to know how these advertised drag reductions would translate into faster swimming time: 1. How was drag measured? 2. Drag is reduced compared to what? 3. How much of the mechanical power applied by a swimmer overcomes drag? 4. Could water flow across the suit in active swimming produce more drag than expected? 5. How is drag force related to swimming velocity? can also determine the power that makes the swimmer move forward when not hitting the pressure pad. The difference is lost power. On Question 3, Toussaint 6 estimates Backstroke and breaststroke is not enhanced by bodysuits, whether a swimmer is unshaved or shaved that 46 77% of the mechanical power applied to the water overcomes drag. Thus, only 46 77% of drag reduction would be utilised by a swimmer. On Question 4, Toussaint 7 concludes regarding the FASTSKIN shark-skin features that the denticles protruded only slightly (about 0.5 mm) and hardly could contribute to turbulence in the boundary layer which would be needed to reduce drag. He concluded that much larger turbulence-inducing features might reduce drag. Given those more prominent turbulators, in active swimming, could the rather unpredictable motion of water negate the drag-reducing properties of the turbulators which require water movement in a particular direction? Certainly, the icing of an aircraft wing disrupts the airflow which reduces lift and increases drag, which can imperil stability 8. Most likely active drag would be higher than expected for surface features evaluated passively. As to Question 5, drag force is proportional to the square of velocity; therefore, velocity is proportional to the square root of drag force. If drag force is multiplied by a factor smaller than one, say by 1 δ, then velocity is multiplied by the square root,which for small δ is about 1 δ/2. Each of the answers to the five questions reduces the impact on active swimming of claimed passive drag reductions. For example, on the FASTSKIN, Tousaaint 7 states: The drag reducing effect of these suits [was] claimed to be 7.5%. However, there is still The answer to Question 1 is that drag was measured passively by towing either a mannequin or a swimmer (depending on the manufacturer) thorough otherwise still water and not while actually swimming. Concerning Question 2, two authors suggest that the comparisons may be to unshaven swimmers wearing loose practice suits neither factor being indicative of competition. Mollendorf et al. 4 used the State University of Buffalo flume and unshaven swimmers: It has been shown that shaving body hair reduces the energy cost of swimming and in this case the suits may not provide any additional benefit. Sanders et al. 5, based on their work in several countries, concluded similarly: It is unlikely that bodysuits will enhance racing performances in championship meets when swimmers are shaved and wearing tight conventional suits. Backstroke and breaststroke swimming is not enhanced by bodysuits, whether a swimmer is unshaved or shaved. H. M. Toussaint s work involves a flume with pressure pads below the swimmer. In that way he can evaluate the mechanical power delivered to the pressure pad and he Table 1. Evaluation of technological change in sport Technological change Olympics after 1952 and before first use Average %I/O First use %I/O on first use % Change Rowing ergometer 1956 1976 1.22 1980 7.42 508 Fibreglass pole 1956 1960 1.64 1964 8.51 419 Fosbury flop 1956 1964 (M) 1956 1968 (W) 2.25 1968 (M) 1972 (W) 4.12 83 Clap skate 1956 1994 1.82 1998 2.88 58 Javelin centre of gravity moved forward 1956 1984 (M) 1956 1996 (W) 2.55 1988 (M) 2000 (W) 0.72 128 Speedo S2000 1956 1988 1.62 1992 0.58 64 Speedo AQUABLADE 1956 1988 1.62 1996 0.10 106 Speedo FASTSKIN 1956 1988 1.62 2000 1.15 29 Speedo FASTSKIN II TYR Aqua Shift 1956 1988 1.62 2004 0.64 61 Speedo LZR Racer 1956 1988 1.62 2008 1.69 4 %I/O indicates percentage improvement per Olympiad (4 years). Swimsuit evaluation is for men s competition. 15

