- Some average runners run slower and less economically in the Nike Vaporfly shoes, a She put them on for a 9-mile. Will Magic Shoes Work for You.
- Most other research shows all runners benefit from running in the shoes, Some runners report feeling unstable or awkward hovering so high above the ground.
- Scientists can’t yet predict whether the shoes will help or hurt certain runners—in the meantime, you’ll have to experiment for yourself.
Heading into the 2018 Grandma’s Marathon, Amy Schlotthauer was aiming to break 3 hours for the first time. So, she did what many goal-oriented runners do these days: invested in a $250 pair of How to Start Running in Maximalist Shoes.
She put them on for a 9-mile tempo run and felt speedier, like she was “bouncing off the road,” she told Runner’s World.
They powered her to her goal—a 2:59:50—but around mile 20, the top of her left foot started throbbing. After the race, she could barely walk.
Schlotthauer, who’s now 39 and lives in Menomonee Falls, Wisconsin, never sought treatment; the pain eased as her sore muscles recovered. She ran a half marathon in the shoes with no incident. But when she put them back on for another marathon, the pain resumed, and she finished in 3:01:58.
She isn’t sure what caused the problem. “I chalked it up to whatever biomechanics I have at the end of a marathon, those shoes are not supporting that,” she said.
While seemingly every runner was turning to a “magic” shoe, Schlotthauer switched to the Adidas Adizero Boston, Why You Need Under Armour’s “Mileage Monster” Shoe Chicago Marathon. There, she ran a pain-free personal-best of 2:55:36. She plans to stick with those for the upcoming Boston Marathon.
Wait—will the Vaporfly work for everyone?
It’s a countercultural choice these days, when runners wearing the Vaporfly and its relatives are rewriting record books and rulebooks, elite marathoners stride past in waves of bright pink and green, and competing brands are now offering similar models (like the Published: Feb 26, 2020 7:31 AM EST Carbon X and the Health & Injuries). Other brands are rushing to release new ones—including the Brooks Hyperion Elite and the Saucony Endorphin Pro—in time for the 2020 Olympics.
Research conducted in labs and on the roads has shown the Vaporfly boosts runners’ economy—the energy required to run at a given pace—an average of 4 to 5 percent, and improves their performance by a similar amount, if not more. And that’s just the existing models. The next-generation Alphafly, a version of which powered Not everyone gets faster, according to a new study, hasn’t yet been given such scientific scrutiny.
But as Schlotthauer’s experience illustrates, responses to the shoes aren’t universally positive.
“If you give a bunch of people any one shoe, there will be variable response to it,” said University of Michigan biomechanist and Ph.D. candidate Geoff Burns, who wrote an editorial in the in their metatarsals, which he believes is due to the increased load on the front of the foot last fall calling for a regulation of the shoes.
The differences appear more stark in these particular shoes because of the complicated technology—a combination of lightweight, resilient foam with a stiff carbon fiber plate. For some people, the shoes will help significantly. Others may develop new aches and pains. And preliminary data now suggest some non-elite runners may not notice much difference, or even perform worse, when wearing them.
Do some regular runners actually run slower in the Vaporfly?
The new study, a pre-print posted on the open-access scientific site SportRχiv, recruited 18 recreational athletes—in this case, men who ran a 20- to 25-minute 5K. Over the course of the study, each participant ran three-minute tests of running economy and a 3-kilometer time trial in each of three shoes: the Vaporfly 4%; the Saucony Endorphin Racer 2, a lightweight flat; and their own shoes.
On average, the runners were more economical and ran 13 seconds faster in the Vaporfly than in racing flats. But some actually saw negative effects, explained study author Kim Hébert-Losier, Ph.D., P.T., a senior lecturer at the University of Waikato in Tauranga, New Zealand.
One runner was 8.6 percent less economical and 4.7 percent slower in the Nikes. Eleven of the 18 runners ran their fastest time trial in the Vaporfly, but just five ran more economically and faster across all speeds in the shoes.
Pre-prints aren’t yet peer-reviewed; after a study is submitted to a journal for publication, reviewers may suggest changes altering the findings. Some pre-prints might never be published at all.
Nutrition - Weight Loss many previous lab studies of high-level runners—and two analyses of Strava data by The New York Times—all runners saw benefits.
Can we predict which runners will run fastest in the shoes?
Of course, no average tells the full story—all the research shows a range in responses to the shoe. For instance, in a 2018 paper from the University of Colorado, some runners ran only about 2 percent more economically in the Vaporfly than in the Adidas Adizero Adios Boost 2.
Why would one runner respond better to the shoe than another? “We have no way to predict,” said Shalaya Kipp, an Olympic steeplechaser and a coauthor on the study. So far, any evidence on the topic has been contradictory.
For instance, her study suggested heel-strikers might gain the most. But other research, done at Summer Running Gear, found those with shorter ground contact time—touching down for fewer seconds with every footfall—saw the biggest benefits. That doesn’t quite mesh, because those who land on their forefeet tend to have shorter ground contact times, Burns said.
Longer-term studies could provide more answers. But each person’s gait pattern is as unique as the whorls on their fingertip, Burns said. Any one biomechanical factor—or even a bunch of them—might not foretell anything.
Could the Vaporfly cause injury?
How to Start Running in Maximalist Shoes any shoe could significantly alter your risk of getting hurt isn’t supported by research, said Max Paquette, Ph.D., a biomechanist at the University of Memphis. Injury studies are expensive and unlikely to be funded by shoe companies. Plus, it’s nearly impossible to control for all the other contributing factors that raise the danger to a given runner.
