How Accurate is the LG Watch Sport Compared to Established Fitness Watches? (Test and Review)

The LG Watch Sport is the device that LG “designed with [their] friends at Google” to highlight the features of Android Wear 2.0.  When I heard about a Google fitness watch, I was thrilled.  The LG Watch Sport went on sale February 10 and I just received my LG Watch Sport yesterday.  Today I took it for a run.  On my other wrist, I wore my trusty Garmin Forerunner 235, which is an excellent fitness tracking watch that I’ve worn on hundreds of runs over the past 18 months.  It is very accurate, reliable, and has long battery life (about a week).  How does the LG Watch Sport compare?  (Note: I have done a followup post after testing the LG Watch Sport several more times.)

Comparison Between Garmin Forerunner 235 and LG Watch Sport
Comparison Between Garmin Forerunner 235 and LG Watch Sport

I think the results speak for themselves.  If you click on the image, you can see that the yellow benchmark line (Garmin Forerunner 235) is consistently accurate, whereas the blue line (LG Watch Sport) is all over the board.  You may also notice that I am not a very fast runner and that this is only a two-mile short run.  Below are more detailed graphs.

Heart Rate Monitor Comparison
The heart rate monitor on the Garmin Forerunner 235 wasn’t even close.

Especially disappointing is the heart rate monitor.  The LG Watch Sport wasn’t even close.  I do not believe this was due to any error on my part – the watch was tight against my skin.  However, I believe the Garmin Forerunner 235 uses a type of smoothing algorithm on the data in nullify outliers, so that might account for some of the difference.  Additionally, instead of using the built-in Google Fit activity tracker, I used Ghostracer.  It is possible that the Google Fit activity tracker will track the sensor data more accurately, but with such large aberrations, I doubt that the software is the problem.

LG Watch Sport elevation comparison
The elevation data was inaccurate.

While running along the shoreline, which is notoriously difficult for smartwatches to plot accurate elevation data, the LG Watch Sport was inaccurate.   Perhaps it thought I was a whale because it plotted me going below sea level by fifty feet and then resurfacing several times.  My trusty Garmin Forerunner 235 does not have a barometric altimeter, but obtains elevation data based on GPS. It appears much more accurate for a shoreline run with a couple small hills.

LG Watch Sport speed comparison
Even elementary measures like speed lack accuracy.

In my test run, I tried to run at a consistent cadence and pace.  The hills threw me off a bit, but overall, the Forerunner 235 shows my true slow pace, whereas the LG Watch Sport was again all over the board.  To be fair, I believe the the accuracy of the GPS data could be improved significantly with a smoothing moving average-type of the data.  The data from the Google fitness app might be more accurate, so I will update this post tomorrow once I can determine if that’s the case.  Below is a comparison of the GPS data accuracy on a map:

LG Watch Sport GPS comparison
GPS accuracy is subpar

The LG Watch Sport (blue line), like the Garmin Forerunner 235 (yellow line), both have GPS with GLONASS, which improves GPS accuracy by recruiting more satellites.  However, the Forerunner’s accuracy is dead-accurate, whereas the LG Watch Sport has me running in Lowman Cover.  (Perhaps that’s why the watch thought I was a whale.)  As I mentioned, the data could be cleaned with a good algorithm, so I will track my run with the built-in Google Fit app on the LG Watch Sport tomorrow.

LG Watch Sport cadence comparison
The LG Watch Sport performed equally well with cadence accuracy

Despite a few blips here and there, which could again be the result of no smoothing applied to the data, the LG Watch Sport performed about the same as the Garmin Forerunner 235 for cadence.

Conclusion

Needless to say, I’m extremely disappointed with the run tracking accuracy of the LG Watch Sport.  For a watch build with “sport” in it’s name, it does not perform nearly as well as established fitness watch competitors.  While my garmin only has rudimentary smartwatch capabilities, it is head and shoulders above the LG Watch Sport with regard to tracking runs.  The primary purpose of the LG Watch Sport for me is to track runs.  The utility of this watch is low if I cannot track fitness activities well, especially considering the cheaper Garmin Forerunner 235 has a week-long battery life and offers some unique features like all-day heart-rate tracking, and sleep tracking.  (Yes – I wore that watch 24/7.)  To reduce this comparison to a soundbite, I’d say that the LG Watch Sport’s most important feature – tracking sport – doesn’t compare to my beloved Garmin Forerunner 235’s run-tracking prowess.

I am hoping that this inaccurate run is an aberration.  I will perform a few more tests wearing the two watches, trying to press the LG Watch Sport closer to my skin to get more accurate heart rate data, and using the built-in Google Fit app. (I have now performed additional tests and posted the results.)

If there is no improvement after future tests, I am strongly considering returning the watch.  It lacks any utility to me if it cannot accurately track my runs.  The neat smartwatch features do not outweigh the daily annoyance of charging the watch or the frustration of inaccurate tracking.

I hope you found this information useful.  Join me on Strava!

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