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Under Armour Armour39 review: This serious fitness tool could do more

The $149.99 Under Armour Armour39 is targeted at those who want to get serious about recording their workouts.

Roger Cheng Former Executive Editor / Head of News
Roger Cheng (he/him/his) was the executive editor in charge of CNET News, managing everything from daily breaking news to in-depth investigative packages. Prior to this, he was on the telecommunications beat and wrote for Dow Jones Newswires and The Wall Street Journal for nearly a decade and got his start writing and laying out pages at a local paper in Southern California. He's a devoted Trojan alum and thinks sleep is the perfect -- if unattainable -- hobby for a parent.
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  • SABEW Best in Business 2011 Award for Breaking News Coverage, Eddie Award in 2020 for 5G coverage, runner-up National Arts & Entertainment Journalism Award for culture analysis.
Roger Cheng
5 min read

With the $149.99 Armour39 system, Under Armour branches out from its comfort zone as a sports apparel manufacturer to make its first foray into the burgeoning fitness-tracking craze. Unlike competing fitness products, such as the Nike FuelBand and Fitbit Flex, which almost anyone can use, the Armour39 is meant for serious athletes seeking to boost their training regimen.


Under Armour Armour39

The Good

<b>Under Armour's Armour39</b> is well-suited for hard-core athletes who want an accurate measurement of their most vital workout stats. The tracker uses a clean and easy-to-read iOS app, which syncs via convenient wireless Bluetooth connection.

The Bad

The Armour39 is too cumbersome to wear all day, and you must strap it on before you work out. Using it without an iOS device provides much less information. There's still no Android version of the app, and the Armour39 doesn't record steps.

The Bottom Line

The Armour39 is meant only for hard-core fitness fanatics, but even those gym rats will be left wanting more.

Indeed, with a sizable strap that goes around the torso, it's much more than just a tiny device you wear on your wrist. But once they hit the gym, even its target audience of extreme fitness fanatics may find the Armour39's intensity lacking. It keeps tabs on your most vital fitness data, then electronically transmits those stats to an iOS app, but missing features keep it from delivering a complete experience.

Under Armour's Armour39 built for intense exercise (pictures)

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When I first held the Armour39 fitness-monitoring strap, I was a little concerned about wearing a gadget that needs to make skin-to-skin contact with my chest. I also didn't want something under my shirt possibly irritating me as I exercised. To my surprise, though, the strap fit snugly around my torso and easily stayed fastened with simple hooks. At times, I barely noticed it was on, but it's not something that you'll want to wear for hours on end.

With yellow accents and a gaudy paint job, the Armour39's design isn't for the timid. Sarah Tew/CNET

Yellow curvy lines flank the front of the black stretchable strap bracket, which acts as a center circular dock for the removable yellow "bug" and is boldly emblazoned with the Under Armour logo. The bug itself is about the size of a 50-cent piece and sports an indicator light that routinely blinks red, letting me know that its Bluetooth connection is working. I do find the splashes of yellow as well as the large Armour39 logo on the side of the gadget a bit garish. Still, it's really a moot point since the device is meant to be worn under your clothes.

The tracker uses a watch battery that's replaceable, but not rechargeable. Sarah Tew/CNET

Rather than a rechargeable battery, Under Armour opted to put in a regular watch battery in the bug. One benefit is that you never have to worry about recharging the device. But you will eventually have to replace the battery. The company told me that the battery is expected to last more than a year if you work out an hour three to four times a week.

That you have to actually put on the Armour39 prior to working out sets it apart from other more casual fitness trackers, which are typically worn throughout the day and track overall activity more than a specific workout. That probably won't be an issue for the devoted workout set, but I don't want to have to remember one more thing to bring to the gym. I mean, it's hard enough to get me there in the first place.

The core metrics of Armour39 are heart rate, intensity, and calories burned. But like what Nike has done with the FuelBand and NikeFuel points, Under Armour has echoed via something called WillPower, its own proprietary measurement of how hard you worked.

The companion app is easy to use and displays information clearly. Roger Cheng/CNET

Also akin to NikeFuel, WillPower is only effective if you buy into it. WillPower takes into account how long you worked out, your gender, height, weight, and heart rate, giving you a score between 1 and 10. Personally, I only got as high as the 5.5 mark, so I probably wasn't pushing myself very hard, but I'd like a more meaningful metric.

What's more, since it lacks an accelerometer, one thing the device doesn't track is the number of steps you take during your exercise session. While running isn't the only workout routine that I do, it's the activity I did the most during my review period. In addition to the other information, I would have liked to know how far I traveled, but the gizmo doesn't have a GPS sensor, either.

I applaud Under Armour for how user-friendly its Armour39 app is. Once it loads, you just set up your profile, input a few key stats like weight and height, and you're off. You can sync the app to the fitness tracker; view a calendar of past sessions, where you can review stats and take notes; and access a settings menu to mess with the profile and device info. In addition, there's an assessment mode that involves running at various speeds for about 10 minutes, which allows the system to record your progress over the long term (the intention is for you to do an assessment once a month).

You don't need to have your iOS device with you to use the Armour39 -- the bug will sync once you're back in range -- but it's a lot handier to keep it around. If your iPhone is near, for example, you can get a breakdown of heart rate and intensity by regular intervals.

The app helps you track progress over time. Roger Cheng/CNET

That's great, but there was one instance in which I left my iPhone in the locker after starting my workout, only to return and find that the app had restarted and my session was lost. It happened only once, but my confidence in the Armour39's ability to keep my workouts straight was shaken. The company said that it has not been a widespread problem, but it is looking at customer feedback and any other issues.

Also, the Armour39 app unfortunately is available only on iOS for the time being. The company plans to release an Android version, but it doesn't know exactly when.

For those who don't have an iOS device and can't wait, Under Armour will offer a watch accessory for $199.99 that syncs with the device and displays exercise stats in real time. The watch, however, is also unavailable, and the company doesn't know when it will sell that device, either.

The sole reliance on the app -- while solid -- is also a bit of a weakness. There's no Web site with more comprehensive stats and data, something I appreciated with Nike and Fitbit. Also, there isn't much of a social element, and you can't share your progress with friends and family against whom you may be competing. It was the social element that I found motivated me the most with some of the fitness gear.

Armour39 occupies its own place in the universe of fitness trackers. Rather than a casual device, Under Armour has gone after hard-core athletes with its system. Still, at $149.99, the Armour39 is priced the same as the FuelBand, close to the $129.99 Jawbone Up, and a good bit more than the $99.95 Fitbit Flex, which offers the most bang for your buck.

For what it does, Armour39 does it well. But I wanted it to do so much more, from incorporating steps as a metric to providing a robust online dashboard with social elements for sharing my progress. Speaking from the vantage point of a theoretical gym rat, which clearly I'm not, if I'm that intense about my workouts, wouldn't I want as many tools at my disposal as possible? That's why the Armour39 is a good start but doesn't quite satisfy.


Under Armour Armour39

Score Breakdown

Design 5Features 5Performance 5