Polar OH1 Review (2019 Update) | Optical HR Sensor, Arm-Worn

FTC: Affiliate Disclosure: All links pay commissionReading Time: 22 minutes

Polar OH1 Review

This Polar OH1 Review (2019 Update) will look in detail at Polar’s first arm-worn optical heart rate monitor.

Polar OH1 Detailed Review Optical HRM HR Band


When the OH1 was first announced I was excited.

As it’s ‘only’ a heart rate monitor this will be a fairly short, but detailed review.

In my opinion, Polar have pressed quite a few tasty sports buttons with the OH1, it should sell well for a variety of sports uses which I have previously covered in more detail here (link to: the5krunner.com) and here (link to: the5krunner.com).

Don’t worry. I’m still excited.


It’s a Bluetooth SMART optical Heart Rate (HR) monitor (oHRM) intended to be worn on the arm.

You can pair it with apps and sports watches as you would do any other Bluetooth SMART heart rate monitor. There are many apps and lots of sports watches that will be compatible.


It’s waterproof and it can record and store (cache) HR data to be retrieved later. Initially, only the Polar FLOW app can retrieve this cached data.

The downside is that IT IS NOT ANT+ compatible and cannot be used with some Garmin-compatible sports devices BUT new high-end sports devices from Garmin such as the Fenix 5 and Edge 1030, are starting to support Bluetooth SMART.

The OH1 is similar to the Scosche RHYTHM+ product (Reviewed, link to: the5krunner.com) but the OH1 caches data, is waterproof and has a superior battery life. The only reason to buy the SCOSCHE would be the ANT+ connection – favourable review permitting, of course.


You can use this device in one of three ways:

  1. As a Bluetooth heart rate monitor, just as you would with a chest strap….but on your arm;
  2. As a CACHING heart rate monitor linking and syncing later ONLY to Polar FLOW; or
  3. Those two ways simultaneously, effectively creating two separate, potentially identical, workouts.


Polar’s initial marketing seems to be focussing on ‘women doing gym classes‘. That’s probably a relatively large market but there are also many other sports markets for the OH1 including ‘men doing Monday night soccer/football‘. Gender stereotyping aside, it is great for sports that require: a safe, comfortable wear-position; a separation of the recording device from the sensor; and/or waterproofing. 18 months after release and I still use my OH1 as one source of HR when testing new sports watches.

So that should at least cover these quite nicely: swimming; open water swimming; team sports; gym classes; any regular sport where you just don’t want to wear a chest strap; and 24×7 HR tracking.

*IF* it’s accurate then many people could switch to it.

Let’s not get ahead of ourselves. The accuracy stats will follow further below, so let’s start off this Polar OH1 Review with a bit more detail on the OH1 itself.


I’ll keep this simple. You get a box; the strap; the sensor; a charging cradle; and, of course, lots of bits of paper that you will never, ever read.


The circular pod has all the clever stuff inside it. The strap just holds the pod in place against the skin on the arm (or wherever you put it).

Polar OH1 Detailed Review Optical HRM HR BandTo charge the OH1, the proprietary cradle is required. That cradle will plug into any standard USB port – for example in a wall socket port or in a computer. When mounted into horizontal computer ports it might be tricky to use adjacent ports and vertical ports are better – as shown below.

Either way, you could buy a £/$/Eu2.00 USB extension cable and leave it to dangle in lots of exciting places.


The stated battery life of 12 hours is approximately correct. I have got somewhere between 11.5 and 12 hours of mixed broadcasting-only and broadcasting+caching usage on a single, full charge.

It is likely that caching and use in different sports will make little, or no, difference at all to the 12 hours of battery life. It only has one job to do.

Polar OH1 Detailed Review Optical HRM HR Band

Like any rechargeable battery, those 12 hours may fall over time and usage. Although Polar do say that you will not notice any degradation in life until after at least 300 full charges.

The biggest danger to the battery life is forgetting to turn it off !

This Polar OH1 review will now turn to the performance characteristics of the product.

In caching mode the ‘battery low’ warning message appears about 2 HOURS prior to total depletion of the battery. The LED flashes change to include RED.

18 months later than has reduced by a couple of hours and, annoyingly, the OH1 loses charge when not in use.


It’s super small (dia 29.85mm x 9.5mm high) and super light (5g sensor + 12g armband). to put that into a real-world context here are some comparisons to an AAA and AA battery, the ones most of us use all over the world, although probably with different names. You know the ones I mean.

Polar OH1 Detailed Review Optical HRM HR BandThis ruler might help even more 😉 as well as a penny/cent.

Polar OH1 Detailed Review Optical HRM HR Band

So IT’S SMALL. Perhaps not ‘tiny’. Here it is compared to the SCOSCHE RHYTHM+ which, by comparison, looks like a bit of a beast.

Polar OH1 Detailed Review Optical HRM HR Band

The pod is even smaller than the Suunto pod and Polar’s relatively new H10 chest strap. H10 reviewed here (link to: the5krunner.com)

Polar OH1 Review

But it looks like the exact same 6-LED sensor used in Polar’s recent higher-end watches, the M430 and M600

Polar OH1 Review



Setting up the OH1 will involve pairing it to the Polar FLOW app and then to other apps or devices of your choice.


