Review – Scosche RHYTHM+ Armband Heart Rate Sensor

20180604_150606This review is for the Scosche RHYTHM+ Armband Heart Rate Sensor and is a six month review of the one I own, and will include some longer-term information on the identical unit that my wife has owned for a couple of years now.

I’ve put a lot of time on my ‘classic’ Garmin Heart Rate Strap.  I’ve had it for years, having gotten it as part of the package that was included with a Garmin Forerunner watch.   It’s been through a few different watches and devices, and many many years of rides, runs, races, rows, and lots of other exercise.  And this of course means a heck of a lot of dirt, rain, and of course gallons of sweat.

So when it started occasionally acting wonky it maybe wasn’t so unexpected.  It does show the durability of Garmin heart rate straps but despite this it wasn’t such a big deal to switch to another HR monitor sensor device.  While I had no complains on the Garmin sensor and it had certainly done it due diligence in providing heart rate data for me covering many years, I didn’t mind trying something new.

But let’s back up a bit.   A few years ago I had bought the Scosche RHYTHM+ HR sensor band for my wife after she had some issues with a couple of different conventional heart rate chest straps.  They just never seemed to work quite right for her, or chaffed when they were cinched up enough to work, possibly the result of skin removal surgery after weight loss.

The Scosche unit worked great for her, seeming to do it’s job where the chest strap hadn’t.   Her Scosche RYHTHM+ went through many miles of running and biking, races and sweat and cold and heat and rain and such.

But after just less than a year she began to experience some drop-outs and we sent it back under warranty.  I had contacted the company before-hand to get a return order number and the company was very friendly and helpful.  Unfortunately I skimped on getting a tracking number and somehow the unit got lost in the mail. 

I resigned myself to buying her a new one but was surprised to find that when I inquired with Scosche they were nice enough to send us a replacement!  We both were incredibly happy with Scosche and their people and how helpful they were.  How many times do you get customer service like that, and people who actually seem to care?  That’s hard to beat.

At one point I bought her a set of replacement bands for the RHYTHM+, which worked great.  One thing you notice is the band is very soft and foamy and will absorb sweat and possibly do it’s best to wick the moisture, but it does get very wet after a good run or other intense exercise.  And it just as quickly dries out – which is fine usually, until you do two sets of some exercise without a good amount of time in between and then you find that it can still be in the process of drying, so the extra straps sometime come in handy.  And they are very easy to Velcro off and on the RHYTHM+ sensor body as needed.

Washing the bands is easy, I take the sensor off the band (of course) and hand wash the band in a little lukewarm water with a bit of dish detergent, then letting the band sit in a mixture of vinegar and baking  soda for a while.  After a bit washing the band out and rinsing it off, then letting it dry.  This does wonders for getting the sweaty smell out as well as dirt and muck from sweat.

So fast forward to last year when I began to experience some intermittent problems with my Garmin chest strap sensor.  My wife decided to get me a Scosche RHYTHM+ as a replacement (for Xmas).

It worked perfectly, just as it did for my wife.   And I have to say that over the past half year of use I have no complaints about it, outside of maybe a nitpick maybe, which I’ll get to.

The unit itself is small and light, grey low profile boxy plastic, kind of like the size of a large watch but lighter and square with just a button on the front and an LED on the front, and of course the back has the sensors.   

One thing I have noticed is that sometimes, if you throw it in your gym bag or whatever, the button can easily be turned on, running your battery down perhaps (though even when my watch says the sensor has low battery power it still seems to run for hours).  Supposedly it is supposed to power off when it does not detect a heart rate but this doesn’t seem to be the case from what I have seen.  If it gets turned on it is flashing the LED’s and trying to get a heart rate, running down the battery.  Simply just make sure it’s in a Tupperware case or box or something where the button won’t accidentally get pushed.

You’ll barely noticed the sensor when it is on your arm, and you can get the bands in various colors from Scosche or Scosche bands from other companies like this one or unbranded ones from third-party companies, like this one.

One thing I did notice (as is common) is that there seems to be a very, very slight delay between a heart rate change and the display/recording go it.  This can be hard to measure and likely I am expecting instantaneous data display when I should be very happy with how well these sensors and the display and recording of data works.  As I have mentioned in other posts I believe that this slight delay is fairly common, and probably even more so with Bluetooth versus ANT+, and it may also have to do with your receiving device and how fast it is. And likely most people reading this are not professionals nor need medical-grade recording so it’s really not an issue, and is barely measurable, but there.

