Sleep tracking

Sleep tracking is the process of monitoring a person's sleep, most commonly through measuring inactivity and movement. A device that tracks a person's sleep is called a sleep tracker. Devices capable of tracking a person's sleep include dedicated sleep trackers, trackers that clip onto a person's pillow, smartphones, fitness trackers, smartwatches, and other wearable devices. Some sleep trackers are capable of tracking the stages of a person's sleep (light sleep, deep sleep, REM sleep), the length/duration of a person's sleep, the quality of a person's sleep, and the consistency of a person's sleep. Some sleep trackers offer other features, such as "sleep scores" that rank how well a person slept, "smart alarms" that wake a person up within a set period of time based on the circumstances of the person's sleep, and the ability to track the amount of light and/or the temperature in the person's bedroom. As of 2017, it is estimated that 10% of adults in the United States use a wearable fitness and/or sleep tracking device on a regular basis. Dr. Alan Schwartz, director of the Sleep Disorders Center at Johns Hopkins Bayview Medical Center, said that while sleep tracking devices can be useful for helping a person recognize patterns in their sleep habits, they are not capable of directly measuring a person's sleep unlike sleep study. Instead, according to Schwartz, "Most sleep tracking devices make some guesstimate as to how much you’re actually sleeping." and that the information the tracker provides to the person using it should be taken "with a grain of salt", but added that the tracker will still "give you something to reflect on". Dr. W. Chris Winter, Men’s Health sleep adviser and author of The Sleep Solution: Why Your Sleep Is Broken and How to Fix It said that the data sleep tracking devices provide can be useful and that the trackers do a good job of providing insight into a person's sleep patterns over time, such as the total time a person's probably sleeping.