New postmodern shoes aren’t cheap.pixdeluxe/Getty Images
If you believe the marketing hype from running shoe companies, every year is a breakthrough year and every new model is a paradigm shift. You can safely tune out these claims most of the time – but occasionally, it turns out to be true.
In a recent issue of the International Journal of Sports Physiology and Performance, two of the world’s foremost independent experts on running shoes argue that one such turning point took place in 2016. According to Geoffrey Burns of the United States Olympic and Paralympic Committee and Dustin Joubert of St. Edward’s University in Texas, we are now in the “postmodern footwear era.” Here’s what you need to know about this brave new sneaker world.
What makes a shoe postmodern?
In 1960, Ethiopian runner Abebe Bikila won the Olympic marathon running in bare feet. Running shoes of that era, Burns and Joubert write, were “little more than a piece of rubber attached to an upper.”
But around that time, the first “modern” running shoes, featuring a soft foam midsole that absorbed some of the impact of landing, were emerging. When Bikila successfully defended his title in 1964, he wore one of these early cushioned shoes. That basic design remained the state of the art for the next half century.
In 2016, Kenyan runner Eliud Kipchoge won the Olympic marathon in a prototype of Nike’s Vaporfly 4% shoe, named for lab tests that showed runners burned 4 per cent less energy when they ran in it. This first postmodern shoe contained two key features: an extra-thick layer of ultralight, ultra-resilient midsole foam, and a curved carbon fibre plate embedded in the midsole.
In the years since then, virtually every major running shoe company has developed models that follow a version of this basic template: thick foam, curved plate. National and world road-running records have been obliterated. In 2015, two women broke the two-hour, twenty-minute barrier for the marathon; last year 26 women accomplished the same feat, and that number will almost certainly be eclipsed this year.
How do they work?
Amazingly, despite dozens of studies and millions of dollars in sales, researchers aren’t exactly sure how the new shoes work. Early theories focused on the idea that the carbon plate acts as a spring, but subsequent research found that the shoes still boost performance even if you slice the plate into multiple pieces with a table saw.
For now, the leading theory is that the thick foam midsole, generally made of a material called polyether block amide, or PEBA, stores energy as it’s compressed with each step and then springs back to aid the next step. The carbon plate may help spread the landing forces out evenly within the layer of foam.
For runners, the upshot is a shoe that takes less energy to run in, which typically translates into a faster race time by 2 to 3 per cent. There are nuances: for example, the benefits may decrease slightly when you’re running more slowly or uphill. But they seem to provide at least some time benefit for nearly everyone.
Many runners are also convinced that the thickly cushioned shoes are easier on their legs, reducing muscle damage and accelerating recovery. There’s only a smattering of evidence for this claim, but it remains a prominent talking point among runners.
How should I choose my running shoes?
These new postmodern shoes aren’t cheap. Saucony’s top-of-the-line Endorphin Elite, for example, retails for $350. When three-time Olympian Malindi Elmore was weighing sponsorship offers in 2020, she took a handful of models to a lab at the University of British Columbia’s Okanagan Campus to test her running efficiency in each shoe and identify the best one for her unique stride.
That’s not an option for most of us, so Burns and Joubert have some simpler advice. Choose a shoe that is billed as having a PEBA midsole and a rigid plate that is curved under the big toe joint. Make sure the shoe is light, somewhere between 170 and 210 grams for a men’s size 9. And don’t worry too much about comfort: studies have found that the shoes runners like best aren’t necessarily the ones that give them the biggest performance boost.
Of course, you may be perfectly happy in your old “modern” runners. But if you find yourself at a local race wondering why everyone around you seems a little faster than they used to be, the answer is simple: they’re postmodernists.
Alex Hutchinson is the author of Endure: Mind, Body, and the Curiously Elastic Limits of Human Performance. Follow him on Threads @sweat_science.