Samsung Galaxy Watch 8 Classic: A Scientific Review – Better Than the Rest?

Jan 25

The Galaxy Watch 8 Classic is arguably the most aesthetically pleasing entry in Samsung's newest 8-series. But for those of us focused on the "Quantified Self," good looks aren't enough. Does it perform as well as it looks?

In this review, we dive deep into the data to see how the Galaxy Watch 8 Classic handles heart rate tracking, sleep stages, and GPS accuracy compared to its siblings and the competition.

Heart Rate Tracking: Hits and Misses

Heart rate accuracy is the cornerstone of any fitness wearable. We tested the 8 Classic across several disciplines to see where it shines and where it struggles.

Indoor Cycling

Indoor cycling is generally the easiest for a wrist-based sensor to track due to the lack of arm movement. The Galaxy Watch 8 Classic performed admirably here, boasting a correlation of 0.96 with the reference device [01:30].

Running & Outdoor Cycling

Running presents a greater challenge. During our tests, the 8 Classic showed some "cadence lock" issues, occasionally tracking the frequency of steps rather than the heart rate [05:18].

Outdoor cycling results were surprisingly better than running, with a correlation of 0.91 [09:36]. While it missed some fine details, it remains a solid mid-to-upper-tier performer for cyclists [10:32].

Weightlifting

Like most wrist-based wearables, the 8 Classic struggles with weightlifting [11:55]. The tension in the forearm makes it difficult for the optical sensor to get a clean reading. For serious strength training, a chest strap remains a necessity [13:04].

How Does It Compare?

When compared to the broader market, the Galaxy Watch 8 Classic sits firmly in the "good enough" category [03:24]. It performs similarly to the Galaxy Watch 8 and the Galaxy Watch 7, likely because they share the same sensor array [03:49].

While it doesn’t quite reach the top-tier accuracy of the Apple Watch or the Google Pixel Watch 3, it is a significant improvement over previous Samsung generations [04:18].

Example Overview of Performance for Spinning

Sleep Stage Tracking: A Major Leap Forward

One of the most impressive areas of improvement for Samsung is sleep tracking. By comparing the watch against an EEG chest strap (the gold standard for measuring brain waves), we found that Samsung has refined its algorithms significantly [14:07].

Deep Sleep: 74% agreement with the reference device [14:58].
REM Sleep: 71% agreement, which is actually quite high as REM is notoriously difficult to detect [15:41].
Light Sleep: This remains the watch's biggest struggle, often being misidentified as deep or REM sleep [15:15].

Overall, the Galaxy Watch 8 Classic is now a "second-tier" sleep tracker, sitting just behind leaders like Apple, Whoop, and the Oura Ring [16:51].

*The sleep stage confusion matrix comparing the reference device and the Galaxy Watch 8 Classic.*

GPS & Navigation

For runners and cyclists, GPS (GNSS) accuracy is vital for tracking pace and distance. The Galaxy Watch 8 Classic offers fast signal acquisition, but the consistency of the track is mediocre [20:44].

In our "circle tests" and commutes, we saw significant signal drift around corners and near buildings [21:48]. It’s functional for casual use, but dedicated sports watches from Garmin or Coros still hold the edge for precision [23:10].

The Verdict: Design vs. Performance

The Galaxy Watch 8 Classic is a high-performing, beautiful wearable that shows Samsung is closing the gap with the industry leaders.

Choose the Classic if you want a professional, "clean" design with a rotating bezel and you are already in the Samsung ecosystem [24:59].
Look Elsewhere (like the Pixel Watch) if you prioritize the absolute highest level of heart rate and sleep accuracy on Android [25:18].

Ultimately, it’s an upper-middle-class performer that finally brings Samsung’s health tracking into a range that is scientifically respectable [24:22].

Watch the full scientific breakdown here: https://www.youtube.com/watch?v=SAOUi5ZQJDY

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Rob ter Horst