Performances

New materials for new records

Aluminium, carbon and even bamboo: sport results today depend highly on the materials.

The take-away

  • Many innovations in sports technology come from new materials and improved design. Parabolic skis, introduced in the 1990s, are an example.
  • While better equipment allowed 100-m runners to go just 4% faster, both pole-vault and javelin performance improved by 30%.

Anyone who doubts the radical impact that technology can have on sport should consider the swimming contests at the 2008 Olympics in Beijing. A few months before the games, British swimwear manufacturer Speedo launched a new all-in-one swimsuit known as the LZR Racer. Made from polyurethane rather than conventional fabrics, the LZR Racer was said to reduce a swimmer’s drag and also boost oxygen flow to the muscles. It proved a stunning success: competitors wearing the suit at Beijing scooped 94% of the swimming gold medals, breaking numerous world records in the process.

That outcome, and the continued setting of new records as other sportswear companies produced their own variations on the LZR Racer, eventually led international swimming’s governing body to ban the full-body suits in 2010. But while observers complained about “technology-doping”, swimming is far from the only sport in which technology has made a huge and sometimes controversial mark.

World records with fibreglass

In a 2009 study, Steve Haake, a sports engineer at Sheffield Hallam University in the UK, worked out the effect of technology in a range of Olympic disciplines over the last century. He found that while better equipment had allowed 100-m runners to go just 4% faster, both pole vault and javelin performance had improved by about 30%. In the former, fibreglass poles introduced in the early 1960s allowed athletes to break the world record 19 times in just a decade, raising the maximum height from 4.8 metres to about 5.5 metres.

Ultimately, javelins had to be redesigned to reduce performance. They were being thrown so far by the 1980s that authorities, fearing for public safety, ordered that their centre of gravity be brought forward by 4 cm. That small change was enough to reduce the maximum throwing distance by about 10%.

Then there’s cycling. In contrast to the steel bicycles of the late 19th century and aluminium racers of the second half of the 20th, modern high-performance bikes are now built from a single piece of carbon fibre. Intended to be extremely aerodynamic, they are designed using computer programs that model fluid flow and tested in wind tunnels.

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Bicycles made of bamboo

Veit Senner and colleagues at the Technical University of Munich are working to further optimise modern bicycle frames. One goal is to improve the safety of mountain bikes by subjecting carbon-composite frames to brutal treatment in the lab. Researchers use infrared, ultrasonic and X-ray imaging to observe how layers of carbon within the frame separate on impact – something that cannot be seen from the surface.

The German group is also developing a frame for a racing bicycle made largely from bamboo, which, unlike carbon fibre, can be recycled. They have carried out an extensive test programme to make the frame stronger, stiffer and more robust. According to Senner, many innovations in sporting technology come about through a combination of new materials and improved design.

He cites modern “parabolic” skis, introduced in the1990s, as an example. Unlike older skis, which were more or less straight, parabolic skis are narrower in the middle and wider at each end. This design makes turning much easier, since all a skier has to do is rotate the skis on to their edge via a slight movement of the hips and knees, apply a little pressure and the curved edge forces the skis to naturally “carve” an arc in the snow. “High-performance skiers could carve with old skis but ordinary people couldn’t,” he says.

Just as parabolic skis required new materials with high torsional stiffness – in other words, that didn’t twist very much – so too the development of new skis by researchers at Ecole Polytechnique Fédérale de Lausanne (EPFL) and Swiss company Stöckli has involved varying material properties as well as working out the relative thickness of each material layer (which can include wood, polymer, aluminium, glass and carbon). The idea, explains EPFL’s Véronique Michaud, is to tune two properties of the skis – flexibility (how much they bend) and torsional stiffness. “We’re looking for an optimal compromise between ease of turn and stability when going fast,” she explains.

Inspired by insects

Scientists are not only developing new materials but also helping sportsmen and women improve their techniques. Josje van Houwelingen, a physicist at the Eindhoven University of Technology in the Netherlands, has developed a new system to improve the strokes of elite swimmers. The system involves creating small bubbles at the bottom of a swimming pool and using an array of six cameras together with a fluid-dynamics algorithm to study how a passing swimmer affects the motion of those bubbles.

Van Houwelingen is particularly interested to find out whether swimmers could boost their propulsion by creating certain kinds of vortices, just as insects take advantage of vortices they create in the air as they flap their wings. “Insects have been observed to get extra propulsive force by pushing against those vortices,” she says. “Maybe swimmers could get a similar benefit.”

This is just the beginning. Cycling may see the advent of spray-on clothing that keeps riders dry and safe but also light, as well as sensors to monitor a rider’s physiological changes and “phase-change” tyres that vary their tread depending on terrain. “Human Enhancement Technologies” could also become far more widespread. South African amputee runner Oscar Pistorius caused controversy when he competed in able-bodied competitions using artificial limbs, but in the future biomedical devices and prosthetics may be used by athletes to enhance their capabilities rather than simply restoring them.

How Switzerland became a sailing nation

Without seashore, the alpine nation won the America’s Cup twice. One reason: ingenious engineering.

The benefits that advanced materials and other cutting-edge technologies can bring to elite sporting contests were highlighted by the twin successes of Swiss syndicate Alinghi in the America’s Cup. Set up by businessman Ernesto Bertarelli, Alinghi showed that even land-locked Switzerland could win the coveted sailing trophy when it beat Team New Zealand in 2003 and 2007.

Véronique Michaud, a materials scientist at the Ecole Polytechnique Fédérale de Lausanne, allows that part of Alinghi’s success came from its top-notch crew – much of which, including skipper Russell Coutts, had been poached from Team New Zealand. But equally crucial were the boats. To optimise the technology, Alinghi developed two boats with slightly different designs for each race.

Starting in 2000, a team of about 20 researchers and students at EPFL carried out a series of experiments and drew on computer models to make the carbon-fibre composite hulls as stiff but light as possible. The researchers also placed thin fibre-optic sensors inside the boats to monitor how their masts changed shape in order to better tune the rigging.

The work paid off. In 2003, Alinghi stormed to a 5–0 win over Team New Zealand, which was hamstrung by a series of technical difficulties, including a snapped mast in the fourth race. Victory came less easily four years later, when Alinghi triumphed 5–2, but with a winning margin of just one second in the final race. “At this level of competition, the slightest improvement in performance can make all the difference,” notes Michaud.

Speedo, Steve Haake (Sheffield Hallam University), Veit Senner (Technical University of Munich), Véronique Michaud (EPFL), Stöckle, Josje van Houwelingen (Eindhoven University of Technology)