Chemistry and sport

Soccer - Association Football
Association football, commonly known as football or soccer, is a sport played between two teams of eleven players with a spherical ball. At the turn of the 21st century, the game was played by over 250 million players in over 200 countries, making it the world's most popular sport. Medieval football in the UK (where villages would play each other with an unlimited number of players on a team) appears to date back to the eighth century at least!

In association football, the football or soccer ball, (according to whether the game is referred to as "football" or "soccer") used in official matches is a specific type of football standardised for size, weight, and material and manufactured to the specifications of the Laws of the Game, specifically Law 2.

Law 2 of the game specifies that the ball is an air-filled sphere with a circumference of 68-71 cm (27-28 in), a weight 410-450 g (14-16 oz), inflated to a pressure of 0.6 to 1.1 atmospheres (59-108 kPa, 8.6-15.7 psi) "at sea level", and covered in leather or "other suitable material". The weight specified for a ball is the dry weight, as older balls often became significantly heavier in the course of a match played in wet weather. The standard ball is a Size 5 and this is used in official FIFA championships all over the world. The football can be made from polyurethane which gives a less soft material but still retains a good feel and is much more durable.

The Science of Football

Early footballs began as animal bladders that could easily fall apart if kicked too much. As time went on footballs developed to what they look like today. This change in the design of footballs was helped by the introduction of rubber and the discovery of vulcanization. Today, technological research continues to aid the change in footballs with improved performance.

The oldest football still in existence, which is thought to have been made circa 1540, was discovered in the roof of Stirling Castle, Scotland, in 1981. The ball is made of leather (possibly from a deer) and a pig's bladder. It has a diameter of between 14-16 cm (5.5-6.3 in), weighs 125 g (4.4 oz) and is currently on display at the Smith Art Gallery and Museum in Stirling.

In 1863, the first specification for footballs were laid down by the Football Association. Prior to this, footballs were made out of inflated leather, with later leather coverings to help footballs maintain their shapes. In 1872 the specifications were revised, and these rules have been left essentially unchanged as defined by the International Football Association Board. Differences in footballs created since this rule came into effect have been to do with the material used in their creation.

Footballs have gone through a dramatic change over time. During medieval times balls were normally made from an outer shell of leather filled with cork shavings. Another method of creating a ball was using animal bladders for the inside of the ball making it inflatable. However, these two styles of creating footballs made it easy for the ball to puncture and were inadequate for kicking. It was not until the 19th century that footballs developed into what a football looks like today.

For the 1970 FIFA World Cup, Adidas introduced the Telstar. Like all other balls in its time, the Adidas Telstar was completely made of leather; however, unlike any other ball it featured 32 hand-stitched panels (12 black pentagons and 20 white hexagons), creating the now-familiar truncated icosahedron for its design and the roundest sphere of its time.

The 1970 ball was made of leather but by 1974 the football had a "Durlast" polyurethane coating that provided waterproofing as well as protection from damage such as scuffs and tears.

Only 20 Telstars were provided for the 1970 World Cup however an estimated 600,000 replicas have subsequently been sold.

1974 Adidas Telstar durlast football 1986 Azteca Mexico Adidas football 2014 Brazuca Brazil Adidas football
Adidas Telstar Durlast 1974, Azteca Mexico 1986 and Brazuca 2014 were the official match balls of the FIFA World Cups.
The 1986 model was the first fully synthetic FIFA World Cup ball.

The 1990 Adidas model used in Italy introduced an internal layer of polyurethane foam and was fully made of synthetic fibers. The underneath layer included fabric coated with latex that prevented tearing and maintained stability. Like earlier models the outer design was based on art forms of ancient civilizations, this time from the Italian peninsula.

The Adidas ball used in Korea/Japan for the 2002 World cup had a glossy finish on the outside, an innovation that has been an inspiration for other balls and sports products since then. Called "Fevernova" it was made of thicker inner layers that guaranteed the accuracy of the ball's trajectory during flight. Fevernova's improved syntactic foam layer, consisting of highly compressible and extremely durable gas-filled micro-balloons, had remarkable energy return properties.

To quote some PR related to the launch of the 2010 ball:
The Adidas JABULANI match ball used in the 2010 FIFA World Cup in South Africa featured completely new, ground-breaking technology. Eight three-dimensional spherically formed ethylene vinyl acetate and thermoplastic polyurethane panels were moulded together, harmoniously enveloping the inner carcass. The newly developed "Grip'n'Groove" profile provides the best players in the world with a ball allowing an exceptionally stable flight and perfect grip under all conditions. Comprising only eight, completely new, thermally bonded 3-D panels, which for the first time are spherically moulded, the ball is perfectly round and even more accurate than ever before.
For the 2014 World Cup the Brazuca was constructed in an Adidas Pakistan factory and details of its construction were reviewed in ChemistryViews.
Surface Panels
The surface of Brazuca is made up of only six panels of absolutely identical shape. Conventional soccer balls consist of 12, 16, or 32 panels stiched together. Besides leading to perfect symmetry, the reduced number of panels of Brazuca requires fewer seams. This means that the ball is more durable and absorbs less moisture (only 0.2 %) which makes Brazuca lighter than other balls when played on wet ground.
The six panels are bonded together using a patented thermobonding technology.

