Review: The Polar OH1+ provides precise heart rate monitoring both on land and in water


In and out of the water, accurate HR data

Compact and light-weight memory for ANT+ and BLE connection data caching

Battery life of 12 hours


Physical buttons are tiny, and the meanings of the LEDs can be unclear.


DESIGN: 8.5/10

EASE OF USE: 8.5/10



The OH1+ was just unveiled by Polar. To measure pulse rate from the temple, the strap, which has BLE/ANT+ connectivity, is attached to swim goggles.

In our assessment, we thought the OH1, its predecessor, was a fantastic device. Heart rate monitoring is now easier than ever. The tiny device can be worn on either the upper or lower arm and is lightweight and comfy. The readings’ accuracy, though, really stood out. It’s far better than a wrist-based heart rate monitor and comes near to what you would receive with a heart rate chest strap.

Over the past few weeks, I’ve been testing the updated version. Find out what I thought of it by reading on.


The OH1+ has the same appearance as its predecessor. The tiny round optical heart rate monitor is about the size of a penny, with a diameter of just under 30mm and a low weight of 5 grams. Actually weighing in at 12 grams, the strap is heavier than the device.

The plastic holder that is fastened to the velcro band accommodates the sensor with ease. The device can once again be strapped to either your upper or lower arm. The armband has a 24-inch circumference and is stretchable, so it should fit everyone even though this is a one size fits all item. There are several colors available for the interchangeable strap.

The OH1+ is machine washable and maintains the 3 ATM water resistance of its predecessor. However, a google clip that can be used to attach the device to swim goggles has made it possible for another unusual manner to use it to exist.

This makes it possible to measure heart rate at the temple. This is a smart decision by Polar because the lack of water interference makes it much easier to collect correct data from this position. The pulse can be easily monitored due to the thin layer of muscle and fat at the side and behind the eye.

The Polar OH1+ is compatible right out of the box with the majority of sports watches, trackers, cycle computers, and gym and studio equipment including treadmills. Your heart rate is transmitted using ANT+ and Bluetooth. Many people have been patiently waiting for this last improvement.

The OH14 +‘s GB of internal memory will be appreciated by those who want to exercise without a watch or a phone. Up to 200 hours of training data can be stored on this.

It’s important to note at this point that the internals of OH1 and OH1+ are identical. The OH1 does not yet support ANT+ transmission, but this functionality will be included in a future firmware version. After that, the swim goggle clip will be the main distinction between the two.

Excellent battery life of 12 hours provides more than enough time for even the longest training sessions. The 45 mAh lithium polymer battery is rechargeable, which is the best part because it eliminates the need for constant coin cell replacement shopping.

The sensor unit fits precisely into an exclusive charger that closely resembles a tiny USB stick. The OH1+ can completely recharge in a few hours when you plug it into a computer port or a USB power converter. It’s interesting how the charger not only resembles a USB stick but also works like one. You can sync and update firmware while charging if you download the Polar Flow Sync desktop application.

Install and use

Simply pair the OH1+ with a device or app to get started, and you’re good to go. There is no special installation required, but you might be prompted to perform a firmware upgrade while pairing with the Polar Beat app.

There are various applications for the device. In broadcast mode, real-time heart rate data is transmitted to compatible devices using Bluetooth or ANT+. Heart rate training data is internally kept in solo mode for later synchronization. For swimming, this last one is ideal.

The ANT+ is a crucial accessory. You may now stream your heart rate in real time through ANT+ to an infinite number of devices in addition to the single Bluetooth connection. In the end, I’ve never had a problem attaching the sensor to any of my equipment. It immediately establishes a connection and maintains that connection until you instruct it to disconnect.

Numerous third-party fitness apps, including Strava, Endomondo, MapMyRun, and others are compatible with the OH1+, in addition to Polar Beat and Polar Flow. If you want to record workouts but don’t have a sports watch, Polar Beat is a wonderful choice. The Beat app and the Polar Flow app seamlessly sync, and the Polar Flow app offers more thorough statistics.

It’s crucial to check that the LED optical green sensors on the underside of the main unit are firmly in contact with your skin while wearing. It is recommended to wear your OH1+ for a little while before beginning a training session in order to ensure accuracy from the start. Like with other optical systems, the user may need to experiment a little to determine the ideal location for the system.

