As sports go, running requires very little equipment. T-shirt, shorts, socks, trainers - you're ready to hit the streets or track. Yet, runners are very particular about their gear. The shorts have to be the right length, shirts shouldn't chafe and trainers must be suited to the terrain and running style.
Enter, 3D-printing. The technology, while around for almost two decades, is still fledgling in consumer markets and homes. In theory, it holds unlimited potential for product personalisation but it is not quite there yet. In an attempt to make it go mainstream, adidas has put its first pair of 3D-printed on sale today.
The 3D Runner pumps are available in limited quantities in London, New York and Tokyo from December 15 - from 9am they will be available from adidas' Oxford Street store. Despite the hefty £240 price tag it won't be a surprise if it's hard to bag a pair.
Before their launch, we got to test out a pair. Coming in black, the trainers are equipped with a so-called black Primeknit, to make the shoe more stylish. The shoe is made using an "engineered 3D web structure with dense zones in high force areas and less dense zones in the low force areas".
This means the mesh is thicker in places that are high-impact; where the foot strikes the ground harder. According to adidas, this allows for the optimum level of performance. The 3D Runner also features a 3D-printed heel design which is built into the midsole, removing the need for the traditional gluing or stitching.
We tried the adidas shoes for one 10km run – consisting of 5km on pavements and some off-road track, and another 5km indoors on a treadmill. As a semi-committed runner (seven half marathons in 2016) the shoes were an initial worry due to their weight. They aren't overly heavy (adidas hasn't released a weight for them) but they are heavier than what I am used to running in.
However, out running the shoes were comfortable and underfoot had a feeling of impressive flexibility. They handled impressively on both the treadmill, tarmac and off-road – although it should be noted this is the first impression from a single run.
Although the trainers were taken out of the box – label still attached – they did not feel like they were brand new when running. It was as though they were a trusty pair of my favourite running shoes. If it hadn't been made clear they were 3D-printed it wouldn't have been possible to tell, either.
The meshing gave an initial sensation of air passing over the foot and was flexible to each stride's movement. Throughout the entire run the 3D Runners were enjoyable to wear, no matter what terrain they were covering.
There are, however, a few gripes. At £240 these are expensive trainers, admittedly they are limited edition and made in a potentially revolutionary way, but the cost is still high. As much as the meshing lets air flow through the trainers it will also let other elements through: think rain and puddles. Also, for off-road courses a couple of small stones stuck in the sole could be noticed when back on pavement.
This new sale isn't the first time the shoes have been shown off. The 3D Runner was unveiled in August and has been trialled by heptathlete Jessica Ennis-Hill, USA swimmer Allison Schmitt and Colombian BMX cyclist Mariana Pajon.
What stands out about them is the promise. Adidas has hinted it may make more 3D-printed objects available to customers in the future. As it does, and printing speeds increase, the price is likely to drop and when it does personalisation is likely to rise.
As long as the 3D-printing technology behind the shoes is invested in and developed it is possible to see a person walking into a shop, running on a treadmill, then a few hours later collecting trainers made specifically for their feet. But that's still to come – for now, only a lucky few will get to try these trainers.