The heart rate monitoring accuracy of the Apple Watch Ultra 2 has been evaluated against established benchmarks, such as the Polar H10 ECG chest strap, and the results indicate a generally high level of precision, although some limitations exist.
Accuracy Overview
- High Correlation in Higher Heart Rates: In tests involving indoor cycling, the Apple Watch Ultra 2 showed an almost perfect correlation with the Polar H10 in higher heart rate ranges. The correlation coefficient (r value) approached 1.0, indicating excellent agreement between the devices at elevated heart rates[1][2][3].
- Deviations in Lower Heart Rates: While performance is strong at higher intensities, the Ultra 2 exhibits some inaccuracies in lower heart rate ranges. In particular, quick dips in heart rate were occasionally missed or inaccurately recorded. This resulted in a few more deviations from the expected values compared to the Polar H10[1][2][3].
- Comparative Performance: When compared directly to its predecessor, the original Apple Watch Ultra, the Ultra 2 performed slightly better overall. However, it was noted that the added weight of the Ultra 2 could lead to minor discrepancies due to increased wrist movement during exercise[2][3].
Specific Findings
- Workout Comparisons: During various workouts, including cycling and weightlifting, the Apple Watch Ultra 2's readings closely matched those of the Polar H10 for average heart rates. For example, during a chest workout, both devices recorded nearly identical maximum and average heart rates (164 bpm vs. 163 bpm)[2][6].
- Signal Loss Issues: Some tests indicated instances where the Apple Watch Ultra 2 would lose signal during workouts, particularly under heavy strain or specific movements like weightlifting. This led to missed heart rate readings during critical moments of exercise[5][6].
Conclusion
Overall, while Siri's heart rate monitoring on the Apple Watch Ultra 2 is quite accurate and reliable for most users, particularly during high-intensity activities, there are notable limitations in lower heart rate detection and during certain types of physical exertion. For users who require precise heart rate trackingâespecially during varied workoutsâpairing the watch with an external monitor may enhance accuracy[6].
Citations:[1] https://www.youtube.com/watch?v=E7otV4ZTFnM
[2] https://www.nextpit.com/apple-watch-ultra-2-review
[3] https://www.robterhorst.com/post/apple-watch-ultra-2-vs-series-9-scientific-review
[4] https://www.reddit.com/r/AppleWatch/comments/1d4dbbi/how_accurate_is_the_bpmekg_measurements_on_the/
[5] https://www.youtube.com/watch?v=KQrYl-AdhQw
[6] https://www.coachweb.com/gear/fitness-trackers/apple-watch-ultra-2-review