Are You an Advanced Sleeper? Scientists Discover One in 300 People Have This Extreme Body Clock Quirk

Around one in 300 people are "extreme early birds" who wake up in the early hours of the morning and head to bed early in the evening, according to scientists who say the phenomenon is likely more common than previously thought.

In those with what is known as advanced sleep phase, the sleep hormones including melatonin are released too early, and the way their body temperature shifts to regulate their biological clock is also different from the norm. This can cause them to wake up as early as between 2 a.m. to 5 a.m., and to feel the need to sleep between 6 p.m. and 9 p.m.

Study co-author Dr. Louis Ptacek, professor of neurology at the University of California, San Francisco, School of Medicine, commented in a statement: "These extreme early birds tend to function well in the daytime but may have trouble staying awake for social commitments in the evening."

While these people generally have good quality sleep for the correct amount of time, the condition can encroach on their social lives and impact relationships. It can also be dangerous for such individuals to drive in the late afternoon or evening, when they may be drowsy.

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A stock image of a woman sleeping. Researchers have investigated why some people are early to bed, and early to rise. Getty

The study involved 2,422 patients who had visited a North American sleep center over a period of nine years. The participants answered questions about their health, sleep habits, and gave sleep logs. Researchers measured melatonin levels in the patients' saliva, and examined them during a polysomnography sleep study. The findings were published in the journal Sleep.

Of the total, 12 patients were diagnosed with advanced sleep phase, but four didn't want to take part in the study. This amounted to 0.03 percent of the participants, which was scaled up to one in 300 of the general population. The number of people with advanced sleep phase is therefore likely to be higher, according to the researchers, due to their problems with recruiting participants.

Patients were diagnosed with advanced sleep phase if they slept once a day, and woke up before 5:30 a.m. and fell asleep before 8:30 p.m., even if their responsibilities meant could get up later if they wished.

These early risers were also more likely to sleep in for just five to ten minutes on their day off compared with the average person, who might indulge in up to an extra 30 to 38 minutes in bed.

The American Academy of Sleep Medicine recommends that those with the condition try to work their daily activities around their body clock rather than fighting against it. They would, for instance, be ideal for an early shift at work.

Attempting to realign their early clock to fit with common sleep schedules can worsen the condition, the organization warned. Drinking too much coffee to stay awake, or using alcohol or sleeping pills to stay asleep, is also ill-advised. "These choices will only make their sleep worse," the AASM said.

Ptacek said: "Generally, we find that it's the people with delayed sleep phase—those night owls that can't sleep until as late as 7 a.m.—who are more likely to visit a sleep clinic. They have trouble getting up for work and frequently deal with chronic sleep deprivation."

"We hope the results of this study will not only raise awareness of advanced sleep phase and familial advanced sleep phase but also help identify the circadian clock genes and any medical conditions that they may influence," he said.

The work is the latest to shine a light on how a person's circadian rhythm can be mismatched with norms relating to when we sleep and wake.

Earlier this year, scientists urged employers to rethink the standard working day after they found the brains of so-called "morning larks," who feel most spritely in the morning, are wired differently to so-called "night owls" who perform better later in the day.

The authors of a study published in the journal Sleep said forcing an owl to live like a so-called "morning lark" can negatively affect their brain function, productivity and health.

Co-author Dr. Andrew Bagshaw, from the University of Birmingham, told Newsweek at the time: "Adequate sleep is crucial for optimal brain function, and one of the main reasons we sleep at all is because of the brain.

"We need more research that specifically investigates how the brain networks that are needed for cognition and good mental health are impacted by differences in sleep patterns between individuals."