20180604_150717But any delay you notice can be magnified somewhat if you are doing something extra strenuous and movement-intense that involves the arm you have it on, and possibly your whole body – a small amount of spurious stray light may be let in under the edges as your arm moves and allows a slight amount of opening, throwing it off for a very short part of a second.  But this is very unusual, and may be more common when doing something like Plyometrics or Boxing or Martial Arts versus running or biking where the arm is not going be be moving as wildly perhaps.  And likely this will depend on the person and how tight they have the strap.  For boxing or Martial Arts my guess is the bicep or right below the bicep is going to be better than anywhere along the forearm or down near the wrist. 

But in general the sensor just works great, it’s probably one of the easiest and problem-free sensor or external devices I have used. 

And it syncs quickly on power up and connect to whatever device(s) you use to display and record your heart rate.  As well as initial set-up and doing a first sync between devices.  A quick hold of the power button on the Scosche turns it  on showing an alternating red/blue indicator light, quickly whatever device you have previously synced it to will connect and the sensor will flash three blues to indicate a sync, then a slow blue flash to show normal synced operation.

For your info the personal devices I have synced to and tested with are the  Garmin Forerunner 620Garmin Virb, Samsung S7, Samsung Alpha, Samsung Tab A.

Initial syncing is easy and quick (just make sure you don’t have people around you who may have the same device) and seems to work on any device I have tried it on.  It also works on multiple devices at the same time, including multiple Bluetooth and ANT+ devices at the same time.  I haven’t seen any limit myself.  Nor have I found any device it does not work with, and unlike some Bluetooth sensors I have there seems to be few or no dropouts on the devices I have synced it to.  On new Android versions you may need to have location turned on for it to reliably sync and stay connected – this may depend on the device – and this has to do with how Bluetooth works on Android itself.

The only occasional dropouts I find when using it are when my wife and I are in close proximity on our bike trainers during the Winter – we usually are within a very few feet of each other.  Once in a while I get a quick dropout, and immediate re-connection.  Usually fast enough that I don’t even notice in real time.  Outside, even when we are riding together, I don’t notice this happening.  I suspect that the reason it happens inside on the trainer is it is either an issue with our devices being so close to each other or two Bluetooth 4.0 devices being so close and causing ‘confusion’ with the recording device, or possibly it is more related to the location service on my phone cutting out once in awhile from being inside – and stupidly Android requires location to be generally turned on for Bluetooth syncing now (not always but with this device it definitely helps).  But it could also have to do with the fact that I am using a phone (Samsung S7 and the Wahoo app) to log and display HR inside, where outside I use my Garmin Forerunner 620 and Garmin Virb.

Placing the armband is easy, the bands are connected to the device via standard Velcro on either side of the sensor  and the soft band can be worn on the upper forearm, tricep, bicep, or even lower on the arm.  Whether you have muscular or very thin arms or anything in between; you may want to experiment a bit with where you place it – for comfort as well as ability to stay in place without cinching it too tight.  The soft band seems to stay in place quite nicely for the most part, no matter where I put mine.  Another nice thing about being able to put it anywhere up your arm is that if you wanted to you could ‘hide’ it under a short sleeve if you do put it up high enough.  You should actually be able to attach it to your ankle perhaps, but would the accuracy decrease?  I’m not sure as this isn’t something I have personally tested.

One of my friends mentioned that some people may have more accuracy with one arm over the other, I don’t have any anecdotal evidence of this but it might be worth a try for those who get low or intermittent readings.

One thing you that may want to consider with the armband is that it may leave an untanned band on your arm if you wear it outside during sunny seasons 😉  Versus the chest strap where it is under your shirt (unless you go shirtless of course).  So I vary the placement of my Scosche Rhythm to avoid tan lines – not only for cosmetic reasons but because I don’t want to have a band of untanned skin that may burn when I am not using the sensor, as well as look funny.  Wear sunscreen too of course!  And you can always switch arms too.  

20180611_140033The sensor itself uses three LED’s; two green and one yellow (I believe the idea here is that the yellow allows it to work across darker skin tones versus comparable units that only use green) to read the heart rate by illuminating your capillaries with the LED’s, and reading this light as it reflects off your blood flow via sensors, using a principle of measuring the light scattered by blood flow. 

Is it as accurate as a chest strap?  From my (informal) tests it does seem to be (with the above caveat when doing extreme exercises of some types).  And I mean pretty much 99%, which is kind of hard to believe, but when checking it against a manual taking of my pulse at the same time as a display of my pulse on a device it is amazingly accurate.  Is it accurate enough for medical use?  Everyone will tell you that it and devices like it are not medical-quality.  And while that may be the case it does seem to be very accurate when at rest  according to my own informal and occasional tests.  I also tested it against a manual heart rate test after immediately stopping in the middle of an activity.  