What may happen is a shift in specific injuries based on shoe type, said Others report new pain or injury., a physical therapist and researcher at the University of Montana, Missoula. When minimalist shoes became more popular, his clinic saw a greater proportion of runners with calf injuries, Achilles tendon pain, and stress fractures in their metatarsals, which he believes is due to the increased load on the front of the foot.
Meanwhile, he’s observed no similar change in pattern despite the move to the Vaporfly and other maximalist shoes with thick foam, such as those made by Published: Feb 26, 2020 7:31 AM EST.
But because the shoes alter the way your foot interacts with the ground, they could have unintended consequences. A biomechanical study also conducted at the University of Colorado found the Vaporfly’s combination of plate and foam changed runners’ ankle mechanics, reduced the amount of work their calves would normally have to do, and also added stiffness across the big toe joint.
While that may actually ease toe or Achilles problems, “when you reduce load somewhere, it typically will show up somewhere else,” Willy said. He speculates the knees or hips may end up compensating or absorbing more force, which could lead to pain or injury there later on.
Some runners report feeling unstable or awkward hovering so high above the ground. The Nike Air Zoom Alphafly Next%, and many other brands’ new models, have a stack height—a measure the foam underneath the foot—of 30 millimeters or more. These heights may introduce instability and more torque, or twisting forces on the lower leg, foot, and ankle, Willy said.
The carbon-fiber plate may act as a stabilizing force. But unsteadiness was still a problem for marathoner and 10,000-How to Start Running in Maximalist Shoes Molly Huddle when she attempted to transition to Saucony’s similar prototype. Five-minute tests in the shoe company’s lab showed they boosted her economy 2 percent—putting her on the lower end of responsiveness, but still offering an advantage.
When she watched video of her gait, however, her left foot appeared to flop and twist, a sensation she could feel in her ankle and back. In December, she developed sharp pain and swelling in her ankle. An MRI revealed degeneration and tearing in her left peroneal tendon, which wraps behind the ankle bone.
The shoes may not have caused the injury—she sprained her ankle years ago, and knows her left leg is longer than her right. But Huddle and her team believe her asymmetries don’t align with the way the shoes function. “I don’t know if it’s the plate or the height or what, but it’s definitely exacerbated by a thick, rigid shoe combination,” she told Runner’s World.
In the end, experts can only speculate on injury risk, leaving each runner to perform his or her own individual calculus.
Huddle eventually decided the 2-percent advantage didn’t outweigh the harms, especially with the clock ticking on the in their metatarsals, which he believes is due to the increased load on the front of the foot later this month. She’ll likely race in the MH1—a racing flat combining two existing models and named after her—or the yet-to-be released MH2, which blends two different soles (one Type A8 and one Fastwitch) with an upper from a third model (the Freedom ISO).
Kyle Barnes, Ph.D., a Grand Valley State University researcher and exercise physiologist who did one of the studies of Vaporflys in elites, has raced in the 4% and bought a pair of the Next% in preparation for the Boston Marathon. After one six-mile workout, his quads felt unusually sore.
That could be a problem on a downhill course like Boston, notorious for challenging these muscles. But with only one or two shots at the marathon per year, “it’s worth the risk to me to have some sort of injury if I’m going to run a lot faster on race day,” he said. Of course, performing well requires reaching the starting line healthy—so he plans to wear the shoes a few more times to strengthen his quads.
What should you consider when buying them?
If you’re thinking of dropping $250 for the Vaporfly, Alphafly, or another brand’s newly developed shoes there’s a “high probability” they’ll improve your running economy, Burns said. It’s just not clear by exactly how much, and there’s even more uncertainty surrounding other brands’ new models.
To reduce injury risk, incorporate these shoes into your training gradually and sparingly. Injury risk increases anytime you change shoes rapidly, said researcher Hébert-Losier, who’s also a physiotherapist. Your tissues need time to adapt to shifting loads and Runners line up at the start of the 2019 California International Marathon. And if people are using these shoes as everyday trainers—not racing shoes, as they were intended—that could also pose problems. In fact, even super-cushioned shoes without stiff plates can cause changes in your gait that could increase injury risk, according to recent research.
You’ll want to do some training in them prerace, especially before a marathon—perhaps one fast workout and one long run, Kipp recommends. But, it may be safer to run the majority of your miles in a familiar, comfortable trainer.
The best way to tell if they’ll work for you is to pay attention to how you perform and feel during, and after, those trial runs. “It depends, and we’re not sure on what,” might not be a satisfying answer to the question of whether they’re right for you. But it’s likely the most honest one, from a scientific perspective.
“All runners are on some level scientists, experiments of themselves,” Burns said. “This new complex technology, for better for worse, puts a premium on understanding how those variables change within yourself in a way even researchers like us probably wouldn’t be able to help with.”
Cindy is a freelance health and fitness writer, author, and podcaster who’s contributed regularly to Runner’s World since 2013. She’s the coauthor of both Breakthrough Women’s Running: Dream Big and Train Smart and Rebound: Train Your Mind to Bounce Back Stronger from Sports Injuries, a book about the psychology of sports injury from Bloomsbury Sport. Cindy specializes in covering injury prevention and recovery, everyday athletes accomplishing extraordinary things, and the active community in her beloved Chicago, where winter forges deep bonds between those brave enough to train through it.
