Tampa Bay Aquatics

By Tom Slear



“These new swimsuits for the male Olympic swimmers look weird. The guys look like they are swimming in T-shirts and jeans.” – Fred Bowen in the Washington Post, August 6, 2004.



Bowen’s hyperbole aside, what the guys – and the girls – are wearing isn’t anything resembling T-shirts and jeans. First, there’s the matter of cost. A T-shirt and a pair of jeans can be had for roughly $50. An over-the-shoulder swimsuit, regardless of the manufacturer, goes for four times that.



Then there’s the fit. T-shirts and jeans hang loose enough to provide liftoff in a stiff breeze. The latest suits with their specially developed seams and fabrics provide more compression than undersized pantyhose. Fitting into one challenges a swimmer’s strength and dexterity for up to 10 minutes. This assumes neither the swimmer nor the suit is wet. If that’s the case, well, picture stuffing toothpaste into a tube.



Finally, there’s the matter of utility. T-shirts and jeans are mere costumes, disposable pieces of material that make a nod to style. The latest suits, on the other hand, are exhaustively engineered garments designed to lower drag.



The TYR Aqua Shift, for example, contains horizontal strips of cloth – called tripwires in marketing parlance, but turbulators by the scientists who created them – that “are placed precisely on the body and are exactly the right size,” says David Pendergast, associate director of the University of Buffalo’s Center for Research and Education in Special Environments, which did the research for TYR. “That way, when the water hits them, it doesn’t separate, but roles around them and stays attached to the body.”



Attached is good, because attached water flows smoothly and creates less drag. Separated water, on the other hand, rolls into eddies around the swimmer and increases drag.



Speedo’s Fastskin FSII consists of two different materials for the purpose of accommodating water that changes speeds as it passes over a swimmer. Here again, the purpose is to keep water attached. And since water velocities vary, depending on stroke and body build, the FSII is gender and stroke specific.



These new suits, regardless of the manufacturer, no more resemble jeans and T-shirts than crop dusters mimic jet fighters. But for all the science and technology they represent, a million-dollar question remains: Do they work? The FS II, the Aqua Shift, and others such as the Nike Swift and the Adidas JetConcept, no doubt play a part in lowering drag, but does that convert to faster swimming?



“It comes down to whether any of this applies when swimmers do what swimmers do,” says Joel Stager, a professor at Indiana University and director of the Counsilman Center for the Science of Swimming. “We don’t move through the water like the hulls of ships, but with arms flailing and legs splashing.”



TOO MUCH DRAG, TOO LITTLE PROPULSION



Competitive swimming’s fundamental challenge during its 170 years of existence has been to overcome the human body. With curves and expansions in all the wrong places, our bodies force water to follow a torturous path as we travel through it. We are built to swim just a little bit better than a boxcar is constructed to fly. Fish undoubtedly double over in laughter every time we enter their environment – our splash and bubbles a never-ending source of comic relief. The best among us can swim at just better than two meters per second, which is slightly slower than when a bottlenose dolphin takes a stroll. In the time it took Gary Hall to win the 50m freestyle in Athens, a dolphin at maximum speed could have swum 215 meters.



The problem is twofold: too little propulsion and too much drag. On the scale of efficient propellers, our arms and feet rank near the bottom, though we have chipped away at this shortcoming with revolutionary advances in technique. The bent-arm backstroke pull in the 1950s serves as a case in point, as do the underwater dolphin kick in the 1970s and the wave breaststroke in the 1980s.



Likewise, our bodies rank near the bottom when it comes to efficient vessels. The sudden changes in circumference between our head and shoulders and waist and hips produce formidable amounts of drag. Scientists have divided this drag into three categories: pressure or form drag, which is the disruption the body itself causes to water flow; wave drag, which is the resistance caused by surface waves; and surface drag, which is the friction generated by a swimmer’s skin and suit.



For years swimmers and coaches focused almost exclusively on lowering pressure and wave drag, because they are far more dominate than surface drag, and they can be countered with relatively simple improvements in technique. Keeping the head horizontal in backstroke, and thereby keeping the hips up, lowers pressure drag. Maintaining bodyline when breathing during freestyle reduces wave drag.



Surface drag was mostly overlooked, as evidenced by the wool suits that hung on until the 1950s. Part of the reason was a tenuous connection between science and swimming. The other part was a sense of fatalism. The general feeling was that suits were what they were, and as for the interaction between human skin and pool water, what, if anything, could be done about that?



LESS IS BETTER



These notions started to change in 1956 when Australian swimmers showed up at the Olympics with nylon suits and shaved legs and proceeded to clean house. Much of the dominance was properly attributed to interval training, which the Australians picked up on early and rode hard. But the suits and shaving also collected a following. By the Olympics in Rome in 1960, they were staples within the competitive swimming community. The push to lower surface drag had begun. Nylon soon gave way to Lycra and traditional standards of modesty were tossed.



“The feeling was to wear the smallest suit possible,” says Tom Wilkens, a bronze medalist in the 200m Individual Medley at the 2000 Olympics. “Less fabric meant less resistance.”



The less-is-better mindset changed in late 1990s with the introduction of the Speedo Fastskin. Its purpose was just as the name implies – a suit faster than skin. The material and seams directed water around the body in such a way as to produce less separation than was the case with exposed skin.



“We kind of took a lesson from sharks,” says Barry Bixler, the engineer who did the bulk of the scientific work underpinning the FSII, which debuted this year. “If you look at a shark under a microscope, the surface (of its skin) changes. It appears to be designed to minimize drag based upon flow conditions. The lesson we took from that was we don’t have to use one fabric in our suit. We can use multiple fabrics. Using CFD (computational fluid dynamics) technology, we learned the velocity of the water, as it flows along the body, speeds up and slows down depending on the geometry it encounters. Using flume testing with mannequins and swimmers, we determined which fabrics were better at which velocities.”



