A first look at the Nike React Infinity Run – Runner’s World (UK)

The Nike React Infinity enters the market making a bold statement – that it will help prevent injury in runners. An apparent upgrade from the brand’s first and second iteration of the React shoe is the reason behind this claim, so we sat down to chat with Brett Holts, the vice president of Nike Running to find out what they’ve actually changed and what this new shoe is all about.

Holts begins by going into detail about the study behind the shoes’ claims. Conducted by the British Columbia Sports Medicine Research Foundation (BCSMRF), researchers divided 226 runners of all ages and abilities into two groups as they trained for a half marathon. Half wore the Nike Structure 22, a traditional motion control shoe, half wore the new Nike React Infinity Run. The findings showed that runners wearing the React Infinity had a 52% lower injury rate than in the motion control shoe, with wearers confirming that they felt less pain in their knees and feet.

According to Holt, this was one of a series of studies “testing and comparing a traditional solution versus a new solution that’s prioritising support and stability in a new way”. He believes the study is significant enough to be applied to all runners, telling Runner’s World, “I think it’s important that it ranged across runners of all levels. For some runners this was their very first half marathon. This isn’t an innovation or a solution that’s being positioned specifically for our most elite athletes like a Vaporfly would be. We really want this product to be positioned against a runner who might be new to the sport, or who might be thinking about joining the sport.”

We’re dubious (some more than others in the office) as to whether the study is significant enough to be applied to all runners, however the study is significant for one reason; a traditional structured shoe needs drastic rethinking and perhaps the Nike React Infinity Run is a first step forward in this?

How is the shoe different?

Looking at the React Flyknit and the React Infinity Run side-by-side there are some noticeable differences; the toe-box looks wider and the heel extends further back from the shoe (much like most Nike shoes now but without the hard point as seen on the Pegasus, Peg turbo, NEXT% etc).. “We are taking a lot of learnings from what’s really worked in the Vaporfly” Holts explains, “obviously the Infinity React is not tuned to be a racing shoe, but we are taking learnings in terms of the total amount of foam underfoot, the stacked heights and also some of the geometry, specifically in smoothing out the transition through the midfoot and getting the foot on and off the ground quicker, which we’ve found to make runners in the Vaporfly more efficient.”

When the brand launched the React Flyknit in January 2018, a lot of the focus was on the cushioning, specifically the brand’s new supportive React foam. Two years later, this is still very much something Nike are shouting about – they’ve added 24% more to the Epic React. “This provides even more cushioning and even more support to the runner” Holt explains, “we believe that’s actually what’s contributing to the protection and keeping runners healthy and helping to reduce some of those chronic run related injury cues”. With the extra foam comes a larger stack height, to give runners more underfoot cushioning – around 34mm in the heel and 25mm in the forefoot. In order to keep runners stable, the structure of the shoe has changed too; “what we call the nets or the width of the heel is significantly wider than where we’ve been with the React in the past. That’s just to create a more supportive and stable platform both in the heel and then specifically also in the forefoot.”

The third significant change is what Holt’s calls the “rocker geometry”. Similar to the Vaporfly, the React Infinity has a more exaggerated heel to toe rocker. “One of the things that we want this product to do and to help keep you healthy is an efficient transition in strides. We really want to get your foot on and off the ground quicker to move you through that transition.”

Despite the extra foam, the shoe isn’t too heavy – 293g for a men’s size 10 and 230g for a women’s size 8 and according to Nike, is best suited to “the kind of runs that don’t fall into the silo of interval or tempo, long run or race” – in other words, moderate runs of anywhere between three to 10 miles.

How does the shoe feel on the run?

Jane McGuire, deputy digital editor.

“On the run, the Infinity React feels dramatically different to its predecessors. The flyknit upper on older models was tight to the point of restrictive on my feet. In the Infinity React, the updated Flyknit feels more relaxed and comfortable. The toebox is noticeably wider and there’s some built in, comfortable arch support that wasn’t there before.

While you’re still running on a great deal of foam, compared to the React Flyknit, the Infinity React feels much more stable underfoot. This is partly because of the wider base the toe box and heel provide, but also because of the significant guide rails that wrap around the shoe. On the React Flyknit 2, the only stabilising measures were at the heel with a wrap around the back of the shoe and some heel cups.

On the new shoe, these rails wrap around to the forefoot, plus the iridescent material used for the swoosh isn’t just decorative, it forms a significant amount of the rigidity in the rear of the shoe. The rocker motion is fairly nondescript, the closest comparison I can make is that it feels a bit like that of the Zoom Fly 3 (a shoe I trained for and ran Berlin Marathon in), but compared to something like the ASICS METARIDE, which is a proper rocker, it’s a very different shoe.”

Kerry McCarthy, commissioning editor

“The React Infinity Run may not have launched to the same fanfare as the ‘Kipchoge shoe’ (the Vaporfly NEXT%), but Nike has still gone big on positioning the React not merely as an update or a perfectly decent every addition to your running shoe rack, but rather as a shoe that can help prevent injury.

To which, as a fan of the brand, their recent work and their powers of innovation I respectfully say: balderdash.

As already stated, Nike is a little sketchy on how the shoe can achieve this panacea, and I’ve yet to see a plausible theory behind how a running shoe – from any brand – can do such a thing. Form, gait, conditioning, training load, recovery and other physiological considerations are behind incidence of injury. Since the whole body is involved in the act of running and the shoes merely the bit stuck onto your appendages, it’s tricky to see how anything else could be the case.

In terms of how the shoe performs: it’s perfectly decent but, in my view, unremarkable. It’s rather different from the previous React which was a faster, slimmer shoe for tempo runs and races. The React Infinity Run is definitely a high mileage training shoe – albeit an impressively lightweight one.

The widened platform and guide rails are reassuring; responsiveness is decent; cushioning will appeal to those who value comfort over speed; and the breathability is excellent.

If you’re interested in checking this out, ignore the anti-injury chat and think of it instead simply as a shoe for wider-footed runners who want fuss-free reliability and an excellent ratio of low weight to cushioning for long training runs. Like the Pegasus but chunkier.”

It carries the React name but it’s safe to say it’s more than a new shoe that an updated version. Both Jane and Kerry agreed it would be decent milage shoe, especially as it felt light on the foot, but the new upper split opinions with Jane preferring the more relaxed knit while Kerry felt it lost some of the original snugness that made the older shoes feel more racey.