Out of the box, it DOES immediately pair to other devices and apps. However, it is prudent to take one minute to ‘set up’ the OH1 using the Polar Flow app (v3.6.0 and above). This simply involves pairing to the FLOW smartphone app and setting the wear-position – upper left arm for me.

It’s likely you’ll be asked to update the firmware, which is automatic and takes 10-20 minutes.

Conceptaully, see Polar FLOW app as the ‘maintenance’ app and the app to view your stats. Polar BEAT records the workout.

I reckon there’s a good chance that Polar will add several features to the OH1 over time and so you should return to Polar FLOW periodically to check if there are any updates to firmware.


All apps will pair to the OH1 in subtly different ways. I paired to all these apps to at least prove to myself that they displayed my heart rate: Polar Beat; WAHOO Fitness; and STRAVA.

If you simultaneously try to pair to more than one OPEN app on your smartphone the last app you try won’t work. Close the apps down. Minimising them is NOT closing them.

Here it is paired and working in Polar BEAT.

And similarly, here it is paired and working in the WAHOO Fitness app

Polar does not specifically state which apps the OH1 is compatible with. It’s likely to be a long list and there’s no reason why it will be any different to those supported by Scosche as this image indicates:

Image Source: Scosche.com



The initial pairing of the OH1 to several devices I tried seemed to take several 10s of seconds. If you just leave it, the pairing figures itself out, unless actively paired elsewhere. In that latter case you will NOT be able to pair it to a new device.

I specifically tested the pairing with several of Polar’s devices as well as to a Suunto SPARTAN, a WAHOO bike computer and several apps via an Android smartphone. Everything I tried worked. Indeed any modern device that supports Bluetooth SMART should work and that includes newer high-end Garmins. So, basically, as a broad guide to you, pretty much everything MODERN SHOULD work with the OH1 except older & lower spec’d Garmins (using ANT+).

You might have problems with how some smartphone manufacturers implement Android and there could be other vagaries. Polar haven’t tested all of the thousands of combinations and neither have I. Sorry.

Points on pairing

  1. You can store the pairing of your OH1 simultaneously on lots of devices and/or simultaneously in lots of apps. HOWEVER only one of those pairings can be active. So if you have Polar BEAT either open or open and ‘minimised’ then you will NOT be able to pair to ANYTHING else. Fully close Polar BEAT (or whatever active app is open)
  2. If your device appears to have suddenly stopped working then there’s a good chance your smartphone in the next room is the cause of your problems 😉 ie the smartphone+app is actively paired to your OH1. That’s Bluetooth SMART for you…Polar can’t change that.
  3. If Polar FLOW is synchronising in the background then you will not be able to pair or connect to your OH1.
  4. If you use many smartphone apps on any one smartphone then you have to pair the OH1 with every app. ie you do NOT pair it with the smartphone, you pair it WITHIN the app. Every app. It will only work with one at once.


This Polar OH1 Review will now cover general usage considerations before going on to look at how to start, stop and cache your workout.


Polar does not specifically recommend wearing the OH1 on the wrist. They show ‘models’ wearing the OH1 on the upper arm or the upper part of the lower forearm. Indeed, those wear-locations are the ones that can be selected when setting up the OH1 in the Polar FLOW app. However, there is no reason at all why you couldn’t wear it anywhere else; you will even get a reading if you hold the sensor against your thumb.

You would typically wear it with the OH1 sensor on the OUTSIDE of the upper arm – that’s what I do.

I found the adjustable strap to be relatively comfortable. You will see later that I got good accuracy results and there was no need to have the strap fastened tightly.

It is one continuous elasticated strap and there is no clasp to unbuckle. You just slide it up your arm into position and ensure it is tight enough. This probably takes 5 seconds and there’s no reason why you would not do that in a leisurely triathlon.

The LEDs clearly indicate the mode the OH1 is in. If you don’t wear the OH1 the ‘right way’ around then you won’t be able to see the LED when it’s on your arm. ie point the LED upwards

It can be worn under a wetsuit. My wetsuit is relatively thin and I would suggest you take a degree of care when getting into and out of your wetsuit. I did wear it under a wetsuit, everything WAS good but I would NOT recommend it. Eventually you will rip your expensive wetsuit.

Polar OH1 Detailed Review Optical HRM HR Band


You might also want to consider these general usage points:

  • Apparently, a battery ‘LOW’ warning appears on polar devices when at about 10% charge remaining.
  • I remain to be convinced about the longevity of the strap material. The Scosche isn’t great on that front either. 18 months on and the strap is still fine.
  • Thin bands, like on the OH1, tend to flip over more easily than thicker ones, for example when swimming. I have not experienced this with the OH1 when in use, with swimming with it on the UPPER ARM. This flipping may happen more readily as the strap ages. However, surprisingly, I find the strap does flip from time to time when I am fiddling with arm warmers. If I were more careful it would be OK.
  • When putting a wetsuit on I would advise caution when pulling the wetsuit over the OH1. The wetsuit could get damaged and the OH1 could flip over and you may not realise that. Once the wetsuit is over the OH1 then obvisouly you can’t see the status LED lights. When swimming you have to use CACHED mode, however, the OH1 will also be broadcasting at the same time so if you optionally choose to wear a sports watch then you would be able to verify that the OH1 is transmitting with the watch before you get in the water.
  • The Oh1 does tend to flip over and roll over itself as you try to get it off from ALL kinds of workout activity.
  • Other Polar HRMs have a ‘heart touch feature’. The OH1 does not have this feature.
  • The OH1 does not work for Polar’s fitness tests (eg V800). But the same built-in sensor in the M430 does support its fitness test but not the orthostatic test. You will see further below that various LED colour combinations DO exist for Fitness Tests, so I can only assume that these tests will be added later either in the Polar BEAT app or supported on watches such as the V800.
  • With any product like this, I would advise against the use of a washing machine. Handwash with cool water.
  • The button is a little hard to press. Conversely Polar would argue that is a feature as it totally prevents an accidental press – I’d probably agree with that assessment.
  • My MIO Link review back in April 2014 (link to: the5krunner.com) first announced to the world that you could actually broadcast ANT+ underwater. Just not very far. But it worked, sort of.
  • Well today, I managed a whole 10cm transmission of a BLE HR signal underwater in my kitchen sink. TA DA. I wouldn’t recommend it. Use the caching mode;-). If you wear the OH1 whilst swimming on the lower arm then you might get lucky with a live HR signal (I doubt it) and if you wear it on your upper arm you won’t get a signal. The 5KHz gymlink signal  (the underwater signal) is NOT transmitted (Link to: polar.com).
Polar OH1 Review: Transmitting underwater
Polar OH1 Transmitting underwater – note the bubbles


A short, single button press turns the OH1 on. If you’ve already paired it to another watch or app then you are good to go.

Next, you can press the button twice to enable cached recording on the OH1.

A long button press turns it off.

A subsequent section looks at the various LED colours/flashes, some of which you will need to familiarise yourself with over time to ensure that the OH1 is doing what you think it is.


The Polar FLOW app helpfully tells us that cached data is automatically synchronised after training. It’s not quite so simple.

Cached data can be sent to Polar FLOW in one of two ways.

Firstly, with the OH1 turned back on after you have stopped recording then all you have to do is start the Polar FLOW APP on your smartphone and your workout will be sent to FLOW on both your smartphone and online. The blue light on the OH1 will flash and your smartphone will probably display two arrows going round in a circle on the top status bar, or similar, as shown below. You will probably also get the message “Polar Flow is syncing” in your notifications, or similar. If you close the Polar FLOW app too soon then your workout may not have completed synchronisation. Open FLOW again and all will be good if you let it finish.

Polar OH1 Review Sync with Flow

Secondly, even if the device is turned off, when charging on your computer it will automatically sync through Polar FLOW SYNC, if you have that software installed.


polar oh1 review sync


The speed of synchronisation will depend on many factors such as number of sessions to be sync’d; duration of settings to be sync’d; whether you use the FLOW app or FLOW SYNC (latter is faster); speed of your Bluetooth/wifi/internet connections. To generalise I would say it will take tens of seconds or a minute, or so, rather than minutes or tens of minutes. It’s relatively quick but not instant on a smartphone.

Synchronisation via Polar Flow Sync on your computer takes seconds and is much quicker than Flow Sync with Polar’s watches.

During synchronisation, the time and date will be set on the OH1. There could be quite a few scenarios where the time used for cached data is a few seconds out from the exact, correct time. When comparing to other devices I sometimes had discrepancies of over a minute, which I was not expecting.

When using cached data it is always assigned to the ‘Other Indoor’ sport profile by default. This default sport setting cannot be changed but the sport can be manually changed in FLOW once your specific workout has been sync’d to FLOW.

polar oh1-other-indoor
Change the sport type in Polar FLOW here

When paired to a watch or used in an app, no sport profile is activated on the OH1, it is just the sports profile on the watch which is active. However, if you enable recording/caching then the ‘other indoor’ profile will be used for the recorded/cached workout regardless of what may be happening simultaneously on a paired Polar sports watch…confused yet? 🙂


This is one of those ‘heads-up’ sections. Especially for those of you with experience of how other vendors implement caching.

If you turn on your Polar BEAT app and then you turn on your OH1, everything should be hunky dory as you start to record the session.

However, if you go out of range then this will happen

Polar OH1 Detailed Review Optical HRM HR Band

ie when you are out of range NOTHING is recorded.

Even when you return to range NOTHING is retrieved from the cache. You will only ever have what is shown above…ie a gap in your recording.


A: You forgot to specifically turn the caching on.


Even if you had turned the caching on Polar Beat would still have recorded the same track as shown above.

BUT with caching enabled it would have recorded a separate heart rate track. This separately cached track will find its way back to Polar FLOW when it synchronises. There will then be a (partial) duplicate workout. There is no way to combine these tracks.

Note Well: I imagined Polar have implemented the functionality this way because it is the easiest way to get the technology working and to quickly start selling the product. I would hope & imagine that the way this functionality works will be expanded upon and improved throughout 2018.

To be clear: the retrieval of cached workout data is CURRENTLY only supported within the Polar FLOW APP environment.