doubt whether hydro dynamically designed suits do aid in faster swimming. Actual performance changes So much for the theory. As for practice, we can examine Olympic winning performances as each of the innovative suits was introduced and see whether they improved at a faster rate than normal. To test this paradigm in swimming, we examined certain known technological breakthroughs 9 from other sports to see if such breakthroughs are similarly detected. Prior to the 1980 Games, a rowing ergometer was introduced that allowed significantly more outof-water muscle-specific training than afforded by bicycling. The more flexible fibreglass pole was introduced for the pole vault at the 1964 Games; it allowed more kinetic energy to be converted to potential energy and thus a greater height could be cleared. The Fosbury flop came in for the 1968 men s and the 1972 women s high jump. And for the 1998 Winter Olympics the clap skate was introduced, which puts the blade on a hinge so that the skater s ankle can rise while the blade remains fully on the ice. The last two innovations allowed use of powerful extensor muscles not fully employed previously 9. To further test the paradigm, the forward movement of the centre of gravity of the javelin for men prior to the 1988 Games and for women prior to the 2000 Games should have resulted in reduced improvement; the intention of the change was to make the javelin dive more so as to leave a mark when it hit the ground. We used the 1952 Olympics as a starting point, those being the first Games after the Second World War. To create Table 1, the average percentage improvement per Olympiad was calculated for each relevant event for the Games of 1956 though to the Games preceding the first use of each innovation. We compared that average to the percentage improvement at the first use of the innovation. In Table 1, the rowing ergometer brought a 508% increase The redesigned javelin could be thrown less far in competition MARK SPITZ (1950 ). American swimmer. Photographed wearing the seven gold medals which he won at the Olympic Games in Munich, 1972, and the kind of briefs he wore to win them. Credit: The Granger Collection/ TopFoto in the improvement per Olympiad. The fibreglass pole (419%), Fosbury flop (83%) and clap skate (58%) showed significant positive increases whilst the reweighted javelin showed, as expected, a significantly negative change in the rate of improvement, of 128%. A change in the rate of improvement of 100% would have meant the winning distance in 1988 was the same as in the previous Olympics; since the figure is still more negative it means that there was an actual decrease in performance, with athletes throwing the new javelin less far. So significant changes in technology do indeed reveal themselves in performances. Our paradigm does identify absolute and relative improvements in technology. So do the high-tech swimsuits qualify as significant technological breakthroughs? Using the same criterion of Olympiad-by- Olympiad improvement, we evaluated the swimsuits introduced from 1992 to 2008. These are also shown in Table 1. The average percentage improvement per Olympiad 16

Table 2. Comparison of high-tech and lower-tech suits for men Competition Years %I/O high tech high tech for men using conventional suits was 1.62%, based on the 1956 1988 Olympics. Did that increase or decrease when the new suits came along? Sadly for the claims of the manufacturers, the suits introduced in 1992 led to a 64% reduction in the rate of increase of improvement. The 1996 suits saw a reduction of 106% again, an absolute decrease in performance. In 2000 it was 29% down on the pre-tech era, and in 2004 it was 61% down. All these years showed significantly less improvement for men than the historic rate; the suits were not transforming performances. We now come to 2008 and the advent of the Speedo LZR Racer and other suits. That year did indeed show an increase over the conventional suit s rate of improvement. The press and media made much of it. But the increase was of 1.69% over the previous Olympiad hardly higher than the 1.62% that swimmers without new technologies had averaged per Olympiad for three decades from 1956 to 1988. This was actually no unusually high improvement: the frenzy was due more to an unusually bad memory or to hype. The end: back to less FINA, the body that governs swimming, banned the Speedo LZR Racer and other high-tech suits used at the 2008 Olympics, with effect from 2010. Suppose that