23 February 2018

Polar M430 - Unusable Optical Heart Rate Monitor? Accuracy Review.

After many years my old Polar S625X started with geriatric problems. For example IrDA drivers bugs on Windows 10, buttons on watch, chest strap, Polar's announcement that PolarPersonalTrainer will be discontinued...
It was time to find a new HR monitor. My wife uses M400 and she is satisfied with it. Polar M430 GPS Running Watch is its successor with optical heart rate measuring and some improvements. I read many reviews and M430 really looked promising. My wishes were: not expensive, GPS, Android and cloud support, optical HR measurement (I have enough problems with chest straps)...
M430 has everything I want and it wasn't expensive in January (189 EUR was my price in local store). The only reservation was an awareness that optical HR measurement isn't very accurate. Having that in mind, I have read this part very carefully on all reviews. The conclusion was that it isn't perfect, but is usable and that M430 has one of the best results in a field trial.

All features are well described on many websites (includes Polar's) and I won't repeat what other reviewers have already said. Only my disappointments follow.

1. Software
The Android software works as it should. From my perspective its main task is to synchronize data from M430 to the Polar Flow. Otherwise, Android PolarFlow is simple to use, user interface is nice and works fast.
With S625X I have used PolarPersonalTrainer. PolarPersonalTrainer will be closed down so all users must move to Polar Flow. Polar Flow looks modern, but PolarPersonalTrainer has more advanced functions and Polar could simply upgrade it with modern design and support for newer devices.
When I tried to transfer training data (10 years!) to Flow, I found out that this can't be done! WTF!
 I have asked Polar and get a classic corporative answer: "Thank you for contacting Polar customer care. Unfortunately you can only transfer data from PPT to Flow when using one of the following Polar products: RCX3, RCX5, RC3 GPS, CS500, CS500+, RS300X, RS800CX, CS600X, FT80, FT60, FT40 and FT7. I apologize for the inconvenience."
Crazily. I'm sure that all records (regardless of watch model) are stored in the same way in their database. They simply don't allow users of S625X to export their own records.

I have tried many tricks and I can at least export data from PolarPersonalTrainer (but only 25 records at once!!!) in XML. And don't expect that XML can be imported in Flow. It has to be a "political" decision, there simply isn't any technical reason.

Then I found the second clumsiness in Flow. You can't compare two (or more) training like you can in PolarPersonaTrainer. Isn't that one of the most interest thing you can do with your sports data?

2. Charging 
Polar M400 uses the standard (waterproof) micro USB cable that is available almost everywhere. With M430 Polar has introduced a custom made port. If you have cable at home, you can't charge your watch in a car or in the office. Forget it. If you run out of battery, your M430 will be useless until you get your cable. You can buy a Polar M430 Charging Cable for about 20 EUR (usury of course).
Not only that, the connector on cable doesn't clip in very firmly.
As far as I know, Polar has problems with USB port corroding and charging on M400, so they had a reason to do that.

3. Battery
Many reviews glorify battery life on M430, but I'm not on their side. To be honest, the battery is not bad and it shows good results if I compare it to competition. But for sure it can last longer. I expect to charge it every second (or third) day. If you have longer training, then expect to charge after every training. My friend also comments that he isn't sure if his M430 has enough battery juice for longer activity (6-8 hours - like mountain day).
Luckily, M430 has some settings where you can lower energy consumption.

4. Optical Heart Rate
Now we came to the main problem on M430. Its main function is HR measuring, but here it fails as deep as it can. What is wrong? First 10 or 15 minutes (or even half an hour) it shows wrong HR.
I now that watch should be positioned as described in user manual. I tried with tightening more, tightening less, move watch higher or lower on the wrist, cover watch and skin (cold factor), wearing watch hours before training... But it simply doesn't work ok at the beginning of training.
First minutes readings are far from real. It is winter in Slovenia, temperatures are near freezing point. It is understandable that on cold weather condition, the sensor performance (heart rate accuracy) could be effected as the blood flow is slower.
It is interesting that HR readings are real when I preparing for training. But after I start, numbers fall down to approximately 95-105 bpm. And stays in that zone for 10-15 minutes. It looks like my blood flow to hand almost stops when I start with training.

I asked Polar Support and here is their answer: "This is a common problem with OHR sensors. They need some time to adjust to your skin and you did everything right: moving the watch, covering it, etc. We recommend to put on the watch some time before your training. This allows your skin to get accustomed to the watch. When putting on the watch the blood flow will be hindered at first, but then the skin gets used to it and the blood flow will improve. But nonetheless it can happen, that the watch needs several minutes to calibrate itself to your pulse. This is not a bug, but an expected behaviour.
And as you described, it differs from person to person."