There are no kinds of vibrations or audible functionality on the OH1. However, there appears to be only one LED on the device yet it can blink and flash in many and varied colour combinations. These colour combinations are included in the Polar OH1 review but are from polar.com. In reality, some of the colours are not as obviously different as you would think..but it’s fine:

LED Guide


  • Charging: Yellow LED blinks slowly
  • Battery full: Green LED continuously on


  • Battery status normal: Green LED blinks five times
  • Battery status low: Red LED blinks five times


  • Heart rate not detected: White LED blinks once every two seconds
  • Heart rate detected: Green LED blinks once every two seconds


  • Training recording set on but first time use not done: Red LED blinks three times
  • Heart rate not detected: White LED blinks quickly twice
  • Heart rate detected: Green LED blinks quickly twice
  • Battery low: Green and Red LED alternate every other second
  • Battery critical: Red LED blinks quickly
Polar OH1 Detailed Review Optical HRM HR Band
This LED Flash = No Heart Rate…Obviously


  • Heart rate not detected: White LED blinks once every two seconds
  • Heart rate detected: Purple LED blinks once every two seconds


  • Connecting, Syncing or Pairing: Blue LED blinks
  • Searching or waiting for confirmation: Blue LED blinks quickly
  • Updating firmware: Blue LED continuously on
  • Error: Red LED continuously on
Polar OH1 Detailed Review Optical HRM HR Band
Blue flashing LED = Sync’ing


Any Polar OH1 Review is not complete without a good look at the accuracy of the product.

The Polar OH1 is bravely targeting the indoor gym/fitness crowd as well as the outdoor endurance crowd. Accuracy is hard to achieve in gyms/classes and when cycling and when running hard intervals and when swimming.

Talking about the accuracy of GENERAL optical technology: For wrist-based optical HR accuracy, I think it would be fair to say that we have only seen widely acceptable levels of accuracy for steady-state running. Running intervals are hit and miss. Cycling is hit and miss. Swimming is hit and miss and miss again. For indoor usage, when there is very significant wrist movement impacting on optical HR accuracy, then acceptable levels of wrist-based optical heart rate performance are as rare as the lesser-spotted, Outer-Mongolian Scosche.

I’ve had to overcome significant difficulties coming up with the accuracy comparisons that follow. You might call it the results of a labour of love. Or not. There are some more comparison to add fro teh tests where all 4 devices played nice.

Hopefully what is shown will give you an insight into the accuracy of the OH1 compared to various devices: wrist-based optical HR sports watch; chest straps (used as a control and assumed to be ‘correct’); and an upper-arm worn Scosche RHYTHM+.

I’ve had several tests with ‘perfect’ results for all devices. Some of those are shown. But I’ve also included some of the ‘warts-and-all’ tests just to ground the concept of ‘accuracy’ within some form of the reality you are likely to experience.


I did a 20-minute workout to simulate a weights and gym session. 75% upper body where the arms were moving. But even with the 25% of the time on the lower body, I was holding weights which should affect/restrict blood flow in the arms to some degree.

The blue line is for the WRIST-WORN oHR device, in this case, it was the Suunto Spartan Trainer. The wrist has the greatest number of potential bad movement for optical technology so you could equally substitute any other wrist device here and possibly get the same sort of inaccurate results.

Even the Scosche was struggling a little at times.

In this workout, the OH1 is clearly the closest to the chest strap (Suunto Spartan Sport). Not perfect, but pretty good.


Below is a similar workout on the following day but this time the Garmin 235 is the source of optical HR. Again, the wrist-based device has the most problems. You could then criticise the Scosche or the OH1 as being equally as good, or equally as bad as each other – depending on your perspective. The only thing of note here would be several ‘straight lines’ from the Scosche, presumably where it read nothing and guessed at what was in between the readings it did have.


I would say that the Scosche and the Polar OH1 are just about acceptable in the above scenario.

Personally, I would use a chest strap in a gym. But, to be brutally frank, there isn’t much point in recording heart rates as low as these. I typically combine weights with, say, a Wattbike in the same session. So really I’m wearing the HRM for the bike that comes later.

However, the charts above represent a typical ‘worst case scenario’. YOU may well be looking at indoor classes rather than weights. My guess would be that for the CLASS scenario you will typically get better results than I got for weights but not as good as those for running. So, I’d say the OH1 should be good enough for recording reasonably accurate HR in classes.


I draw the line at wearing a plethora of electronic gadgets whilst swimming for any review let alone this Polar OH1 review. So here we have to assume that the Suunto SMARTBelt is correct. As you can see the wetsuit hold the OH1 in place and everything is good (enough).

Not sure why avgHR is zero. Strange (was created as part of a Suunto multisport session)

This time it’s a pool swim. And I have to say this is probably the best ever optical HR I’ve seen in a pool. It’s not perfect. but it’s the first time I’ve been able to use an arm-worn sensor. There was a wristwatch at the same time but the results were not good and distracted from the message about how good the OH1 is when compared to the Suunto chest strap below. I really tried to dislodge the OH1 but failed, I tried so hard I got cramp. I tried all sorts of paces and rests and, as you can see, it’s pretty cool.




