Adidas Ultra Boost X

Adidas is no stranger to the sports world, especially when it comes to running shoes. They have long released quality shoes, and have also experimented with both style and function in ways that other companies might not be as inclined. The Adidas Ultra Boost X is one of these more experimental shoes. Offering a unique shape, materials, design, and being exclusively for women, the Ultra Boost X is definitely not an ordinary shoe, and this review will cover its different facets.

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Pros & Cons
  • Decently lightweight

  • Optimized for women

  • Made with fairly high-quality materials

  • Unique arch support

  • Comfortable fit

  • Decent price

    • On the higher end of the price spectrum

    • No men’s version

      Key Features
      The outsole of the Adidas Ultra Boost X is a very high-quality carbon rubber. Carbon rubber is frequently used due to its high durability, and ability to resist impacts. The Ultra Boost X actually uses a blend from Continental, a tire making company, meaning that the outsole is extra durable compared to shoes which use standard rubber blends. Like tires, this also means that the outsole has good traction on different surfaces, and even when water is present. The Ultra Boost’s outsole has a Stretch Web design, which was actually debuted in this shoe, after Adidas used extensive research from places like NASA and BMW to better understand tension and impact in running shoes. The Stretch Web design is supposed to shift and adapt with the foot and with each step to better improve flexibility in the outsole, and create a more efficient stride overall. The outsole of the Ultra Boost X is very good, and does its job of being durable and resisting impacts well, while also expanding upon flexibility.
      The Ultra Boost X has a midsole composed of Adidas’ special Boost system, as the name implies. Adidas’ Boost material is pretty unique and is different from most EVA styled foams that tend to make up midsoles. The Boost material is made up of tiny Thermoplastic Urethane, or TPU pellets that are all layered next to each other to make one piece. TPU is somewhere between elastic and hard plastic, making it a great choice for the midsole, as it can absorb impacts while also returning energy effectively. The special way the pellets are layered and placed next to each other also serves to increase the protection and efficiency of the midsole. The Ultra Boost’s midsole also has a Torsion System, which is a pretty common feature of Adidas shoes. This Torsion System basically is just a piece that helps hold the foot in place while running, in order to reduce unsteadiness and stabilize strides. The midsole of the Ultra Boost X is also quite solid, and again offers good materials that fulfill their purposes.
      The Ultra Boost X has a mesh upper that is an Adidas special design called Primeknit. Primeknit is another Adidas experimental design that proved to be very successful and has since found its way into many Adidas shoes. The Primeknit design is done in a way that knits the entire upper in one piece, using fused yarn. This allows for much greater flexibility and stability in the upper overall. Another added bonus is that it allows for better breathability, as the upper is knitted, and not a solid synthetic construction. The upper also contains one of this shoe's signature pieces, the Dynamic Arch design. This special shaping is what gives the shoe its special look, and is designed to help the upper better support the foot by encompassing it in a certain way. Overall, the upper of the Ultra Boost X is pretty solid.
      The Adidas Ultra Boost X is fairly lightweight, coming in at around 8 ounces. Though not extremely light, this is definitely a bit less than the standard 10-11 ounces that many trainers tend to come in. The weight of the shoe is definitely a decent plus, but it isn’t exactly the most amazing feature either.
      Breathability is quite good in the Adidas Ultra Boost X thanks to the previously mentioned Primeknit upper. This upper allows for great circulation thanks to the way it is uniquely knitted into one whole piece. This knitting leaves tiny holes throughout the upper, which allow air to flow in and out of the shoe naturally. The Ultra Boost X is good in the breathability department and shouldn’t see too many troubles with sweat buildup and odor.
      The Adidas Ultra Boost X is very good in the comfort department due to several pieces within the shoe. First, the outsole contributes via its special Stretch Web design. As mentioned before, this design allows the shoe to flex and move with each step as is needed, for a more seamless and natural stride. This, of course, contributes to comfort a good deal. The midsole adds to the comfort of the shoe via its unique Boost material. This material absorbs impacts and redistributes them well, stabilizing each step and making runs less harsh on the feet. The torsion system in the midsole also helps with comfort, by securing the foot and preventing slips or twists. Finally, the upper provides comfort once again with its Primeknit design. This knitted design allows air to flow in and out and also secures the foot snugly while still maintaining mobility. These all are very nice features when it comes to comfort. The Ultra Boost X is a pretty comfortable shoe overall thanks to these factors.
      Adidas shoes tend to be top of the line when it comes to style, and the Ultra Boost X pretty much follows this trend as well. The Ultra Boost X however, does have a unique curvature to it that many other shoes do not. While it looks pretty stylish with the curve, some might not find it as appealing. When it comes to the overall look, however, the shoe has a slick design that is very attractive. It also has a huge range of colors, from Core Black/Glow Orange to Trace Pink, which means there is likely a color for everyone. Because of the extra curvature, it might be difficult for some to double the Ultra Boost X as an everyday shoe, though it should be doable for those that don’t mind the slightly more athletic look. Overall, the Ultra Boost X is a fairly stylish shoe.

