The Life of a Person Who Wakes Up Really, Really Early
“Extreme larks” get up naturally when some people have hardly gone to bed, reports The Atlantic.
There are some limits to this study. Since Ptáček and Jones ran their study at a sleep clinic, most of the patients had sleep apnea. Ptáček said he found that the presence or absence of sleep apnea does not affect whether someone will be a lark or a night owl, but Abbott and other experts I asked were not so sure that the data are perfectly generalizable to the general population.
from Sleep Review http://www.sleepreviewmag.com/2019/08/the-life-of-a-person-who-wakes-up-really-really-early/