Things look great on this steady state run with all 4 devices performing in a manner that I would consider acceptable for my needs. A good sign is that they all give the exact same average HR but, more importantly, drilling down to the detail shows a great match. The Garmin 235 (optical, wrist) is the worst of the 4. Visually inspecting the lines when the chart is enlarged shows that the Polar OH1 is perhaps even a closer match to the Suunto chest strap than the SCOSCHE


Slightly different run and one of the better I’ve ever had with 4 devices concurrently. This time the Polar M430 (with the same Polar 6-LED sensor) takes the role of the wrist-based HR device, with the Polar OH1 data being cached. Only a very slight dropout of the M430 near the start. This session was under-over aerobic threshold with a fast bit at the end to see how the devices reacted to an immediate stop afterwards. All good.


Finally here are some half-hearted hill reps. Awesome performance against the HRM-TRI.

They REALLY are different if you look VERY closely


Here is another chart that illustrates that wrist-worn oHR is prone to issues, with the SCOSCHE and Polar OH1 performing well. The Scosche got it notably wrong in a couple of places, the Polar OH1 performed slightly better but didn’t quite make it all the way down to the true troughs that the Suunto SMART Belt recorded – very close though.



And here is a 5 device HR extravaganza. It is no coincidence that the two wrist-worn sensors effectively fail miserably – the Garmin 235 and the Polar M430. Over a 2.5 hour ride, there is no hiding the potentially obvious conclusion that wrist based optical HR can be inaccurate when cycling (we already knew that).

At about 23 minutes there is a blue spike. This is potentially the only interesting anomaly of the non-wrist devices. Here the chest strap spikes…so we are in a situation where the Scosche and OH1 are probably right and the chest strap wrong. the chest strap may have moved, for example.


Here’s another saying pretty much the same thing. This time it’s the two devices to show how close the OH1 is to a chest strap.

They REALLY are different if you look VERY closely


A key aspect of the Polar OH1 review is that we, at least, get a feel for its accuracy.

When worn on the upper arm both the Scosche and the Polar OH1 can be classed as ‘ACCURATE’ across all the sports tested.

From previous experience, I would have called the Scosche ‘the most accurate optical HR sensor’. The OH1 provisionally deserves that same accolade.

Polar OH1 – Jointly and provisionally; the most accurate optical HR sensor.


The Scosche RHYTHM+ (link to: Scosche RHYTHM Review) is the only directly comparable alternative that I would even recommend you to consider. Broad alternatives include chest straps and optical wrist watches and optical bands of various flavours.

  • Scosche – it’s bigger and has a shorter battery life. Scosche’s big plus is simultaneous ANT+ and BLE transmission of your HR. It can’t cache HR data. It can’t, therefore, work underwater except in close proximity to the recording device (watch). Accuracy seems broadly the same as the OH1, perhaps the OH1 is very, very slightly better from my experience.

DETAILED REVIEW: SCOSCHE RHYTHM+ Optical HR Band Review Dual Bluetooth Smart + ANT+

Staying with Polar you could instead upgrade to their best chest strap which is the H10 (link to: Polar H10 Review)

Polar H10 Review (2019 update) ❤️ Comparisons, Polar’s Greatest HRM

Or you could use Polar’s exact same LED sensor on their M430 sports watch (link to: Polar M430 Review) but you might not find the WRIST to be able to produce as accurate data as the OH1 worn on the upper arm.

Polar M430 Review + Discount | Detailed | GPS & Optical Run Watch

2018 sees the arrival of a directly competing product from Wahoo Fitness called the TICKR FIT. I’ve not yet tested the accuracy of that but it should be good enough to give the OH1 a run for its money. As well as having ANT+ and BLE support it also beats Polar with the battery life and a slightly wider strap. The Polar OH1 would still win on its ability to cache workout data for the Polar environment and both may well morph in 2018 to include extra metrics – but it would then only be likely that such metrics will only work on the manufacturer’s own branded hardware. Tread carefully, you Polar owners.

Edit: Here is the review!

Wahoo Tickr Fit Review | Best Optical Heart Rate Monitor?



This Polar OH1 Review has mostly contained my experiences, here is the stated compatibility of the OH1:

  • Polar Beat v2.4.0 (iOS/Android and above) – this will be used to update firmware capabilities
  • Polar Flow v3.6.0 (iOS/Android and above)
  • All Polar products. Latest firmware may be required eg Polar M460 watch v1.0.70
  • It will work with any of Polar’s Bluetooth-compatible products


Source: Polar (link to: Polar.com)

  • Weight Sensor 5g, armband 12g
  • Height 9.5 mm
  • Diameter 29.85 mm
    Armband Size M-to-XXL, machine-washable
  • Compatibility: iOS mobile devices: iPhone 4S and later; Android mobile devices with Bluetooth 4.0 capability and Android 4.3 or later.
  • Firmware Updates: Via Polar Flow (free app)
  • Memory: 4 MB, up to 200 hours of training time
  • Battery: Rechargeable 45 mAh lithium polymer battery, giving 12 hours of training time (TBC – I will update the Polar OH1 review on this specific issue
  • Water resistance: 30 m

Product Manual (link to: Polar.com)


Courtesy @hrdlpn


I like the OH1 and would recommend it and I hope this Polar OH1 review demonstrates that. I’m including these problems for completeness. Most of them are minor.

