By Julie Walsh

Suits Slicker than Skin

Looking for a way to shave a couple tenths off your 100 PR or seconds off your 1500...without spending any additional time training? New high-tech competition suits may help you do just that.

Years of research by fiber manufacturers like DuPont and swimwear manufacturers have resulted in new fabrics and suit designs that are more technically advanced than ever. Speedo, Nike and TYR are leading the charge to develop suits that enhance performance. Today, the difference in winning and losing may come down to the suit you're wearing...or so the manufacturers would have you believe.

Let's take a closer look at the performance swimwear offered by these companies—how they're developed, how they're tested for drag and whether they live up to the manufacturers' slicker-than-skin claims.

Bare-all to Full Body
For racing, swimmers used to taper, shave and wrestle their bodies into the skimpiest suits possible. Now, instead of wearing next to nothing, swimmers are wearing more suit. Women are racing in high-neck and full back suits or leg suits that cover the thighs. Jenny Thompson, Brooke Bennett and Amy Van Dyken have all set personal bests wearing these latest suits made of Speedo's Aquablade fabric.

Men are also opting for torso suits or leg suits from Speedo and Nike. Entire heats of men at the U.S. Masters Swimming national championships could be found unabashedly clad in torso suits. While at this year's NCAA Division I Championships, nearly half of the Stanford's men's team, which won the team title, wore Nike's Teraz thigh-length suit, says Jeanne Gibbons, assistant coach of the University of Arizona's men's and women's swim teams.

"Swimmers are wearing the new suit designs that cover more skin because they're realizing that the fabrics can provide an advantage," explains Kristine Lebow, brand manager for Nike Swimwear.

Peter Nunan, winner of the 100 yard freestyle for men 40-44 at USMS nationals in a lifetime best 47.76, agrees: "The (Speedo) Aquablade makes me more buoyant; I figure that's worth a few tenths of a second per 100."

Studies conducted on these fabrics have found that the fabrics are more efficient at reducing drag than shaved skin, explains Jane Cappaert, biomechanics engineer at U.S. Swimming's International Center for Aquatic Research (ICAR). "Now, more and more age group and Masters swimmers are beginning to wear these new high-tech suits," says Lebow.

Suit Science
Almost all training suits are a combination of nylon and Lycra (usually 20-22 percent Lycra and 78-80 percent nylon). High-performance suits are made from polyester and much more Lycra (up to 34 percent). The additional Lycra creates a form fit, and initial studies from Penn State University found that activewear made with a high percentage of Lycra that covers working muscle groups can improve muscle strength and performance by improving the efficiency of muscle movements.

Nylon has been replaced with microfiber polyester to help create a smoother, flatter, lighter suit, says Lebow. Polyester is also used because it holds water-repelling finishes applied to fabric to reduce drag, while nylon fibers do not hold finishes well, says Dan Hunt, manager of DuPon'ts Lycra Swimwear division.

To understand how these suits may enhance performance, you first must know the drag forces that swimmers encounter.

"There are three main types of drag," says John Waring of Bolte Technologies, Inc., in Ottawa, Canada (Waring developed the technology to create vortex generators used on Speedo's newest Aquablade suits). "They are wave drag, form drag and surface drag (also called skin friction or surface drag)."

Skin friction drag accounts for 10 percent of all drag, while 90 percent is from wave and form drag. "When manufacturers claim a suit reduces drag, the type of drag they're talking about is mainly skin friction drag," says Cappaert.

Each manufacturer uses different ways to test its suits for drag reduction. As a general rule, the best way to test is by using swimmers wearing the suits in a flume while a sophisticated computer program is able to compute drag forces at varying water speeds. These tests are expensive and can only be completed in a few research settings, such as ICAR, that have such equipment. Other tests are conducted with the fabric only, usually stretched over a body form and placed in a mini-flume that is calibrated to detect changes in drag forces at varying water speeds.

Speedo's Aquablade suits appear to be the most technically advanced and have been thoroughly tested at ICAR since Speedo is the official swimwear provider for U.S. Swimming and the Olympic team through the 2000 Games.

Aquablade is made of polyester and polyurethane that's treated to repel water. It also has alternating stripes of rough and smooth fabric which create two currents—one slow, one fast. These currents create vertical vortices or spirals of water, which increase water flow away from the body, which, in turn, decreases both skin friction drag and form drag.

"Studies using swimmers wearing Aquablade suits resulted in as much as a 10 percent reduction in skin friction drag or one-to-two percent reduction in overall drag," says Waring. That small percentage change in drag may equal tenths of seconds in short events and seconds in long events.

A Nike-commissioned study of its Teraz fabric found the fabric reduced surface drag by 16 percent compared to the same Teraz fabric that doesn't have the special calendared finish, says Nike's Lebow. (This was a test using fabric only in a flume.) Teraz is a polyester/Lycra blend that has a special finishing process that helps make it more water-repelling.

Neither TYR nor The Finals publishes results of studies conducted on the fabrics used in their high-end competition suits, however, TYR's PowerFlow and The Finals' Ultra-Tech suits are both lightweight, polyester/Lycra blends that have been coated with water-repelling resins. Both companies are offering more traditional styles of suits; neither offers a men's thigh-length or torso suit.

Impact on Performance
How much of an impact will these trick suits have on performance? Each swimmer can expect something different, because there are many factors involved, explains ICAR's Cappaert. She adds that the swimmer's body type, stroke swum, speed and distance all have an effect.

Freestyle has the least amount of friction, followed by backstroke, fly and breastroke. The longer the event, the greater the benefit; and the faster you swim, the greater the benefit. If you're swimming a high-resistance stroke, like breaststroke, or a distance event like the 1000, 1650 or open water race, you definitely can get a little edge by wearing a suit like the Aquablade, says Cappaert.

"You shouldn't feel uncomfortable wearing the new suit designs," comments Cappaert. "They're faster, and it makes sense that if you have a fabric that reduces drag better than skin, you will want your body covered in as much of the fabric as possible."

New York Masters swim coach, Boris Talan, adds, "The new suits are great for distance events or for open water swims that don't allow wet suits. I know it was probably just in my mind, but when I wore a thigh-length suit for the first time, my legs felt more buoyant, and my legs didn't fatigue as quickly."

Fit Tips
If you're going to spend $50-90 on one of the latest suits, it won't do you any good unless if fits like a second skin. In the '70s, East German swimmers took this dictum to the extreme: they glued their suits on to race. While no one recommends taking such drastic (and painful) steps, it's important that the suit fit like a second skin. Use these guidelines: