A little-known company made smart fitness clothing you might actually wear at the gym

It has lots of potential, but it's expensive and only available in the UK for now.

Mat Smith/Engadget

Smartwear hasn’t quite had its moment. Innovators like Hexoskin and Omsignal, not to mention huge companies like Adidas and Ralph Lauren, have struggled to make an impact, demanding a lot of money for dedicated shirts and sensors, while contending with mediocre accuracy, polarizing style choices and not many compelling reasons to exist. As Adam Crofts, founder of the startup Prevayl, puts it, there have been a lot of lessons to learn from other companies’ mistakes. He’s hoping to get it right.

Prevayl, whose first products launch in the UK later this month, combines a small tracking sensor with a line of fitness “smart” shirts, from crop tops through to vests and compression shirts, in addition to a companion app (of course) and an online community. Usually, that means something approximating a forum, but according to the company’s website, it’s created “a members-only private community designed for amateur athletes and the sporting elite.”

It’s limited its first wave of users to 700 people. The audience seems to be, well, the fittest friends and acquaintances you know. The ones that know what they can benchpress, their fastest 5K time, or their VO2 Max. The latter is not a haircare product.

Prevayl’s sweet spot is this area between amateur athlete and biometric obsessive, and it’s approaching the fitness tech fight with style. It has a slick promotional video featuring pro athletes, a moody black logo and a surprisingly slick, well designed app. (Seriously, it amazes me how poor most entry-level fitness apps can still look.) And the shirt? Well, it looks good on the athletes.

Prevayl smart shirt

At a preview event in London, the team set me up in one of their first shirts, ahead of a planned launch early next year. It feels like a premium, luxury sports tee. It’s breathable, soft to the touch and tight. An elasticated band across the chest on all of the garments houses the conductive sensors, connected with graphene-augmented knitted electrodes. The fibers connecting these sensors look like metallic shoelaces and are machine washable. The shirt can go straight into a warm laundry wash; you just need to ensure you’ve taken the sensor out from the tiny pocket on the front of the clothing.

Prevayl smart shirt
Mat Smith/Engadget

There’s no need to fasten the sensor in place, as it comes in contact with the conductive fabric as soon as it’s in the front of the shirt. The sensor itself is an evolution from the chunky haphazard sensor unit design of smartwear’s past. The sensor has a plastic stopper that protects the USB-C charging port, while the charging cable is a small, machined aluminum clasp that magnetically folds in on itself.

The company makes everything here in-house, and Crofts believes this is why Prevayl can do things differently. “Usually, it’s been tech [companies] trying to make clothing or visa versa.” The company’s approach to the clothing itself was “style led” design. Prevayl’s head office has entire machines and technicians dedicated to knitting the clothing part of the equation.

Despite the sensor itself being so small, it’s packed with tech. There’s a “clinical-grade” ECG, that tracks your workout with four times the frequency of Polar heart rate monitors. It also monitors breathing frequency, motion and even body temperature. There’s even a bioimpedance sensor, which can be used for body composition scans, but there didn’t seem to be any feature that takes advantage of that yet. Prevayl is trying to do it all.

The company puts all this biometric data to use through many of the features and guidance you’ve seen on other fitness devices and services. Like Whoop, the system can be used to gauge whether your body has fully recovered from a workout; like MyZone’s traffic light system, it color-codes your workout effort into five categories, measuring both how hard you’re working out and when your heart rate has recovered. This is all in addition to tracking your heart-rate, caloric burn and more. Within the app, you can even see an accurate cardiogram of your heart as it beats away.

Prevayl smart shirt
Mat Smith/Engadget

One of the bigger challenges, which many fitness trackers and wearables struggle with, is ensuring a decent level of accuracy. Crofts mentioned multiple times during our interview that the company has been obsessed with gathering data.

The company worked with the UK’s University of Salford to validate the accuracy of its ECG unit. The team also recruited professional athletes, including British Olympic and Paralympic athletes and professional sportspeople, to test its prototypes and offer up crucial data for the team to chew over. The next stage is testing with more typical gym-goers, weekend warriors and the marginal gain-chaser, kicking off this month.

Even sized at a large, my tee felt a little too snug. I know many of us aren’t fans of the compression fit, but this, a tank top and crop top are the only options for now. Fortunately, Prevayl is working on loose fit and long-sleeved options, which I’d find more appealing. More colors, beyond Personal Trainer Black (my name, not theirs), are also incoming. The issue remains, though: If you wanted to use this system frequently, you will need more than one top. Or to do a daily laundry run.

As the sensor is removable, this should strip away some (most?) of the cost of additional shirts. But Prevayl wants to invade the luxury sportswear segment and that means prices to reflect that ambition. To begin with, it will cost you at least £120, which is roughly equivalent to $160. This starter kit includes a sensor priced at £60, and a tank top. Not including the sensor, the Smart Tank will cost £60, while the Smarts Sports Bra will be £65. The Smart T-Shirt, which I tested, will cost £70. The impressive specs and tight app integration will go up against the expensive cost of entry.

Judging from my demo with Prevayl’s team (and my own early testing), the product is already looking polished. I spoke with a fitness professional at my local gym who, conveniently, had also tested out Prevayl. She noted that any new smartwear product would have to fight against incumbent chest straps and fitness trackers. Unlike a smartwatch, it’s nearly impossible to wear this top in tandem with a chest strap from another manufacturer. People are creators of habit — especially when it comes to exercise. People swear by Strada or their Apple Watch because it’s familiar and consistent. At this early stage, Prevayl’s online community isn’t yet live.

For now, the company is focusing on the UK and Ireland, but Prevayl’s spokesperson told me that the US will be a priority. I’m planning to test the smart shirt further, but I might have to invest in more items if I want to get serious about using Prevayl regularly.

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