Brazuca has five polyurethane layers: The outer layer of the skin comprises three compact layers of polyurethane each with different thicknesses. They are responsible for the outstanding resistance to external influences and abrasion, and for the ball's high elasticity.
The innermost layer of the skin is an adhesion coating that connects the textile substrate to the layers above. On top of this is a roughly 1 mm thick polyurethane foam layer which is made up of millions of gas-filled microspheres. This foam is highly elastic so that the ball, after being deformed from being kicked, immediately returns to its spherical shape to ensure an optimal trajectory.

The bladder in the middle of the ball holds the air. In the Brazuca, this is made from butyl rubber, but it can also be made from latex. Both have their benefits: butyl rubber retains the air for a longer period of time, whilst latex provides better surface tension. Butyl rubber can also be found in the valve through which air can be pumped into the ball, where it aids air retention. Silicone valves can also be used.
Australian Football League (AFL)
Note that the AFL (founded as the Victorian Football League, VFL, in 1897) continues to use leather footballs.

John Macadam was a Scottish-born analytical chemist, medical practitioner and politician. As a student he showed a flair for analytical chemistry, and later studied medicine. He arrived in Melbourne, Australia in 1855 to take up an appointment as lecturer in chemistry and natural science at Scotch College, a position he held until 1865. In 1857 Ferdinand von Mueller named the Macadamia nut after him. He officiated as one of two umpires at one of the earliest recorded games of Australian rules football, between Scotch College and Melbourne Grammar in 1858.

Sherrin AFL football

Thomas William Sherrin, born in Melbourne in 1857, repaired and manufactured saddles and other equestrian equipment. A local VFL club would regularly send English made leather rugby balls to Sherrin to patch and repair. One day he decided to try and improve on the imported product by creating an oval shaped ball with rounder points to give the ball a better bounce. The local teams loved it and it was swiftly adopted as their ball of choice. Sherrin began production in 1897 in a workshop in Collingwood, which had produced sporting goods since the 1880s. The sport known as football, or "footy", was rapidly increasing in popularity, and Sherrin footballs soon became the icon for being the first ball made for Australian rules football. They remain the official ball of the AFL. Sherrin makes more than 600 balls each day (2012) and every one is still handmade.

Cricket may have its origins in Guildford, England from as early as the 1550's. By the end of the 18th century, it had developed into the national sport of England. The expansion of the British Empire led to cricket being played overseas and by the mid-19th century the first international matches were being held. The ICC, the game's governing body, has ten full members. The game is played particularly in Australasia, the Indian subcontinent, the West Indies, Southern Africa and the British Isles. It is the world's second most popular sport.

early cricket game early cricket game
A 1774 representation of a cricket game and some of the equipment needed for the modern game.

In 2002, the WICB board received a formal request from the management team to use Kookaburra balls for home series because these balls were being used by all other Test-playing nations. Prior to this, the WICB had used balls produced by Dukes, which had a more pronounced seam. By contrast, the Kookaburra's seam is much less "raised" and there are claims that the wear-and-tear suffered from West Indies pitches means that after 20+ overs they become soft and therefore less helpful to the Windies fast bowlers.

Red Cricket Balls - new and after 21 overs The cork and rubber core of a Kookaburra ball
Red Cricket Balls - new and after 21 overs, and the inner cork and rubber core of the ball
Note that one side still retains some semblance of shine compared to the other.

Cross section of a cricket ball and the consistency of manufacturing.
Despite the claims above, a study in Australia of 5 different brands found that the Kookaburra Special Test was the only cricket ball consistently manufactured with respect to weight and "stiffness". The other four models studied were found to have inconsistent stiffness, which could play an important part in performance of the ball in play. Softer balls like the Kookaburra brand Special Test balls were more forgiving by causing a smaller impact force, a longer contact with the bat, larger deflections as well as larger contact areas during impact, and thus allowed placing the ball more precisely. Maybe the bowlers do have a grouse then if the batsmen are able to control the ball more consistently! I must admit to always being amused by the expression "level playing field" when the most hallowed cricket ground of Lords has a distinct slope to it!

What difference is there between red and white cricket balls?
All cricket balls (whether red, pink or white) are made from a core of cork (or cork/rubber mixture), that is layered with tightly wound wollen thread, and covered by a leather case with a slightly raised sewn seam.
Cricket balls are constructed from either 2 or 4 pieces of leather and many companies still use predominantly manual labour in their production. Traditionally, the most expensive cricket balls used in test matches were from 4 pieces of leather and cost around US $ 100 while those used at other games were from 2 pieces and considerably cheaper.

When the covering is constructed from four pieces of leather, one hemisphere is rotated by 90 degrees with respect to the other. The "equator" of the ball is stitched with string to form the ball's prominent seam, with a total of six rows of stitches. The remaining two joins between the leather pieces are stitched internally.

For men's cricket, the ball must weigh between 155.9 and 163.0 g and measure between 224 and 229 mm in circumference.

