APPAREL VIEWS / SEPTEMBER 201046

Theory

Hydrodynamics plays an essential role in swimming

performance regardless of the particular event

(freestyle, butterfly, breaststroke or backstroke).

Studies estimate that over 90 per cent of the

swimmer’s power output is spent overcoming

hydrodynamic resistance. The hydrodynamic

resistance can be divided approximately into three,

almost independent components:

• Wave drag • Form drag, and • Skin friction drag

The wave drag is associated with the work required

to generate waves, form drag is the resistance to

motion due to the shape of the body, and skin friction

is the resistance to motion due to the area of the body

with the water (the wetted area). The form drag is

believed to constitute almost 56 per cent of the total

drag. All three components are time-dependent as

the swimmer completes the stroke, and all three

components depend on the speed of the swimmer, as

well as his/her shape, length, and style.

History of competitive swimsuit

Historically, the people used to swim nude and it was

socially accepted. Today’s swimsuit has travelled a

long path and gone through a series of changes of

styles and designs. Notably, in the early 18th century,

wool and flannel were chosen as a suit fabric covering

almost the entire skin of the swimmer. However, this

suit became bulky when it came to contact with water.

In 1908, the Australian swimmer, Annette Kellerman

created the first practical swimsuit made of one piece

plus bathing socks. This suit exposed the knees and

arms of the swimmer for the first time in the history

of swimming.

Officially, the women’s swimming events were added

to Olympic game in 1912 and swimmers were allowed

to use relatively shorter swimsuits. In 1920s, swimsuits

A swimsuit, bathing suit or

swimming costume is an item of

clothing designed to be worn

while participating in water sports

and activities such as swimming,

water polo, diving, surfing, water

skiing, or for any activity in the

Sun, such as Sun bathing.

Competition swimsuits differ

somewhat from fashion swimsuits

in style, fit, and fabric. Because

they are designed to stay in place

and facilitate swimming speed in

the water. The manufacturers of

competitive swimsuits pay

attention to several factors that

are not generally important in

fashionable or recreational

swimsuits. Because speed and

smoothness in the water are so

essential to a good competition

swimsuit, manufacturers have

paid close attention to the skin of

water animals. While colours,

prints, and cut are the most

important factors in recreational

swimwear, texture and tightness

are the most important factors in

competitive swimwear.

were shortened even more, but women had to wear a

short skirt called “modesty panel” and by this time a

two-piece swimsuit became very common.

In 1930s, bikini was introduced as an innovative

swimwear. After the World War II, Nylon replaced

the silk and wool in major events’ competitive suits

and the colour was allowed in 1964 while the modesty

panel was eliminated in 1973. In 1990s, swimsuits

continue to evolve to mimic skin and the Lycra was

introduced and quickly became popular.

In 2000s, Speedo® lunched the full-body Fastskin™

swimsuit based on so called shark’s skin pattern and

mimicked in V-shape ridges. Since Beijing Olympic

2008, almost all major sports wear manufacturers

introduced full-body swimsuits made of semi- and-

full polyurethane combined with Lycra fabric.

Engineered competitive swimsuits

Special swimsuits for competitive swimming are

designed to reduce skin drag and resemble unitards.

Commercial swimsuit manufacturers have claimed

and counterclaimed about their swimsuits

performance by reducing aerodynamic drag and

enhancing buoyancy. These suits are made from

spandex and provide little thermal protection, but they

do protect the skin from stings and abrasion. Most

competitive swimmers also wear special swimsuits

including partial and full bodysuits, racer back styles,

and jammers and racing briefs to assist their glide

through the water and gain speed advantages.

The manufacturers claimed these suits have features

such as ultra-light weight, water repellence, muscles

oscillation and skin vibration reduction by

compressing the body. Recently, swimsuits have been

aggressively marketed principally as a means for

reducing the skin friction component of the total drag,

thereby conferring a competitive advantage over other

swimmers.

APPAREL VIEWS / SEPTEMBER 2010 47

The technological innovation in both design and

materials has played a crucial role in sport achieving

its current standing in both absolute performance

and its aesthetics. Few studies also revealed that

textiles can play a vital role in high performance sports

where speed is a dominating factor. The aerodynamic

properties such as drag and lift can play a dominant

role in swimming especially in swimsuit design. The

swimmers usually involve very short winning time

margins in events that often have much longer

timescales, making hydrodynamic resistance and its

associated energy loss during the event significant

in the outcome.

In this article we tried to study the latest swimsuits

available in the market.

Basic characteristics of swimsuits

• Opacity

• Higher order of stretch and recovery

• Higher order of resistance to abrasion

• Strong and durable

• Colour fastness to light

• Colour fastness to sea and chlorinated pool

water

• Less absorbent and should have wet strength

• UV protection

Evolution of competitive swimsuits

The journey of Engineered Competitive Swimsuit

started when Speedo®, the world's number one brand

of swimwear, introduced Fastskin™, the most

technically advanced competitive swimsuit ever

made. Among the most dramatic elements was the

introduction of a full-body silhouette, the first to be

offered in the company's history.

The swimsuit looked to a creature that is fast in the

water but not naturally hydrodynamic -- the shark,

whose highly developed skin minimises drag and

maximises swimming efficiency. The secret behind

the shark's skin is its dermal denticles, which look

like tiny hydrofoils with V-shaped ridges. As a shark

moves through water, it creates turbulence and drag.

Its dermal denticles decrease drag and turbulence by

directing water flow over the body, which allows

surrounding water to pass over the shark more

effectively.

The Speedo® Fastskin™ fabric has ridges that are

scientifically calculated for height and width to the

exact proportion of the shark's dermal denticles --

the most efficient formula for speed. The athlete's

initial concerns with full body silhouette focused

upon a loss of the "feel of the water" along the inner

forearm, an area critical to generating propulsive

forces. To combat this, the Speedo® Fastskin™

incorporates a gripper fabric on the forearm, which

mimics skin, and enhances the sensory feedback

for the swimmer.

Brand Swimsuit Year of development Principle

Adidas Jet concept bodysuit 2003 Jet concept

TYR Tracer A7 2007 Zoned compression

Speedo LZR 2008 NASA (Hydro Form Compression system)

Diana Submarine 2008 Submarines

Arenas X-Glide 2008 Arena Stealth Fabric (lightweight)

Table 1 Evolution of competitive swimsuits

Shark skin texture

Speedo® Fastskin™ Fabric with shark’s skin texture

Shark skin is composed of small jagged, overlappingscales, seen here with a backscatter detector. Thiseffects produces a covering that offers low resistanceand turbidity when the shark swims and has been copiedin the body suits of Olympic swimmers.

(By Vasant R. Kothari, Assistant Professor,Department of Fashion Technology, NIFT,

Bangalore, Neha Goyal & Megha Sheoran,MFTech, NIFT, Bangalore)