Chronotypes or individual rhythms in physiology, cognition and behavior vary up to 10 hours from individual to individual regardless of age.

‘Sleep chronotypes vary widely, both over an individual's lifetime amongst age groups as well as among individuals.’

The sleep rhythms that reflect circadian systems peak later in teenagers than in adults, and vary as much as 10 hours in individuals across at any ages, according to a study published in the open-access journal PLOS ONE by Dorothee Fischer from Harvard T.H. Chan School of Public Health, USA, and colleagues. 




Currently, 30% of the U.S. workforce has unusual work schedules, such as alternating or extended shifts, and on-call duty. These unusual schedules are linked with health and safety risks. Chronotype-tailored schedules might help minimize those risks.
To investigate chronotypes variation in the US, Fischer and colleagues analyzed self-reported data from 53,689 respondents of the American Time Use Survey from 2003 to 2014. The researchers used the mid-point of sleep on weekends as a proxy for chronotype.
The researchers found that sleep chronotypes vary widely, both over an individual's lifetime amongst age groups as well as amongst individuals. The greatest difference in chronotypes is during adolescence and early adulthood.
Chronotypes become later during adolescence, peaking in lateness at about age 19. The average chronotype, or mid-point of sleep, at age 17-18 was 4:30 a.m., compared to 3:00 a.m. at age 60.
Advertisement
In addition, the researchers found that chronotypes vary up to 10 hours from individual to individual regardless of age. This may provide opportunities for tailoring work schedules to chronotypes, which is important because syncing workers with their optimal work times could help minimize health and safety risks.
Advertisement
Source-Eurekalert