Traditionally cricket balls are dyed red, most likely originally by the use of the dye obtained from rose madder and it is the red balls that are used in Test cricket and First-class cricket. In June 2007 the ICC legalised the use of the white ball, which some believe is actually due to it having better visibility in TV coverage. The white balls were first introduced when one-day matches began being played at night under floodlights, as they are more visible under these conditions. Professional one-day matches are now played with white balls, even when they are not played at night.

According to crickettamasha:
It has been claimed that the white ball is capable of swinging more, especially during the first half of an innings, than the red ball and that it deteriorates more rapidy, although the manufacturers claim that their white and red balls are produced using the same methods and materials. In some research done by the BBC in New Zealand with the help of the bowling machines showed that the white ball swung appreciably more than the red ball at a pace of 70 mph. Further analysis has made it clear about the manufacturing differences between the white and a red ball. In a conventional red ball, the leather is dyed red, greased and polished with a shellac topcoat. The final polish disappears quickly during the course of the game and it is only the grease in the leather that produces the shine when the bowler polishes the ball. Whereas in a white ball, the leather is sprayed with a polyurethane white paint like fluid which is then heat-treated so that it bonds to the leather like a hard skin. An extra coating of clear polyurethane based top coat is again applied on the white ball so that it does not get dirty. It is this extra coat in a white ball which changes its aerodynamics making it able to swing more.

It has been suggested that the amount of swing is dependent on the humidity during the game. However research published in 2012 in Procedia Engineering and summarised at dreamcricket and at the BBC suggests that humidity during the game may not have such a large impact on the swing of the ball.

It is possible that exposure to longer periods of low humidity may cause cricket balls to shrink by a greater amount and become lighter, producing outcomes that are more consistent with what has been observed in baseball at the Coors Field, at high-altitude Denver, Colorado, USA.
Prior to 2002, large variations were observed at that ground compared to other low-altitude grounds, but once the baseballs started to be maintained at 50% humidty in humidors, this variation was reduced.

Because a white ball becomes discoloured towards the end of a 50-over one-day innings, making it difficult for the batsman to pick out, the International Cricket Council regulations changed to require the use of two new balls, one from each end.

Other essentials are: gloves, shoes, protective helmets and other protective wear, sunglasses and BLING.

A cricket joke, probably started by a woman goes:
'The first testicular guard (Box) was used in cricket in 1874 but the first cricket helmet was used in 1974.
It took 100 years for men to realize that their brain is also important.'

Cricket Helmet
Graham Yallop of Australia was the first to wear a protective helmet during a test match in March 1978 when playing against West Indies at Bridgetown. Later Dennis Amiss of England popularized it in Test cricket. Tony Greig was of the opinion that helmets might make cricket more dangerous by encouraging bowlers to bounce the batsmen.

Helmets began to be widely worn thereafter. Nowadays it is almost unheard of for a professional cricketer to face a fast bowler without a helmet, and in under-19 cricket they are compulsory for all batsmen and any fielder within 14 m of the bat.

Cricket helmets cover the whole of the skull, and have a grill or perspex visor to protect the face.

Fielders who are positioned very close to the batsman (e.g. silly point or short leg) often wear a helmet and shin guards.

The design of the cricket helmet has trailed well behind the technologies available and in mid-2004 university tests showed that helmets can delay a batsman's reactions by up to a quarter of a second partly due to heat build-up and low comfort levels caused by the weight. Inspired by those tests, designer Ravinder Sembi suggested a new design for the cricket helmet with a view to overcoming this fundamental problem. The helmet is designed with two forward-facing vent holes to promote airflow when running, conducting the air inside the helmet up and away from the head. There is no indication however that this has yet been adopted by cricket gear manufacturers anywhere.

innovative cricket helmet design
An innovative cricket helmet design.
1. Titanium guard, 2. polycarbonate with film on inner side to prevent fragments hitting face if shattered
3. ABS solid plastic injection molded with holes to allow maximum ventilation 4. polyester strap with velcro

Ayrtek filed a patent for a new design in 2009. This may have led to the helmet seen worn by Michael Carberry from 2013.

Ayrtek helmet

The helmet is designed to deflect the ball and the rigid peak helps to reduce the risk of grille penetration. It has a liner with an Air Cushion Impact System (ACIS) that can be inflated or deflated to deliver a perfect fit by pushing buttons on either side of the helmet.

R.I.P. Phil Hughes 1988-2014

Golf Balls
An appendix to the "Rules of Golf" defines that a golf ball must not weigh more than 45.93 grams (1.620 oz), that its diameter must not be less than 42.67 mm (1.680 in), and that its shape may not differ significantly from a symmetric sphere. Like golf clubs, golf balls are subject to testing and approval by the Royal and Ancient Golf Club of St Andrews, Scotland and the United States Golf Association, and those that do not conform with the regulations may not be used in competitions (Rule 5-1).

How are golf balls made and what changes to their composition have been made in recent years?

