Adidas is putting a lot of its time and effort into research and advancing its running trainers, the result is the latest Adidas Ultra Boost.
The First Adidas Boost trainer launched to much fanfare with the big sell being a sole that harvests impact energy and effectively bounces the runner back up. The Ultra Boost has taken this to the next level to offer what Adidas says is "the best shoe ever".
The soul of the sole
The core of the Adidas Ultra Boost is in its sole. This is made up of thousands of "energy capsules" which are effectively a springy material that's able to flex under the weight of the runner before pushing that energy back.
Most trainer soles on the market today are made from an ethylene-vinyl acetate (EVA) plastic foam. The Ultra Boost uses a special thermoplastic polyurethane (TPU) to create the individual pods that make up the sole. These not only offer better energy return but also stay in the same state despite temperature changes. This means you still get the boost and flexibility in the cold and they don't go soft in the heat, unlike EVA.
The first generation Adidas Boost runners used an EVA edging for support but by ditching that for a pure TPU sole the Ultra Boost now offer 20 per cent more bounce while also enhancing flexibility. Plus they last, without losing spring, for hundred of kilometres.
Extending your foot freedom
The heart of Ultra Boost appears to be in a trainer that allows your foot maximum freedom, by moving with it. By doing so the wearer avoids friction and the injuries like blisters that go with it. This was achieved using Aramis analytical kit that NASA, Boeing and Audi also use.
Aramis uses a system of cameras and sensors to show the flexion in the subject thanks to a 3D location measured image. This means any movements in the foot from skin, muscle and bone can be mapped. By wearing a marker laden sock runners were measured to find how the foot moves when running. This was then compared to the Boost Ultra as it was being developed to make sure there was perfect similarity, while offering support where needed thanks to the Stretchweb bottom and supportive heel.
The result, as you can see from the photo, is that the Ultra Boost and barefoot running flex in similar ways. The competitor example, that uses EVA, was less flexible.
Upper class upper
The flexibility of the top of the trainer is also of key importance. This is often where a lack of movement can lead to foot damage from friction. The foot can expand by up to 10mm when running. So flexibility here was also achieved by using a 4-way flexible Primeknit upper which flexes with the foot while also offering support.
Adidas says the Primeknit upper "provides comfortable support in less expansive areas of the foot and adaptive stretch where it’s needed to deliver maximum comfort".
Support from the rear
The heel of a shoe is massively important in protecting and assisting the Achilles tendon to hold the entire body up. The Boost Ultra has had a reconstructed heel that should offer natural feeling while also cradling the foot all the way to the highest extension of the Achilles.
Even the sock liner in the Boost Ultra has been designed to offer adaptive support. It's featherweight and should adapt to the runner's natural form while running.
But rather than keep the heel locked as the front flexes free Adidas used its dual-density Torsion System. This allows for more independent movement between the heel and the forefoot. The result is greater stability for a more controlled run.
Are Adidas Boost Ultra worth buying?
We're not going to tell you what to think. You've read the argument put forward by Adidas which shows the development efforts Adidas put into the Boost Ultra trainers. Of course this might affect different runners in different ways. For some people they may not create a noticeable difference, for others they may.
The world's second fastest man, Yohan Blake, seems to like them. He is sponsored by Adidas though so he would.
In our experience these are extremely comfortable trainers, though we needed a size larger than normal. The original Boost never gave us a single blister in a year of running so presumably these will be even better. The Adidas Boost Ultra are available from 11 February for £130.