A Garmin runner’s watch like the Fenix 6 Pro Solar is an obvious choice if you want a wearable to track runs, walks and bike rides. But does it really do the job better than an Apple Watch Series 6?
I decided to test these watches’ heart rate sensors in the context of a run. An Apple Watch on one wrist, a Garmin Fenix 6 Pro Solar on the other, and a Wahoo Tickr HR strap around the chest, acting as a control for this not-quite-scientific test.
Here are the results over a roughly 7km run, one dotted with breaks and slow-downs to see how the trackers cope with sharp changes in effort. The Garmin is the red line, the Apple Watch Series 6 the blue line and the Wahoo Tickr the green.
The most obvious fault here is the Wahoo Tickr chest strap’s. Or, to be fair, my own. Its readings are all patchy and intermittent at the first increase in pace, most likely because the strap wasn’t quite tight enough to start.
However, it is otherwise the most accurate of the three. And I’ve left the first few minutes of tracking in this graph to highlight the main wearable takeaway.
The Apple Watch Series 6 starts off from a much better position than the Garmin Fenix 6 Pro, whose results are too high. This is a common observation of Garmins and wearables in general: their HR tracking algorithms tend to assume your heart rate will be far above your resting rate as soon as you begin tracking an exercise.
If you start the session as you warm-up, it will not be. The Apple Watch Series 6’s readings are very accurate from the first seconds onwards.
This issue with lower heart rate readings continues throughout the run. In each decrease in pace, or outright stop in the case of the deepest dip in the graph, the Apple Watch Series 6 tightly matches the lowest reading recorded by the Wahoo Tickr chest strap. But the Garmin’s are all routinely slightly higher.
The Garmin Fenix 6 Pro shows significantly higher readings during the cool-down too, aside from an aberrant blip at the end where the recorded rate drops, and then compensates with an artificially high peak.
Apple’s Watch Series 6 only failed to keep up, slightly, with the Tickr when I went from running to sitting on a bench, to cause a very steep fall in heart rate. The Apple and Garmin’s falls are similarly cliff-like, but not as steep as the Tickr’s.
The Apple Watch Series 6’s heart rate hardware is superb, obviating the need for a chest strap, for most people. There is another side to this story, though.