Galaxy Watch 8 Classic - SCIENTIFIC Review (Better Than Normal Version?)
These notes were generated by AI and may contain inaccuracies.
The Galaxy Watch 8 Classic is arguably the best looking Galaxy Watch from the newest 8 series. The Galaxy Watch 8 and Galaxy Watch Ultra 2 were released at the same time. It looks the best, but does it perform the best? Tests cover heart rate tracking during exercise, sleep accuracy, and GPS/location tracking (e.g., bike speed, running pace).
Rob, a post-doctoral scientist specializing in biological data analysis, uses data to analyze the Galaxy Watch 8 Classic performance. Video delayed due to Samsung Health data export issues, but new data collected with interesting results.
Easiest exercise for devices due to minimal movement. Galaxy Watch 8 Classic shows good agreement with reference device; high correlation of 0.96 (0.95+ is good enough). Dots close to blue line in scatter plot.
Individual bike rides (intervals):
- First interval HR increase, long break, then 2nd-5th intervals: Watch in red follows reference in blue-green very well.
- Other rides: minor details missed, almost perfect; one longer ride started late, performed well; minor issues with slightly too high HR twice.
Overview plot: further top-right is better. Galaxy Watch 8 Classic (red) at 0.96 correlation, middle but good enough.
Zoomed (0.95+): Similar to Galaxy Watch 8, Galaxy Watch 7 (same sensor). Bug shows Classic twice.
Top (0.98+): Huawei devices, Pixel Watch (Android), Pixel Watch 3, Helio strap, Apple Watches better. Still recommendable for indoor cycling.
Limited to two runs due to injury.
Scatter plot shows issues: points below blue line (too low HR). Possible cadence lag (measuring running frequency instead of HR).
Individual runs:
- First: red line below blue.
- Second: better, some deviations.
Mixed results.
Poor showing; many devices better. Galaxy Watch 8 Classic at low correlation.
Zoomed (0.8+): Close to Galaxy Watch 8.
0.95+: Apple Watches, Pixel Watch, Amazfit Helio Strap (biceps preferred), Garmin Forerunner 165, 570, 970, Coros Pace 3 (retest worse).
Not the best; limited testing.
0.91 correlation, okay for hard exercise (commutes, road bike rides). Points close to blue line, some too high/low HR.
Individual rides: okay (details lost), not terrible, some worse (fit/positioning matters; positioned high from wrist bone).
Upper middle class. Similar to Galaxy Watch 7, 8, Ultra 2.
Top: Apple Watches, Pixel Watch, Amazfit Helio strap (bicep).
Improved over years; good enough if preferring Samsung ecosystem/design.
Poor: 0.67 correlation, big deviations at high HR. Most watches struggle.
Sessions: too high/low HR, missed peaks.
Comparison: Low performer. Only Apple Watches, in-ear devices decent (with dropouts). Recommend chest strap (ECG best); cannot connect external HR to Galaxy Watch. Use Polar Beat/Flow apps instead.
Major Samsung improvements (firmware/algorithm using HR, movement). Tested vs ECG chest strap (mini brain wave monitor; focuses on deep, light, REM; ignores awake).
Confusion matrix:
- Deep sleep: 74% agreement (rest light sleep).
- Light sleep: 60% worst, overestimates deep/REM/awake.
- REM: 71% decent (often hard for devices like older Garmin, Amazfit).
Average agreement (equal weight REM/deep/light); vertical worst of three. Galaxy Watch 8 Classic near Ultra 2, Galaxy Watch 8; second tier with old Fitbit/Google, Whoop.
Recent updates improved Fitbit/Google, Whoop (big difference in University of Salzburg study).
Top: Apple Sleep 2/NUA, Pixel/Google, Whoop, Oura Ring, Helio pod (six brands); Galaxy close.
Apple Watch weak on deep (2025 update improved). Decent for healthy sleeper in Samsung ecosystem; rough impressions.
Tests: cycling (same route multiple times, check overlap), running (same circle).
Six to-work rides: fast signal acquisition (good).
Consistency mediocre: deviations at start, traffic lights, corners, buildings, roundabouts, construction.
Ten from-work: mostly instant acquisition (one delay); deviations at start, roundabouts, signals erratic.
Two runs, same circle multiple times: signals should overlap.
Overall, GPS tracking is not that great. The reviewer has seen much better performance. Signal acquisition struggled after briefly going under a building, and it took time to reacquire the signal. Not the worst seen, but the Apple Watch Ultra 3 performed better, though it is more expensive. Sports devices like Garmin, Coros, Suunto, and Polar typically excel at GPS tracking.
For running, the first run in the same circle multiple times shows poor results. There's a bigger wall on the right side, causing significant deviation in signals. The left side looks better but still noisy compared to other devices. The reviewer is not happy. A run three days later looks cleaner and more acceptable, with less deviation on the right side. There's a lot of variation—some parts good, some not. Overall, mediocre to upper middle class GPS performance, perhaps upper middle class.
Heart Rate, Sleep, and GPS Summary
- Heart rate tracking: upper middle class to middle class
- Sleep stage tracking: upper middle class, close to better performers
- GPS tracking: mediocre Average: upper middle class device, not bad. Samsung is improving health and sports tracking over generations, with similar performance across Galaxy Watch Ultra, Galaxy Watch 8, and Galaxy Watch 8 Classic compared to older devices.
Prefers Galaxy Watch 8 Classic and Galaxy Watch 8 over Galaxy Watch Ultra due to its chunky design, which is not clean. Galaxy Watch 8 Classic looks classy and classic; Galaxy Watch 8 has a clean design. Choose based on battery life and especially design. If in Samsung ecosystem, not the worst choice. For Android users seeking performance, prefer Pixel Watch for better sleep stage and heart rate tracking, if you like its design.
Previously thought you couldn't connect an external heart rate monitor to Galaxy Watch, but checked: as far as could find, you cannot. This would have been a plus over Pixel Watch, but it's not possible. If viewers have different info, comment below.
Not a bad choice, but better options exist depending on interests. Makes sense if in Samsung ecosystem, and good deals available compared to Apple Watches.
Affiliate links in description for Galaxy Watch 8, Galaxy Watch 8 Classic, Galaxy Ring, Polar Loop, Whoop strap, Eight Sleep pod, Apple Watch, or anything on Amazon (even toilet paper) to support the channel and get best discounts.
Suggested videos: long-term review on Galaxy Watch Ultra 2 or video on HLE Pod.
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