Nike Infinity RN4 Introduction

When I reviewed the Infinity Run 3, I said that it was in dire need of a facelift because it had the exact same midsole as the first 2 versions. No matter how good the ride is, 3 years of the same thing will get boring. Midsole foams are advancing so fast and they become outdated very quickly. This is why Nike updates the midsoles of popular shoes like the Pegasus and the Vaporfly every 2 years.

The Infinity Run versions 1-3 were neutral trainers but they felt like stability trainers due to the poking arch sensation. After testing, I used them for casual sneakers for work, not for running. I prefer my trainers to have softer, more lively rides. The Infinity Run felt a bit bland.

Version 4 of the Infinity Run gets the major overhaul that I wanted last year. It features Nike’s brand new ReactX midsole foam which has never featured in a shoe before. The outsole and upper have also been redesigned.

The InfinityRN 4 isn’t classified by Nike as a max-cushioned trainer but it’s priced like one. At $160, it competes with most max-cushioned trainers. The Nimbus, Glycerin, Triumph and New Balance 1080 are also priced at $160.

The weight of the InfinityRN 4 has increased to 11.2 oz (319 g). This is an entire ounce (28 g) more than the previous version. Each year, the shoe gets heavier and heavier. They’ve also changed the name this year to the InfinityRN, which was previously Infinity Run.

Nike Infinity RN4 First Impressions

My first run was a 17 kilometre recovery run. It felt like the recovery pace was perfectly suited to the InfinityRN 4. The ride felt slightly softer than the previous versions but it still felt a bit too firm for a max-cushioned trainer.

I was disappointed with ReactX because it felt really similar to regular React foam: dense, without much energy return. Overall, it was more comfortable than the Infinity Run 3.

The upper of the InfinityRN 4 reminded me of the Nike Free RN Flyknit 3.0 while the midsole reminded me of the Under Armour Velociti Wind.

Nike Infinity RN4 Upper

The upper of the InfinityRN 4 has a snugger fit than last year’s version with a softer Flyknit that’s more stretchy. It has a narrow fit but is still true to size. The upper conforms to your feet and I find it overall more comfortable but it feels more like a lifestyle sneaker.

The padded tongue is semi gusseted and it doesn’t move around at all during runs. Foot lockdown is very good, even without using a runner’s knot. An internal heel counter provides heel structure and support while the collar is very well-padded so comfort around the ankles is superb.

My least favourite thing about the upper is that it runs warm. It soaks up a lot of sweat as well so it’s more suited to cool climates. It has a new water repellent liner in the toe box but I didn’t get a chance to test it in wet conditions.

The heel pull tab makes a return in the InfinityRN 4 which was missing in the Infinity Run 3 but there are still no reflective elements.

Nike Infinity RN4 Sole Unit

The most important update to the InfinityRN 4 was a crucial one: the heel clip needed to be modified because it extended under the arch and caused a poking sensation in the previous version. In the InfinityRN 4, they’ve removed the clip completely so it’s much more comfortable, especially for runners with flat feet.

I was hoping for something like ZoomX, but ReactX is not a fun foam. It doesn’t compress much when loaded so it feels dense and rubbery. It doesn’t feel energetic like ZoomX, Fuelcell, Hyper Burst Pro or Pwrrun+ and I know that Nike could have come up with something much better considering how much R&D they have at their disposal. This was a missed opportunity in my opinion.

The ride of the InfinityRN 4 can’t match other max-cushioned trainers in terms of cushioning and energy return and the best way to describe how it feels is flat. It’s the kind of no-frills trainer that you just put on so you can get your daily mileage in. I did a 27 km long run in it and it felt really sluggish with an outdated ride.

I only use it for easy and recovery runs. This shoe does not like to go fast. It’s heavy and it has a very flexible forefoot unlike the rockered MaxRoad 6 and the GlideRide 3 which help you to pick up pace if you need to.

The InfinityRN 4 is more suited to heel strikers than forefoot or midfoot strikers and the shoe encourages you to heel strike due to the high amount of cushioning in the rearfoot with much less in the forefoot.

The words “supportive” and “stability” are mentioned quite often on the InifinityRN 4’s product page on the Nike website. It has a fairly wide midsole base with raised edges that guide your feet so landings feel decently stable but I wouldn’t classify it as a stability trainer. It feels like a neutral trainer.

The entire outsole now has thick, waffle rubber coverage so the midsole foam doesn’t get scuffed anymore. This is where the majority of the ounce of extra weight comes from.

There’s very little outsole wear showing on my pair and I think the InfinityRN 4’s outsole can rival the Pegasus 40 in terms of durability. Traction is better than the previous versions because the lugs are raised and the outsole is no longer completely flat.

Nike Infinity RN4 Conclusions

After the 1st run, I didn’t look forward to running in the InfinityRN 4. Even though it has been completely redesigned, it still lacks excitement. The new midsole doesn’t provide enough energy return and it doesn’t have a unique ride. ReactX doesn’t feel like a new-age midsole foam and it needs to be much softer.

InfinityRN 4 is the best version so far in the series because it has the most comfortable upper and is arch friendly, however it’s disappointing that it has picked up an ounce of weight. It feels like a heavy shoe during runs because there isn’t a prominent rocker to make transitions more efficient.

The InfinityRN 4 is an average running shoe with no major flaws but at $160, I can’t recommend it when there are much better max-cushioned options, like the Skechers MaxRoad 6 which is only $130. The MaxRoad 6 has more cushioning, a softer ride, and much more energy return.

In many ways, the InfinityRN 4 feels like Nike’s version of the Ultraboost Light: a lifestyle trainer which you can also use for the occasional run. They both have knitted uppers, firm rides and are overpriced.