Nike is one of the most innovative running shoe brands out there. While they do stick to some popular models for years (ie the more than 30 years history of the Nike Pegasus), they constantly introduce new technologies and with them, new names and classification.

This article will help you make sense of all those model names, technical jargon and finally understand which of Nike’s running shoes is meant for which runner.

Nike Running Shoes Categories: Neutral, Stability, Racing, Barefoot-like and Trail

Up to last year, Nike classified their shoes based on the cushioning technology. Air Zoom shoes fit into a “Run Fast” category thanks to the responsive feel of that tech; shoes with the soft Lunarlon foam were in the “Run Easy” category and the Nike Free soles belonged to the “Run Natural” category.

Since last year’s Breaking2 effort, the Oregon-based brand has come up with so many new technologies that this classification does not work anymore and they seem to have returned to a more traditional way of segmenting their line up.

Neutral Ride

In the “Neutral Ride” category we find three shoes for daily training for runners with no particular support needs.

Stable Ride

This is the category for runners who not necessarily over-pronate, but that need a shoe with a little more support than a purely neutral one. The category in general seems to be losing relevance in the market – and there does not seem to be a lot of innovation from Nike in here either.

Our guess is that after the introduction of the new technologies and the amazing response from the running community, Nike will soon apply the new techs to new shoes in this area.

Racing Shoes

Nike has definitely upped their game in the racing department since last year’s Breaking2 attempt. Two shoes in particular enter the market and got sold out pratically immediately.

Barefoot-Like Running Shoes

Before minimalism was a thing and before barefoot runners started burning their shoes, Nike quietly introduced the Free range with a simple idea: a shoe to add to your training rotation, to stimulate your own foot muscles and balance. So while your daily training and racing shoes might protect you, once in a while you should introduce some extremely flexible shoe so that your feet can train naturally.

Nike Trail running shoes

Last, the selection of Trail shoes. To keep it simple, there are only two:

An overview of Nike running shoe upper technologies

Understanding the meaning and design principles behind the tech names will help you navigate through the catalog faster. Here’s an overview.

Flyknit

Flyknit is a special woven fabric that makes the upper of a shoe feel like a sock, by placing yarns and knits strategically around the structure in order to support the foot of the runner when needed and leave it free everywhere else.

Flyknit running shoes are lightweight: a light yarn replaces multiple stitched or glued panels. Flyknit also allows for extremely precise upper fit, being able to seamlessly integrate tight-knit areas where support is needed and wide-knit areas to allow for flexibility.

Flyknit is environmentally friendly as it produces 60% less waste than traditionally constructed running shoe uppers.

This technology is Nike’s latest, so expect to pay a premium for Flyknit shoes.

Most notable examples of Flyknit shoes are the Flyknit Racer (as the name implies, a fast and light shoe for racing distances all the way to the marathon) and the Nike Free Flyknit (an extremely flexible and lightweight running shoe to strengthen and train the muscles in your feet).

Engineered Mesh or Flymesh

Engineered Mesh (sometimes called “Flymesh” by Nike) is a lightweight mesh construction that is – compared to traditional mesh fabrics – more breathable and is at the same time both more durable and flexible.

Engineered Mesh features more prominent perforations than traditional mesh. It is a completely different construction than the previously mentioned Flyknit and shoes with Engineered Mesh usually have a lower price-point.

You’ll find Engineered Mesh on many of the Nike’s most popular running shoes. Notable ones are the Nike Zoom Structure and the Nike Lunarglide.

An overview of Nike running shoe midsole technologies

Midsoles of running shoes are made of foam. Each company has their own trademark foam mix that tries to achieve the following: be as lightweight as possible, be soft in order to absorb the impact with the ground, be elastic (in order to compress on impact and release propelling you forward), be durable (foam does deteriorate with use, so all foam materials need to be engineered to maintain its characteristics for a decent amount of time).

Nike Lunar Foam

In 2009, Nike introduced Lunarfoam, sometimes referred to as Lunarlon. Lunarlon is Nike’s softest, most cushioned and lightest foam compound.

Lunarlon is usually encapsuled in a container of harder Phylon foam in order to give structure and support to the foot where needed.

In short: choose Lunarfoam if you are looking for a soft, plush, cushioned ride.

Phylon

Phylon is Nike’s basic foam material. It is made of EVA Foam Pellets that are compressed then heat expanded & then finally cooled into a mold. It is easy to identify by the fine wrinkles the foam shows after usage.

Cushlon

Cushlon is a mix of Phylon and rubber additives that makes it lightweight and responsive.

Nike Air

Everybody knows Nike Air. That’s how Nike got big in the 80s in the first place. But do you exactly know what Nike Air is ?

Nike running shoes in the “Air” category often use Cushlon foam in their soles. Soft and resilient, this foam has 2 limitations: it is quite heavy (as most foam is) and it is not as “bouncy” as many runners expect their shoes to be.

The solution? Cutting off areas of the Cushlon-foam-made midsole and filling them up with plastic bags filled with “Air” (Nike’s secret gas compound). What this achieves is to reduce weight (by replacing the heavy foam with a very lightweight “airbag”) and to increase cushioning (being these airbags softer and springier than the Cushlon foam).

Depending on the shoe, you can have Nike Air bags in the heel, the toe, or both.

Air bags come in 3 formats: Air, Air Max and Zoom Air.

• Nike Air -> the most common, medium sized air bags that fit well especially under the heel.
• Air Max -> very thick and highly cushioned bags of air. In our opinion too unstable for proper running, mostly used on lifestyle shoes.
• Zoom Air -> the thinnest units, ideal to fit in low-profile shoes. They were initially developed for soccer shoes, where normal Air bags would not fit inside the ultra-thin sole

Nike Free

Nike Free is a concept. Started around 2005, the idea was to create a shoe that is so flexible that leaves the foot completely free to move in the most natural way.

Some people object that the Frees are still very cushioned shoes, therefore preventing the runner to have a true feeling for the ground below them.

While this might be true, the extreme flexibility of the Free sole unit, combined with very open-mesh and unconstrained upper make for a treat.

What do the numbers next to a Free shoe mean?

Nike abandoned the use of numbers in the Nike Free line in 2016, when they completely revamped the category.

Originally Nike Frees came in different versions, depending on how flexible they were. Their flexibility was ranked on a scale that goes from 1.0 to 10.0, where 1.0 means “bare feet” and 10.0 is a traditional running shoe.

In 2016, with the coming of the new auxetic construction, the Nike Free range is completely new and the numbers are gone. We’ll go through the line and the models in a minute. Keep reading!

The new principle behind the Nike FREE line of running shoes is called “auxetic design”.

When your foot hits the ground, it expands both in length and width. Picture bouncing a ball on the floor: it squeezes and deforms because of the impact, then the opposite happens while it bounces back.

Nike engineers were looking for a way to design a midsole so that it would expand in both directions during the foot strike. The issue is that most materials, when stretched in one direction, become smaller in the perpendicular direction. Again think of an elastic band. If you pull it to stretch it long, it will most likely become narrower in the middle.

The auxetic design, characterized by the triangular cuts you see in the picture, allows the sole to do that. A stretch in one direction will equate to a stretch in the other.