In the 1960s, when traditional ash athletic tracks were replaced with spongy and synthetic surfaces, endurance racing underwent a revolution. Long distance runners started recording much faster times on synthetic tracks, breaking several world records.
Today, another revolution is underway: the development of the so-called “super shoe”, which brings about another record peak in endurance racing. New shoe technology was introduced to road running in 2016 and track running in 2019, and since those key dates virtually all endurance racing world records, from the 5,000m to the marathon, have been broken. .
This has divided opinion in the athletic world, with some claiming the shoes are unfair while others claiming they are like synthetic running tracks: an inevitable technological leap that endurance runners can take. capitalize.
Research in sports biomechanics helps explain exactly what goes on inside these shoes. While super shoes are clearly disrupting old records – some of which have been around for decades – this technology should simply be seen as another entry in the long list of sports performance-enhancing innovations.
Nike’s new shoes
In the 2016 Olympic Marathon, all three male medalists stepped onto the podium in the same shoes. It was a Nike prototype, later released as “Nike Vaporfly 4%”, which are now almost ubiquitous at the feet of elite roadrunners.
Then, in 2019, similar super-shoe technology hit the athletics track. A large number of Nike-sponsored athletes wearing Nike’s prototype cleats began to run incredibly fast times.
The performance enhancement offered by both types of super shoes – the trainer and the track tip – is generated by improving the running economy of athletes, which means reducing the energy cost of running at a given speed. .
The original Vaporfly improved the running economy of highly skilled runners by around 4% compared to a control marathon shoe – hence the nickname 4%. In practice, this equates to a gross improvement in operating performance of between 2% and 3%.
The shoes delivered on this claim. In the years since the advent of the Vaporfly in 2016, the times of the top 50 male marathoners improved by around 2% on average. For the top 50 female marathon runners, that figure was closer to 2.6%. Nike’s track spikes are also considered to provide significant run economy for athletes.
A very good footwork
Several characteristics of the shoes are responsible for this improvement in performance. They include the weight of the shoe, its material composition, the thickness of its heel, and what is known as its “longitudinal flexural stiffness,” which in layman’s terms is the flexibility of the shoe from heel to toe.
The inclusion of a carbon fiber plate, running from heel to toe in the foam sole of the Vaporfly, was the be on the first page innovation. These plates aren’t really a new concept, but their specific scoop shape is credited with the latest performance improvement. This causes a “swing” effect, which effectively helps restore energy to the runner whenever their foot hits the ground.
The Vaporfly also uses PEBA foam, which stores much more energy from kicks, and returns more energy to the runner, than the TPU and EVA materials that are traditionally used in sneakers. PEBA foam is also lighter: the Vaporfly weighs around 50g less than previous competitors.
Finally, the heel thickness of the shoe up to 40mm is about 10mm thicker than that of other running shoes. This is partly to adapt to the other technology of the shoe and partly to increase the length of the wearer’s leg, which contributes to its energy saving. The above features likely also formed the basis for Nike’s new track picks.
Nike’s new shoes aren’t the only technological and scientific interventions to bring “marginal gains” to the world of endurance running.
When Eliud Kipchoge broke the barrier of the two-hour marathon in an unofficial race in 2019, breaking his own world record of 2:01:39, he was wearing great shoes. But everything else – his race kit, course design, pace and training strategies – everything has been comprehensively researched and scientifically optimized.
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Likewise, advanced shoes certainly help athletes run faster. But other innovative tools – such as wave light stimulation technology, used in the 5,000m and 10,000m world records in 2020 – may also contribute to their increased speed.
World Athletics, the governing body responsible for endurance racing, released updated footwear guidelines in August 2020, allowing heel thickness of up to 40mm in road running shoes and 25mm in distance running spikes. Many have called for further restrictions.
There are parallels with other sports. The introduction of NASA-designed full-body swimsuits into competitive swimming in 2008 was blamed for the world records that fell that year. The full-length swimsuit was quickly banned, although the technology is perpetuated in a reduced form in today’s swimwear.
The super-shoe arms race will inevitably extend to sprint distances in the near future. The new technology will usher in a new cohort of world record holders. During this process of recalibrating the ranking, more emphasis should be placed on results than on times. After all, whatever the technology, these are titles that transcend generations and medals that last longer.
This article by Jonathan Taylor, Senior Lecturer in Sport and Exercise, Teesside University is republished from The Conversation under a Creative Commons license. Read the original article.