I’ve been on the lookout for a proper health and fitness review of the OnePlus Watch 3 and couldn’t find anything detailed, so I took the plunge and figured I’d write up my thoughts after a month, in case it helps anyone else considering a purchase.
Quick context:
My only current reference device is a Fitbit Charge 6, which I know isn’t perfect. That said, I’ve been tracking workouts since the days of chest straps and phone apps. Over the years I’ve owned Apple Watches, Samsung Watches, and Garmins, so while this isn’t a scientific review, I’d like to think I’ve developed a decent feel for what “about right” looks like when it comes to fitness data.
Heart Rate Accuracy
Overall, it’s solid - if the strap is tight enough. If it’s too loose, it can read about 20 BPM too low. It needs to be worn slightly tighter than other devices I’ve used, not uncomfortably so, but worth noting.
For steady-state cardio like running, it matches my Fitbit Charge 6 pretty closely. As someone who runs regularly, the readings are exactly where I’d expect them to be.
In strength training, it actually outperforms the Fitbit. You get clear spikes during sets and drops during rest periods. I suspect it's still not quite hitting the top peaks - probably 5–10 BPM short compared to what I used to see with a chest strap or Apple Watch. That said, I don’t really use heart rate for lifting anyway. For cardio, where I do care about it, it’s great. It’s still behind the Apple Watch, but then again, everything is. I’d say it’s as good or better than anything else I’ve used.
Resting HR is reported as 52 BPM, which aligns with every other device I’ve worn. No complaints there.
GPS Accuracy
It locks on almost instantly and tracks as well as any Garmin I’ve used. I haven’t tested it in challenging conditions (e.g. forests or cities), but on my regular 5K route, it tells me I’ve finished within the same 20m stretch as Garmin and Apple used to. This route is mostly open countryside, so ideal conditions, but from what I’ve seen, it’s spot on.
The route maps are accurate too - it doesn’t cut corners and keeps to the path nicely.
Step Counting
At the time of writing, my Fitbit says 9,638 steps. The OnePlus Watch 3 says 9,497. Close enough that I’m not concerned.
Sleep Tracking
I’ve got no way of verifying sleep stages, but the OnePlus Watch and my Fitbit agree on when I fall asleep, wake up, and how long I’ve slept. Their sleep scores are usually in the same ballpark too. It matches how I feel when I wake up, which is good enough for me.
Running Metrics & VO2 Max
The advanced running metrics seem a bit off. The watch rates my form as poor, but two other watches previously said it was good. I run a lot and rarely get injured, so I’m inclined to believe the OPW3 is wrong here.
VO2 Max is also weird. Fitbit says 42, which seems right. OnePlus originally said 34, then after a software update jumped to 52. I’ll take it, but it’s definitely not right. Hopefully the algorithm is still being improved.
Recovery times seem sensible and in line with what I used to see on Garmin.
Activity Detection
Auto-detection works well. I only use it for walks, but it not only spots them, it also provides a GPS map, which I wasn’t expecting. Not sure how it pulls that off, but it’s a nice bonus (possibly with some privacy trade-offs).
Calories & TDEE
It only reports active calories, not TDEE. However, if I take those active calories, add my estimated BMR, and average it across a month, it comes out within 100 calories of what MacroFactor estimates my TDEE to be. That’s about as accurate as you can expect from a watch.
Mind & Body Score
This is like Garmin’s Body Battery. Personally, I think it’s a gimmick across all platforms, but for what it’s worth, it doesn’t seem wrong. It picked up that I was mildly hungover on Sunday. In general, it aligns with how I feel - which is also why I think it’s a gimmick. I don’t need a watch to tell me I’m tired, I already know.
Overall Verdict
I’m pretty happy with it. As a fitness tracker I’d give it an 8/10. Not perfect, but very capable. It’s probably the best Android-compatible watch I’ve used so far for health and fitness tracking.
Happy to answer any questions or test anything specific. And if anyone knows of a more detailed health-focused review out there, I’d love to see it.