      Durability is quite good as well in the Ultra Boost X, due to the midsole, outsole, and, to a lesser degree, the upper. The midsole’s source of durability is once again the Boost material that comprises it. The TPU pellets are quite good at maintaining their shape, even after being exposed to many impacts. This helps the midsole provide good cushioning even after extended use. The outsole remains durable thanks to its Continental quality rubber. This rubber is essentially equivalent to tire rubber blends, which last for countless miles. The outsole shouldn’t see too many problems with wear and tear as a result. The upper’s durability comes from its knitted design. The knitted design is less likely to rip than other uppers that are made of several pieces. Durability is quite solid in the Ultra Boost X overall.
      The protection offered by the Ultra Boost X is decent though not amazing. The main sources of protection are the midsole and the upper. The midsole protects the foot via the Boost material once again. The TPU pellets absorb shocks and impacts, which of course is beneficial for protecting the feet from damage that can occur from running long distances. The torsion system in the midsole also helps protect the feet from slipping and twisting, which is another nice protective measure. The upper protects the feet by stabilizing them well, and preventing dirt and debris from getting into the shoe. Apart from these features, the Ultra Boost X doesn’t do too much to protect the feet, but it does a decent job despite that.
      Responsiveness is fairly good in the Ultra Boost thanks to the midsole and also the special curved design. Once again, the midsole’s Boost design and TPU pellets play a role. They return energy quite well, partially due to their makeup, and partially due to the strategic distribution of the pellets throughout the midsole. The curvature of the shoe also contributes by providing different levels of contact with the ground and at each point in the stride. The main purpose of this is for better support and efficiency. Thanks to these pieces, responsiveness is decent in the Ultra Boost X.
      The main parts of the shoe that add support are the upper and the midsole. The upper’s Primeknit design does a great job at supporting the foot by snugly holding it in place. The midsole’s main supporting mechanisms are the torsion system and, of course, the Boost material. The torsion system supports the feet by holding them in place and preventing twisting and sliding. The Boost material supports the foot by absorbing impacts and by being the layer between the feet and solid ground. Support, as a result of the upper and midsole, is fairly good in the Ultra Boost X.
      The Ultra Boost X is like most running shoes in the sense that it shouldn’t have much trouble on a majority of terrains. Performance will likely be best on city terrains like roads and sidewalks, as the Ultra Boost is not a trail shoe, but it should definitely still see pretty good results on other terrains like grass or dirt. Only very extreme terrains might bring about some problems for the Ultra Boost X, and in these terrains more specialized shoes should be used.
      Price is one weak point of the Ultra Boost X. The Ultra Boost X is a pricey shoe, even for a good running trainer. In this case, the quality of the shoe and the unique styling are probably to blame for the high price tag. Deals can probably be found, but even still, for those seeking a lower cost shoe, the Ultra Boost definitely does not fit the bill. The shoe isn’t obscenely expensive by any stretch, it just falls on the higher end of the spectrum.
      Traction with the Ultra Boost functions similarly to the way the shoe handles different terrains. Overall, thanks to the Continental rubber located in the outsole, the shoe grips pretty well on basically all commonly ran on surfaces, and shouldn’t see much trouble on them. Again, in very harsh conditions, like icy areas, or rocky areas, or extreme rain, some caution should be exercised and issues might arise.
      Flexibility is good in this shoe thanks to its upper and its outsole. The upper comes in once again with its Primeknit material. This provides flexibility thanks to the material and the way it is uniquely woven in one cohesive piece. The outsole contributes with its Stretch Web design, which pretty much allows the entire shoe to flex as needed to each runner’s steps and strides. Though these are the only two main features that contribute to flexibility, the Ultra Boost X manages to do a pretty good job overall in this department.
      Stability in the Ultra Boost X is solid thanks to the upper and midsole. The upper does a great job of stabilizing the foot by being a very snug fit, while also maintaining flexibility. It is able to do this thanks to its knitted mesh design. The combination of these two traits goes a long way in making each stride more secure and preventing twists and missteps. The midsole contributes through the TPU cushioning pellets dispersed throughout it. These mitigate the effects of shocks, which makes for a more stable ride overall. The Ultra Boost is fairly stable.
      Thanks to the unique curvature of the shoe, the drop on the Ultra Boost X is a bit hard to measure, as the heel of the shoe remains off the ground in a neutral position. The heel of the shoe itself doesn’t make up too much height, but the drop is a bit unique in this regard.
      Key Features
      - Lightweight
      - Primeknit upper
      - Stylish design
      - Boost cushioning
      - Unique Curvature

      Bottom Line
      The Adidas Ultra Boost X is a pretty high quality, albeit expensive, shoe. For those seeking to try out a unique and stylish trainer with high quality materials, the Ultra Boost X might be the perfect choice. Its only real deterrent is its high price tag, which is definitely a bit off putting.
      Where to Buy
      Backcountry Link
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      Holabird Sports Link
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      By Abbie Copeland
      Last updated:
      Where to buy
      Best offer on: Aug. 01. 2021

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