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adidas Ultraboost 21 - Shoe Review

3.6 out of 5 | 362g (mens) 312g (women’s) | 10mm | Neutral | £160 


First impressions:

Mo:  I instantly noticed that adidas have gone for more premium packaging. I like the simple black and white colour making this a modern-looking every-day trainer. The designs have consistently looked attractive and the cushion and bounce have always felt good on the run. 

Reka:  I do really like the black and white design, they can be worn as an everyday trainer with jeans and tee too.

Fit and width: 

Reka: This ultimate upper is Primeknit + Primeblue. I love the use of this recycled material. Primeblue is a high performance material made with 50% parley ocean plastic – upcycled plastic waste that has been intercepted on shorelines and coastal areas, preventing it from polluting our oceans. The Ultraboost 21 is heavier than I was expecting and the radical midsole design is completely different from any previous Ultraboost. There really is no other shoe like this. The upper provides a snug sock-like fit, which is stretchy and loose around the toes, while around my ankles the shoe feels quite tight. 

Mo: My first run in them was 6 miles, and while the Boost underfoot felt firm and cushioned at the same time, for me they still felt a little too firm. After trying the Ultraboost for several longer runs I started to getused to the feel of the shoes. I do think they make a great 5-10km shoe, but would also be perfect for the gym.  
The Prime knit+ upper on the Ultraboost feels very soft, smooth and comfortable and the width of the shoes is prefect for my foot shape and very comfortable. I am usually 9.5 in most brands but I have gone up half a size in these as they felt a little small.

Wear it works best:

Mo: I ran in these shoes for 50 mile weeks and surprisingly found the fit was very suitable for my easy miles. The Prime Blue material is top notch and good quality and stretchy. I have noticed these shoes work better for rear foot strikers rather than forefoot runners. 

Reka: My first run was a 10k run and it felt really good, but I still find this shoe a little heavy. For weighted training, so that your race day shoes feel as light as a feather, then this could be the shoe for you. 

The full-length Boost is the most responsive midsole foam designed to provide a cushioned running experience, and the Continental outsole rubber is soft enough to offer a nice grip of hard surfaces even in the rain. The durability of the rubber has been excellent in my time of testing it and there is very little wear showing.




An impressively well built and durable shoe. It may be a little on the heavy side but will be a great workhorse for regular medium distance training runs.

This shoe has been tested by Reka and Mo. They have run in the shoes for a minimum of 4 weeks or about 50 miles before submitting their reviews. The scores they have given the shoes are based on their experiences, their running styles and their training types. These shoes were gifted by adidas for the purpose of this review, however no input was made by adidas. The views are entirely that of our testers. 


Hi I’m Mohamed,

I’m a middle/ long distance and cross-country athlete. I run usually anything from 1500m on the track to half marathon distance on the road. I normally train 7 days a week sometimes twice a day getting up to 70/80 miles per week. I enjoy track and road at national level all over the country. I love anything running related from working within running specialist retailers, big brands you name it. I’m definitely really excited about reviewing all the new products coming out and giving you my opinion.


Hi I'm Reka,

I love running, running has been in my life since I was 11 years old. I have done many cross-country races, Triathlons/ Duathlons too. I have run a dozen half marathons and half a dozen marathons over the years, but now I am training for my first ultramarathon. I found running is a great way to explore London and the countryside. My mileage is between 30-50 miles, mainly run commuting and long run on a weekend.




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