adidas Ultra Boost 21 Running Shoes

Prototype after prototype. Innovation after innovation. Testing after testing. Meet adidas in the hot pursuit of the pinnacle harmonisation of weight, cushioning, and responsiveness. Ultraboost 21. Say hello to incredible energy return.

PrimeKnit+ Upper

A Primeknit+ upper encases each foot in breathable comfort. Feeling like a second skin, its seamless construction surrounds the foot in a fused yarn that combines pure comfort with lightweight performance. Designed with motion in mind, the Primeknit+ adapts to the changing shape of your foot through the gait cycle, the breathable, sock-like design is engineered to provide enhanced support and increase comfort to areas of the foot that require it most. Additionally, Tailored Fibre Placement offers target support around the midfoot. The stitched-in reinforcements ensure support and structure where it is needed to most so you can enjoy a comfortable, supportive fit. Tailored Fibre Placement has been used around the side of the upper to increase structure around the midsole to prevent the foot from rolling. A supportive heel counter delivers a secure and comfortable fit to reduce the risks of chafing and irritation so you can go further for longer in complete comfort. The elastane moulds to the shape of your heel for a supportive fit. Completing the upper is a lace closure system which works to lock down the midfoot to reduce in-shoe slippage so you can enjoy distraction-free strides. These shoes are made with Primeblue, a high-performance recycled material containing Parley Ocean Plastic and a minimum of 90% recycled material in total.

Boost Midsole

adidas again take cushioning and responsiveness to new heights, with their ultra-responsive midsole. As many know now, Boost is constructed from tiny TPU capsules that are moulded together to form a platform that is different to standard, solid foams; absorbing energy and then expelling it back out for a bounce-like effect. This energy return technology reduces the use of superfluous muscle power, diminishing fatigue and enhancing performance; keeping you going for longer. Capturing the energy you put into running and blasting it right back out, the newly optimised Boost midsole brings even more energy return to your ride. What makes this boost arguably better than other midsole compounds is that adidas has made the boost firmer to deliver 20% more responsiveness and cushioning compared to the original Ultra Boost. Boost also manages to maintain its special function and bounce in conditions as low as -20 degrees, making it a reliable, durable and hard to beat midsole. Furthermore, the midsole features a new tuned torsion spring that offers enhanced support on landing and a snappy transition as you surge ahead. The reason is simple: a running shoe shouldn't get in your way; it should propel you forwards. Both of these unique technologies work in tandem to push you ahead of the competition as well as giving you a good basis to break PB's.

StretchWeb Outsole

Manufactured from Continental rubber, the StretchWeb outsole completes the Ultra Boost 21 for superior grip and a smooth transition through the gait cycle. Its web-like structure cooperates with Boost to allow the shoe to stretch, for a flexible and lightweight underfoot feel. The web pattern also means a large surface area which also means better grip. Inspired by tyre technology, continental rubber supplies traction on wet and dry surfaces, giving you no excuse not to get out and run. The outsole is designed to be just as durable as the Boost midsole, leaving you with a resilient, cushioned and grippy running shoe.