“Stand back,” warned the engineer. “Don’t be alarmed when I open it.”
Crouching beside the pressurized canister, he slowly twisted the valve. A long hiss filled the room, sharp and insistent. The air grew tense.
Fifty seconds passed and the anticipation mounted. Finally, the canister fell silent – matching the mood in the room.
Clemens Dyckmans, director of Athlete Solutions, eased the lid open, and I nervously joked that it felt like we were about to uncover a radioactive vial of uranium.
Gently lowering his hand into the container, Dyckmans gingerly pulled out the contents.
It wasn’t a volatile chemical, but something arguably just as explosive: a pair of Adidas’ most radical running shoes.
Prototypes so finely tuned they had to be stored under pressure until the moment of use. Shoes built for a single, audacious purpose – to help five athletes break the 100km world record and run the distance in under six hours.
Secret project to go sub-six
The sub-six barrier stood untouched until August 26, when South African runner Sibusiso Kubheka made history by breaking it in 5:59:20.
Taking place at the iconic racing track Nardò Ring in southern Italy, Kubheka shaved an astonishing six minutes and 15 seconds off the previous fastest time of 06:05:35.
The five competing athletes wore specially designed Adizero Evo Prime X footwear and bespoke, precision-engineered and custom-tailored to each athlete. They’re some of the most advanced, best running shoes ever made.
American Charlie Lawrence and Lithuanian Aleksandr Sorokin both beat the current fastest time (held by Sorokin himself), running 6:03:47 and 6:04:10 respectively.
For six months, Adidas’ innovation team worked on the secret project, maximizing marginal gains in every way possible. At the center of Chasing 100 was the Ultracharge shoe.
Every component – the foam, the traction, the upper, the stack height, even the stiffness built into the sole – was reimagined. Each prototype was bespoke to its runner.
And I was the only journalist in the world who had gotten to try Adidas’ craziest shoe yet.
Luckily for me, Japanese athlete Jo Fukada had a spare pair – which were just the right size.
“After I ran with these shoes, I recognized that, okay, I can get through 100km,” said Fukada, speaking via a translator. “Usually after 30km my body is tired, but after wearing these, the next day, I was full of energy, no fatigue, nothing. That’s why I was amazed with the shoes.”
Aleksandr Sorokin, the official world record holder (the Adidas event was held outside World Athletics rules) was equally effusive about the shoes.
“It gives a boost to your pace,” he said. “Your running becomes very economical. The shoes feel like they do 50 per cent of the work.”
Running with the world’s fastest
I’ll admit, I was terrified. The plan was simple: run a couple of loops around the block with Aleksandr Sorokin. The official 100k world record holder – something I am, well, not.
To have a comparison point, I started the first 800m loop in my everyday Saucony Ride 18 road shoes. We ran at my parkrun 5k speed, Sorokin extremely relaxed but still smashing out an incredibly fast cadence, despite the fact he was clearly running at his easy pace. I could just about keep up, but I wasn’t chatting. Breathing hard, legs ticking over, concentrating on not falling behind.
Then came the moment. I swapped into the Adidas prototypes straight out of the canister. Immediately they felt strange, almost unstable, as if I were balancing on stilts. They were incredibly light, weighing just 136g, and as soon as I started running, I understood why the canister unveiling had felt so theatrical.
It was like running on pogo sticks. Boing, boing, boing. Every step rebounded. My pace quickened without me trying, and what had felt like hard work a minute before suddenly felt like an easy jog. I wasn’t floating, exactly, but I was definitely being propelled.
The added height – edging towards 50mm in the heel – made me wobble slightly and pushed me into over-pronation. But the responsiveness was unlike anything I’d ever worn. I’ve tested plenty of carbon-plated shoes and I’m a fan of the Hoka Rocket, but these were next level. Fast, bouncy and almost cartoonish in their spring.
For 800m, I could run alongside multi-world record holder Aleksandr Sorokin at ease.
What’s inside the shoe?
That’s the question everyone is now asking, and Adidas is not ready to divulge everything – just yet. There’s a stiffening element hidden in the midsole, tuned individually for each runner, but the company won’t confirm whether it’s a carbon plate or something else.
What we do know is that the shoes are made from a new grade of Lightstrike Pro EVO foam, up to 35 per cent lighter and bouncier than anything currently on the market. Each athlete had their stack height, foam density, and bending stiffness customized to their biomechanics. Pressure maps of their foot strikes were used to place Continental rubber only where they needed grip, shaving away unnecessary grams.
Perhaps the wildest detail is the Ultracharge process. Adidas engineers discovered that if you store shoes in a pressurized vessel for up to five days, the properties of the foam change. The process forces air into the bubbles of the foam, altering its mechanical properties and making it livelier underfoot.
“It’s a bit of a magic trick, almost,” said Dyckmans. “You put a pair of shoes in, you wait a few days and a different pair comes out.”
That’s why the canister moment is so striking. The shoes are literally supercharged before they ever touch the track. And it’s a process that can be repeated – to keep instilling new life into the shoe.
However, Adidas stressed that the prototypes I tried won’t appear on shelves in the exact form the athletes used.
A very limited release is planned for November, but the version coming to market will use a standard configuration rather than the one-to-one customization given to the athletes. Meanwhile the key innovations – lighter foams, tuned stiffness, and traction insights – will feed into Adidas’ wider road racing line.
Adidas also hinted that Ultracharge – the canister process that changes the foam’s properties –won’t stay locked in the lab. The company described it as a major opportunity for the future, though it hasn’t yet decided how runners will experience it. Whether that means in-store charging, home kits, or special retail programs remains to be seen.
Beyond the shoes
The record attempt was about more than just footwear.
The five athletes, including Ethiopian Ketema Negasa, also used CLIMACOOL Pre-Cooling and Per-Cooling systems, starting their warm-up with Formula 1–style cooling vests and insulating jackets, then swapping to cooling necks throughout the race to control core body temperature.
On the apparel side, the Clima 3D singlet improved airflow and sweat evaporation, while TechFit short tights used stiffening bands to stabilize hips and reduce fatigue.
The Clima 3D singlet and TechFit tights are scheduled for release in 2026, and both were a big hit with the athletes.
For me though, the lasting image of the whole innovation project is still that hiss of air, the lid of the canister unscrewing, the shoes revealed like some dangerous experiment.
I’ll always remember the day I laced up the world’s craziest shoes – and, for one lap, kept pace with the best.
