Verdict from 9.1 hours of research from the internet

6 reasons to buy

  • One of the consumers said that the design of the product was lovely and appealing.
  • A runner commented that the cushioning was bouncy and flexible.
  • The shoe was comfortable, according to a reviewer.
  • A lot of testers mentioned that the breathable nature of the Nike Air Zoom Structure 21 Shield was reliable.
  • This shoe was lauded for utilizing durable materials.
  • A runner noted that the rubber sole provided enough traction, even in wet conditions.

1 reasons not to buy

  • According to one of the users, the shoe was expensive.

Bottom line

Many consumers commented that the Nike Air Zoom Structure 21 Shield was comfortable, breathable and durable. They were also happy with the product's flexible and bouncy cushioning. Although one consumer said that the shoe was expensive, others still recommended it mainly because of its appealing and great-looking design, as well as the excellent traction that it provided.

Tip: see the best running shoes.

Expert reviews:

User reviews:

  • The Nike Air Zoom Structure 21 Shield is a road running shoe that is strategically designed for overpronators. The upper area is constructed using Flymesh and a DWR (durable, water-repellent) coating, which ensure lightweight breathability and protection against mild water infiltration.
  • It features the Waffle lugged outsole that aims to provide added traction and durability. This material is essential in efficiently handling all the runner's running needs.
  • The water-repellent version of the Structure 21 uses the dual-density midsole. This technology offers support and shock absorption.

The Nike Air Zoom Structure 21 Shield is a stability shoe that is designed for runners who overpronate. It is best used for road running activities. When it comes to size, the product has a standard shoe length. The available widths are medium for both the men and women's versions.

Utilized in the outsole is the Duralon Blown rubber that is located in the forefoot area. This technology's purpose is to provide enhanced cushioning and comfort.

Along with the Duralon Blown rubber is the Waffle outsole design. This component of the shoe is meant to improve cushioning and multi-surface traction.

It also features the BRS 1000 carbon rubber, the goal of which is to add more grip and durability. This durable rubber material is also used in the new Air Zoom Structure 22.

To provide a smoother ride, Deep Anatomical Flex Grooves are utilized. The purpose of this material is for added mobility and flexibility.

Phylon and Cushlon foams are fused together to create a dual-density midsole. These materials are located on the medial and lateral side to promote a more resilient cushioning and softer feel.

At the bottom of the heel is the crash pad. It is a gender-specific, decoupled unit that aims to reduce impact shock and correct overpronation.

Located in the forefoot area is the Zoom Air unit. It is made up of a responsive insert that is focused on providing a springier cushioning.

The upper area utilizes the 360-degree Reflectivity. This component of the shoe makes it highly visible, especially in low-light conditions.

The Flymesh is composed of monofilament yarns that aim to improve breathability and create a lighter material when compared to previous models. It’s treated with DWR (durable, water-repellent) coating to stave off splashes and mild exposure to water.

The last two eyelets that cover the midfoot have Flywire cables. The goal of these materials is to provide unmatched fit and lockdown while maintaining a lightweight structure.

The Dynamic Fit technology, which includes an internal arch band and the Flywire cables, is integrated into this running shoe. This design is centered on providing an adaptive fit and total lockdown support.

An inner mesh cleatie design is added to give a soft and sock-like fit. Notches on the side of the tongue unit allow easy on and off.

The upper also utilizes an internal heel counter. This technology wraps around the Achilles to provide a more secure fit.

Size and fit

True to size based on 9 user votes
Small (0%)
True to size (89%)
Large (11%)
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Same sizing as Nike Air Zoom Structure 22 Shield.

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How Air Zoom Structure 21 Shield compares

This shoe: 85
All shoes average: 86
53 98
This shoe: $135
All shoes average: $119
$40 $350
This shoe: 10.4oz
All shoes average: 9.5oz
3.5oz 16.2oz
Jens Jakob Andersen
Jens Jakob Andersen

Jens Jakob is a fan of short distances with a 5K PR at 15:58 minutes. Based on 35 million race results, he's among the fastest 0.2% runners. Jens Jakob previously owned a running store, when he was also a competitive runner. His work is regularly featured in The New York Times, Washington Post, BBC and the likes as well as peer-reviewed journals. Finally, he has been a guest on +30 podcasts on running.