Polar H10 Heart Rate Monitor Chest Sensor and Soft Strap (and some comparisons to the H9 and Scosche RHYTHM+) – Review

Polar H1 HR sensor and strap

Recently I was in the market for a new heart rate monitor to replace my Scosche RHYTHM+ Armband Heart Rate Sensor (review link), which I have had for many years.

The Scosche still works fine except for the battery which, after many years of use, is ailing and not lasting for the length of a long bike ride and requires constant charging to maintain. Without a full charge, it sometimes shows some erroneous readings too. But it has been a very dependable long-lasting piece of equipment, except for the charger which I have had to replace a few times (amazing what sweat does, even with trying to wipe it off the armband and charger and clean them as much as possible).

My previous heart rate monitor before that was a Garmin Heart Rate Monitor and Chest Strap and while I liked the armband HR monitor and it was very accurate – I wanted to go back to the chest strap ECG HR sensor for a few reasons.

One of course is the absolute highest accuracy, the sensor is right over your heart and attached as closely and tightly as possible. The sensors pretty directly measure the electrical signals from your heart via the electrodes in the band that contact your skin, similar to a medical-grade ECG – versus the armband or wrist sensors on a watch which use optical sensors to measure the blood flow in the veins that are situated right below the sensor. And of course, something that uses optical sensors has the chance of errant light getting in as the optical sensor tries to measure your heart rate. Something that may be less important while biking but more so when running and especially when doing any active sports where your arms are moving.

So obviously the heart rate monitor system that contacts directly with your skin via a strap and electrodes is going to be generally more accurate across a whole range of sports, especially ones with a lot of arm movement.

I also think I liked the heart rate strap under my shirt/jersey better than on the arm as a personal preference, for cosmetic reasons (having it hidden and also to eliminate a tan line), as well as the fact that sometimes flexing my arm required a bit of an adjustment on the velcro strap. And lastly, when pulling on long sleeve shirts it was sometimes hard to get the armband strap to stay in place as the arm was pulled through the sleeve.

All minor things really, and I would not in any way hesitate to recommend either the newer Scosche Rhythm 24 Heart Rate Monitor Armband or the older Scosche Rhythm Heart Rate Monitor Armband like I have been using or other good quality armband heart rate monitors.

Polar sensor and strap connection close-up

So on to the review.

I did a lot of exhaustive research and while my initial preference was to get another Garmin heart rate strap and monitor, with the thought of getting something with running dynamics, possibly the Garmin HRM-Pro. But I don’t run that often that I feel that I need something that expensive and with the extra running features, necessarily. As a fitness data enthusiast, I would have liked it, but for the extra money, it was more than I really needed.

I went looking and while others like the Wahoo Fitness TICKR and others were really good choices too; when it comes to accuracy Polar heart rate sensors and straps are highly rated across the board, compatible with pretty much everything, and are durable.

I was particularly impressed with the in-depth research and testing they do with their equipment, neutral comparisons that they make with other comparable HR sensors as well as certified medical heart rate monitoring.

I started leaning toward the Polar H10 or Polar H9, which are the 5th generation of Polar’s Heart Rate tech, which started in 1977.

According to Polar’s testing against medical-grade heart rate equipment and other heart rate sensors – the ECG H10 sensor detects HR within 2 ms accuracy at 92.9% for running, 99.3% for cycling, 95.3% for weight training, 95.6% for all activities combined.

Amazing accuracy, and very much as good or better than the informal tests I have done of previous Garmin and Scosche HR sensors and straps that I have had – my tests being comparing them to other equipment as well as manually using the old tried and true ‘two fingers on the neck or wrist and a watch’ method.

There are differences between the H9 and H10 of course.

Firstly the sensor itself is a different color but whether the differences in sensor specs are the result of different hardware or just different firmware is up in the air, from what I have read.

Both can connect perfectly to the chest straps made for the opposite device.

Polar shows the H10 as being more accurate, but this could be due to the increased sensor area of the H10’s strap. This sensor IS quite wide and extends across a large part of the strap compared to the smaller area of the sensor on the softstrap that comes with the H9.

Polar strap and sensor disconnected
This entire section is the HR sensor area.

So it makes sense that the H10 is going to show as more accurate, but perhaps pairing the H9 with the H10 strap negates this advantage? No stats on whether this is true.

The H9 also only outputs one Smart Bluetooth channel while the H10 can do two, with ANT+ both will connect to multiple ANT+ channels and there is a proprietary GymLink connection also – which connects to some fitness devices.

