Ever since the Nike Tailwind’s debut in 1978, the evolution of Nike’s signature cushioning technology is predicated on making a single dream into reality: the feeling of walking on air.

Aeronautical engineer Frank Rudy originally conceived (and patented) the idea of a cushioning system based on an inert gas in a polyurethane plastic capsule. This provided the basis of Nike’s trademarked Air tech, and it’s been updated considerably since then. But 30 years ago, the Air Max 1 broke the magician’s rule of never revealing how an illusion works—adding a visible window on the sole to show people that they were indeed running on an invisible layer of Nike Internationalist Donna air.

According to Kathy Gomez, Nike’s VP of Underfoot Cushioning Innovation, it took 15 tries Adidas ZX Flux Damen to get the VaporMax sole right.

“To create this, we had to balance durability with stability, and of course cushioning and sensation,” she says. “It was really figuring out how to marry all those things together and find the perfect balance of wall thicknesses and geometry to create the platform that worked.”

Extensive testing in Colorado consisted of experimental soles fused on the running upper of the streamlined Lunar Racer 1 silhouette. Feedback from runners on these early versions showed signs of promise to continue moving forward.

“That created a tremendous amount of confidence and momentum for the whole project because feeling it is believing it, and so many people experienced what the dream was,” says Gomez.

How the shoe looks Adidas Ultra Boost Dámské is as important as the performance aspects. The clean lines and sheer functionality of the low-top Lunar Racer 1 upper, replete with Nike’s Flywire lacing system, ensured a snug fit on runners.

“If you think about the upper and the sole unit as a system, you start to understand that the two have to go together, and you have to have the same approach with the upper as you have with the bottom,” says Andreas Harlow, VP and Creative Director of Footwear Design for Nike Running. “It was all about reduction, getting rid of all the extraneous things that get in the way of that sensation, and amplifying the feeling of running on air.”

The low-top silhouette was chosen as the launch model because it’s what most wear-testers preferred. Harlow says Nike tested several different versions of the VaporMax, but that silhouette proved to be the one Adidas Superstar Dámské attractive to the widest array of runners.

“We had to reimagine how the shoe is built, and remove layers from the whole process,” says Gomez. One of the biggest breakthroughs came when Nike was able to create an outsole that locks directly to the Air bag.

The VaporMax sole is crafted in an entirely new way. The entire sole is made of TPU, with the outsole being a different grade. There is no glue in between, and the engineering team was able to eschew extra layers of glue, foam, and rubber.

“From a design perspective, we have a goal to create a simple, elegant solution,” says Harlow. “It’s harder, but at the end of the day, the more elegant and clever it is, chances are it’s going to run like that, and feel better.”

Whereas previous models like the Air Max 2016 and 2017 used the airbag as more of a mattress under the foot, the Adidas Superstar Donna Vapormax opts to turn Air into specialized pistons that provide support where athletes need it most.