  • Be careful not to insert the OH1 into the charging cradle or strap upside down. It won’t work if you do that. This is a design issue that should have been prevented in my opinion.
  • If it won’t work with your compatible app or watch then the chances are that you already have the OH1 paired and active somewhere else. close all active pairings and try again.
  • I don’t like how cached recording has to be specifically enabled once the device has been turned on – I sometiems forget. I would personally prefer to have everything cached by default and then later ‘matched’ to an exercise. ie more like how Garmin’s HRM-TRI chest strap works ie you just put it on. Polar would argue that Garmin’s chest strap cannot cache and work in a ‘standalone’ without a watch – I’d probably agree with that assessment and I can see how changing from how the OH1 currently works would potentially introduce logistical nightmares with handling cached data eg what if the OH1 is left on?


Polar OH1 Detailed Review Optical HRM HR Band


Best REI/Wiggle/PMC price is linked to. $/Eu/£70 and UNlikely to fall in 2018/9.


At the end of this Polar OH1 Review all I can say is that this is a great product that I do not hesitate to recommend

Its strengths lie in the support for the increasing number of sporting APP users and the comfort of the wear-position. It has many and varied uses across lots of sports.

It’s one of the most accurate optical HR devices I’ve used. If not, THE most accurate one.

Polar addresses the needs of its target markets very well.

It’s not perfect. If Polar had only addressed these 3 areas then it would be a world beater and would address the needs of wider sporting markets:

  1. Does not support ANT+ (older Garmin devices, lower end Garmin devices and some gym equipment);
  2. Does not support GYMLINK 5Khz transmission (for some gym uses and underwater live usage to the V800); and
  3. Strap performance could be improved and the longevity of strap is suspect.

Still. None of that is going to stop me using it A LOT.


10% off…see below

Availability now. Initial pricing is $/Eu80 and GBP70. Replacement straps are £17 or Eu/$18.

Best REI/Wiggle/PMC price is linked to. $/Eu/£70 and UNlikely to fall in 2018/9.
Power Meter City
Use the checkout 10% discount code: the5krunner10
Best REI/Wiggle/PMC price is linked to. $72 or £60 and UNlikely to fall in 2018/9.

If you enjoyed this Polar OH1 review then please purchase through PowerMeterCity in the USA or NewRunningGear in the UK. Both sites will give you a 10% discount on most models with the codes: TFK10 (for NewRunningGear) – if it doesn’t work try the5krunner10 (teething probs! sy) and the5krunner10 (for PowerMeterCity). If you buy anything from there you help keep this blog running.

polar newrunninggear alchemynrg discount the5krunner
NewRunningGear with 10% discount code

Reader-Powered Content

This content is not sponsored. It's mostly me behind the labour of love which is this site, meaning it's entirely reader-powered content ❤️ I'd really appreciate it if you'd follow, subscribe or Buy Me A Coffee ❤️ Alternatively please buy the reviewed product from my partners (which costs you no extra) and, for that, I receive a small commission. Thank you! FTC: Affiliate Disclosure: All links pay commission. As an Amazon Associate I earn from qualifying purchases.

44 thoughts on “Polar OH1 Review (2019 Update) | Optical HR Sensor, Arm-Worn

  1. I got mine yesterday and did a 21k trail run with my Spartan Ultra today. It worked flawless from. the 1st to the last second. I love it!

  2. v810 baby…
    what stryd/bt issue is that. I had a few (some of them v800 related…some personal 😉 ). i ahevn’t used v800+stryd for a while (almost did yesterday as it happens)
    yep the multiple protocol broadcast does my head in. someone should tell polar that they would do MUCH better if they supported ANT+. i’ll drop dcr an email as i bet he hasn’t thought of mentioning that to them either 🙂

  3. Good write up. To be honest, I never found the Scosche Rhythm + to be all the great. Maybe I got a bum one, but there was never a great place to put the thing on my arm (either arm). Not only that, but the ant + signal to be splotchy at best (I haven’t tried it via BTS). As for efficacy, Can’t say it performed all the much better than the OHRM found on the watch. It would have this nasty habit to have a lock on HR and then magically drop to 72 BPM for a spell and then repeat this every few minutes. And as I said above, I tried it all over my arms and nothing seemed to work. As for this OH1..ehhh…

    I get it for the person that might hate the chest strap, but really it’s still just a OHRM, the shortcomings of the tech are still there whether you have it on your wrist or your forearm or bicep. I have the H10 and plan on using it exclusively when the V800 replacement comes (if it’s worth it to buy in the first place) All Polar needs to do for someone like me is let me pair multiple external sensors to the watch over Bluetooth and i’m golden.

  4. Yes still waiting for this fix, would much rather use my scosche rather than a unpaired h7, only for comfort

  5. For some strange reason my Wahoo Tickr works reliably with V800+STRYD while Scosche Rhythm+ / Polar OH1 don’t. The latter two usually work directly after pairing STRYD + V800 but understandably I don’t want to re-pair (no pun intended) the two before every run.

    Hopefully Polar gets this sorted out with the V800 successor, I’d love to use V8xx + STRYD + OH1.

    1. which tickr?
      you could probably spend a few hours seeing if the order in which the devices are paired makes a difference. and/or if the paired but inactive devices makes any difference. (I wouldn’t !! you probably have a life)
      I think there is a known bug to do with pairing but I can’t recall the details.
      I would report it as a bug with the OH1 as that is likely to get a reasonably high priority to be fixed.
      also note that the OH1 is NOT HRV. so that will most likely restrict some of the functionalities with any successor to the V800.

