Video summary

Samsung Galaxy Fit3 : Scientific Review (BEST deal?!)

Main summary

Key takeaways

Product Review

Product reviewed

Samsung Galaxy Fit 3 (fitness smartwatch/health band). The review focuses on heart rate tracking, sleep stage tracking, and comparisons versus Galaxy Watch models and other wearable brands.

Key features (as discussed)

  • Health & sports tracking
    • Heart rate
    • Sleep stages
    • Activity including indoor cycling, outdoor running, outdoor cycling, and weightlifting
  • No built-in GPS
    • Uses phone GPS for GPS tracking, so performance depends on your phone’s GPS
  • Battery life
    • Rated 13 days
    • Compared to Galaxy Watch 6 at roughly ~40 hours
  • Samsung ecosystem fit
    • Works within the Samsung ecosystem, but the reviewer implies it doesn’t feel as premium as Samsung’s higher-end watches

Main tests & findings

1) Heart rate tracking — indoor cycling (Rob)

Setup: Compared Galaxy Fit 3 heart rate to a Polar H10 ECG chest strap (treated as the accurate reference).

Performance:

  • Correlation: 0.95 (good overall, not perfect)
  • Most points stayed on/near the agreement line in both low and high HR ranges
  • Occasional “weird artifacts” / exaggerated peaks (brief incorrect spikes)

Verdict for indoor cycling: Decently accurate; suitable if indoor cycling is your main goal.

2) Heart rate tracking — outdoor running (Rob)

  • Correlation: 0.92 (decent, but better watches exist)
  • Tendency: points often sat slightly above the reference line, especially at higher HR
  • Issue type: cadence lock
    • The watch tracked running cadence rather than true heart rate
    • Example described: watch reading leaned toward cadence-derived values (e.g., 142 BPM vs cadence 163 SPM)

Verdict for running: Mixed bag—generally okay, but cadence lock can cause notable errors.

3) Heart rate tracking — outdoor cycling (Rob)

  • Correlation: 0.69 (poor)
  • Many deviations: points above and below the agreement line
  • Sometimes reported about half the actual heart rate (reviewer notes the implied ~50% detection)

Verdict for outdoor cycling: Not reliable across rides; accuracy is inconsistent.

4) Heart rate tracking — weightlifting (Rob)

  • Correlation: 0.69 (mediocre)
  • Peaks during lifts/sets were often missed, usually detecting too-low HR
  • Reviewer notes that for lifting, even generally good watches should reach ~0.9+ correlation to be acceptable; Fit 3 falls short

Verdict for weightlifting: “More or less useless” for accurate HR peaks. Best option: ECG chest strap—though the reviewer couldn’t connect the Polar H10 to the Fit 3 (unclear if possible; asks viewers for input).

Additional tester (“Rafael”)

A smaller set of trials by Rafael (friend/colleague) to check whether results generalize.

Rafael — spinning / running / cycling / weightlifting

  • Spinning: looks okay (peaks mostly match; some tendency slightly higher HR)
  • Running: correlation 0.93 (mostly good)
    • No clear cadence lock signs
    • Minor artifacts; one run showed deviations but not clearly cadence-driven
  • Outdoor cycling: correlation 0.56 (worse overall)
    • Some rides looked good, but at least one showed the “half heart rate” behavior
    • Mentions big gaps, likely when the watch isn’t recording while not cycling (autopause-like behavior)
  • Weightlifting: again struggled (low correlation; missed peaks)

Overall heart-rate scoring (combining both testers)

  • Reviewer’s final heart rate assessment: ~3 out of 5 stars
    • Okay for indoor cycling and running
    • Major problems for cycling outside
    • Poor/unusable for weightlifting

Sleep stage tracking

Method

  • Tested across 13 nights
  • Compared Fit 3 sleep stages vs zMAX EEG headband (brain-wave reference, with limitations around wake detection)

Results (Rob)

  • Deep sleep agreement: about 20% (poor)
  • Much of deep being predicted as light sleep (~55%)
  • Light sleep agreement: about 75% (better)
  • REM sleep agreement: about 30% (poor)
  • Wake time:
    • Reviewer mostly avoids heavily judging it
    • Notes Fit 3 detected ~40% of awake time as awake

Why agreement was poor

  • On some nights, Fit 3 marked the user awake when EEG indicated sleep
  • Also missed sleep onset timing (example: plots suggesting “fell asleep too late”)
  • Similar marginal agreement issues for REM segments

Context vs other watches

  • Fit 3 compared to many devices using different reference setups (polysomnography vs Dream/EG vs zMAX)
  • Fit 3 was placed near the bottom-left (poor overall), not among top performers
  • Reviewer notes Galaxy watches generally aren’t top sleep trackers; Fit 3 may be even worse in this setup

