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Adidas Ultra Boost 21 Performance Review

The Adidas Ultra Boost has updated 10 generations. It’s popular on the market. Since Adidas paid to Kanye West to wear the white UltraBoost 1 on the stage. Many people start to wear Ultra Boost as casual shoes. Ultra Boost can be professional sneakers and casual shoes.

Is the new released UltraBoost 21 the sneaker or fashion casual shoes? Or does it have both functions?


We can see the thick Boost insole after unboxing. The tail is upturned.

The shoe tongue is integrated design. It doesn’t need to worry that the shoe tongue will move when running.

Due to the integrated shoe tongue, the shoelaces need extra support to be fixed. The transparent TPU adidas logo improve the supporting performance.

The extending shoe heel is convenient for putting on and taking off.


Adidas Ultra Boost 21 uses Primeknit technology. The fitness and supporting performance of Primeknit material is good. It also has good air permeability.

The vamp and shoe-pad uses Primeblue materail. Primeblue is made of Parley ocean plastic. It’s a kind of recycling environmental protection material.

The unit weight of EUR40 is 309g. It’s not light. As the target location of Adidas Ultra Boost 21 is not racing. It’s suitable for jogging.

The drop height of forefoot sole and rear sole is 10mm. The height of forefoot sole is 20.5mm, and the height of rear sole is 30.5mm.

The drop height of Adidas Ultra Boost 21 is high. Normally the drop height of racing shoes should below 5mm. But the high Boost of rear sole can absorb the impact force. It’s suitable for the beginners.

Boost Insole:

As the official said, the insole material of Adidas Ultra Boost 21 is increased 6% than last generation. The 6% is the result after trail and error. So we can see that the insole of Adidas Ultra Boost 21 is thicker.


The Adidas Ultra Boost 21 uses Continental Stretchweb outsole. There is a big area of semi-transparent rubber.

The characteristics of this kind of outsole is the noise when running.

Another core upgrade is the new Adidas LEP(Linear Energy Push) system. Comparing with normal lacing system, it increases about 15% bending rigidity of forefoot. This kind of design is beneficial to running.


Court: Plastic track and road.

Speed: 4’30

Distance: 15km

The sole is very soft when running in soft plastic track. It’s very comfortable. It’s not too soft and not too stiff when running in stiff road.

For me, Adidas Ultra Boost 21 is comfortable when running at the speed 4’30.


The insole of Adidas Ultra Boost 21 is thickened. It improve the hardness. With LEP system, Adidas Ultra Boost 21 is more suitable for running.

With the wide outsole, thick Boost insole and the reinforced frame,  Adidas Ultra Boost 21 is suitable for the runners with heavy weight.

If you want to choose a pair of running shoes for aerobic pace training, you can choose Adidas Ultra Boost 21.

Adidas Ultra Boost 21 has 24 colorways. You can find your favorite colorways.  Adidas Ultra Boost 21 is not only a pair of sneaker, but also a pair of fashion casual shoes.