Millions of Americas use fitness trackers to track their daily activity, but they are also being used to collect data on sleep.
Doctor Cathy Goldstein, a Neurologist at the University of Michigan Sleep Disorder Center cautions that most activity trackers tend to overestimate sleep time.
But she also says anything that makes you more aware of how much sleep you're getting can still be helpful.
The data can help you spot connections between lack of sleep and other health factors.
Doctor Goldstein says the most useful new features of sleep trackers and smart phones is focused on helping you maintain a consistent sleep schedule.
She also says keeping your bedtime and wake time the same, even on weekends, can dramatically improve your sleep.