Sleep score + verdict

  • Reviewer gives 1.5 out of 5 stars for sleep stage tracking
  • Overall impression: not great (deep/REM errors and too much “awake” detection)

GPS performance

  • No built-in GPS
  • Uses phone GPS, so tracking should match the quality of your phone’s GPS

Pricing / value claims and comparisons

  • Reviewer positions Fit 3 as better value than Galaxy Watch series
  • Fit 3 purchase price: about $65 equivalent
  • Galaxy Watch 6 cited as 3–4× more expensive
  • Despite value, the reviewer says Fit 3 doesn’t feel premium, and HR + sleep performance is limited versus many competitors

Comparison mentions (brands)

  • Galaxy Watch 5 / 6 / 6 Classic / 5 Pro
    • Similar-ish performance within Samsung’s line, but not top overall
  • Other alternatives mentioned as better (especially for sports/HR accuracy):
    • Huawei (e.g., Huawei Band 8, Huawei watch/fit models)
    • Fitbit Charge 6
  • Apple Watch and some high-end devices
    • Described as top sleep stage performers
  • Whoop and some selected devices
    • Sometimes similar or better correlation depending on activity

Pros (from the video)

  • Great battery life: ~13 days
  • Indoor cycling heart rate tracking: good (correlation ~0.95) with only occasional artifacts
  • Decent for running overall
    • ~0.92 correlation for Rob
    • ~0.93 correlation for Rafael
    • Errors can still happen

Cons (from the video)

  • Outdoor cycling heart rate tracking is poor
    • Rob correlation 0.69
    • Rafael correlation 0.56
    • Sometimes shows “half HR” behavior
  • Weightlifting heart rate is unreliable
    • Misses most HR peaks
    • Correlation ~0.69
    • Judged “more or less useless”
  • Sleep stage tracking is bad
    • Deep ~20%
    • REM ~30%
    • Overall 1.5/5
  • No built-in GPS
    • Relies on phone GPS
  • Possible cadence lock during running for at least one tester
  • ECG strap connectivity limitation:
    • Reviewer couldn’t connect Polar H10 ECG strap to Fit 3

Overall verdict / recommendation

Recommendation: Buy the Samsung Galaxy Fit 3 only if you mainly care about battery life and indoor cycling / general running, and you can tolerate major accuracy limitations for outdoor cycling, weightlifting, and sleep staging.

If you want reliable heart-rate tracking for hard workouts or accurate sleep stages, the video suggests looking at other brands (often Huawei/Apple/Fitbit-class devices) or using an ECG chest strap (if compatible).

Overall ratings given by the reviewer (stars)

  • Heart rate tracking: ~3/5
  • Sleep stage tracking: 1.5/5

Unique points mentioned (consolidated)

  • Fit 3 is positioned as no-brainer value vs Galaxy Watch pricing (roughly $65 vs Watch 6 3–4× more)
  • Samsung reportedly not globally released (US/UK/Canada excluded); availability varies (e.g., via Amazon)
  • Indoor cycling HR: correlation 0.95, mostly accurate with brief artifacts/exaggerated peaks
  • Outdoor running HR: correlation 0.92, sometimes cadence lock (tracks cadence rather than true HR)
  • Outdoor cycling HR: correlation 0.69 (Rob) and 0.56 (Rafael); inconsistent and sometimes half HR detection
  • Weightlifting HR: correlation ~0.69; missed peaks; judged not good/useless
  • Sleep stages (13 nights vs zMAX EEG)
    • Deep sleep agreement ~20%
    • Light sleep ~75%
    • REM agreement ~30%
    • Fit 3 detects lots of awake time while EEG indicates sleep
  • Sleep comparison vs other watches: Fit 3 among the worse, not top performers (Apple watches and others do better)
  • No built-in GPS; uses phone GPS
  • Battery life: 13 days vs Galaxy Watch 6 ~40 hours
  • Reviewer suggests preferring an older Galaxy Watch (e.g., Watch 4/5) over Fit 3 in Samsung ecosystem for a more premium experience

Speaker-specific views

  • Rob (primary tester)

    • Indoor cycling HR: strong (0.95) with artifacts
    • Running: decent (0.92) but clear cadence lock
    • Outdoor cycling: poor (0.69), including half-HR issues
    • Weightlifting: poor (~0.69), missed peaks
    • Sleep stages: bad (deep/REM poor; overall 1.5/5)

  • Rafael (secondary tester)

    • Spinning: okay
    • Running: mostly good (~0.93), no clear cadence lock
    • Outdoor cycling: worse correlation (0.56) with at least one half-HR ride
    • Weightlifting: again poor; missed peaks
    • Notes about gaps due to autopause-like behavior when not cycling

Original video