those suits, rather than better swimmers, had actually been the source of the 2008 return to the historic 1956 1988 level of improvement. It should follow that their banning should have resulted in significantly reduced performance from 2010 on. Table 2 looks at two four-year improvements that span the change, and two that that do not span the change. The 2004 and 2008 Olympics, and the 2003 and 2007 World Long Course Championships, all used high-tech suits; their average improvement of the second year over the first was 1.03%. Between the 2007 and 2011 World Long Course Championships there was a change back to old-fashioned suits; as there was between the 2006 and the 2010 World Short Course championships. There the average improvement of the second year over the first was 1.50% much greater. The average fouryear improvement when the lower-tech suits came back was higher, not lower. Clearly the return to more basic swimsuits proved no real handicap at all. Summing up %I/O high tech lower tech Olympics 2004 2008 1.69 World Long Course 2003 2007 0.37 World Long Course 2007 2011 0.91 World Short Course 2006 2010 2.45 (2.10) Average 1.03 1.50 %I/O indicates percentage improvement per Olympiad. It should be noted that there were 4 years and 8 months between World Short Course competitions in 2006 (in Shanghai) and 2010 (in Qatar), hence the actual improvement of 2.45% was reduced to 2.10% to be scaled to 4 years. The high-technology suits brought in in 1996 saw an absolute reduction in swimming speeds Tables 1 and 2 indicate that the high-tech suits actually had little significant impact on improved swimming performances, either when they were introduced into competition or when they were removed from it. Returning to the evocative 1924 photograph that began this discussion, the three swimmers set world records and won medals in various types of suit. Weissmuller, wearing the 1924 vintage suit, set 67 world records, about the same as the sum of those set by Spitz (33) in his brief Speedo and by Phelps (39) in his high-tech suits. More than 85 years have elapsed since that photo, whilst suits for men have cycled from full coverage to scanty coverage back to full coverage and now to less coverage. Weissmuller won the 1924 Olympic 100 m final in 59 s, breaking the one-minute barrier. That feat caught the public eye, contributing to his movie career as Tarzan. Yet a relay of 15 Weissmullers, each swimming 100 m in 59 s, would cover 1500 m in 14:45 only to lose by more than one second to the last two 1500 m Olympic champions. They would lap Charlton four times, since his 1924 time would leave him more than 400 m behind in a 50 m pool. No swimsuit can be responsible for that magnitude of improvement. It was the dedication and hard work of swimmers like Charlton, Weissmuller, Borg, Spitz and Phelps that set records and won medals, not the suits. I suggest that it will also be so in London. References 1. The Adelaide Mail, January 12th, 1924. 2. http://explore.speedousa. com (accessed August 19th, 2011). 3. http://www.tyr.co.za (accessed August 19th, 2011). 4. Mollendorf, J. C., Termin II, A. C., Oppenheim, E. and Pendergast, D. R (2004) Effect of swim suit design on passive drag, Medicine and Science in Sport and Exercise, 36(6), 1029 1035. 5. Sanders, R., Rushall, B., Toussaint, H., Stager, J. and Takagi, H. (2001) Bodysuit yourself: but first think about it. American Swimming Magazine, 5, 23 32. 6. Toussaint, H. M., Beelen, A., Rodenburg, A. et al. (1988) Propelling efficiency of front crawl swimming. Applied Physiology, 65(6), 2506 2512. 7. Toussaint, H. M. (2002) The FAST- SKIN body suit: Hip, hype, but does it reduce drag during front crawl swimming? In Proceedings of the XXV Congress on Swimming, Porto, Portugal. 8. Gent, R. W, Dart, H. P. and Cansdale, J. J. (2000) Aircraft icing. Philosophical Transactions of the Royal Society, 358 (1776), 2873 2911. 9. Stefani, R. (2008) The physics and evolution of Olympic winning performances. In Statistical Thinking in Sports (eds J. Albert and R. H. Koning). Boca Raton, FL: Chapman and Hall/CRC. Ray Stefani is a professor emeritus at the California State University, Long Beach, with over 40 years of experience in sports performance analysis. 17