Nike Air Zoom Structure 21

9.8 score
[Editors rating (9.7) + Users rating (10.0)] / 2 = (WalkJogRun) score (9.8)/10

Editor rating: 9.7 / 10
User's rating: based on 3 user ratings
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Nike Air Zoom Structure 21 Review Facts

Nike proves time and time again why they are on the top of this industry with how well their series do throughout the years. The Zoom Structure 21 is the 21st iteration of this series and it is stronger than ever.

The Nike Zoom Structure 21 can compete with the best stability running shoes in the industry, thanks to its clever design and use of materials. This running shoe seems to have it all from looks to quality and performance, and for an affordable price as well.

Editor's Pros & Cons
  • Highly breathable, but sturdy
  • Provides cushioning and improves balance
  • Excellent traction and grip
  • Great on wet or dry terrain
  • Terrific colorways
  • Excellent arch support
  • Heel lacks support
  • Stiff out of the box


The forefoot area features the Air Zoom technology in the form of tiny air pockets. Not only do these air pockets provide excellent traction on many different surfaces, but they also help the runner plunge him/herself forward during toe-off with incredible lightness and springiness.
Adding greatly to the traction this shoe delivers is the BRS (Blue Ribbon Sports) 1000 carbon rubber, which is a highly durable material as well, making for a long-lasting running shoe.
Although they might seem a bit stiff at first, they provide a seamless transition throughout the gait cycle.


When it comes to the midsole, Nike kept it pretty much the same as the Zoom Structure 20. The midsole is made out of a combination of Phylon and Cushlon foams respectively.
The Phylon foam is the one responsible for the stability portion of the midsole. It is a very light and responsive EVA foam that stretches along the inner portion of the midsole, giving excellent stability and support to the shoe.

The outer portion of the midsole is made of Cushlon, a mix of Phylon foam and rubber additives, which are in charge of the bounciness of the shoe. Together with the Phylon foam, they are Nike’s Dynamic Support System, balancing support and cushioning in a very clever way.
Nike also introduced a gender-specific crash pad into the heel portion of the midsole, which helps with overpronation problems and absorbs the shock of impact efficiently, making the transition feel smooth throughout the gait cycle.

The forefoot portion doesn’t lack in anything either. Nike’s Air Zoom Technology features tensile fibers inside the air unit, which stretch out and compress during contact upon impact, much like a rubber band, providing great forward propulsion for the runner with every step.


The upper is where all the innovations come in for the Zoom Structure 21. It’s made out of Nike’s Engineered Mesh, called the Wrap-Knit Mesh. This type of mesh material is very lightweight, which is why the Zoom Structure is lighter than its predecessor. It contains monofilament yarns, which are interwoven into the mesh with minimal overlays and many pores through which the air can circulate freely, making the upper of the Zoom Structure not only extremely lightweight but highly breathable as well. In addition, it is also very flexible and stretchy, making it suitable for both narrow and wide footed runners.

Another thing Nike improved in the Zoom Structure 21 is the lacing system. Namely, the laces are flat, instead of round, which help combat the mid-run untying of the laces that many runners find annoying. They also go through loops instead of eyelets. Nike also included its Dynamic Fit with Flywire cables. However, the Zoom Structure 21 features only 8 Flywire cables per shoe, unlike many other models. They are also limited to the rear of the shoe, making for a snug and secure fit around the ankles without putting pressure on the top areas of the feet.
The padding on the tongue and heel portions of the Zoom Structure 21 is not on the plush side, but it does provide enough cushioning. Nike also included a bootie made of mesh for a more comfortable and sock-like fit. One thing that users noted was that the heel could use a little more padding for extra support.


The Nike Zoom Structure 21 is a little heavier than some other running shoes, but they are lighter than the Zoom Structure 20, thanks to the material of the upper. They weigh 10.4 ounces for a men’s US 10 size, which is still pretty lightweight, considering that they are stability running shoes. Customers reported that they didn’t feel weighed down by the Zoom Structure 21 and could maintain a springy run.


The Nike Zoom Structure 21 features a Flymesh upper, consisting of monofilament yarns with minimal overlays and plenty of pores scattered throughout the shoe, that allow the free circulation of air from the forefoot to the heel of the shoe. This proper ventilation helps keep the feet cool and dry for the entirety of the run.


Many runners had doubts about the Nike Zoom Structure 21 being a comfortable running shoe since it is categorized as mainly a stability running shoe. However, they were pleasantly surprised when they discovered that Nike has thought of everything.

Starting from the midsole, which is a combination of Phylon and Cushlon foams, Nike fused support and stability with comfort in an effortless manner. While the Phylon foam takes care of the stability portion, the Cushlon provides just the right amount of cushioning and bounciness without taking away from the structural stability of the shoe.

The upper of the Zoom Structure 21 plays a big part in providing comfort for the wearer. Made from Nike’s Engineered Mesh, the upper is ultra lightweight and incredibly breathable. Thanks to the strategically placed Flywire cables, it wraps around the feet like a sock without putting pressure on the top areas of the feet. The tongue and collar of the Zoom Structure 21 have a decent amount of padding as well, making the shoes fit comfortably on the feet. The toe box is also quite roomy without letting the feet move from side to side too much during use, which made both wide and narrow footed runners happy.

The only thing some customers noticed was that the removable insole made of blown foam felt a little stiff, so if that kind of thing bothers you, you can always insert your own preferred insole.