  6. Thanks for review
    Major deal breaker is the lack of support for the GYMLINK 5Khz transmission (for some gym uses)

  7. So we are back to a strap, this time around the arm etc.
    For that trouble I will rather stick with the H7 / H10, as it is more persistently reliable across a variety of sports.
    (Also the user of an SST, and after doing some benchmarks between Polar and Suunto Trainer the performance of oHR is still disappointing and unreliable.)
    Yes, it is perhaps accurate to within 1-2% of HRM strap for say 80% of the time, but you don’t know where you are on the ‘fault spectrum’ during your activity.
    So until reliable measurement can be repeated, oHR is not for serious record keeping and analysis.

  8. I’ve been looking at a few options and I’m honestly not sure which way to go with it. I have the M430 which would work with both the OH1 and the H10. I have previously used (and no longer own) the M400 with the H7.

    The part that most tempts me about the OH1 is the placement. As someone who has to wear a large sports bra the chest strap and the bra band wasn’t always the best combination, but I’ve made it work.

    However, from what I understand the H10 is the more accurate option, compared to the OH1. It’s also supposed to be more comfortable than the H7, but it doesn’t specify wether that’s including the interaction with a bra. The better connection with the watch while swimming is also a big plus.

    Ironically enough, I don’t really run. I do however love skiing, swimming, dancing, and lifting, and an HR monitor would make a big difference in my measurements.

    Personally, the price points aren’t different enough that it’s a consideration.

    Basically, how does the H10 compare to the H7 in terms of comfort when combined with a bra, and is it worth switching to the OH1 for just that one consideration? What would I be losing out on?

    1. h10 and h7 are near identical.
      for the consideration of comfort many people, like you, will find arm worn evices LOTS better.
      you lose on HRV data (if you don’t know what it is you don’t need it!)
      you have to physically turn the oh1 on whereas the h10 is activated by a hr signal
      h10 will be a tad more accurate. but you’ve seen the oh1 accuracy in the charts above…the oh1 is GOOD for optical. very good.

      1. You’re right in that I’m not upset about losing HRV data (though I do know what it is). Having to physically turn it on is a slight minus, but it’s one of those things I can live with. I’ve always been suspicious of optical, but based on the charts you’ve shared I can’t fault it for that, and it would be plenty accurate for me I expect. Thank you for responding and I’m now leaning slightly in favour of the OH1 🙂

        1. i would be suspicious on the wrist and I would be suspicious in activities that require lots of wrist movement. even the latter will affect the oh1 to a (an acceptable imho) degree.

  9. Good write-up.. thanks. My Scosche has started playing up, so I’m looking at the OH1. Do you know if a cached workout, synced to polar flow, will feed through into Sporttracks as an activity with just a time and HR track ?

  10. Hi! Is there any way how to sync cached data from OH1 with the swimming metrics from/in V800 after workout. That I could not find so far. Thanx.

    1. probably you could use ffrt (fit file repair tool) as a one off to create one merged file
      in things like sporttracks 3.1 you could do what you say but you would merge it i nthe softare not in the file

  11. Ok, i just have merged the 2 file but if i try to import to garmin as tcx, garmin connect doesn’r recognize the activity like a pool swim… i can only review correctly with sport track web but i think it’s a paid service and my free subscription last until the end of january… After this date what happen? Can i use sporttrack with few feature or simply i can’t use it anymore?

    1. yes garmin will not recognise a pool swim and its details from a tcx file.
      a tcx file has bits missing compared to a fit file
      i have not used sporttracks web. i use v3.1 desktop. you may need omb’s garmin fit file importer for v3.1 for the special garmin fields and the pool swimming plugin too even if you then export out of sporttracks into tcx you will still not get all the fields you want.

      st3.1 will probably be pretty awesome for you if you get all the bits working. it’s WAY better than garmin connect
      try golden cheetah…its free. not sure you can combine data sources for one workout tho


  12. If i export in .fitlog from st3.1, i can import in ST web and see all my data like garmin connect + Heart rate from polar OH1! So, the steps are: import fit file from garmin connect to SportTrack desktop, import tcx file from polar flow, merge the 2 file with sporttrack 3.1 desktop and than, export in fitlog to sporttracker web!

  13. I currently have the H10 and the A300, I love my Polar products because of the accuracy, however, I HATE changing the battery in my chest strap. After several changes, the opening gets stripped and I can no longer change the battery without almost prying it open. I would like to have a battery free option but I also need the accuracy. I don’t work with a lot in the chest area so wearing the strap isn’t a problem, I just simply hate changing the ding dang battery!

    1. are you sure its the h10? that has a much better battery cover release than the h7
      maybe some small amount of grease might help…never tried that.
      look at the battery brands you use. all coin cell batteries are not made equal and some last MUCH longer than others.

      1. I do get a really good battery life because I only pair the chest strap when I’m training and I’ll disconnect it to save the battery. My only problem is when the backing get stripped.

