Future of Fast: Behind the Evolution of Nike's Vaporfly NEXT%

The Nike ZoomX Vaporfly NEXT% running shoes

Eliud Kipchoge didn’t look surprised.

The world marathon record holder waved his finger in the air in celebration during the final 200 meters of the 2019 London Marathon. He saluted the crowd lining the runway—first on his right, then his left—as Buckingham Palace shrank into the background.

Kipchoge looked relaxed in the home stretch. He looked playful as he addressed the spectators cheering for him. He looked like he never expected any other outcome.

The TV broadcast cameras tracked Kipchoge on approach, always staying a step ahead of him. His feet a bright green blur on camera, tracing perfect ovals through the air like waving a burning sparkler through the night sky.

Finally, he held out his arms, embracing the unbroken tape in front of him. The timer above his head ticked to 2:02:37 as the tape snapped and dropped to the pavement.

Kipchoge slowed to a walk, smiling like a competitor does when everything goes according to plan. He paced around in his green shoes as race officials, coaches and cameras swarmed him.

Ethiopian runner Mosinet Geremew joined Kipchoge at the finish 18 seconds later. Fellow Ethiopian Mule Wasihun followed.

The three runners pressed shoulder to shoulder and posed together for photos—all wearing the same green shoes with a swooping black swoosh across the toe.

Speed Meets Cushion in Vaporfly

A runner holds a pair of Nike Vaporfly NEXT% running shoes

The best marathon shoes of the past were lighter and less cushioned than the everyday training shoes runners wore leading up to race day.

Big stacks of foam and rubber often make running shoes softer and more suitable for high-mileage training, but those same properties historically made shoes heavier. So, instead of plodding around marathon courses in training shoes, running companies make thinner, more responsive racing flats for the big day.

“I think the general train of thought was a racing shoe, particularly for a marathon, was just the fastest road racing shoe for 5 or 10Ks,” says Elliott Heath, a product line manager for Nike Track & Field. “Fast just meant less. Fast just meant more minimal. Fast was just as lightweight as you can go.”

Flats like the Nike Zoom Streak led to elite times, but the number of runners wearing fast, race-specific shoes was very small, Heath says. So, Nike set out to change that.

A prototype of Nike's energetic ZoomX foam used in the Vaporfly NEXT%

In 2013, Nike designers and engineers started developing the Vaporfly 4% system to give runners a never-before-seen combo of race-day speed and everyday cushion.

The original Zoom Vaporfly 4% featured Nike’s ZoomX foam, which weighed less and returned more energy than any foam compound before it. Nike's previous foams returned 60-65 percent of the energy runners put in with each step. The original ZoomX foam, on the other hand, returns approximately 85 percent. The tiny weight also meant Nike could pack a shoe full of ZoomX without weighing it down.

Designers then sandwiched a curved carbon fiber plate in the midsole to increase the shoe’s stiffness and give it a propulsive feel.

“I’ve heard over and over again from athletes that it puts them in good body position to be light on their feet with a quick (ground) contact time and be on to the next stride almost right away,” Heath says.

Together, the full-length plate and the bouncy new foam gave runners an unprecedented taste of efficiency. Lab tests, scores of major marathon victories and a marathon world record backed up Nike’s claim that the shoe made runners 4 percent more efficient—and proved that big shoes could go fast.

“Fast and racing no longer means just flat,” Heath says. “And a huge part of that has been the foam. Having a very responsive foam that returns (more) energy than some of our previous foams but that’s also very lightweight at the same time—those two things have to go together for this whole idea to work.”

But it could be better. The team went back to the lab.

The Next Percent

Nike Footwear Designer Vianney de Montgolfier sketches the ZoomX Vaporfly NEXT%

One of the biggest challenges of making Nike’s best shoe better was expectations.

Nike Footwear Designer Vianney de Montgolfier says the new Vaporfly had to be faster than the previous one, but it also had to maintain the trust runners put into the original version of the Nike running shoes.

“We started with the Vaporfly 4%, so that was a very, very big challenge for the team because it’s been such a successful shoe,” de Montgolfier says. “Our runners really loved (the 4%), so we had to be really careful with how to update the shoe because we know so many people trust it for their races and everyday runs.”