Nike is very well known to be a brand that pays special attention when it comes to the looks of their shoes. The Zoom Structure 21 is no exception to this. It comes in many different color schemes and features a gradient effect, starting from a darker color at the heel of the shoe and slowly fading into lighter colors towards to forefoot. One thing that really appealed to customers was that the midsole also features this characteristic, making the Zoom Structure 21 look modern and stylish.


The Nike Zoom Structure 21 is all about durability. Starting from the hardy double rubber outsole with a waffle-like pattern that provides excellent grip and traction on many different types of surfaces, this type of outsole is bound to last and last. Customers reported that they didn’t show any signs of wear and tear even after 50 miles of running in them. The Zoom Structure 21’s estimated lifespan is about 400 miles, which is more than most running shoes on the market.

The midsole is also pretty impressive. The combination of the Phylon and Cushlon foams provides just the right amount of cushioning and support, and since it isn’t all plushed-up, it will keep its original shape for far longer.

The new single-knit Engineered Mesh is super durable as well. Nike was able to construct a quality stability running shoe without sacrificing anything through the process like many others. This new mesh material combined with the Flywire cables is super lightweight and breathable, yet extremely comfortable and durable at the same time.


When it comes to protection, the Zoom Structure 21 will keep your feet secure and stable from shorter runs to long distance running thanks to its durable rubber outsole that grips onto the ground and doesn’t let you slip even on wet surfaces. Combined with the Dynamic Support System midsole, that provides a balanced fusion of comfort and stability, especially in the arch of the foot, this running shoe is excellent for people with overpronation problems, since it won’t cause injuries caused by overpronation such as ankle sprains, shin splints, toe fractures or hip and lower back pain. Additionally, the new Engineered Mesh design with the cleverly placed Flywire cables will keep your feet nice and secure inside the upper.


The Zoom Structure 21’s responsiveness lies in the construction of its midsole, namely the Phylon foam. This type of foam comes from EVA foam and is super lightweight and highly responsive. The Phylon foam is placed on the inner side of the midsole while a Cushlon foam makes up the outer side of the midsole, giving ample cushioning and bounciness to the runner.


The Zoom Structure 21 is praised by many as being one of the best running shoes they have ever tried and no wonder. The sole unit alone was designed to provide the wearer with maximum support throughout use. The rubber outsole grips firmly to the ground and has excellent traction while the midsole keeps the arch of the foot supported, which people with overpronation appreciated the most.

The upper also features improvements which add to the overall support factor of the shoe. Mainly, the new mesh design has minimal overlays while still retaining its structure and the Flywire cables placed at the top part of the feet help keep them snug and in place during the entire run. Perhaps the only place that customers felt was lacking in support is the heel area, which felt too loose for some.


The Nike Zoom Structure 21 is an extremely sturdy running shoe and as such, can be taken out on a variety of surfaces, from treadmills, pavements, roads and tracks to lighter trails as well. This is made possible due to the materials used for this shoe such as the durable rubber outsole with excellent traction, the highly responsive and stable midsole and the ultra breathable and lightweight, yet sturdy upper.


Prices will vary depending on where you want to purchase your shoes from. However, for a quality running shoe that checks all the requirement boxes such as the Nike Zoom Structure 21, the price tag is fairly reasonable. Besides, there are always great deals out for those who are willing to dig a little deeper.


The Zoom Structure 21 is praised by many customers for its traction. This is all due to the construction of the outsole, which consists of a highly durable rubber combination of blown rubber and carbon rubber with waffle-like logs stretching from the forefoot to the heel.


Being a stability shoe first, the Zoom Structure 21 might seem too stiff in the beginning. However, this running shoe has a decent amount of flexibility in the form of tiny air pockets scattered in the forefoot section of the outsole, which help propel the wearer forward. The midsole features a Cushlon foam on the outer brim that provides the wearer with enough cushioning and bounciness, while the upper conforms to the shape of the feet, providing a natural ride. If it seems too stiff at first, it might just take some getting used to.


As mentioned before, the Zoom Structure 21 is an excellent stability running shoe. The heart of its stability lies in the midsole, more precisely the Phylon foam which keeps the feet stable, especially in the arch area, which is great news for people with overpronation problems. However, people with regular pronation will also enjoy the stability this shoe has to offer. Additionally, the upper keeps the top part of the feet nice and secure with its Flywire cables.


The Nike Zoom Structure 21 features a standard 10 mm drop, which is the usual with many running shoes, so there are no surprises there.

Key Features

  • Engineered mesh with monofilament yarn and minimal overlays for a lightweight and breathable yet sturdy upper

  • Strategically placed Flywire cables to help keep the feet secure

  • Blown foam removable insole

  • Dynamic Structure System midsole

  • Durable rubber outsole with hexagonal logs and tiny air pockets

  • 10 mm drop
  • Bottom Line

    The Zoom Structure 21 is a moderately lightweight stability running shoe. It features a durable rubber outsole with hexagonal logs which provide excellent traction. The midsole is a combination of two types of foam, a stable and responsive Phylon foam and a cushioning Cushlon foam for maximized stability and comfort, while the upper is a type of Engineered Mesh that is highly breathable, yet sturdy. The only downside is the lack of heel support, according to some customers.
    The new Zoom Structure features a modern design with a gradient finish, which many customers applauded. For a stability shoe of this proportions, the Zoom Structure 21 is fairly inexpensive.
    All in all, the Zoom Structure 21 is an excellent stability running shoe that everyone should try.