The outsole rubber is laid out in a familiar format. The outer side has the ‘crash rail’ strip with multiple flex grooves, a design first used on the Pegasus 31. The Nike Structure is all about balance. The upper has smooth interiors and fits well. The inner strapping system which was re-introduced on the Structure 20 finds its way into the 21, and that’s a good thing. The Flywire cords are restricted to the rearfoot, and this means that the midfoot is secured entirely by the straps. The lacing panel and the Flywire areas are now reinforced with a thinner and transparent laminate which also helps reduce weight. Forefoot strikers will find the ride to be very responsive due to the large Zoom Air bag. Conversely, heel strikers will experience a flat and unresponsive rear-end. A Zoom Air bag also makes the forefoot stiff so runners who want a flexible shoe should bear this in mind. The last year’s Structure 20 was an improvement over the 19. Coming to think of it, this should be the case with each update. But given the long lead-times involved in the design and delivery of a shoe, a new model isn’t necessarily an improvement over its older version.

However, the Zoom Structure 21 is significantly lighter than the 20. The heavier weight of the latter means that users are more likely to suffer from foot fatigue. The Flymesh upper of the 20th version provides structural support while promoting air circulation throughout the shoe. In contrast, the 21st iteration features a lightweight seamless wrap-knit mesh which envelops the foot and expands to mould around the shape of the foot for a second-skin fit. Alternative Nike Running Shoes The Nike Zoom Span 2 is much nimbler shoe than the Structure while being cheaper and lighter. The midsole has a hint of support, and the upper feels fast trainer like. It is one of Nike’s most under-rated shoes which also happens to be great value for money. RECOMMENDED ROTATIONFor reasons best known to Nike, the Zoom Structure has rarely had a plushly padded tongue or heel lining. Thankfully, the Structure 20’s tongue quilting is nowhere as bad as the Structure 18. Overall, the Nike Zoom Structure 20 and 21 are responsive, well-cushioned and deliver an energised ride with smooth transitions. They are engineered to meet the needs of overpronating runners with plenty of midsole foam cushioning to keep wearers stable and support the collapsing arch. Additionally, both models also accommodate users with broader feet by offering wider width sizes for buyers. If our memory serves us right, the Zoom Structure 18 was the first Nike running shoe to feature Flymesh. This upper material is made of a single layer of engineered mesh and borrows aesthetics from the Flyknit.

In his experience the older versions with the medial cage held up much better than the Dynamic Support in the 20 (and 21), which compressed inward as the miles were added, while the outsole durability remained the same despite its overhaul in structure. The Nike Air Zoom Structure 22 is a running shoe designed for people with flat feet. It helps runners to train with appropriate support. Plantar fasciitis or flat feet problems can be treated by regular stretching but wearing a shoe that supports the arch and heel correctly is a more lasting solution and that's where the Zoom Structure 22 comes in. The product is also a good choice for anyone who trains daily with a view to covering longer distances as it its hard-wearing and offers good support over an extended period of time. Support On Hard Surfaces The new Structure is nearly an ounce lighter than its predecessor, thanks to a new knitting technique, with the same magical balance of stability and cushioning—not too stiff but with the added support overpronators need. If you’re looking for a stable, relatively lightweight shoe that can handle a ton of miles, well, you don’t have to look any further. Runner’s World Wear Testers Say The Structure 21 has a softer interior feel than the 18, 19, and 20 due to the updated mesh which also has better breathability. RIDE QUALITY AND BEHAVIOR From the outside, the Structure 21’s midsole appears to have more than two densities. But that effect is produced by the midsole paint rather than separate foam sections.

Nike Air Zoom Structure 22

I know what Nike is trying to do with the Structure 25 and the latest InfinityRN 4: they want to push runners who need support away from the InfinityRN to the Structure and vice versa. The ride quality hasn’t changed at all, so the upper gets all the new updates. That being said, all changes are design and material related. Little has changed in how the Structure fits.

The Structure 21 is a support shoe with a harder medial post. For this reason, we’ll exclude products like the Nike Lunarglide or the adidas Supernova ST from this list.

Nike Structure 25 Upper

There’s plenty of outsole rubber, the midsole is relatively firm, and the upper is sleeved and double layered. These attributes help make the Structure durable. My podiatrist informed me that one’s preference in drop height of a shoe relates to one’s Achilles flexibility—but no two people are alike in terms of an exact “if this then that” diagnosis: you’ll have to try out a few different types to see what really works for you. Nike Zoom Structure 21 General Info The Streak 6 is a lightweight Nike model fitting for shorter road races and distances for up to a half marathon. The Structure has a firm ride, so the Lunarepic Low makes a good rotational choice as a softer shoe. The ride is cushioned yet supportive, making the Lunarepic suitable for longer runs. The upper has a narrower feel due to the Flyknit upper. Two shoes from New Balance complement the Structure 21 perfectly. The first is the newly released 1260V7 – a cushioned stability model. The second shoe is the 1500V3, one of our favorite road racers which combine lightweight cushioning with mild support. SIMILAR MID-PRICED SUPPORT SHOES

I could feel the airbag under the forefoot which has always been a characteristic of the Structure series. It was comfortable right out of the box and didn’t need any break in period. The new midsole made Structure a few mm higher (while maintaining a 10mm drop from heel down to toe height), and ironically, I kept feeling like I wanted the shoe to be closer to the ground, before I even learned about this change. My first impression of Structure 21 was that it’s a shoe with a flat insole (I like at least a little more arch) that was otherwise unremarkable (which isn’t always a bad thing). The midfoot upper really snugged up nicely, though—that surprised and impressed me. Changing the engineered mesh to a lighter and vented kind leads to a significant weight reduction. The Structure 21 is nearly an ounce lighter than last year (for a size US 10). Minor improvements have been made to the laces (flat instead of round) and the Flywire cord placement. LOWER PRICED ALTERNATIVE?

SUMMARY, AND CHANGES BETWEEN THE STRUCTURE 20 AND STRUCTURE 21

The Structure 23 felt like a supportive neutral trainer, not a “true” stability trainer. I reviewed both the Structure 23 and 24 (the 24 was only an upper update). I found them to be the best versions of the Structure to date because they felt stable and supportive without the firm ride or poking arch sensation that you normally associate with stability trainers. When I walked around in the Structure 25 for the first time, it was noticeable how much more it felt like a stability trainer than the last 2 versions. There was a prominent arch sensation which wasn’t there since the Structure 19 but it wasn’t painful or uncomfortable. The heel has a hard counter which is non-collapsible, and the toe-box has a flexible internal bumper. The rearfoot rides flat because there’s nothing there except for the dual-density foam and the outsole. Though the open foam area below the heel plus the removable insole helps with the cushioning, the rearfoot is noticeably firm.