This of course is not checking the accuracy in the middle of an intense exercise while in actual progress, without stopping.  But I did do a few quick non-manual tests by temporarily linking my old Garmin chest strap to a phone app and checking it against the Scosche while it was connected to my Forerunner.  At the time the Garmin heart rate strap seemed to be functioning just fine and the heart rate measurements were in accord.  This was not a long-term test but was good for a quick spot check for when I first got the Scosche.

My guess is that for biking and running under normal circumstances it is going to be as correct as the average person needs it to be, with momentary inaccuracies or delays if going over rough ground or a rough road perhaps but nothing that will affect the overall accuracy.

Devices like the Fitbit series are meant to be worn a bit looser, and with higher level exercise these begin to lose accuracy quite quickly unless they too are cinched up tight to the wrist.  But the Scosche is meant to be somewhat tight to the skin and thus does not allow any errant light in under normal circumstances.

One possible controversy with armband versus chest strap measurement is the idea that your blood may have slowed a bit by the time it reaches your arm, and this may come into play proportionally higher at high heart rates, thus increasing the error rate.  Is anyone reading this review a pro athlete?  Probably not, and likely the small difference (if there is a measurable one with this device) is moot.  


A sample of heart rate data from a short bike ride.

A few stats… 

The Scosche RHYTHM+ Armband Heart Rate Sensor is IP67 waterproof, which makes it quite waterproof, at least to one meter or so.  What chlorine will do to it and the band is maybe up for debate.

The RHYTHM+ has a long battery life, around eight hours according to Scosche and with my own tests this seems about right, give or take.  

The Bluetooth is the newer version which is supposedly good for a hundred feet.  In reality this is much less but better than the old Bluetooth formats, certainly.

20180611_135950A one year warranty and money back warranty too. 

You get a small band and a large band which will cover most anyone, and the charger for it, which can be plugged into a USB port on a computer, hub, or wall USB transformer, etc.  The sensor, with or without the strap on it, can be snapped into this quickly and easily and securely and snapped out just as easily.   It charges fairly quickly.

I recommend keeping a little rag or absorbent cloth near your charger or where you take the unit off your arm and giving the sensor a little wipe down after use, to keep the ‘muck’ off the charging ports, LED’s and sensors. 

Also included is a quick little instructional piece of paper (you can also download the manual off their website).

A bit of advice for using the the Scosche Armband HR sensor with long-sleeved shirts in cooler times of the year – and which has nothing to do with the design of the device but is just the nature of how it attaches – sometimes you may need to cinch or secure it a bit tighter for when you pull on or off long sleeve shirts.  It may get pulled or slid up with your sleeve if you tend to wear the RHYTHM+ a bit looser, or you have thin arms, as possibly with tighter long-sleeve shirts it can detach the Velcro so you don’t want to have it get lost or stuck in your shirt when you wash it, as well as not be recording your HR data.  Strangely enough I have had this happen as well as my wife and in the darkness of the long-sleeves it still recorded what looked like accurate data.  

A nitpick or issue that I do have is that unfortunately there is only an app for iPhones/iPads for updating the firmware, nothing for updating the firmware on any other device.  For those who don’t have an iPhone or iPad they must either send the RHYTHM+ back to the company for a firmware update (or even a check to see if there is a firmware update) or find a friend with an iPhone who will install the Scosche app and see if there is a firmware update, and update it.   A few people have reported some issues with the update and app, perhaps it might be best to send it back to Scosche?  I want to mention though – the preceding is only in reference to updating the firmware – any Android device will work fine with the Scosche RHYTHM+ for syncing and normal tracking of heart rate.

As I mentioned earlier my wife had one go bad but recently she had a little trouble with her’s not charging. But cleaning the charging contacts on both the sensor and the charger did the job.  Usually a little alcohol on a cotton swab works just fine but in her case one contact had some thick muck so I used a miniature wire brush from a Dremel kit, spinning it a little across the contacts by hand (not attached to the Dremel) when nothing else helped.  

As I conclude this I want to mention another probably more indepth review of the Scosche RHYTHM heart rate sensor band from my favorite fitness device reviewer – DC Rainmaker.

If you are looking for a replacement, or an alternative to the standard chest strap heart rate sensor, then check out the Scosche RHYTHM+ Armband Heart Rate Sensor.  I don’t think you will not be disappointed in how well it works, the sensor data from it, nor how durable it is for your exercise and fitness activities.

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.

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