The first golf balls were made from wood and this continued until the early 17th century when the featherie ball added a new and exciting feature to the game of golf. A featherie is a hand sewn cow hide leather pouch stuffed with chicken or goose feathers and coated with paint. Because they were hand produced and this was a time-consuming process the balls were expensive and consistency was an issue.

In the 1840's the gutta-percha ball was invented and it was found that indentations in the leather helped the ball achieve a truer flight. Ever since then manufacturers intentionally added indentations to the balls and now the number of indentations is generally quoted in the publicity surrounding the ball.

traditional golf ball Nike DuPont golf ball
Traditional and the Nike 20XI-X golf ball.

Nike and DuPont teamed up to create a new range of golf balls. The Nike 20XI ball design replaces rubber cores with a highly engineered, DuPont thermoplastic (HPF 2000 Mg ionomer) resin developed specifically for use in golf balls. This advanced core technology makes the 20XI ball faster, and Nike's new design makes it possible to achieve both greater distance and greater control.

surlyn copolymer
Surlyn copolymer

According to the DuPont web site: DuPont Surlyn ionomer resins are a family of high-performance ethylene copolymers containing acid groups partially neutralized using metal salts such as zinc, sodium and others. The result is an ionically strengthened thermoplastic with enhanced physical properties versus conventional plastics. The DuPont manufacturing process for Surlyn® enables highly tailored combinations of properties: outstanding resilience, broad hardness and stiffness range, and excellent resistance to cuts and abrasion - all highly desirable for golf ball applications.
To meet golf manufacturer needs, DuPont offers more than 20 commercial grades of Surlyn®, plus a number of grades developed to meet confidential requests.

See their video describing the Nike golf ball

A review of the chemistry of golf balls and clubs was recently published in J Chem Educ 2008, (85) 1319.

Golf Clubs

The shafts of early Golf club woods were made of different types of wood before taken over by hickory. The varieties of woods include ash, greenheart, purpleheart, lancewood, lemonwood, orangewood, and blue-mahoo. In the middle of the 19th century the shafts were then being replaced by hickory wood. Despite this strong wood being the primary material, the long-nose club of the mid nineteenth century was still prone to breaking at the top of the backswing. The club heads were often made from thorn, apple, pear, dogwood, beech in the early times until persimmon became the main material. Golf clubs have been developed and the shafts are now made of steel, titanium, carbon fiber, or other types of metals. The shaft is a tapered steel tube or a series of stepped steel tubes in telescopic fashion. This has helped the accuracy of golfers. The grips of the clubs are made from leather or rubber.

From the early 1930s through the 1970s, the shafts of clubs were made predominantly from steel. Experiments with lighter aluminium shafts being deemed unsuccessful due to poor torque performance. Steel has good shaft performance but is quite heavy for the average player. Replacing steel with graphite reduced the weight of the club significantly and allowed for the use of longer shafts.

Golf clubs can be distinguished by their appearance and use in the game.
Most 'woods' are made from different metals, although they are still called 'woods' to denote the general shape and their intended use on the golf course. Most woods made today have a graphite shaft and a titanium, composite, or steel head. Woods are the longest and the most powerful of all the golf clubs.

Today, many metal wood clubfaces (and most driver clubfaces) are constructed out of titanium. Titanium has a higher strength to weight ratio than steel and has better corrosion resistance, so it is an ideal metal for golf club construction. Manufacturers can also make clubheads with greater volume, which increases the hitting area, and thinner faces, which reduces the weight.


Golf terms for Irons Golf terms for Irons
Defining Loft and Lie Angle for Golf Irons
W= clubface width at sweet-spot center, H= tee height, D= golf ball diameter θ= loft angle

Irons are golf clubs with a flat angled face and a shorter shaft than a wood, designed for shots approaching the green or from more difficult lies such as the rough, through or over trees, or the base of hills. Irons are used during the middle of each hole off the roughs, fairways or sand traps. There are long irons, medium irons, and short irons all with flat heads. They are called irons because they were made of metal.

A recent innovation in the chemistry of alloys has led to what are called "liquidmetals" a series of amorphous metal alloys developed by a California Institute of Technology (Caltech) research team.

Liquidmetal alloys (commercially known as Liquidmetal and Vitreloy) combine a number of desirable material features, including high tensile strength, excellent corrosion resistance, very high coefficient of restitution and excellent anti-wearing characteristics, while being able to be heat-formed in processes similar to thermoplastics.

One of the first commercial uses of Liquidmetal was in golf clubs, where the highly elastic metal was used in portions of the face of the club. These were highly rated by users, but the product was later dropped, in part because the prototypes shattered after fewer than 40 hits. Since then, Liquidmetal has appeared in other sports equipment, including the cores of golf balls, skis, baseball and softball bats, and tennis racquets.

YouTube clip from Liquidmetal technologies

A recent commercial alloy (Vitreloy 106a) that forms a glass under less rapid cooling conditions has the composition:
Zr: 58.5 Cu: 15.6 Ni: 12.8 Al: 10.3 Nb: 2.8

Putters are a special class of clubs with a loft not exceeding ten degrees (except chippers), designed primarily to roll the ball along the grass, generally from a point on the putting green towards the cup. These clubs were originally made of wood but have now been developed using metals as well. These are the shortest clubs of the set.