The H9 only works underwater with certain Polar watches but the H10 can be used with any device underwater.

The only other difference between the H9 and H10 is that the H10 has an internal memory that can save one training session on its own and can be accessed with one of the Polar apps like Polar’s Beat app.

I bought the H10 because I got it for a great price, but I’m not sure that A) for the accuracy that I need the H9 wouldn’t have been just fine B) I am ever going to use the internal memory outside of testing it for this blog C) how much I am going to use it underwater as I don’t swim that intensely where I particularly need it and my Garmin Fenix‘s wrist HR works fine with third-party swimming apps.

So whether it was worth the extra money I am not sure, but it’s nice having the features available and the highest accuracy.

Now I am going to go back to covering the H10 review specifically – which as you probably gathered from above is going to also apply to the H9 in the majority of features.

The H10 works with pretty much everything and anything that we use for fitness nowadays. Anything that receives Bluetooth (Bluetooth 4.0 and Bluetooth BLE) or ANT+ and the Gymlink 5 kHz signals. It will output Bluetooth and ANT+ at the same time and even two Bluetooth devices at the same time (as I mentioned above the H9 only does one Smart Bluetooth channel).

This of course includes watches by nearly all manufacturers as well as nearly all bike computers (not including non-smart old-style bike speedometers/odometers without ANT+ and Bluetooth), and any smartphone. This list is extensive and covers Polar, Garmin, Apple, Suunto, Peloton, Wahoo, Lezyne, and fitness apps like Strava and Nike.

The HR sensor is not rechargeable but uses the common 2025 battery, Polar says that it lasts 400 hours. One thing you may want to do to extend battery life (recommended by Polar themselves and individuals who have used it over time) is to pop up one of the sensor pod’s connectors out of the strap so that it goes to sleep, I have tested it many hours after I have stopped an activity and taken off the chest strap, and sometimes it still is transmitting. So this is something to keep in mind.

Sensor disconnected

The battery is easy to change, via what looks at first glance to be a quarter-turn battery hatch that you turn with a coin to open but it actually is quite different, as it snaps open with a little tab. The battery door is of course sealed with an o-ring and everything seems very tight and secure.

The total weight with the strap is 60 grams with the sensor pod itself being 12 grams by itself.

The soft strap is very easy to put on, wet it with a little water so the sensor can get good contact with your chest skin (you can wait for a little sweat to do it for you but then the sensor may not read well until that happens). You position the sensor monitor pod itself in the front of your chest, which puts the long wide sensor strap in a very good position all across your chest. This sensor area is quite extensively wide to give you that nice accuracy.

You could even position this fairly inaccurately and it may still probably work – whether you positioned it by accident or deliberately as perhaps the strap does not fit you well for whatever reason. Some people do have problems with chest straps for many reasons, so I think those who do might find this works better than other chest straps with smaller sensor areas. It even works if you get it too low or too high on your chest, within a reasonable range.

Strap 'bumps' to keep it situated

There are little rubbery dots on the strap itself to keep it in place. Does this actually make it work better? I don’t know, but it seems like a great idea. I have never had one move on me so I can’t say whether this makes any difference to me personally, but perhaps to others who have issues with HR chest straps staying in place, it might be just the thing to help.

The latch snaps into place easily with one end snapping directly into the other end, to take it off you push a button on the latch and it disengages easily. The button is slightly recessed so you never accidentally pop it off (at least I have not as yet) and also won’t get squeezed even by a tight jersey or compression shirt.

The strap is very adjustable, with a conventional adjustable loop system to tighten or loosen it. There are two size options for the strap when you order – XS/S and M/XXL. The smaller one covers chests 20-30 inches (58-71 cm) in diameter while the larger one goes from 30-45 inches (67-95 cm).

While riding or running or lifting or anything else I can’t even feel it unless I consciously make myself aware of it. In this aspect, it is very similar to the Garmin HR strap, but somewhat unlike the Scosche HR armband which I was much more conscious of, though perhaps that was more because I was much more likely to see it out of my peripheral vision sometimes or feel it when I flexed or moved my arm a bit. The armband for the Scosche did have to be relatively tight on my arm so it didn’t loosen or work loose – so that probably had something to do with it too. Again, I still recommend the Scosche HR armband and others for the arm as good HR sensors to use, I just guess I have a preference for the chest strap.

The Polar H10 sensor monitor is easily cleaned with a little dish soap and water, and a quick wipe to dry it. The soft strap is also very easy to clean with soap and water, or you can put it in a washer – though I recommend using a small washer bag to keep it from snarling and getting bent around other things, and maybe air-dry it instead of using a dryer Make sure you take the sensor off first of course.

