Adidas Ultraboost 21 review (early verdict): adorable and chunky running shoes with all the BOOST in the world

The Adidas Ultraboost 21 is bigger, bolder and even more comfortable than before

Adidas Ultraboost 21 review
(Image credit: Future)

Even I can get lucky sometimes and receive an early review pair of the new Adidas Ultraboost 21, the latest iteration of the beloved running shoes franchise. New Ultraboost shoes are always exciting and I was looking forward to the Ultraboost 21 even more than usual: they promised more responsiveness and just looked plain cool on the press photos. I'm happy to confirm, the new Ultraboost 21 is everything I expected it to be, and more (BOOST).

First, I would like to address the elephant in the room: despite being one of the best Adidas running shoes franchise ever, the Ultraboost series are not designed for racing. For racing purposes, the Adidas Adizero Adios Pro is still the best choice as it is much lighter and have better performance mechanics than the Ultraboost 21.

What is the Adidas Ultraboost 21 best for? How does it perform on the road? And, most importantly, is it worth your hard-earned money?

Adidas Ultraboost 21: price and availability

The Adidas Ultraboost 21 is available to buy now at Adidas US and Adidas UK for a recommended retail price of $180 / £160. The shoes are also available to buy at selected third party retailer,s such as

Adidas Ultraboost 21 review

(Image credit: Future)

Adidas Ultraboost review (early verdict): what's new?

It's in the name: the Adidas Ultraboost 21 is all about the BOOST, or, to be more precise, the BOOST midsole, which consists of little BOOST capsules compressed into a responsive foam. The Ultraboost 21 packs 6% more BOOST than its predecessor, wedged under the heel, so the shoes are even bouncier than before.

Adding extra material to the midsole does come at a price: the Ultraboost 21 is pretty heavy. The size 10 (UK) review sample I had weighs a whopping 384 grams, compare this to the Saucony Endorphin Shift, an also rather sizeable shoe that's 'only' 330 grams. Not to mention running shoes geared toward racing, such as the Salomon S/LAB Phantasm, weighing a mere 212 grams.

The Adidas Ultraboost 21 is the first shoe to feature the new Adidas LEP torsion system: as opposed to embedding it in the midsole, the Adidas LEP is fitted to the outsole and said to provide a 15% increase in forefoot bending stiffness. Basically, it keeps your feet in line by making the forefoot stiffer but without actually making the midsole stiff. It's quite cool, kind of reminded me of the Energy Rod system, used in  in Adidas racing shoes, that replaced full-size carbon plates with rods for a more fine-tuned propulsion.

Finally, the Adidas Ultraboost 21 is also the first Adidas running shoe to feature the Primeknit+ upper, which, as you might have guessed, is the updated version of the Primeknit technology used in previous Ultraboost shoes: the sock-like construction of the upper is said to "adapt to the changing shape of your foot through the gait cycle". The shoes are also made with Primeblue, a high-performance recycled material containing Parley Ocean Plastic and a minimum of 90% recycled material in total.

Adidas Ultraboost 21 review

(Image credit: Future)

Adidas Ultraboost review (early verdict): ergonomics

Putting the shoes on is a bit of a hassle. Although there is a tab at the back which is really easy to grab, thanks to the aforementioned sock-like fit of the collar, you will need to force your feet into the shoes as opposed to slipping them on. Once you managed to put them on, though, you will be rewarded with sublime comfort levels through and through. One might even say that the Adidas Ultraboost 21 is ultra-comfortable (sorry).

As mentioned before, the Ultraboost 21 is a heavy running shoe but it really doesn't matter. Thanks to all the BOOST cushioning and the advanced rocker geometry, rolling forward in the shoes is effortless. You certainly won't be chasing PBs in the Ultraboost 21 but for slower training sessions, recovery runs and jogging, I can't think of any other shoes that provide a more comfortable ride. The 10 mm midsole drop (heel 30.5 mm / forefoot 20.5 mm) makes the Adidas Ultraboost 21 even more accessible for beginners.

Adidas Ultraboost 21 review

(Image credit: Future)

Adidas Ultraboost review (early verdict): aesthetics

The Ultraboost series has a bit of bad reputation in running circles for being a bit too sneaker-like, and for better or worse, this seems to be the case with the Adidas Ultraboost 21 too. I, for one, appreciate that the design moved away from yesteryear's techno aesthetics: as much as I like Akira, the design of the current iteration of the shoes suits the series way more.

The extra BOOST, big pull tab, wide nose and the vibrant colours make the Ultraboost 21 look like one of those fair caricatures with exaggerated features that emphasise the unique characteristics of people. It also has a bit a throwback design: to some degree, the Ultraboost 21 is more similar to the UB19  than the UB20, but without the external heel counter cage-thing.

I like the look of the Adidas Ultraboost 21 and I think a lot of other people will like it too.

Adidas Ultraboost 21 review

(Image credit: Future)

Adidas Ultraboost review: early verdict

Based on my very thorough initial assessment (aka running in the shoes a few times), I have a positive feelings about the Adidas Ultraboost 21. They are comfortable, responsive and display all the features I expect to see in great training shoes.

Better still, they look rather sexy too, albeit especially this time of the year, it will be pretty difficult to keep them box fresh for too long. I guess it doesn't matter, as people will either buy the Ultraboost 21 to add it to their sneaker collection or to run in them, and both parties will use them shoes accordingly. As in, either keep the shoes in the box and only get them out when the weather is dry or run in them, regardless of the weather.

The latter group (runners) will thoroughly enjoy cruising through their daily runs in the Adidas Ultraboost 21. I have a feeling that people who would buy the shoes have already made up their mind anyway, so I'm here to tell you, it's a good investment, either way. 

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Get Fit for 2021!

This is part of T3's Fit for 2021 programme, which will be running throughout 2021 to get everyone fit and healthy. We aim to bring you tips on diet, lifestyle and exercise that will help you shape up for what is certain to be a challenging year for many. One thing we can guarantee: it WILL be better than last year. And hopefully we'll help you get the most out of it. 

Matt Kollat
Section Editor | Active

Matt Kollat is a journalist and content creator who works for and its magazine counterpart as an Active Editor. His areas of expertise include wearables, drones, fitness equipment, nutrition and outdoor gear. He joined T3 in 2019. His byline appears in several publications, including Techradar and Fit&Well, and more. Matt also collaborated with other content creators (e.g. Garage Gym Reviews) and judged many awards, such as the European Specialist Sports Nutrition Alliance's ESSNawards. When he isn't working out, running or cycling, you'll find him roaming the countryside and trying out new podcasting and content creation equipment.