Tennis Racquet Strings

A patent for a string made from gut covered by synthetic fibres was filed in 1982.

How synthetic strings are made

Why do squash balls change their properties so much after they have been in use for a while?

Squash balls are between 39.5 and 40.5 mm in diameter, and have a mass of 23 to 25 grams. They are made with two pieces of rubber compound, glued together to form a hollow sphere and buffed to a matte finish. Different balls are provided for varying temperature and atmospheric conditions and standards of play: more experienced players use slow balls that have less bounce than those used by less experienced players (slower balls tend to 'die' in court corners, rather than 'standing up' to allow easier shots). Depending on its specific rubber composition, a squash ball has the property that it bounces more at higher temperatures. Small coloured dots on the ball indicate its dynamic level (bounciness), and thus the standard of play for which it is suited. The recognized speed colours are:

Colour Speed Bounce
Orange Super Slow Super low
Double yellow Slow Very low
Yellow Slow Low
Green or white Medium/slow Average
Red Medium High
Blue Fast Very high

The "double-yellow dot" ball, introduced in 2000, is currently the competition standard, replacing the earlier "yellow-dot" ball. There is also an "orange dot" ball, which is even less bouncy than the "double-yellow dot" ball, intended for use in areas of high altitude such as Mexico City, Calgary, Denver, and Johannesburg. The lower atmospheric pressure at these high altitude regions means that the ball bounces slightly higher, resulting in the need for such a ball.

The Dunlop squash balls are used in all international professional competitions. The balls are made of 2 pieces of extremely durable, high quality rubber compound, glued together and filled with compressed air. Like compressed air tennis balls, they lose pressure over time. In addition, as many as 15 different reagents are used, including polymers, fillers, vulcanising agents, processing aids, and reinforcing materials to produce the various coloured dot ball types.

Competitive swimwear
Men's swim suits
There was much controversy after the Beijing Olympic Games in 2008, when many Olympic swimmers broke records an unprecedented number of times using revolutionary swimsuits. It should be noted that it is rare to break world records, but in 2008, 70 world records were broken in one year, and 66 Olympic records were broken in one Olympic Games (there were races in Beijing where the first 5 finishers were swimming faster than the old world record). Michael Phelps stated that despite many of his records having been won in these suits, he might boycott the competition after his record was beaten by another swimmer with a more advanced suit.

The Speedo LZR suit was developed in association with the Australian Institute of Sport, with the help of Speedo's sponsored athletes. NASA's wind tunnel testing facilities and Ansys fluid flow analysis software supported the design. The material used was woven spandex (elastane) - nylon and polyurethane

Like other suits used for competition, it allows for better oxygen flow to the muscles, and holds the body in a more hydrodynamic position, while repelling water and increasing flexibility. The seams of the suit are ultrasonically welded to further reduce drag. The suits are manufactured at Petratex, a textile factory in Paços de Ferreira, Portugal; the technology is patented in that country. The suit is also 100% chlorine resistant and quick drying. The suit includes patented Core Stabilizer and Internal Compression Panels.

The Beijing Olympics proved to be an unprecedented success for the LZR Racer, with 94% of all swimming races won in the suit. 89% of all medals won at the Beijing Olympics were won by swimmers wearing the suit. In total 23 out of the 25 world records broken, were achieved by swimmers competing in the LZR suit By August 2009, 93 world records were broken by swimmers wearing a LZR Racer, and 33 of the first 36 Olympic medals have been won wearing it. Every winner in every men's event in the Beijing Olympics was wearing this swimsuit.

The number of records broken since the introduction of the swimsuit prompted the introduction of a new phrase to the sport: "swimsuit technology doping". In Beijing, Speedo handed out the suit to any swimmer who wanted to try it and since they were US$ 550 each this countered the argument that only rich nations could afford to use them. However some countries had restrictions due to sponsorship and initially could not use the suits. The suit takes around 15 minutes to put on, with the aid of two plastic bags (one over each foot) and possibly some talcum powder!!

The combined effects of the LZR both compressing the body and trapping air for buoyancy led to some competitors who used the LZR to try wearing two or more suits for an increased effect. Therese Alshammar from Sweden lost her world record in the 50 meter butterfly because she was wearing two swimsuits. However, all other records set by a swimmer wearing the suit stood as valid.

The World Swimming Federation's decision to ban hi-tech swimsuits came amid calls from a number of national swimming federations who additionally called for all records achieved while wearing them to be indicated with an asterisk in the record books.
FINA bans hi-tech suits from 2010

Speedo LZR swimsuit
Speedo LZR swimsuit now disallowed from competition swim meets

As of New Year's Day 2010, men are only allowed to wear suits from the waist to above the knees. They are also only permitted to wear one piece of swimwear; they cannot wear speedos underneath jammers. This law was enacted after the controversy in the Beijing Olympics and Rome World Championships.

