I have an Apple Watch (AW), primarily so I don’t need to carry my phone with me all the time. Being a data nerd, and using multiple devices and platforms I just had to perform an Apple watch vs Garmin Forerunner 935 (my “go to” training device) technology comparison.
Before the data, a couple of things about the AW. If you listen to music when you run and are looking to leave your phone at home and stream through the watch you can only do so if you subscribe to Apple Music. Spotify does have an AW app but you need to have the phone on you as streaming and offline playback are not available through the app at this time (Fall 2019). Apparently there is a work round if you download your playlists and podcasts from Spotify, convert them to MP3 format and then sync them with the AW. This is next on my list to try as it would be great to not have to carry my phone when I’m running.
More importantly the AW 5 has a horrible battery life. With day to day use, Apple says you should have around 18 hours of battery life. I don’t. By 12 – 13 hours my battery is down to 15%. Turning off high battery use apps (like Noise and the always on display) helps, but why have the watch if you’re going to turn off all the functions? In this 25 minute test run my battery reduced by over 20% and this was without streaming music – not good news for a distance runner.
On the Road
As for the run itself, N=1, this was a test simply to get an idea how similar or disparate the data was.
| Garmin | Apple | |
| Distance | 2.29 miles | 2.39 miles |
| Total Time | 24:19:00 | 24:20:00 |
| Moving time | 23:53 | 23:36 |
| Elapsed time | 25:26:00 | 25:34:00 |
| Pace average | 10:37 min/mile | 10:09 min/mile |
| Average Moving Pace | 10:26 min/mile | 9:51min/mile |
| Pace best | 7:53 min/mile | |
| Average Speed | 5.6 mph | 5.91mph |
| Average moving Speed | 5.7 mph | 6.09mph |
| Maximum Speed | 7.6 mph | 8.1mph |
| HR average | 160 bpm | 168bpm |
| HR Max | 180 bpm | 178bpm |
| Cadence average | 164 spm | 169spm |
| Cadence Max | 175spm | 283spm |
| Stride length | 0.92m | 0.98m |
| Active energy | 234 cal | 236 cal |
| Calories | 272 cal |
GPS and Route Maps
Most of the time Garmin does a nice job, however sometimes, as this run highlighted, it just doesn’t pick up a GPS signal and your route/elevation doesn’t get recorded. The AW has a recognized history of “cheating” when plotting your route on a map. It smooths out corners and has people running off route. On this run, the starting point was the same as the ending point (not in the middle of the parking lot), and you can see some smoothing but overall it wasn’t so bad.
Time and Distance
The AW wasn’t set up to pause when I stopped running so I was swiping and manually hitting pause, which didn’t always work (pressing bezel and side button simultaneously will pause your activity, and can set the watch to auto pause when you stop running). As a result the total time and total moving time should have been about 30 seconds apart (after first stop I kept both recording continuously until end of run).
As for the distance … Garmin recorded 2.29 miles, Apple 2.39. How significant is 0.1 mile difference? Well, over a marathon you’d gain/lose 2.62 miles which is pretty significant. But … which of these distances is correct? Having measured the route using three other mapping tools I came up with:
| Map My Run | On the Go Map | Mappedometer |
| 2.51 miles | 2.3 miles | 2.48 miles |
Who knows? This is one of the reasons I use the same device all the time.
Heart Rate
The AW sensors are “industry leading”, however there were some anomalies with my data. At the 1 mile mark it acutely dropped from 170 to 158, a significant change. This type of drop has been noted by others (DC Rainmaker) and was not apparent in the Garmin data. The drop in pace recorded by the AW at the same time was a result of a 180 degree turn as I reversed route – knowing the speed and duration of the turn I question the degree of change, especially when compared to the Garmin, that showed a change, but not of the same magnitude.
HR Zones
The AW doesn’t show HR zones without using a 3rd party app, in this case, the information (top left chart) is from Final Surge (Garmin data in the top right chart).
Using a variety of devices and software, you can start to see how different algorithms can affect data. The graphic at top right is the Final Surge interpretation of the Garmin data (black box at the bottom) – while close, there is a difference. The calculation of the average HR differs with Final Surge calculating 157bpm, compared to Garmin at 160bpm.
Finally, the elapsed time between devices also appears to reflect the total time for the Garmin versus the moving time for the AW. The difference between the AW and the Garmin is significant, and without having used a chest strap to get an accurate HR it is impossible to tell which, if any, is accurate.
In the Gym
Garmin has never performed well in the gym as it is not geared towards equipment such as spin bikes or ellipticals. Data is pretty much limited to heart rate, training effect, HR Zones, and duration, although if you are on a treadmill and walking/running you get a distance calculation (as long as you are swinging your arms).
There were 2 parts to my test – Air Runner and Octane. I’m recovering from a hip injury and needed to hold onto the arms of the air runner no not surprisingly had no distance recorded by the Garmin. Very surprisingly I did from the AW and it matched that of the Air Runner console.
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The Octane provided the big surprise. Time and duration were identical, however HR was significantly different, enough that I questioned which the accurate device was (if either).
I repeated the Octane workout the next day using a chest strap with the Garmin.
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I admit that I am biased towards Garmin so was very surprised that the results from the Garmin using the chest strap confirmed that the Apple Watch was the accurate device when just the optical reading were used.
With devices differing in their technology and algorithms used I was not surprised by the variations in data, and was actually surprised by how close the results were. While this was a one off, non scientific experiment it confirms my opinion that as data will never be identical across platforms you need to pick a device/phone app and analysis software that meets your needs (e.g. someone whose passion is lifting weights would not need a Garmin Forerunner 945 with triathlon features) and that you are happy with and stick with them, focusing on changes over time (rather than focusing on day to day changes) to monitor your progress towards your goal.
I am going to continue to use Garmin for running due to its battery life, GPS tracking, and available run dynamics. As the Apple Watch appears more accurate inside (as has been highlighted by others (the Techy Agent), I will use it when I’m at the gym, and for general day to day fitness. Using an Oura ring for monitoring sleep, I need a platform able to combine all my data. My choice – Final Surge where I plan training and check progress over time.