Nike’s New Pinnacle Trail Shoe Is Its Most Capable Call to the Wild Yet

The brand’s pinnacle trail runner is now more comfortable, more inclusive and all-around more capable.

Close-up of an orange Nike running shoe with textured white sole and silver swoosh logo.Nike

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Many runners see the marathon as the ultimate test of endurance and determination.

For Caleb Olson, a rising star in ultrarunning, it’s a warmup.

After posting the fastest-ever debut at last year’s Western States, a 100-mile race through the Sierra Nevada mountain range, Olson followed up the feat with a win in 2025.

On this, there is little doubt: fitness and an aggressive strategy were both paramount to his victory. But Olson also came into the race a few extras arrows in his quiver — or rather, on his feet.

One was the ACG Ultrafly, now available for purchase after an official unveiling last fall.

Pair of bright orange Nike running shoes with white swoosh logos and black soles on a white background.
The ACG Ultrafly is a new max-distance race shoe based of the Ultrafly from 2023.
Nike
A male runner wearing a white mesh long-sleeve shirt, a white hydration vest with two water bottles, dark green shorts, and gray running shoes is running on a snowy and rocky trail at dusk. He has a white cap with sunglasses on top and a beard. In the background, a person with long hair, a white cap, and sunglasses is sitting on the snow, holding a camera or phone. The scene includes mountains and a sunset sky.
American ultrarunner Caleb Olsen (pictured) won Western States in a prototype of the ACG Ultrafly.
Nike

Served on a plate

Announced in conjunction with the All Conditions Racing Department, an elite team of runners attempting to relaunch ACG as a competitive force in extreme sports, the new shoe is easily Nike’s most ambitious trail runner to date.

Pair of bright orange Nike ACG sneakers viewed from the back with white midsoles and black outsoles.
Along with a new racing division, the ACG Ultrafly is among Nike’s newest efforts to rebrand ACG as a serious force in extreme sports.
Nike

That means it’s much more than a rebranded version of the existing Ultrafly released in 2023.

According to Nike, the ACG Ultrafly is the product of over a dozen rounds of testing “encompassing more than 30,000 miles.”

A man wearing a white long-sleeve mesh shirt, dark shorts, white socks, white running shoes, and a blue cap is running on a treadmill inside a metallic, industrial-looking room. The treadmill has black handrails, and various cameras and sensors are mounted around the treadmill, likely for motion or performance analysis. The room is lit with overhead fluorescent lights and has a black curtain on one side.
Nike claims the ACG Ultrafly went through 13 rounds of testing that covered over 30,000 miles.
Nike

Both shoes share the same midsole technology, which pairs ZoomX foam with a carbon-fiber plate. However, the one found in the ACG Ultrafly is less rigid; it’s also split down the middle, with a spine that allows it to better bend over roots, rocks and other elements of technical terrain.

Bright orange Nike running shoe with silver swoosh and white cushioned sole.
Like most of NIke’s top-shelf racers, the ACG Ultrafly features a ZoomX midsole.
Nike

According to Brenden McAleese, who oversees footwear at ACG, both variations help to increase the torsional flexibility and control. But the plate’s thinness, in particular, makes the shoe more inclusive to runners of all stripes.

“That was really well received,” McAleese says, “particularly by our lower body weight athletes where they felt they could actually engage the plate that much more.

“We know that no two steps are the same on the trail, and this shoe really allows it to work with the terrain.”

“We know that no two steps are the same on the trail, and this shoe really allows it to work with the terrain.”

Close-up of an orange Nike running shoe heel with white midsole and black and red textured outsole.
The plate’s thinness caters to both men and women, especially those at lower body weights.
Nike

Loosen up

The midsole isn’t the only aspect of the shoe that charts its own course.

Nike also retooled the upper to improved breathability and drainability, a boon for ultrarunners who often face water crossings throughout races.

Bright orange running shoe with white sole and large white swoosh logo on the side.
Thanks to a retooled upper, the new shoe is more breathable and drainable than the 2023 Ultrafly.
Nike

But the most impactful change can’t be seen, only felt — and appreciation for it only goes up as the miles start to stack.

The ACG Ultrafly boasts a brand-new last that features a wider toebox, addressing many runners’ beef with the narrowness of the original Ultrafly.

“Over the course of a hundred miles, really even a few steps, your feet swell and change in shape and size,” McAleese says. “This really helps provide that overall accommodating fit over the course of a run or race.”

Pair of bright orange Nike running shoes with white swoosh logos, viewed from above.
A wider toebox gives feet room to swell over the course of a 100-mile race.
Nike
Black and red Vibram Megagrip shoe sole with circular white traction dots on a white background.
The Vibram Litebase outsole is similar to the one on the original Ultrafly.
Nike

Availability and pricing

The ACG Ultrafly is available from January 29, 2026, at Nike and select retailers, such as Running Warehouse.

It costs $270 and comes in a single color at launch, a bright orange called “Hyper Crimson.”

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