Samsung Galaxy Watch 4’s Heart Rate Accuracy Test

The Samsung Galaxy Watch 4’s heart rate accuracy is tested scientifically in this article (Samsung galaxy watch 4). Many people were upset with this pricey piece of technology’s poor heart rate tracking capabilities when it was first released. Tests revealed that the watch could not accurately track my heart rate for long periods. Find out if the situation has improved since Samsung published a significant firmware upgrade.

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Galaxy Watch 4’s Heart Rate Accuracy graph

Galaxy Watch 4 Spinning Result With Gragh:

Specifically, I’ll compare the galaxy watch 4 to the Polar h10 ECG chest strap, widely regarded as one of the most accurate consumer devices available for heart rate measurements. Begin with the accuracy of the heart rate measurement while spinning. Here is an overview of the heart rate accuracy during a total of 5 spinning sessions. Each dot represents a single heart rate measurement taken with the long horizontal axis, which corresponds to the value obtained from the Polar H10 ECG chest strap. The vertical axis corresponds to the value obtained from the galaxy watch 4.

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Blue and Black Dot Graph

Perfect agreement is indicated by the blue line, which means that any measurement along this line will result in about the same number for both the Polar h-10 and the Galaxy Watch 4. Generally speaking, the greater the number of measurements taken in a certain region, the darker the black will be. As you can see, with the ecg chest strap, the galaxy watch 4 is lubricated quite well. However, there are still a few points away from the blue line where we see the same thing.

First and Second Spinning:

in the beginning, it missed a dip in my heart rate now this third right here is almost perfect again. However, for two of the rides, i struggled a bit more and this is one example of those you can see quite a few times. It feels to pick up on my increase in heart rate as you can see here. But also here now it could be that for this ride the watch wasn’t positioned as well by accident. So it couldn’t get a good signal now we cannot be sure of that now this right here also shows some issues do not as severe only for this segment here the watch was unable to pick up on my increase in heart rate now.

I should know that the galaxy watch 4 already performed quite well during my original testing for cycling inside and it was more during cycling outside. It showed some issues and that is displayed here. If we put the old results and the new results for the new firmware side by side for spinning the old results here on the left and the new results here on the right. We actually see that the results for the old firmware might have even been better as you can see on the left there appeared to be fewer points away from the blue line though. Of course, it could just be a complete coincidence that for the new firmware.

Problem with biking

I just happened to have more trouble tracking two of the rides so this is definitely not conclusive evidence but just an interesting observation. So let’s now take a look at a cycling outside did that improve at all or is it still pretty bad the problem with biking. i had before was that the galaxy watch would not record my heart rate for large parts of the ride here I displayed one of those rides for the old results. You can see for most of the middle of my ride. It missed tracking my heart rate at all now very often. It was less severe as you can see for this ride. However, you can still clearly see that for some parts of the ride the values are missing and we see the same here with at least two parts missing values.

Measuremant of Heart Beat Rate And Bike Riding

Sometimes it would happen that would just record the heart rate for a few minutes. As you would see here so here it seems that it only recorded my heart rate for about four minutes. Whereas the total right was about 20 minutes let’s look at the new results now. I tested the new firmware during seven bike rides here.

We have the first bike ride with the new firmware now there are no major missing segments and the agreement between both devices is quite okay. We see something similar for this second bike ride and also for this third bike ride or the disagreement might be a bit bigger here. This seems to be basically true for all bike rides there’s an okay agreement for the most part for some parts of the ride is really good. But for other parts is not as good as you can see for instance here but also here. We see the same for this last bike right here so there’s luckily no longer any missing segments. But for some segments, the agreement between the heart rate is not as good.

If we actually put the old and new results side by side for biking the old results on the left and a new firmware here on the right. I would say that the original firmware here on the left showed a slightly better accuracy. But it had many more dropouts or in other words, missing heart rate values, the algorithm likely dropped those values at the least confidence which means it only kept those values. You had the most confidence in I would speculate in a new firm where more results are kept in. But these are measurements the algorithm is less certain about. Of course, this is purely speculation based on the results I got when testing it myself finally.

Measurement of Weight Lifting

let’s take a look at weight lifting. Weight lifting is one of the hardest things for a watch to accurately track. Since there’s so much tension on my arm and wrist here. I plotted those side by side for the old firmware and the new firmware to my eye these graphs look more or less the same. So their performance should be mostly the same though the new firmware might be ever so slightly better. If we look at the individual training sessions for the new firmware we see that the galaxy watch 4 does not perform that badly.

It misses the highest peaks in my heart rate for each of the sets that I did. But it’s not as bad as some devices we see something similar for the second weightlifting session though. This is arguably a bit worse with it missing more of the peaks in my heart rate completely and again we see something similar for this third weightlifting session. The latest firmware does appear to have brought some significant changes to the heart rate algorithm of the galaxy watch 4.

This is most noticeable whilst biking where the watch no longer shows missing heart rate measurements however what seems to have happened is that with the old firmware. I dropped quite a lot of the least accurate heart rate measurements. Whereas now it is lower this threshold and it shows more of the measurements. However, these heart rate measurements are of course going to be inherently less reliable one could even argue that the old system was better or alternatively.

It would be cool if the reliability of the different segments was shown in the graph overall the heart rate measurements of the galaxy watch 4 are definitely not bad. They will likely suffice for basic measurements during cardio exercises that do not involve too much bumpiness. However, they are nowhere near as accurate as of the apple watch which is basically in a league of its own. I do think Samsung could learn a lot from Apple in that regard.