The soft strap now comes in not only the standard black but a burgundy with a design on it.

Strong heart clipartThe H10 is fully waterproof and can be used underwater for swimming and other things, up to 30 meters deep.

And you don’t need your watch or phone with you for swimming or anything else, at least for one session as the internal memory can store one workout. To set this up you use the Polar Beat app so you do have to connect it to your phone first, set it up and then you can use the strap without the phone present or nearby. When you are finished you reconnect and download the sensor data to the Polar Beat app, which can upload it to a few other sites or allow a download.

The Polar Beat app also can be used to keep the firmware updated, check battery power, etc. And there are a number of workouts and such that you can use it for. The Polar Beat app can also estimate your Vo2 Max, you find this in the app under Upgrades (not sure why – as it’s a free option) and then under Fitness Test. It estimated mine at 49, somewhat above what Garmin VO2 estimates mine at but very close.

Also, the Polar Flow app is another app with training and syncing to other services.

And of course any other device you sync it to will have it’s own abilities when connected to the Polar H10.

You can even test your HRV (Heart Rate Variability), which is a good test of your health and recovery.

You could use this as a 24-hour monitor with the right app, I suppose, but the H10 is really meant for exercise. But if you wanted to test your HR and HRV over an extended period of time you could (maybe using an app like HRV Inspector – https://hrvinspector.com/). I think it would be comfortable sleeping, depending on the person, but it’s not really made for that and it’s possible that the sensor area might dry out over such a long period of inactivity.

BTW, here’s a nice overview of taking care of the strap and sensor directly from Polar – https://www.polar.com/us-en/sensors/h10-heart-rate-sensor As you can see it is quite easy.

Lastly, I was going to include some comparison charts between the H10 and other HR monitors that I have but, outside of a few dropouts by optical heart rate sensors because of arm movement – which is to be expected, they all performed within pretty much identically. I had to really go data point by data point comparisons to see much difference.


So in conclusion I would very highly recommend the Polar H10 – you are not going to be disappointed in accuracy, comfort, usability, connectivity, and compatibility. It may be a little pricey compared to some other options but comparable to Garmin’s offerings in the same category.

Polar H10

UPDATE Spring 2023 – For the last few months the output has become increasingly erratic with low heart rate readings. I have tried to wash the strap as much as I could and added extra moisture to the sensor pads, and even electrode gel. Both things seemed to help for a while, yet the strap became more and more intermittent over time, despite washing and using the electrode gel. It had to be thoroughly washed in the washing machine after each use for it to have any chance of working halfway decent. Once I started biking outside a few times it went in the opposite direction and started sometimes showing super-high HR readings.

I was going to send it back to Polar for warranty but it seemed obvious that it was the strap and not the sensor itself, and instead of paying the shipping cost to send it back for warranty I decided to just buy a cheap replacement strap.

That did the trick and it works perfectly and reliably again. The replacement maybe isn’t as nice as Polar’s but the important thing is that it works, I will see what the durability is for it.


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Marc M

I am a web developer and fitness geek, but I have a heck of a lot of differing interests.  Biking, the Internet, technology, movies, fitness, running and walking and hiking, science fiction, photography, graphics, WordPress, flying and aircrafts, pets and animals, history, and much more.  I like to stay very fit but I don’t mind sitting at my computer for work and play either.  I live in upstate New York (that’s far from New York City) in a rural area, yet close to a small city, with my beautiful awesome wife, a bunch of beloved cats and dogs and chickens in a very old multi-century house.


  1. You should explain if the sensors are compatible with the other manufacturers straps. I have 3 Garmin straps and inop sensors. Do I need to replace the straps when I move to say a Polar H10?

    • Generally I believe that a HR strap made by one manufacturer won’t work with another’s sensor. This post is for the H10 sensor and it’s included strap, so I can’t speak to nor have any info on how compatible sensor units and straps are between the various manufacturer’s.
      You can find some generic replacement straps on Amazon that are supposed to be compatible for both Polar and Garmin devices. https://amzn.to/42KNF6X
      So I suppose it is possible that the Garmin strap might with with the H10, but it is outside the scope of my blog post and testing.
      Probably your best bet is to do a little research on Google and try to find your answer on another site where someone has tried this, or buy the H10 sensor itself with the strap (which is a cheaper option) and try your Garmin straps, if it doesn’t work you can always bear a Polar strap or a generic version.
      Let us know if you find something definitive.

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