Women's swim suits
Women wear one piece suits with different backs for competition, though there are two-piece suits that can be worn to compete as well. Backs vary mainly in strap thickness and geometric design. Most common styles include: racerback, axel back, corset, diamondback, and butterfly-back. There are also different style lengths: three quarter length (reaches the knees), regular length (shoulders to hips), and bikini style (2 piece). Also as of New Year's 2010, in competition, women are only allowed to wear suits that do not go past the knees or shoulders.

Equipment - New materials such as carbon fibre give great strength three times stronger than steel and flexibility without the weight. Tennis rackets, golf clubs, poles or vaulting and Formula 1 racing cars all benefit from this - giving an improved performance.

Pole Vaulting
Pole vaulting is a track and field event in which a person uses a long, flexible pole (which today is usually made either of fiberglass or carbon fiber) as an aid to leap over a bar. Pole jumping competitions were known to the ancient Greeks, as well as the Cretans and Celts. It has been a full medal event at the Olympic Games since 1896 for men and 2000 for women.

One of the most notable examples of innovation in athletics equipment is the flexible fibreglass pole. In the early 1960s performances rapidly improved when the relatively rigid poles made from steel or bamboo were superseded by highly flexible poles made of fibreglass or carbon fiber which allowed vaulters to achieve greater height. Physical attributes such as speed and agility are essential to pole vaulting effectively, but technical skill is an equally if not more important element. The object of pole vaulting is to clear a bar or crossbar supported upon two uprights (standards) without knocking it down.

Competitive pole vaulting began using solid ash poles. As the heights attained increased, the bamboo poles gave way to tubular aluminium, which was tapered at each end. Today's pole vaulters benefit from poles produced by wrapping pre-cut sheets of fiberglass that contains resin around a metal pole mandrel, to produce a slightly pre-bent pole that bends more easily under the compression caused by an athlete's take-off. The shape of the fiberglass sheets and the amount of fiberglass used is carefully planned to provide the desired length and stiffness of pole. Different fiber types, including carbon-fiber, are used to give poles specific characteristics intended to promote higher jumps. In recent years, carbon fiber has been added to the commonly used E-glass and S-glass materials* in order to create a pole with a lighter carry weight. Pole vaulters do not need a highly flexible pole to successfully perform a pole vault (a rigid pole will do), but they can achieve a considerably greater height through choosing a pole with an appropriate stiffness. Typical pole lengths are 4.90-5.40 m for elite male vaulters and 4.30-4.60 m for elite female vaulters.

*S-Glass is 64-66% Silicon dioxide compare to E-Glass at 52-56%. S-Glass has no Calcium oxide where E-glass has 16-25%. S-Glass has more Aluminium oxide at 24-26% where E-Glass is 12-16%. S-Glass has no Boron where E-glass is 5-10%. S-Glass does have 9-11% Magnesium oxide where E-glass very little. The price of S-Glass is higher than E-Glass. A possible reason for this is that S-Glass is processed at a higher temperature than E-glass and burns through oven liners faster and this replacement cost is the reason for the higher price. S-Glass looks and handles almost identically but is made from a higher-strength fiber that gives about 40% higher tensile strength, 20% higher modulus, and greater abrasion resistance.

As in the high jump, the landing area was originally a heap of sawdust or sand where athletes landed on their feet. As technology enabled higher vaults, mats evolved into bags of large chunks of foam. Today's high tech mats are foam usually 1-1.5 meters thick. Mats are growing larger in area as well, in order to minimize any risk of injury. Proper landing technique is on the back or shoulders. Landing on the feet is avoided, to eliminate the risk of injury to the lower extremities, particularly ankle sprains.

Rule changes over the years have resulted in larger landing areas and additional padding of all hard and unyielding surfaces.

The pole vault crossbar has evolved from a triangular aluminium bar to a round fiberglass bar with rubber ends. This is balanced on standards and can be knocked off when it is hit by a pole vaulter or the pole. Rule changes have led to shorter pegs and crossbar ends that are semi-circular.

Men's pole vault records modern pole
Men's pole vault records and modern pole construction
1. Unidirectional carbon fibre / epoxy resin 2. Woven carbon fibre / epoxy resin 3. Filament wound glass fibre core

Nordic Sport has developed a new pole, which they say is manufactured from a unique and secret mixture of material. The mixture is completely different from all other poles on the market. The Evolution pole has been tested thoroughly with help of both national and international elite vaulters with very impressive results. Tests show:

Javelin Throw
The javelin throw is a track and field athletics throwing event that can trace its origins as a sport back to the Olympic Games of ancient Greece. In the modem event the javelin must be thrown using one hand only without the aid of a sling or other throwing device. Because an athlete can generate a greater release speed with a lighter implement, the competition rules in the throwing events always specify a minimum weight for the implement. In the javelin throw the spear is approximately 2.5 metres in length and the minimum weight is 800 g for men and 600 g for women. The javelin thrower gains momentum by running within a predetermined area.