The original Vaporfly 4% quickly dominated the world marathon circuit, propelling runners to podiums in Tokyo, Boston, London, Chicago and New York. Kipchoge wore a custom version of the shoe when he ran 2:00:25 in Nike’s attempt at breaking the two-hour marathon, and a year later he set the official world record in Berlin with a time of 2:01:39.

To be faster, the Nike NEXT% had to be lighter—or at least as light as the original—and have more cushion.

So, De Montgolfier and his team spent 18 months building shoes, listening to feedback and tweaking designs to meet the expectations of elite and everyday runners around the globe in order to create the next fastest running shoe ever: the Nike ZoomX Vaporfly Next%.

Designing the Nike ZoomX Vaporfly NEXT%

A close-up photo of the heel on the Nike ZoomX Vaporfly NEXT% running shoe

You don’t get less by adding more. So, Nike created a brand new material called Vaporweave.

Nike’s design team used Vaporweave for the new shoe’s upper. The transparent, mesh-like material is made from two types of thermoplastic, TPU and TPE, that give the final product a balance of stretch and lockdown.

Vaporweave gave the shoe the light starting weight designers were looking for, but it also made it lighter throughout a race. By absorbing 93 percent less water than the knit upper on the Vaporfly 4% Flyknit, Vaporweave doesn’t get weighed down as much by heavy rain (or heavy sweat), a problem racers like Shalane Flanagan had during the 2018 Boston Marathon downpour.

With a lighter upper in hand, Nike could afford to add more foam to the midsole where runners wanted it. Heath says they added 1 mm of stack height to the heel of the shoe and 4 mm of foam to the forefoot. All that extra foam reduced the heel-to-toe drop from 11 mm in the Vaporfly 4% to 8 mm in the NEXT%. Then they added another helping of foam to increase the width of the midsole in the forefoot for more stability in the toe off.

“Whether you’re a heel or forefoot striker, your last point of contact before you take off is always the forefoot,” Heath says. “We felt like that was going to benefit all of our runners regardless of foot strike.”

A runner holds a pair of the new Nike ZoomX Vaporfly NEXT% running shoes

Nike made three other major changes in development:

  • Forefoot shape. The forefoot is roomier in the NEXT% than it was in the 4%, giving runners a wider platform for their toes to splay
  • Heel fit. Nike added a soft, low-profile pad in the heel that wraps around the Achilles tendon to prevent a runner’s heel from slipping out. From our early testing, this is a huge fit improvement
  • Lace location. An offset lacing system rolls the laces toward the outside of the shoe. De Montgolfier says moving the laces out of their normal position on top of the foot reduces pressure on important tendons and bones

“It’s our fastest shoe ever, but it’s also maybe the most accommodating racing shoe ever,” Heath says.

After solving for weight, accommodating for fit and stabilizing the ride, Nike dyed the shoe a shade of green called Phantom Glow and stamped the bold swoosh across the toe where they were sure it would be seen.

“We used Eilud Kipchoge as our muse,” de Montgolfier says. “He’s the guy that you don’t take pictures of from the side. He’s the first one to cross the finish line, so you take shots from the front. That’s the reason why we wanted to use this swoosh in (the forefoot) because this is what you see first when he’s crossing the finish.”

Made to Break Records

A runner does a track workout in the Nike ZoomX Vaporfly NEXT% shoes

Eliud Kipchoge was making history as he cruised toward the finish line.

His 2:02:37 time set a new London Marathon record. Even though it was almost a full minute slower than his world record 2:01:39 set at the 2018 Berlin Marathon, it still counted as the second-fastest official marathon time ever.

The man right behind him was Mosinet Geremew. His time of 2:02:55 now stands as the third-fastest marathon time in history—only behind Kipchoge’s two races. And in third? Mule Wasihun, whose 2:03:13 makes him the seventh fastest man over 26.2 miles.

Nike’s Vaporfly NEXT% powered all three to the finish.

The Nike ZoomX Vaporfly NEXT% is available on fleetfeet.com and at select Fleet Feet locations.

By Evan Matsumoto. Evan played many sports growing up but didn’t go pro in any of them. Now, he’s the digital copywriter for fleetfeet.com and editor for the Fleet Feet blog where he writes about different foam densities and engineered mesh uppers.

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