Additional data-such as the length of time your movements are indicative of sleep behavior (such as rolling over, etc.)-help confirm that you’re asleep. When you haven’t moved for about an hour, your tracker or watch assumes that you’re asleep. While this method is the gold standard for measuring sleep stages ( source), your device can estimate your sleep stages in a more comfortable, convenient way.įitbit estimates your sleep stages using a combination of your movement and heart-rate patterns. Sleep stages are traditionally measured in a lab using an electroencephalogram to detect brain activity along with other systems to monitor eye and muscle activity.