  14. Hi 5K! I have a question regarding the OH1 ability to register a workout by itself. If I understood it well, when you pair the OH1 with Flow or Beat afterwards, the HR data appears as a new workout in your profile. My doubts are:

    If you’ve registered the same workout with another device (let’s say, an V800, for swimming), it will automatically merge the two workouts?
    Or is it better, in that case, to pair the OH1 with the watch and it will transfer the data automatically once the workout is over to the device?

    Finally, does the OH1 also work with another brand’s software, such as Movescount? Paired with the SST for swimming, does it transfer the data after the workout as the Suunto strap does or does it broadcast the data live?

    I hope my questions are clear. Just for letting you know, I’ve had a SST but I was disappointed with the oHR (you’ve recently answered me at the DC’s website about valencell sensors). I’ve been waiting for Polar to announce a new tri-watch but I’m starting to think that will never come, so I’m re-opened to the Suunto, which was nearly perfect aside from the oHR data at the beginning (I suspect it pairs with the cadence instead of the heart rate, mainly in the first minutes of the runs), or the AW3 (after reading your post by Ian).
    As I do a lot of gym (crossfit style) training, I’d like a sensor that is able to record my hr leaving the watch at home (to avoid unintentional hits with weights) and then pair the workouts with the same app. That’s why I asked for the compatibility with Movescount.

    Thanks a lot for your time!


    1. the workouts are NOT merged in the scenario you describe
      caching ONLY works on the device (and then directly sync to flow) or on the device (from memory) and sync to BEAT and then beat syncs to flow
      if it’s not clear in the review above please let me know what can be improved.

      polar WILL introduce a new tri watch. i suspect sept2018 now.

      any support via amazon apprecaited 😉

      1. Many thanks!

        The review is pretty clear with the “cache” recording, my doubt (I may not have read it , my mistake) is for swimming… I mean, I won’t use it for running or cycling on cache mode as it is able to transmit the data.

        So the OH1 WON’T work with Movescount or another app for the cache workouts. But can it be paired with another brand watch for swimming? Would it transmit the data once the workout is over?

        Many thanks!

        PS: for the Amazon support, do I have to write any code or I just have to click the advert in this page? 😀 You really deserve it!

        1. the cache will onyl work within the polar environment.

          you can pair the oh1 to any bluetooth watch…but bluetooth will not work underwater on distances over about 2cm (centimetres)

          amazon: when you next buy something jsut click from my site first on the amazon link. i get a small commission from amazon (you pay the same price)

          1. Thanks! I’ll do that in my next purchase 🙂

            Just to conclude the trend: if I have not misunderstood you, the OH1 can be used for swimming only with a Polar device, as the bluetooth connection won’t work underwater and the OH1 won’t transmit the data after the session is over (if I’m not mistaken, that’s how the HRM Tri, H10 or Suunto Smart Belt work for swimming).

            Is that right?

          2. no!
            the oh1 can only be used for swimming with the polar beat app when it will retrieve cached data.
            the hrm-tri works in a similar way BUT the hrm-tri syncs to a watch.

      2. Ps2. I’ve been in love with Polar and their ecosystem since I started training with my M400 hehe. September is OK for me to wait, but I read a DC comment about Polar struggling with the V800 2.0 that ‘frightened’ me 😛

  15. This incredibly thorough review has convinced me this the OH1 will likely fit my needs. I would like to also purchase a very inexpensive (dare I say cheap) bluetooth watch the only purpose for which would be to show the live BPM from the OH1. You said “you can pair the OH1 to any bluetooth watch” but as a total novice to the world of fitness watches and bracelets, I don’t know what specifications or criteria to look for to determine if whichever product will work with the OH1. Can you offer any guidance or examples of what to look for?

    (If it could also show the current time or lap time, that would be icing on the cake.)

      1. This is exactly the sort of thing I’m looking for, especially the distinction between supporting BLE/Bluetooth sensors and not just “bluetooth compatability”.

        I also am slowly starting to understand that there is no market for simple inexpensive BLE wrist displays that rely on external sensors/transmitters. All of the wristbands that seem to be compatible with the OH1 are expensive because they have all the features already and are more or less designed to be used independently.

        Nevertheless, thank you for your reply! I greatly appreciate it.

  16. Hi, quick question as I’ve had one of these for just over 3 months and used infrequently. My experience is that there is terrible battery drain when it is off. For example, I have used it for around 3.5 hours of workouts, gone done to battery “Half Full” (I haven’t figured out if I can actually get a % battery from somewhere?). Then a week later without use, it would be empty.

    Is this your experience, or might I have a dud?

    1. my experience is similar. although not after 3 months …more like after over a year.
      but i tend to keep it plugged in after its uploaded a cached workout . so its normally charged

  17. I have had the polar OH for less than a year. It worked really well for about 6 months (probably used it 100 times) and then no more heart rate. It does connect via bluetooth but the polar beat app doesn’t see it anymore. (an iphone and a samsung S8 still see it via bluetooth & connect but the app on both phones does not find the heart rate sensor)

    Also, i imagine it is very easy to loose the charging adapter. Having to charge every day is also a big minus. I’ll go back to a chest strap.

    1. I hear ya!
      I tried to connect my oh1 to an android phone earlier in the week (beat app) and had to persever a few times. it did it in the end.
      obviosuly you know it can’t actively pair to two devices

Leave a Reply

Your email address will not be published.