I accept that M430 reacts a little slower, this is usual behavior for optical sensors. I checked the datasheet of the manufacturer of sensor and they say that sensor's response time is 8 seconds. It is understandable and doesn't lose HRs because it simply writes them a little later.

I prepared a simple video to show the problem:

Note: Old S625X was with me some months ago when I was on medical heart test. And it was very accurate.
Cold is definitely an important factor here. I tried with ski gloves on my hands and although problem still exists, M430 readings were at least a little better.
It is interesting that M430 has problems if my heart rate is high (or increasing). On the other hand, when my heart rate decreasing (for example when I turn downhill after ascent), it starts working ok. I even noticed that if my track on the ascent comes to gentle part, the HR readings on M430 starts to increase (opposite from real where HR starts to decrease).

Things are even worse. HR readings can be inaccurate from time to time even when the device is in "good area".

5. Other annoyances 
There are some minor annoyances. For example, buttons are a little soft and user don't get good feedback. Another annoyance is three seconds long press for finish training. If I add a little delay from a soft button, then this long press is way too long for me.

What can I say? Polar M430 isn't usable if you want to follow your HR with optical HR.
What will I do? I don't know yet. Maybe buying a chest strap is the cheapest solution. You can believe that I'm not very keen to buy an expensive strap because I already feel (at least partly) cheated from Polar. And then give them more money - hm, is this smart?
All in all, I am disappointed with M430, but otherwise (except upper issues), M430 can be a very interesting device. I'm also waiting for the higher temperature to see if readings will be more accurate.
UPDATE (24th February 2018): I have tried with borrowed Polar H7 (chest strap) and M430 works like a charm.

That's it. I would like to read your comments and suggestions.


Pieter Oosthuizen said...

Coming from an M400 I bought the Suunto Spartan Trainer hoping the oHR will be OK. After lots of frustrations I switched back to a chest strap HRM.

It seems the wrist based oHR tech in general is quite useless for the person who is interested in accurate HR measurements.

Iztok Grilc said...

I fully agree. Now I have a chest strap H7 and it works as it should.
It is nice to have a backup (oHR) when you forget a strap :-)

Jh said...

Bought the M430 back in the summer...after using the rs400 and the protrainer for many years...overall do like the M430..
happen to be in California and use indoors..so little different useage

Battery...get about a week out of it...so shut down the gps (that saves a ton of battery)....but I do,wear it all the time so it is recording the continuous heart rate...and tracking sleep activity (which is interesting)

Heart rate....I too switched to a chest strap H7...but simultaneously wore the M430 without the strap and the rs400 with strap during several workouts....M430 was pretty good for steady runs ...matched up pretty well with the rs400...just lags the chest strap results.....where the optical reader was challenged was anytime the heart rate was changing rapidly both up and down....just couldn’t keep up...so switched to chest strap and seems to be fine

Finally in terms of the polar flow....not thrilled with it either...2 things...has different functionalities between the mobile application and what is available off a pc (why?)....and the feature I miss the most from the old protrainer...was the ability to use “error correction” to fix heart rate spikes/anomalies that you just get time to time

So sorry for the long response...but just I would share....

Iztok Grilc said...

Jh thanks for the comment.
I agree the chest strap is a must-have if you want to get accurate readings. I bought it now and it works. Cold is definitely an important factor here. Maybe also my problems with veins, who knows. As you can see in the video, it simply doesn't work when I start training. After some time, it starts to work ok.
Protrainer is super :-)

Branko Hrovat said...

par dni nazaj sem kupil M430 prej sem imel m400, s katero sem bil zelo zadovoljen, vendar je po 2 in pol letih baterija zelo oslabela. problem je bil tudi z usb-jem in tipka ok je bila slaba. zato sem se odločil za nakup nove. kupil sem pač m430. včeraj sem šel v hrib in sem opazil iste težave, s tem da po 30 minutah ni bilo bolje utrip se je zmanjšal na uri za kakih 20-30 in to v neenakomernih časovnih intervalih. če si merim utrip doma, zgleda vse uredu. pri novi urci sem opazil tudi, da ni menuja na uri kjer kaže nadmorsko višino in spremembe, kar mi je bilo pri m400 zelo všeč, ko vadbo prenesem na polar flow so ti podatki sicer vidni. prebiram navodila, pa nikjer ne najdem zapisov o tem. ali morda ti kaj veš o tej nastavitvi?.

lp Brane

Iztok Grilc said...

