When it comes to comparing the best fitness trackers, sleep-tracking is a core pillar to consider. But when testing different sleep-tracking devices like the Oura Ring, Fitbits, and even the Apple Watch, it can be difficult to tell from anecdotes alone which wearable provides the most accurate data overnight.
For anyone craving more rigorous sleep tracking comparisons, there's now scientific evidence that one of these devices is more accurate that the others.
