Steve Jobs once said, “You can’t connect the dots looking forward; you can only connect them looking backward.” So, in 2009 when Christopher McDougall published his New York Times best-selling book, Born to Run, in which he told the story of an ancient running tribe called the Tarahumara and suggested that running shoes were the root cause of many running-related injuries, it was impossible to foresee the ripple effect he would have on redefining modern footwear.
In the book, McDougall referenced a 2004 study by Harvard professor Daniel Lieberman, Ph.D., titled “Endurance Running and the Evolution of Homo.” In the study, Lieberman argued that human beings are evolutionarily built to run long distances and have been doing so for nearly 2 million years—long before running shoes were invented. This leads to the notion that running barefoot is in our DNA and, therefore, more natural and better for us. And, just like that, the minimalist-footwear era was born.
Trendy? Yes, but the minimalist movement was rooted in weak scientific claims. The idea that running barefoot or with minimalist footwear reduced injuries because it caused runners to land more on their forefeet was largely anecdotal. The American Podiatric Medicine Association was skeptical, too, putting out a statement saying: “Research has not yet adequately shed light on the immediate and long-term effects of this practice.” Then came the nail in the coffin for the movement: Vibram, the maker of the minimalist shoe, FiveFingers, agreed to a $3.75 million class action settlement for touting unfounded claims about the benefits—including that they strengthened feet and leg muscles—of running in their footwear.
Still, the minimalist boom, shortcomings and all, forced Big Footwear to rethink the state of the running shoe and ask: If less wasn’t the answer to improved running, then what was?
“Before the minimalist boom, there were a lot of shoes that were clunky and heavy, and the materials weren’t that great,” says Brian Metzler, author of Kicksology: The Hype, Science, Culture & Cool of Running Shoes. “I remember running in 2005 and thinking, ‘These [shoes] are horrible. They are just so heavy.’ ”
It was a French brand, Hoka, that forced the next big adaptation in running footwear when it ran away from minimalism and introduced the first maximalist shoe, the Bondi, in 2009, which was lighter and more cushioned.
What was clear was that there was no one best running shoe for everyone. Each movement or fad laid the groundwork for further innovation. Over the next decade, running shoes would transform from a piece of gear that protects the foot to a tool that helps you run faster and more smoothly. Here, we outline the three most significant innovations in the past 10 years.
Cory Smith is an athlete based in Santa Barbara, CA, who has been running at an elite level for 25 years, an online running coach (runyourpersonalbest.com), and a journalist specializing in running- and climbing-related content. Head to storiesbycory.com for more of his work.
Starting in the mid-1970s, ethylene-vinyl acetate, or EVA, was the standard foam found in all running shoe midsoles (a layer of material between the inner and outer soles to absorb shock). It was inexpensive and easily mass-produced, but the problem with EVA was that it came in only a few levels of densities. As a result, engineers made cushioned midsoles that focused on reducing the shock your feet felt when they struck the ground.
“Then, as companies got smarter, they realized they could tweak EVA to different densities and weights, and things evolved out of that,” Metzler says.
Engineers also began experimenting with other materials, and then in 2013, the folks at Adidas struck gold by introducing the Adidas Boost—a highly cushioned shoe that offers exceptional spring thanks to the use of a flexible plastic called thermoplastic polyurethane, or TPU.
“Boost was the first one that took off and really made a difference,” Metzler says. And suddenly, the dual-purpose midsole, which means it is both cushioned and responsive, burst onto the scene.
It’s not that one foam (EVA versus TPU) or process is better than another, but Adidas Boost inspired and pushed other brands—such as HyperBurst, Nike ZoomX, and Under Armour Hovr—to further innovate their midsoles.
As a result, midsoles are more cushioned, responsive, and lighter. For example, Metzler recalls running in a shoe weighing 14 ounces, whereas the same type of shoe may weigh 10 ounces now.
2 of 3
Anakumka
Engineered Mesh Uppers
Surprise, surprise, the weight of running shoes plays an integral part in how fast (or slow) you’ll run. One 2016 study found that for every 100 grams added, 3,000-meter times slowed by 0.78%. And this isn’t the only study confirming the correlation between weight and speed in
running shoes.
A decade ago, shoemakers grappled with how they could lighten their product while keeping the footwear durable and secure. Using foam was the first step, but then engineers turned to the upper—the materials that wrap around the top of the foot.
In 2012, Nike came along with the FlyKnit, a digitally engineered mesh upper. Shortly thereafter, engineered mesh became the de facto standard, offering up a more breathable, better-fitting, and lighter alternative to leather and synthetic uppers.
3 of 3
Hadrian
Carbon Fiber Plates
The most significant breakthrough in the past decade, and perhaps since the inception of the running shoe, is the embedded carbon fiber plate in the midsole. Though Adidas experimented with carbon fiber plates in the early 2000s, it was Nike that popularized the innovation with its Vaporfly 4% in 2017—the same shoe that elite runner Eliud Kipchoge wore during his first attempt at breaking the sub-two-hour marathon in May 2017.
The Vaporfly 4% earned its name from a Nike-funded study that proved it improves running economy in elite male runners by 4%. Subsequent independent studies, such as a 2017 one published in the journal Sports Medicine, confirmed these claims to be true.
It’s uncertain exactly how the carbon plate helps, but it’s believed to act as a rigid platform for the toes to spring off, which decreases the energy lost as they push off the ground.
Nike has seen great success with this shoe. Both men’s and women’s marathon records have been set with the Vaporfly 4%, and five of the top 10 faster male marathoners have donned the shoe. It’s so effective that the World Athletics Organization, which oversees international track-and-field events, issued a moratorium on any shoe with a heel height of more than 40 millimeters and more than one rigid embedded plate (of any material). Nike’s newest addition to the Vaporfly series, the Alphafly Next%, measures in at 39.5mm.
So it’s no surprise that other running shoe brands were quick to release their own versions of a carbon fiber racing shoe. Hoka One came out with two long-distance-focused carbon fiber shoes, the Carbon Rocket and Carbon X, New Balance created the FuelCell 5280, and Saucony just released the Endorphin Pro.
“We’re definitely at a new paradigm of shoe design,” Metzler says. During the past decade, running footwear has evolved more so than during any other period. It’s clear how each innovation led to another, then another, connecting the dots and leading to what we call the modern running shoe. Today’s shoes are more comfortable, more durable, lighter, and more responsive than ever.