Rules and Competitions
The size, shape, minimum weight,and center of gravity of the javelin implement itself are all defined by IAAF rules. In international competition, men throw a javelin between 2.6 and 2.7 metres in length and (at least) 800 grams in weight, and women throw a javelin between 2.2 and 2.3 metres in length and (at least) 600 grams in weight. The javelin is equipped with a grip, approximately 150 mm wide, made of cord and located at the javelin's center of gravity (0.9 to 1.06 metres or 0.8 to 0.92 metres from the tip of the javelin for men's and women's implements, respectively).

Javelin Throw Arena Javelin Throw Records
Javelin Arena and World records for the Javelin Throw

The projectile used in javelin consists of three distinct parts: the head, constructed from a light weight metal; the shaft, made from carbon fiber or other composite synthetic materials; and the grip, the portion of the javelin where the object is held by the thrower prior to delivery. The shaft of the javelin is of hollow construction to increase the surface area and promote the greatest flight time. During the first half of the twentieth century the majority of competitive athletes used javelins made from Finnish birch wood. Nowadays javelins are constructed from steel, aluminium alloy, or carbon fibre. A modern javelin differs from the early designs in that it has a much larger cross-sectional area. Dick Held is credited with introducing the 'aerodynamic' javelin in the 1950s. His experiments led to the realisation that it is better for the javelin to have a larger surface area to augment the javelin's flight capacity through producing a greater lift.

Modern Javelins
Nordic brand Men's 800 g javelins, top: Orbit, middle: Champion, bottom: Airglider

Javelin Redesign
On April 1, 1986, the governing body (the IAAF Technical Committee) revised the regulations with respect to the men's javelin (800 grams (1.76 lb)). They decided to change the rules for javelin construction because of the increasingly frequent flat landings and the resulting discussions and protests when these attempts were declared valid or invalid by competition judges. In addition, the world record had crept up to a potentially dangerous level, 104.80 metres by the German Uwe Hohn in Berlin in 1984 and further increases could result in the javelin reaching the crowds even in standard athletic stadiums! The javelin was redesigned so that the centre of gravity was moved 4 cm forward, further away from the centre of pressure (the point at which the aerodynamic forces of lift and drag act), so that the javelin had an increased downward pitching moment. This would cause the nose to come down earlier, reducing the flight distance by around 10% and causing the javelin to stick in the ground more consistently. In 1999, the women's javelin (600 grams (1.32 lb)) was similarly redesigned.

Modifications that manufacturers made to recover some of the lost distance, by increasing tail drag (using holes, rough paint or dimples), were outlawed at the end of 1991. Records made using such modifications were removed from the record books. The Finnish javelin thrower Seppo Räty had achieved a world record of 96.96 metres in 1991 with a modified 'Nemeth' javelin and this record was nullified. This javelin was designed by former Olympic Champion, Miklos Nemeth, and had surface roughness on the tail to reduce aerodynamic drag which was not approved of by the IAAF. Räty's best record with the current javelin design was in 1992 (90.60 m), a significant reduction in distance.

Like sports equipment, modern clothing is highly sophisticated and has a great impact on the feeling of physical comfort in any kind of sport. Optimal water permeability allows sweat water droplets out but does not let rain water in. Polyurethane fibres ensure that the body wear has a perfect fit and offers the highest comfort because it stretches but still keeps its shape.

According to Nick Linthorne at Brunel University:
"For many athletes, running shoes are the most important piece of their gear. Under IAAF regulations the purpose of the athlete's shoe is to give protection and stability to the foot and provide a firm grip on the around. The shoe must not be constructed so as to give the athlete any additional assistance and no spring or device of any kind may be incorporated in the shoe. The design of running shoes has shown a steady evolution towards minimising the weight of the shoe. A lighter shoe reduces energy consumption during a distance event, gives a quicker acceleration and a higher top speed in a sprint and allows a greater vertical take-off speed to be produced in a high jump or long jump.

Adidas produces a 'performance plate' that consists of a rigid carbon fibre plate that is inserted into the sole to stiffen the shoe. The stiffness of the baseplate of a sprint shoe can have a significant effect on performance and experiments on sprinters running over 20 m showed an improvement of just over 1% when using a stiffening plate in their shoes.

In the high jump, the design of the athlete's shoe is believed to have a small but significant influence on performance. In 1957 an athlete using a take off shoe that had a 2-4 cm thick sole set a new world record of 2.16 m. The most obvious advantage of a built-up shoe is that the athlete's centre of mass is higher above the ground at take-off and so the height of the jump is correspondingly increased. Taken to the extreme, an athlete could wear what is essentially a pair of stilts and then simply step over the crossbar. The IAAF viewed the built-up shoe as giving 'unfair assistance' to the athlete and it was banned shortly after being introduced. However the record was allowed to stand. Since 1958 the thickness of the sole of the high jump shoe has been restricted to 13 mm.

Modern Sports shoes are chemical marvels, from the complex adhesives that ensure the shoe remains intact under extreme conditions, to the breathing fabrics that keep your feet cool and dry.

The design of athletic shoes is one example in which chemistry and biomechanics are employed to help minimize strain to the lower body and enhance athletic performance. A shoe should not only provide support and protection to the foot and ankle, but must also provide maximum traction and flexibility and, above all, be lightweight. In track and field sports, for example, a few grams of extra weight can reduce a runner's speed enough to lose a race. To this end, manufacturers have introduced ultralight shoes that use thin, liquid-crystal polymers that act like suspension bridge cables to resist shoe stretching and maintain stiffness without adding weight. For cushioning and support, many shoes employ lightweight gel cavities or air pockets.

