Run Shoe Tech Terms No Longer Apply

Forty or so years ago the first “stable” running shoe came to market. Fifteen years after the commencement of the stability experiment a new technology emerged that set a new standard in shoe construction. Not much changed from then until very recently, but it’s changing now.

Let’s talk about what’s changing and why the old ways of looking at footwear are no longer valid. But can we take a walk through history, which will help explain where we are today and where we are heading?

The shoe construction motif has carried us over the last quarter century is the basic two-piece midsole: A soft piece of compression molded EVA (CMEVA) with a second firm piece of EVA placed on the medial (arch) side, usually colored grey. Stability shoes became the major driver of the running shoe market. When a new runner with no running experience walked into a running store there was a simple formula for the seller: “When in doubt support them out.”

This wasn’t necessarily conscious, or planned, it’s just what actually happened.

This form of construction is slowly going away. It’s being replaced by geometrically designed, non-invasive guidance shoes we’re calling “organic support”. Before we get to these new shoes how about some background?

The Early Days

Prior to 1972 running was for hardened folk who could weather the endless miles prescribed by their coaches. In 1972 Frank Shorter won the Olympic Marathon in Munich. That’s important for two reasons. He was an American, and it was on TV. The next day Frank was on the covers of newspapers. The world fell for Shorter and by extension running. At the time, Adidas and Asics (Tiger, back then) were the runner’s shoe companies. The brand Nike was a year old when Shorter won his gold.

This was the catalyst for the first and probably the most important running boom. Baby boomers were entering their prime activity years. They had some disposable money and time. Running was their thing. The only known way to run was to run like the best in the world. These new runners put in big miles and many of those miles were quite hard. Shoe companies began to realize that protection from the pain of running was important.

The first true midsoles showed up around this time. Midsole drop was established and protection became a key phrase in running shoes. The materials used for the uppers were either leather or nylon with sheet EVA for the midsole. Imagine you’re making cookies and you stamp out your design from a sheet of dough. That’s essentially how sheet EVA works. It was fast, repeatable and an effective form of protection.

America’s running hero did it again. In 1976 Frank Shorter fought hard for a Silver medal in the Olympic Marathon. He was the face of running and the running boom was solidly in place. By this time books about how to run were written and running magazines surfaced. In 1976 the 6-year-old New York City Marathon moved from Central Park to the streets of the city. Just over 2,000 people ran that year; 50,000 will run this year.

Around this time Brooks, Saucony and New Balance joined Nike, Asics and Adidas as shoe makers supporting the running craze (and they remain atop the running shoe market). The running magazines took the information coming from these brands and tried to narrate the information using a new language runners could understand.

The Birth of Stability

The small company Brooks noticed that some runners (many actually) had unstable heels. As this foot rolled through impact, the heel would cave to the inside, which would cause the foot to toe off at an sub-optimal angle. It was believed then that this was one of the causes of the injuries that were occurring. In 1976 Brooks introduced the Vantage (highest pic above), advertising soft support. They showed pictures of a compromised heel and a supported heel (see the ad just above). The foam was still sheet EVA and the solution was the Varus Wedge. That shoe won awards in the magazines and a new category of shoe emerged. It wasn’t called Stability yet, but this recognized shoe category was coming. Brooks used that Varus Wedge construction for more than 10 years. Not long afterward every brand had its version of supportive construction.

Two other advancements happened around this time that really changed shoes: First, the advent of Polyurethane (PU) as a cushioning material. Brands learned how to mold PU into the shape of a midsole. The material brought a great deal of cushioning as well as durability. It became an integral part of both Nike and New Balance footwear. PU offered more cushion than sheet EVA and its density could be changed, making it harder or softer. These companies also learned how to glue things to PU. The first TPU support pieces that functioned like a Varus Wedge came out.

In 1978 Nike changed the running market for years to come. The first Nike Air hit store shelves. With PU as the base material Nike figured out how to insert their Air units into the midsole process. Cushioning felt good.

From 1978 to 1990 or so, the brands learned a lot. They were listening to the demands of runners and were learning new construction techniques. They were also watching each other. Asics came out with Gel cushioning, Brooks introduced HydroFlow and Saucony introduced GRID. The runners were asking for more protection. The brands went down two paths: Support and Cushion. The neutral cushion shoes of this time are etched in the minds of runners. The Nike Terra TC, Nike Air Max, Saucony Azura and Asics Epirus (above) were among the favorites. New Balance hit the market with the most advanced and expensive ($100) shoe in history, the 990 (below). The support shoes were square and heavy. They were not beautiful shoes.

During this time they also learned a new technique in building running shoes. PU was a great cushioning material but it was heavy. Lightweight was and always will be a factor in building a running shoe. The process started with the EVA in pellets. They could overstuff a mold, add high amounts of pressure and the result was lighter and softer. Compression Molded EVA was born.

The brands also started to play with the last or shape of a running shoe. Every brand had a straight lasted shoe for super support, a semi-curved last for moderate support and a curved last for no support.

The race for marketshare was on. The brands were now driving the running market. When new shoes came out in the shoe reviews the runners flocked to their stores to buy them up. The advancements in shoe construction were fast and furious. Some worked; many didn’t. That was the risk of innovating fast. With CMEVA they found they could do a great deal more with shape and with the density or softness of the midsole.

In 1993 Saucony introduced the first ever dual-density CMEVA shoe. They put a blocker in the mold of the midsole and then replaced that piece post-molding with a firm, almost hard, piece of EVA. That piece was glued to the medial (arch) side of the shoe. They hid the glue lines and called out the piece by painting that firmer section grey. Within a couple of years virtually every running shoe brand was using this process. One of the all time favorite shoes the Asics Gel Kayano debuted during these early days of dual density CMEVA. These stability shoes became the staple model at running stores around the world.

This shoe solved problems. Runners who were being told they needed support were never happy. They didn’t want square, clunky shoes; they wanted the soft and light shoes their friends had. These new shoes gave them the support they needed and the look and feel they wanted.

This new form of construction to support feet took over quickly. The names of the shoes developed at this time are still evident at retail store sales running events today. Beside the Kayano Asics produced the GT 2000, and Brooks the Adrenaline (above). At this time the brands also created Motion Control and the #1 shoe in that category, the Brooks Beast, came out.

From 1995 to 2008 the running shoe industry went wild. The number of running stores grew, the internet helped push the industry’s story out, and these big brands scaled up their sales numbers to levels hard to imagine.

I wrote in the beginning of this article that, “the old ways of looking at footwear are no longer valid.” In the next article I’ll talk about a shoe Adidas made in the 1990s that changed the trajectory of running. Because this shoe’s introduction was coincident with the second running boom its contribution to stability was legion.