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Galaxy Watch 9 & Ultra 2 - Initial Scientific Review!https://youtu.be/Pe-oWH2hfto?is=sUYjmwXwBg7tafWZGemini:
This video, Galaxy Watch 9 & Ultra 2 - Initial Scientific Review!, features The Quantified Scientist (Rob) testing Samsung's latest smartwatches for heart rate precision, sleep stage accuracy, and GPS tracking performance.
Key Takeaways & Test Results
Heart Rate Accuracy (Watch Ultra 2) [00:00:38]
Spinning: Reached a 0.99 correlation compared to a Polar H10 chest strap [00:01:06].
Running: Strong 0.98 correlation with minor high-end spikes [00:01:42].
Outdoor Cycling: High 0.98 correlation [00:02:47].
Outperformed ~71% of tested devices in indoor cycling and ~88% in outdoor cycling [00:03:48].
Heart Rate Accuracy (Watch 9) [00:04:10]
Spinning: Matches the Ultra 2 with a 0.99 correlation [00:05:24].
Outdoor Cycling: Solid 0.96 correlation [00:06:54].
Running Note: Battery died mid-workout, so full run data requires re-testing [00:05:46].
Sleep Stage Tracking [00:08:22]
Evaluated against the ZMAX EEG headband reference [00:08:28].
Ultra 2: 81% deep sleep agreement, 51% light sleep, 76% REM sleep [00:09:05].
Watch 9: 86% deep sleep agreement, 48% light sleep, 69% REM sleep [00:10:03].
Both watches tend to overestimate deep and REM sleep, earning a Tier 2 performance rating alongside Garmin and Amazfit [00:12:36].
GPS Precision (Watch Ultra 2) [00:14:37]
Multi-lap park run showed strong signal overlap with minimal drift near obstacles [00:15:13].
Final Verdict
Rob concludes that Samsung has made notable sensor improvements over previous generations [00:16:23]. Heart rate tracking and GPS accuracy are noticeably improved, making both devices easy to recommend based on these early tests [00:16:48].