The best sleep trackers of 2025: Expert tested and reviewed
The Oura Ring 4 is a competitive sleep tracker, with insights into sleep efficiency, restfulness, readiness, latency, and more. I've been using the Oura Ring for a while now, and it has not only given me deeper insight into my sleep but also supplements those data points with explanations behind the numbers. Oura claims to accurately track sleep cycles, total sleep time, resting heart rate, heart rate variability, and movement. These features have been enhanced with the rollout of the fourth-ge