Allbirds Trail Runner SWT Blends Sustainability With Rock-Solid Off-Road Performance

Men running in the Allbirds Trail Runner SWT trail running shoe on a dirt road
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Shortly after Allbirds first launched on Kickstarter in 2016 with an everyday sneaker made of merino wool, I got a mint green pair for my birthday. They were light and airy, and they became my favorite travel and everyday shoes. Since then, the company has steadily expanded its lineup to include running shoes, high tops, slip ons, activewear, socks, underwear, and more. Today, it launched its first-ever trail shoe: the Allbirds Trail Runner SWT.

I took them for a spin ahead of the release to find out how they performed in the wild—here’s how they stack up.

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The Allbirds Trail Runner SWT
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What It Is

Allbirds already has three running shoe models on sale, but the Trail Runner SWT is the company’s first trail-specific running shoe. While many shoes are made from petroleum-based materials, this shoe features natural materials like sugar, wool, and trees—that’s what the “SWT” in the name stands for.

Sustainability is a common thread that runs through nearly every piece of the Trail Runner SWT. Every Allbirds shoe features merino wool, and this one is no different. The merino wool lining on the interior of the upper feels soft against your feet, but it also helps with odor, moisture, and temperature management. On the outside, the upper is made from tough recycled polyester for durability and protection in wet or dry climates, and a low-cut sock cuff keeps out dirt and precipitation. The laces are made from recycled water bottles, and the midsole is made from Allbirds’ proprietary cushioning material called SweetFoam; it’s derived from renewable sugarcane grown in southern Brazil. Even the rubber outsole is FSC-certified, meaning it’s natural and sustainably sourced.

With a heel-to-toe drop of seven millimeters, the Trail Runner SWT falls in the medium drop category (stack height is 18mm at the forefoot and 25mm at the heel). The outsole lugs are shaped like macaroni elbows to provide grip on rocky, muddy, and grassy surfaces. According to Allbirds, the design was inspired by mountain bike tires and David Hockney pool paintings, and it aims to inject a sense of playfulness into a category that tends to be overly aggressive.

According to Allbirds, the Trail Runner SWT has been tested over 2,000 miles by trail runners and hikers, including Allgood Collective members Jorge Maravilla, a two-time San Francisco Marathon winner, and Iman Smith, a marathoner and running coach.

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The Allbirds Trail Runner SWT outsole lugs
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Why We Like It

As someone who’s loyal to Hoka One One trail shoes for their supreme cushioning and bounce, I was worried that the Trail Runner SWT would leave my feet sensitive to small bumps on the trail. Usually when I test new shoes, it takes about a week of running in them for my feet to adjust (if they do at all).

But right out of the box, the Trail Runner SWT was comfortable on a five-mile trail run. During the first half-mile on pavement, the rubber was adequately grippy, but I didn’t feel like I was running in cleats like I do in some trail shoes with big lugs.

As soon as I hit the trail, they started to shine. The noodle-shaped lugs stuck to the ground and kept my feet stable even in loose gravel, and my footfalls felt softer in the dirt than on pavement. Even though this pair has a slimmer profile than my usual kicks (Hoka’s Speedgoat 4), they had plenty of surface area to grip the terrain and absorb impact.

Shoes that are too stiff tend to tire out my arches quickly, as my toes and heel flex without the rest of the foot moving with them. Too flimsy, on the other hand, and there’s not enough protection from rocks and roots. The Trail Runner SWT fell perfectly in the middle, with both enough flex and adequate support for longer efforts.

We’ve only had one frost here in Flagstaff, where I live, so I’m not sure yet how these will feel in the cold or perform in the mud and snow. But the merino wool upper should give them a cozy feel, and wool’s natural antimicrobial properties will help keep foul smells at bay.

Overall, Allbirds gets two thumbs up: One for finally making a trail shoe and a second for the use of sustainable materials in footwear (which makes up a significant portion of the waste that ends up in landfills).


I have medium-width feet, and I filled these out. Runners with wide or narrow feet might have issues with the fit—either too little or too much room.


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