Modern athletic shoes have at least four components: the upper, the insole or insert, the outsole, and the midsole. The upper holds the shoe together and protects the foot. The insole lies directly beneath the foot and provides cushioning and arch support. Insoles are removable in many shoes, and extra insoles called inserts can be added for comfort or moisture control. The outsole is the part of the shoe in contact with the ground; it's usually made of rubber or a synthetic polymer and has treads or cleats for traction. The midsole is the hidden layer between the outsole and the insole, mainly designed for shock absorption.

Chemistry of a typical sports shoe
The insole is a thin layer of man-made ethylene vinyl acetate (EVA). The components of the midsole, which provides the bulk of the cushioning, will vary among manufacturers. Generally it consists of polyurethane surrounding another material such as gel or liquid silicone, or polyurethane foam given a special brand name by the manufacturer. In some cases the polyurethane may surround capsules of compressed air. Outsoles are usually made of carbon rubber, which is hard, or blown rubber, a softer type, although manufacturers use an assortment of materials to produce different textures on the outsole.

The rest of the covering is usually a synthetic material such as artificial suede or a nylon weave with plastic slabs or boards supporting the shape. There may be a leather overlay or nylon overlay with leather attachments. Cloth is usually limited to the laces fitted through plastic eyelets, and nails have given way to an adhesive known as cement lasting that bonds the various components together.

Air Jordan shoe dissected
Air Jordan shoe dissected

Adidas designed the Lone Star spike running shoe for the 400m Texan runner Jeremy Wariner. The Lone Star featured the first full-length carbon nanotube reinforced plate and an innovative compression spike.

After studying Wariner's running pattern by high-speed video and pressure mapping, Adidas' engineers and designers were able to see how Wariner used each foot as he ran, which in turn enabled them to custom-design a shoe for his running style. His shoes have differently designed treads for the right and left foot to assist his cornering.

Stadiums - these days artificial turf, made of polyolefins to ensure toughness, is used in many stadiums. The turf is connected to the ground using polyurethane adhesives. Another type of chemical material, polycarbonates, have become the preferred material for roofing sporting arenas as they are lightweight and transparent enabling weird and wonderful architectural designs. PVC is used in all parts of the stadium from the flags and banners waved by fans to the seats they sit in to the field drainage system.

The University of the West Indies (UWI), Mona Campus training facility, used by Usain Bolt and other Jamaican runners, received a new Regupol® tartan track in April 2010, with the same Berlin Blue coloured surface as the Regupol® track at Berlin's Olympic Stadium.

Regupol track base Regupol track
See the layered structure in the Regupol athletic tracks similar to that used at Mona.

A prefabricated Regupol® elastic layer [4], 10 mm thick, is glued on the asphalt base [6] (photo at left above). Afterwards the pores of the elastic layer are sealed with polyurethane [3] and liquid polyurethane [2] is applied as wear layer to which the EPDM granules are added [1].

The top layer [1], usually 3 mm thick, is composed of mixed-size, spike-resistant EPDM granules embedded into liquid polyurethane. Copolymerization of ethylene and propylene would result in a saturated backbone such that sulfur vulcanization could not be used for crosslinking since no unsaturation exists. To get a sulfur-curable rubber, a non-conjugated diene is introduced as a third monomer during polymerization. Appropriate third monomers contain one double bond which takes part in the polymerization and one which does not. The diene(s) currently used in the manufacture of EPDM rubbers (ethylene propylene diene Monomer (M-class) rubber) are DCPD (dicyclopentadiene), ENB (ethylidene norbornene) and VNB (vinyl norbornene).

International technology gap
A comparison of 2008 Beijing Olympic results for 'Technology driven sports' such as Track cycling, rowing and sailing with 'Non-technology sports' such as athletics.

Total medals - 'tech' Total medals - 'non-tech'
Great Britain 24 USA 23
Australia 7 Russia 18
New Zealand 6 Kenya 14
Netherlands 5 Jamaica 11
France 5 Ethiopia 7
Spain 5 Belarus 7
Germany 5 Cuba 5
USA 5 Ukraine 5
China 5 Australia 4
Canada 4 Great Britain 4
Italy 2
"The role of technology in sporting performance", Prof Claire Davis, School of Metallurgy and Materials University of Birmingham, UK.

Design and Materials in Athletics. Nick Linthorne shows the changes technology has made in a number of athletic events and plots the average result for the 10th best athlete in the world for these events.

Much of the information in these course notes has been sourced from Wikipedia under the Creative Commons License. Students taking this course will be expected to contribute to Wikipedia as a part of their course assignments.
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Created and maintained by Prof. Robert J. Lancashire,
The Department of Chemistry, University of the West Indies,
Mona Campus, Kingston 7, Jamaica

Created September 2011. Links checked and/or last modified 27th November 2014.