Nike (U.S. Patent Application Publication No. 2018/0116335)

Who Needs Wings When You Can Vaporfly? By Jon Western

Back in 1954, a British medical student named Roger Bannister took to a track at Oxford University and, with the help of pacers running alongside him, accomplished a milestone previously believed impossible – the sub-four-minute mile. His time, 3:59.4, would amount to a new world record and push forward our perception of human limitations.

*Roger Bannister crosses the finish line to achieve the first ever sub four minute mile by six tenths of one second.*

Since then, the four-minute barrier has been broken repeatedly. Over 1,400 athletes have accomplished the feat, slowly but surely chipping away at the mile record, which currently stands at 3:43.13 – a full 16 seconds faster than Bannister’s original groundbreaking time.

As records for running the mile advanced, so too did the shoe technology. When Bannister ran the first sub-four-minute mile, he did it in a pair of running spikes that resembled Oxford dress shoes with nails hammered into the sole. The shoes were lightweight, just the way Bannister wanted them, and made with thin leather. Bannister said: “I could see there was an advantage in having the shoe as light as possible.”

Today, running shoe technology remains crucially important, not to mention lucrative, as brands battle for footwear innovations that provide runners an all-important edge. Unquestionably, one of the companies responsible for advancing the state of running shoes to where it stands today is Nike. Since the original “Waffle Trainer,” invented by co-founder Bill Bowerman, Nike has been prolific in patenting its shoe designs, having obtained hundreds of patents relating to footwear alone.

*Nike shoes U.S. patent (filed August 30, 1972) granted to Bill Bowerman.*

Perhaps Nike’s most notable running shoe breakthrough within the past decade has come on the heels of its uber-fast, and uber-controversial, carbon-fiber-plated shoe: the Vaporfly. Across its various iterations, each Vaporfly is made with an exceptionally bouncy midsole cushion coupled to a full-length carbon-fiber plate that Nike boasts is “intended to minimize energy loss during toe bend without increasing demand for the calf.” Now, this isn’t mere marketing fluff; it’s backed-up by science. Laboratory studies (not funded by Nike) found wearing the carbon-fiber-plated Vaporfly shoe makes runners as much as four percent faster than other running shoes – hence the name given to the shoe’s original iteration: Vaporfly 4%.

Nike’s carbon-fiber-embedded Vaporfly 4%

Aspects of the Vaporfly are described in U.S. Patent Application Publication No. 2018/0116335 (“Footwear Sole Structure Including A Spring Plate”). For some context, the patent describes the physical mechanics of running and the energy expenditure which takes place in muscle tendons of the foot with each footstep. The patent explains: “In conventional footwear, little to none of this mechanical energy is recovered to contribute back to ongoing movement. Reducing this energy expenditure and/or improving the energy recovery can potentially improve locomotion efficiency and elicit a new sensation to a person who is walking or running.”

Referring to the images below, the patent describes a shoe (100) constructed with a midsole cushion (122) made of either conventional materials, like EVA or TPU, or in the case of Vaporfly, a high-tech, nitrogen-infused concoction of springy foams known as ZoomX. The shoe also has a spring plate (123) made of a carbon-fiber material situated between the midsole and outsole (114). When there is no weight placed on the shoe, the carbon-fiber plate rests in its natural or “unloaded” state with a forefoot portion that is downwardly bent, as demonstrated below. When weight is applied, the plate flattens and, much like a compressed spring, loads up potential energy that is released when the wearer lifts the shoe off the ground. The process of loading and unloading the plate is explained in the patent:

“As weight is increasingly shifted to the forefoot as the foot rolls forward, potential energy from body mass is stored in the spring plate as the spring plate changes from a bent to a more flat configuration. As the foot continues to roll forward and the heel lifts off the ground, the metatarsophalangeal joints begin to extend and additional energy is stored as the spring plate bends further upward. By the time that the runner nears the toe-off portion of the gait cycle, substantial energy has been stored in the spring plate. This energy is released back to the runner as the runner toes off at the end of the second half of the stance phase.”

Interestingly, the benefit of the plate isn’t that it makes the runner faster per se, but that it makes the runner more energy efficient. Energy efficiency, in running terms, refers to the energy expenditure of covering a given distance. So, a runner who runs a six-minute mile in a conventional shoe should expend less energy—four percent less, to be exact—running at the same pace in the Vaporfly. Spread that improvement in running economy across a 26.2-mile marathon, and the six-minute-mile runner would, theoretically, slash his finishing time by more than six-and-a-half minutes.

*Exploded view of Nike’s ZoomX Vaporfly NEXT% (image courtesy of Nike)*

I took the Nike Vaporfly for a test drive last fall, running the ridiculously scenic Mount Desert Island Marathon in Bar Harbor, Maine. The verdict? My legs were noticeably fresher toward the end of the race. I’ll say it confidently – Nike’s technology is for real.

Of course, with the patent application still pending, the ultimate scope of the claims is unclear. Nike has already submitted claim amendments to recite a specific contour shape of the plate. But judging by the rabid popularity of the Vaporfly, I suspect Nike will resist further amendments that substantially narrow the claims to ensure its carbon-fiber-enhanced footwear is well-protected.