Convenient form factor. Practically weightless. Rechargeable battery. Onboard memory. Works with Strava.
Only reads heart rate. Limited app connectivity.
- Bottom Line
The Polar OH1 is an optical armband heart rate monitor rather than a chest strap, and is one of the better devices in the category.
Comfortable, reliable, and featherlight, the $79.95 Polar OH1 should be at the top of your list if you're looking to buy an armband heart rate monitor (HRM) rather than a chest strap. A rechargeable battery ensures you never have to go shopping for replacement coin cells, and Bluetooth syncing means you can use the OH1 directly with supported fitness apps, including Strava. The Polar OH1 is among the best heart rate monitors we've tested, and an excellent alternative to a chest strap.
Chest strap HRMs and armbands use two different types of technology. Chest straps use electrical pulse technology while armbands use optical, the same thing used in the Apple Watch and many fitness trackers for running. The OH1 is an optical device.
Without getting too technical, chest straps read the small electrical signal that your body creates to make your heart constrict. Optical technology sends light into the skin and reads the light that comes back. Based on that information and what we know about how light scatters when it hits bloodflow, the device figures out your pulse. Electrical technology is considered slightly more accurate, but for the purpose of everyday athletics, the differences are moot.
Another technological difference seen among HRMs is whether they sync via ANT+, Bluetooth, or both. ANT+ is often used for HRMs that are designed to connect with specific devices, such as runners' watches and bicycle computers. Bluetooth is a better option if you want to sync directly to your phone, which you'd need for any companion apps that include real-time coaching based on your heart rate.
The OH1 uses Bluetooth, as well as direct USB syncing, which is unusual but handy. You can upload data stored on the device directly to your computer while you're recharging the battery. The OH1's internal memory stores up to 200 hours of training data.
Speaking of batteries, it's certainly a bonus to be able to recharge the lithium polymer one inside the OH1 so you never have to buy a specialty size coin cell, which is what most HRMs use. A full charge can last 12 hours, and it's waterproof to 30 meters, which means you shouldn't swim with it but heavy rain and sweat are no problem.
Design and Fit
The Polar OH1 is so light, I actually worried that the sensor was missing. At 0.176 ounces (5 grams), you can hardly tell it's there. The armband itself only weighs 0.42 ounces (12 grams).
The soft and flexible black band uses a minimal amount of plastic and metal for adjusting the fit and snapping the sensor into place. A tag that's tucked away from your skin indicates that the band is machine washable. The strap is the same material you find on most HRM chest straps, which is world's better than the textured strap used on the Scosche Rhythm + armband, which attracts dust bunnies like crazy.
One size fits all. The OH1 stretches to about a 24-inch circumference and works on either the upper or lower arm. No living human's forearms are that big.
The sensor snaps into a compartment on the inside of the strap. When you remove the sensor from the chamber, helpful reminders are printed inside: 1x=On, 1x Long=Off, 2x=Rec. These are instructions for pressing the silver button on the side of the sensor. One press turns it on, a long press turns it off, and pushing it twice begins recording.
An indicator light on the opposite side of the button flashes green to let you know the sensor is on or recording, and red when changing modes. It blinks orange while charging and keeps a steady green when at 100 percent.
Compatibility and Use
The OH1 has its own onboard memory, so you can record a workout with it and leave your phone behind. Alternatively, you can connect it to Android and iOS devices to use it directly with certain fitness apps. The phone requirements are low: You need an iPhone 4S or later, or Android 4.4 and later with Bluetooth 4.0. The OH1 is also compatible with all Bluetooth-compatible Polar watches, fitness trackers, and cycling computers, such as the M430, V800, and M600, and the M460 bicycle computer.
The Polar Beat app works with the OH1 directly, letting you record your heart rate while doing any activity in the app's very long list. I've used the app before when testing Polar products while running, dancing, doing yoga, cycling, and more. It does a great job of tracking metrics, and I especially like that there are limited features behind paywalls. Everything is included for free.
If you want to use other non-Polar branded fitness apps with this HRM, just check whether they can connect to Polar Flow. Strava, for example, connects to Polar Flow, rather than connecting to the armband directly. Polar Flow is the central service used for Polar devices. It's basically the app used to track all your activities, set up new devices, enter personal information such as height and weight, and so forth. Polar Flow collects all your Polar data in one place. There's a web app, desktop app, and mobile apps.
After trying on the OH 1 in a few different ways, I chose to wear it on my upper left arm. That's information you need to know in advance, as you have to enter it during setup (you can always change this setting later). You also need a computer with a USB port and the Polar Flow desktop app to set up this particular device; you cannot do it from a mobile device.
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On the arm, the OH1 feels as weightless as it did in my hands. I loosened the strap a few times while getting used to it, as I realized it doesn't need to be so tight as to make an imprint, just snug enough to stay in place and have good contact with my skin.
One of the first time I wore an armband HRM was back in 2014 when the Mio Link debuted, and I have been waiting ever since for more companies to copy one excellent feature from that device. The Link has an indicator light that changes color based on your current heart rate zone. It's so simple and yet so beneficial. Unfortunately, the Polar OH1 does not have a color-changing indicator light for heart rate zones.
You can still buy the Mio Link, although the company is now pushing instead its wrist-based fitness tracker with optical heart rate, the Mio Slice. It's a nice tracker, but it also lacks those color-coded lights that I love so much.
To get a sense of accuracy, I wore the Polar OH1 and Wahoo Fitness Tickr X at the same time both at rest and while working out. I connected each HRM to a different phone and used an app that shows my heart rate in real time for both of them, Polar Beat and Wahoo Fitness.
It took 30 to 45 seconds for the HRMs to connect and get a stable heart rate reading. From there on out, my heart rate was never more than about five beats per minute different between the two readings, and usually the difference only lasted a few seconds. The two readings were always within the same range.
Price and Comparisons
The Polar OH1 costs $79.95. There are two things to keep in mind when comparing its price with those of other HRMs. First, the OH1 only reads heart rate, whereas a few other HRMs in the same price range include internal motion sensors that can read other data, too. Second, the OH1 is an arm band, not a chest strap, which some people prefer for comfort and ease of use. Women in particular will find that adjusting an armband during a workout is much more convenient than reaching under their shirt and possibly also under their bra band to futz with a chest strap.
Most top-of-the-line HRMs also have a sticker price around $79. Our Editors' Choice, the Wahoo Fitness Tickr X, retails for $99.99, but you can usually find it for $79.99. The Tickr X can track advanced workout metrics, such as reps during strength training and ground contact time during runs, so it packs a lot of value.
Budget-conscious shoppers can save money and still get a reliable device by opting for a standard chest strap that only reads heart rate. Two solid options are Garmin's Soft Strap Premium Heart Rate Sensor ($69.99) or a slightly older model simply called Garmin Heart Rate Monitor ($49.99).
If you're in the market for an armband HRM rather than a chest strap, the Polar OH1 should definitely be in your list of consideration. It works well and is convenient to wear. Make sure it or the Polar Flow service can connect to the devices and apps you want to use with it, however.
If you're undecided about the form factor, the Wahoo Fitness Tickr X and Garmin HRM-Run come with added value because they each have an internal motion sensor. And the Polar H10 is a reliable and option if you already own Polar devices.
About the Author
Jill Duffy is a contributing editor, specializing in productivity apps and software, as well as technologies for health and fitness. She writes the weekly Get Organized column, with tips on how to lead a better digital life. Her first book, Get Organized: How to Clean Up Your Messy Digital Life is available for Kindle, iPad, and other digital forma… See Full Bio
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