Po eni strani bi rekel, da me veseli, da imaš enake težave :-) no, zgolj zato, da nisem edini.
Jaz sem poskusil res vse, kar mi je padlo na pamet. Zelo resno sem preizkušal, pa mi (načeloma na začetku) ne deluje pravilno in konec.
Dokler se jaz ne "zaženem", je merjenje v redu. Takrat pa enostavno pade. Kupil sem (praktično nerabljen) pas in z njim ni bilo težav. Tako, da ... ok, načeloma sem zadovoljen z uro (z izjemo tega optičnega merjenja). Očitno gre za kakšne posebnosti na koži/telesu, ki pri nekaterih onemogočajo pravilno merjenje. Imam še dve stvari, ki jih moram poskusiti s pomočjo ur pri znancih (enkrat bom vzel Suunto z optičnim merjenjem, drugič pa prav M430). Da bo vse skupaj čim bolj relevantno.

Če prav razumem drugi del vprašanja, potem poglej na spletni strani flow.polar.com. Klikni na svoje ime (desno zgoraj), izberi "Sport profiles", potem pa pri posameznem profilu "Edit". Sedaj imaš na voljo tudi "Training views", kar je verjetno to, kar želiš.

Ruth Bosmans said...

I noticed the same problem with the heart rate but in my case the showed heart rate goes through the roof. Even when running a slow tempo my heart rate is in the 180's where it should be 130 or so...It's pretty annoying and totally not reliable... Tried everything to get better results, but I think the optical sensor is very sensitive to temperature and wind and those conditions you just can't change... bummer :-(

Iztok Grilc said...

After publishing this review, I have tried many tricks, but nothing helped. It is interesting that even if my route is up and down, then HR readings are often not reliable. It works quite ok if I go on long ascent (after first 10-20 minutes of course).
On the other hand, it works ok with strap. So I suggest a strap :-)

Nicole Calder said...

I’ve also been experiencing the same problem - my Polar M430 used to be extremely accurate with its heart rate readings, but now it’s saying my HR isn’t getting over 160bpm during an intense soccer training. I live in Australia and the weather is still warm so the temperature isn’t affecting its accuracy. So either in the space of a week I’ve become so fit, it’s taking a lot more to get my HR up, or there’s a fault in the HR sensor.
I’ve also had problems with my buttons getting “stuck” - permanently pressed down - has anyone else had this issue?

Iztok Grilc said...

Interesting. I can confirm that temperature isn't an issue. Here in Slovenia is now warm enough (winter is over :-)) that I can say it isn't problem.

Michael R said...

Thank you for a good review. My experience is the same as you. I commute on my bike 25 km each way every day and I use exactly 1 h., but avg HR can vary as much as 30 bpm. Today it took 37 minutes before the M430 adjusted to actual HR (a very steep and sudden increase in the HR graph from around 105 to 140). For activities like football and hockey with large variations in HR its totally useless.

Iztok Grilc said...

I agree with you. Unbeliavable (or not, to be honest :-)) how HR can swing.

Jan T said...

M430 is intended as a running watch so it responds quite slow to the change of a heart rate. It behaves as it is described in a review. When your heart rate changes watch just responds with a lag of approx 30s. For running at a constant speed it is quite ok I guess as the result is +-5 beats from the strap. For a sudden change in a heart rate strap is needed. I got an impression that during winter and cold less than -10C results were a little bit lower than usual i am thinking something aroud 10 beats per minute but when the temperature is above -5C it is quite OK.

Iztok Grilc said...

I agree with lag. It exists (for me maybe approx 10 seconds), but this is not a big deal.
The main problem exist because first 10-40 (yes, to 40 minutes!!), M430 doesn't work properly if I use it on skin. It simply shows very low HR and then suddenly starts with a jump :-)

Unknown said...

Hi. Have any of you experienced the HR feedback stopping mid run? This has happened twice now once in a 6km run near the end and then on a 15km run at about an hour in. Nothing I did got it to refresh, took it off, dried my wrist and the sensor. Wrt my wrist and the sensor, loosened and tightened the strap :-( the other issue was GPS on medium accuracy added 4.5km onto a 46km race. I was testing it as I have a 90km race coming up and need the longer battery life but the accuracy was so bad I couldn't trust anything on the watch during the run. Looking on the route after the run I was barely on the road according to the watch and yet my running friends had not issues with other brand watches or the M430 on high accuracy. Surely the expected behaviour is not to be that inaccurate otherwise why offer the option?