I had no issues using the OH1+ in any of the three positions (upper arm, lower arm, and swim goggles). The only problem I had was that the sensor unit and band felt like they would topple over because of how thin they were. Not an issue when the HR monitor is on your arm, however swimmers might want to think about wearing the device beneath a swim hat to keep it securely in place. When rinsing swim goggles in between pool lengths, you should take extra care. You might not even notice if it turns over.

By pushing the lone physical button on the side of the gadget, you can start your session by turning the sensor on. This will be verified by an LED light at the opposite end repeatedly flashing green. Numerous different uses exist for the LED light. When there is no heart rate detected, a white light flashes every two seconds; when it is on and recording, it flashes green.

Press the button twice to start solitary training mode. Two fast flashes followed by a shift in the pattern of the light’s subsequent flashes will serve as confirmation. Simply press and hold the button to turn it off. The battery has to be charged, and blue flashing means it’s ready to sync. I won’t delve into additional flashing patterns with distinct meanings that exist.

It’s understandable if you find all of this to be a little perplexing. The physical button works as intended, however it is small and challenging to press. A bigger button is what I would have preferred. Additionally, it takes time to recall the significance of each flashing pattern. This could have been made a little easier, I can’t help but think.

However, the OH1+ is quite dependable and performs well. The Polar Flow/Beat app on your smartphone wirelessly uploads all the data from your session for easy analysis. There is no need to engage any buttons. Your data will automatically transfer to your smartphone as you launch the app and turn on the sensor.

App Polar Beat

The programme labels every session that was stored in memory as “Other.” You can change this for the session by selecting a workout from a long list with only a single press on the smartphone screen.

App Polar Beat

For more thorough statistics, check out Polar Flow.

App Polar Flow

You can use the Polar Flow web service to organize your training, keep track of your accomplishments, export data, obtain advice, and view a thorough analysis of your training performance.

Review: The Polar OH1+ provides precise heart rate monitoring both on land and in water.

Web service Polar Flow

Using 6-LED optical green sensors on the underside of the main unit, the data Polar monitors your heart rate. A photodiode measures the intensity of the green light that is reflected back after the lights attack your skin at a high rate. Less light is reflected back when the blood flow between heartbeats is weaker. To determine your heart rate, the OH1+ computes these variations.

You’ll discover that the OH1 is amazingly accurate, far superior to a wrist-based heart rate monitor, and on par with results obtained by using a chest strap. In my test sessions, I discovered that any discrepancies were typically simply one or two beats. And only at the start of a session or when engaging in very high intensity activities.

Here is how it compares, for instance, to the Scosche RHYTHM+. Even more accurate than its more current sister, the RHYTHM 24, the Scosche RHYTHM+ is regarded by many as one of the best upper arm HR monitors. The picture depicts a recent 5K run. As you can see, the average heart rate is the same, with the exception that the OH1+ (dark blue line) displays a maximum heart rate of 168 while the RHYTHM+ shows a maximum heart rate of 167.

You might be asking yourself at this point, “What about a chest strap?” I’ll compare it against the Polar H10 chest strap in this additional run. Again, quite similar. The OH1+ (dark blue line) displayed a maximum of 170 bpm and an average of 154 bpm across 5K. The Polar H10 has a range of 155 to 168 beats per minute.

all of these have Bluetooth and ANT+ connectivity and operate from the upper/middle arm. However, Scosche’s gadgets come with a basic app while Wahoo’s lacks offline caching. Additionally, the OH1+ is the only or best option overall for swim tracking and has improved water resistance.

Most importantly, the Polar OH1+ is just as excellent as or better than the others in terms of accuracy. When it comes to battery life, it only pales in comparison—12 hours as opposed to 24 hours on the Scosche Rhythm 24 and 30 hours on the TICKR FIT. Not that having a battery life of 12 hours is anything to complain about. It permits a number of training sessions.

Review of the Polar OH1+ for precise heart rate monitoring in and out of the water.


The result

The Polar OH1 has a few modifications that are quite effective in its new and enhanced form. A long-awaited feature, ANT+ connectivity, has been added, along with a unique method of measuring your heart rate while swimming from the temple. It should come as no surprise that accuracy is superb on land and in the water given the positive ratings of its predecessor.

Of course, nothing is flawless. It never is. The physical button on the OH1+ is probably a little too small for my tastes, and it takes some getting used to the many LED flashing patterns and colors.

Leave a Reply