The other manufacturers – TYR, Nike, and Adidas primarily – followed the same general path as Speedo. They engineered materials and created designs that directed water flow so as to minimize separation and lower drag. They also tapped into the latest in seam technology so that swimmers would have both freedom of movement and muscle compression.



“Being an old purist, I wasn’t convinced about the value of muscle compression until I saw swimmers on video and their muscles undulating,” says Steve Furniss, executive vice president and founder of TYR and a 1972 and 1976 Olympian. “You can see the muscles vibrating and the resistance they create.”



WHERE’S THE DATA?



The suits made a splash, so to speak, beginning with the 2000 Olympics. Swimmers liked the muscle compression and the feel. Though the manufacturers made no claims of added buoyancy, which kept them on the safe side of FINA rules, the swimmers reported a sense of riding higher in the water.



“It’s an amazing feeling,” says Diana Munz, a silver medalist at the 2000 Olympics in the 400m freestyle and a bronze medalist in the 800m freestyle in Athens. “I practice in the conventional-cut suit, but I will never go back to a conventional suit in meets.”



Skeptics, however, have found plenty to chew on. Stager, who has spent most of the last 25 years researching swimming in one form or another, admits he has a slight bias. As a former competitive swimmer, he’s uncomfortable watching the focus shift, however slightly, to the suits and away from the swimmers. That aside, he asks a simple question: Where’s the data?



“From a scientific standpoint, there isn’t any data to support the differences these suits are supposed to make as far as performance goes,” he says. “(The manufacturers) might say that their suit causes a four percent or five percent reduction in drag, but that is as far as they will go. They are not willing to say what effect, if any, the suits will have on performance.



“Everyone recognizes the importance of lowering resistance as a means of improving performance,” Stager adds. “The problem is, how do you quantify that with the body going through the gyrations we go through when we swim? The manufacturers will tell you, ‘There were this many American records set using these suits and this many world records.’ Well, you know what? Maybe they would have been even faster if they didn’t have these new suits. There is no way to run that study.”



Bixler concedes Stager’s point. Less drag should mean faster swimming, but as to how much, if any, Bixler says, “We don’t know.”



Of course, the manufactures don’t mind if the news media make the mental leap from a decrease in drag to an increase in speed. In fact, they subtly encourage it. A recent news release from Speedo labels the FSII “the world’s fastest suit.” Another news release says the “Fastskin FSII increases speed (author’s emphasis) by reducing passive drag by up to 4% more than the next best suit.”



TYR is only slightly less subtle. One of its marketing brochures includes statements such as, “Aqua Shift can shatter records before it even enters a pool,” and, “Four years in the making, and all you care about are milliseconds.” During an interview, Furniss was more direct: “All I can say as a former swimmer is, ‘Hey, if it reduces drag, it’s going to get me from Point A to Point B either with less effort or in less time.”



Stager disagrees with such statements. According to his studies, the amount of drag in question is small to begin with, even less than the flex of a finger. Any reduction, he insists, will have minimal effect overall.



“In our labs we had swimmers hold their fingertips in an upward flex, and we could see that (extra drag),” he says. “Yet when we compared swimmers in conventional suits with the (original) Fastskin, we couldn’t see any difference.”



But there’s one aspect of these new suits that Stager can’t dismiss. If the swimmers think they help, then they do. It’s a situation similar to shaving. No study has presented convincing evidence that shaving significantly reduces drag, but try telling that to a swimmer just after he enters the water with clean-shaven arms and legs.



“How the suit feels in the water is one of the key questions,” says Roque Santos, director of team business for Nike and a 1992 Olympic breaststroker. “If it doesn’t feel right in the water, regardless of the science, the swimmers won’t wear them.”



Good point, and it’s the only one that really matters. It’s the opinion of the swimmers, and not the findings of researchers, that will prevail. Pendergast advocates full-body suits (wrist to ankle), saying, “If no drag reducing material is on the upper body, the benefit of covering the lower body is very small.”



Yet in Athens, full-body suits were more the exception than the rule. Of the 16 swimmers in the semifinals of the women’s 200m individual medley, five were in conventionally cut suits, seven in suits to their knees, and four in suits to their ankles. None wore a full-body suit. Even in events that involved one stroke, the variety was startling. In the final of the men’s 800m freestyle relay, the four Americans wore three different styles of suits, none of which were full-body. Michael Phelps, despite endorsing the full-body FSII before the Olympics, wore a waist-to-ankle FSII for his leadoff leg.



Stager argues that this illustrates what little significance the suits play in the athlete’s overall performance. After all, the tenet of evolution states that important genes evolve to a single, most efficient design, while less significant genes tolerate variation.

“If the suits really mattered,” he says, “would you be seeing all of this variation? What’s happening is that the swimmers are expressing their opinion that maybe these suits don’t make much difference.”



Then again, maybe the swimmers are saying they like these new suits but aren’t finished experimenting. There are, after all, a wide number of variables in swimming, which differ from stroke to stroke and swimmer to swimmer.



Regardless, the push to replace skin, as evidenced by the scarcity of conventionally cut suits in Athens, is on the fast track, and there’s little chance it will be diverted anytime soon.



“Would I have swum faster in one of these suits back in 1992 when I set a world record (in the 100-meter backstroke)?” asks Jeff Rouse, who came out of a five-year retirement in 2001 in an attempt to make the 2004 Olympic team. He wore an FSII jammer (waist to knee) in the finals of the Olympic trials. “I don’t know. I don’t think there is any way to tell for sure. But I would have liked to have had access to them.”