Many people are 'advanced sleepers' -- Here's what that means

Many more people are 'advanced sleepers' than previously believed, according to a new study out of the University of California, San Francisco. The term doesn't refer to someone who is particularly capable of sleeping, instead describing individuals who naturally go to bed and get up at very early times compared to most people.

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An advanced sleep phase is one that starts earlier in the day that usual — at 8PM, for example — and ends at a much earlier time than most people would want to get up, such as 4AM. Advanced sleepers are believed to be very rare, but the new study out of UCSF indicates that may not be the case.

At least one in every 300 adults may be an 'advanced sleeper,' according to the newly published study. For these people, their circadian rhythm releases the sleep hormone melatonin much earlier in the day than what is considered normal, causing them to go to sleep shortly after dinner and wake back up hours before breakfast.

Unlike people who may force themselves to wake up at an early time, the researchers say natural advanced sleepers wake up feeling rested and are fully functional during the day. There's a downside to this sleep arrangement, however, in that advanced sleepers may miss out on evening social events that take place after work.

The researchers found some other differences in advanced sleepers compared to everyone else, including that they were satisfied with only five to 10 extra minutes of sleep on days they didn't work. These people also take less effort to wake up in the morning compared to people who naturally get up at later times.

In the case of this study, the researchers considered someone an advanced sleeper if they fell asleep before 8:30PM and woke up before 5:30AM. This is a naturally occurring sleep cycle, which means it happens regardless of the person's job or socialization habits, without the aid of sleeping pills or stimulants, and is observed in the individual before the age of 30.