Truth About Garmin Fenix 9 Heart Rate Accuracy (TrackLab Analysis)

Fenix 9: https://geni.us/HqB2Ef9 Polar H10: https://link.amazon/B0gztxr3p Is the Garmin Fenix 9 optical heart rate sensor finally accurate enough to replace a dedicated chest strap? In this video, we put the $1,200 Garmin Fenix 9 head-to-head against the gold standard $120 Polar H10 to uncover the truth about wrist-based HR accuracy. Using custom TrackLab software, I process the raw FIT and CSV data from both devices to move past manufacturer claims and look at the actual math. We break down the interval latency, MAE, RMSE, and Fréchet Drift to see exactly where the Fenix 9 sensor drops the ball—or holds its own—during dynamic shifts and intense intervals. As always on Mountaineer Journey, this Fenix 9 was purchased out-of-pocket for a 100% independent, unsponsored review.