Comfort Recognized by Runners Who Pursue Ultimate Wearability! The Functionality of UNIQLO's "UV Protection Seamless Arm Covers"

We've been seeing blazing sunlight day after day. And with it, more and more people are turning to arm covers.

Nowadays, arm covers aren’t just a must-have for people wanting to avoid tanning. They're an essential for cycling, sports activities, and outdoor work. Among the options out there, UNIQLO's UV Protection Seamless Arm Covers has especially high support among runners.

Runners pour sweat and build up fatigue as time goes by. Serious runners who don’t skip training, even in the heat of summer, are especially particular about what they wear.

Take eyewear that bounces with each step or apparel that easily chafes and traps moisture—these are annoyances that can become major distractions on a run. So, why are runners who are so selective about their gear choosing the non-sports item "UV Protection Seamless Arm Covers"? We spoke with UNIQLO’s PR team to find out.

Beyond Just UV Protection: Supreme Comfort in Wearability

This item debuted in UNIQLO's Spring/Summer 2020 collection. At the time, UNIQLO’s "AIRism UV Protection Full-Zip Hoodie" was enjoying strong sales.

"Around then, we noticed that more and more people nearby were wearing arm covers. Since the 'AIRism UV Protection Full-Zip Hoodie' offered not just UV protection but was also made of AIRism fabric, it got us thinking: wouldn’t it be convenient to make arm covers out of the same material?"

You likely know that “AIRism” is a must-have for summer. Not only does it have excellent sweat-wicking and quick-dry capabilities, but it also delivers instant cooling and anti-odor properties.

"On top of that, the fabric touching your skin is ultra-smooth, thanks to AIRism’s unique texture. The dry function helps keep your skin feeling silky, and the instant cooling effect makes putting them on feel refreshing.

"Also, arm covers are designed to fit snugly on your arms, right? AIRism uses 'corespun yarn,' a polyurethane material with elasticity and a high rate of stretch recovery, so it quickly snaps back into shape. That’s why it’s the perfect fabric for arm covers."

Seamless Design for Enhanced Comfort

At UNIQLO, even their blockbuster items go through ongoing R&D and are repeatedly updated to improve functionality. Arm covers were no exception.

"At first, we made them simply by cutting the same fabric as our parkas. But we started hearing feedback that the seams felt rough on skin and the stretch made it hard for the sleeves to fit snugly on your arms."

So, UNIQLO re-examined the sewing and threads and, in 2022, released the updated seamless version of the "UV Protection Seamless Arm Covers."

"To offer a sensation of wearing nothing at all, we use ultra-fine fibers in the yarn. After testing various fiber thicknesses to maximize AIRism's trademark smoothness and comfort, we landed on this ultra-fine specification."

Instead of woven fabric, they use a knit construction. That means there’s no need for stitching, greatly improving the fit. The thumbhole is ergonomically designed and switched to a bonded finish, resulting in extra softness and preventing fraying or stretching even with prolonged use.

"We also changed the cutting method. The usual cutting approach had the flaw that the fabric would easily fray at the edges, so UNIQLO independently developed ultrasonic cutting equipment.

"On the other hand, because the arm cover material is stretchy, using the normal cutting method led to distortions and a lot of wasted fabric. With this ultrasonic cutting technology, even with stretchy materials, we’re able to maintain smooth edges and a clean shape."

Yarn, knitting method, cutting, and an ergonomically tailored design—all these elements blend together to create an exceptional fit acknowledged by runners.

As a side note, these arm covers have a cooling-touch feature. We’ve heard feedback that "if you pour water on them, the evaporative cooling makes them feel even cooler." For runners training under the blistering summer sun, it’s a much-appreciated detail.

"Thanks to this, since launching the seamless type, our sales have steadily increased year after year. Something that surprised even us was how many size requests we received from men. That’s why, starting with spring/summer 2024, we began offering an L size for men via our online store."

The lineup includes five basic colors that work well from lifestyle wear to sportswear, making them easy to match with any outfit. They are long enough to cover from the back of the hand to the upper arm completely.

"Moving forward, while keeping the popular functional features, we want to explore new textures and designs so these can be styled as broader fashion items."

With Japan’s summer heat lingering, there’s a reason why runners braving such tough conditions choose these arm covers. It isn’t just about sun protection—the stress-minimizing design and unexpectedly comfortable fit allow you to focus on your run. Once you try them, you’ll be surprised how good they feel.

This summer, why not keep the heat at bay with the runner-approved creation from UNIQLO?