12 April, 2017

The secret weapon of Nike, revealed

In February I published a post on Nike's Breaking2 project that consists in breaking the 2-hour barrier in men's Marathon. I voiced my doubts by wondering whether the project was science or farce. Now it appears that it is essentially shoe technology.

First, let us be fair about Nike. At no point did they pretend that the Breaking2 attempt was going to be one that could lead to a world record to be homologated. So, people did offer speculation about the possible ways to attain the objective: downhill racing (not without disadvantages), wind assistance (how do you control this?), doping (would the athletes risk their career for this?). My take was fresh pacemakers (but if you cannot follow their pace, they are useless). Given that Nike is a shoe manufacturer the most obvious solution could be some very special shoe. It turned out that this was the secret weapon of Nike.

The new shoe of Nike is called Vaporfly Elite.

The official description of the shoe states that Vaporfly features a thick midsole embedded with a stiff carbon-fiber plate which allows the shoe to return about 13 % more energy. Nike claims that the plate saves 4 % of the energy needed to run at a given speed. You can see the curved plate in the scan below.

So now the obvious question is "does Nike cheat by using this shoe?". Ross Tucker at Sportscientists.com does think so. He has an excellent article on the matter. He bases it on two historical cases, the Pistorius blades and the Speedo LZR swimsuit. In the case of Pistorius no action was taken because Pistorius had never been an outstanding runner. Thus the technology that allowed him to run a 45.3 s 400 m was viewed as tolerable. (I have made explicit my thoughts on blade runners and augmented humans in two posts of mine). On the other hand the LZR swimsuit resulted in practically all olympic records being broken in the Beijing, 2008, Olympics. As a consequence it was banned (and dragged down with it even the non-polyurethane-reinforced suits, something that I deplore).

Ross makes some excellent points as to whether the carbon-fiber plate should be banned. First it is clear that Nike themselves are presenting (in their patent application) the insert as a spring plate. Moreover they state explicitly that the foam padding of current shoes returns a very small amount of energy. Ergo, what matters is the plate. What I did like a lot in Ross' presentation was his gradual build up argument. You start with a prototype that offers a very small advantage. People say it's OK, just carbon-fiber and foam, so there is nothing to worry about. Then you work on the prototype and improve it, without making your progress public. Finally you optimise everything and it really works. Suddenly you get a world record and nobody knows if this is an outstanding performance or just technology at work. Ross concludes that "any external device inserted for the purpose of energy return should be banned" adding that "performance evolution should be trusted to have occurred as a result of human physiology".

I do not think that human physiology has changed appreciably over the last century: the human-factor-based progress we have witnessed is due mainly to better nutrition and hygiene, as well as selection among an ever-growing pool of candidates. The evolution of training methods have greatly contributed to improvement of performances. However we should not neglect the fact that technology has been at the service of athletics since the beginning. Better running surfaces and better equipment are essential in the progress over the years.

Having presented these arguments I do not really know where we should draw the line. On the one hand I strongly believe that the material used should not bestow any unfair advantage. But then what about everybody using carbon-fiber-plate fitted shoes? (Unfortunately, Nike are talking about specially adapting the shoes to be used in the Breaking2 attempt for each runner. If so, what about the guy next door? We are back to the unfair advantage argument). On the other hand, if the shoes are allowed and widely used, aren't we going to enter an era of before and after, just as in the case of pole vault? Is this worth it? I seriously doubt it.

For the time being I think that I'll wait patiently for the Breaking2 attempt: it would certainly be exciting to watch a human break the 2 hours Marathon barrier. Still we should not forget that 2 hours are not magical but just a sign of the human obsession with round numbers. 

PS Just not be left by the wayside, Adidas announced that they also had a revolutionary marathon shoe, the adizero Sub2, that would be instrumental in their Sub2 project. It has a special foam, Boost Light, that is supposed to provide 1 % improvement in running energy economy. But at least the Adidas shoe does not have a carbon fiber blade.

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