Scientists have proven, and people have long noticed that there are such extreme individual properties of a person that affect his activity and well-being at different times of the day. Some stand up “not a dawn light” and immediately get down to business. Others suffer and suffer if they get up early for work and enjoy the night with the night.
The most common and generally accepted classification is considered, according to which people are divided into the evening type – “owls”, the morning – “larks” and daytime – “pigeons” or arrhythms.
The characteristics of internal circadian rhythms arise from the need to synchronize individual circadian rhythms with external changes (day and night) with the help of light. Sunlight is a time marker for our biological clock at the time of the morning awakening. If this did not happen, and we could live according to our internal cycles of sleep and wakefulness, then, as we have already mentioned, the period of our circadian rhythms would last about 25 hours. But the external environment has an active influence on the biological circadian rhythm. In proof we give the following scientific fact.
If, in the experiment, we isolate a person from external stimuli and daily shift his time 1 hour ahead, then after 2 weeks he will be able to stay awake at night and sleep during the day. Thus, the close relationship of the rhythm of sleep and wakefulness with the external environment of a person is demonstrated. Especially it can be clearly seen in the sun-moon and light-dark cycles. In order to To synchronize these external 24-hour and our internal 25-hour cycles, you need to reduce your biorhythm by 1 hour, affecting the eyes with light. This synchronization process is called a phase shift. It has been established that the exposure of us to bright light at different times of the day causes our rhythms to become frequent (phase advance) or less common (phase lag). These are very important scientific results, because they allow us to understand the mechanism of the emergence of various types of people (“owls”, “larks” and “pigeons”), and also to treat insomnia caused by desynchronization of external and internal rhythms.
“Owls” – people who have a lag phase of sleep. They have a period of fluctuations in circadian rhythms longer than 24 hours, or the so-called syndrome of the delayed sleep phase . It has been established that persons of the evening type are easier to adapt to working at night and three-shift work. Owls better control the rhythm of sleep-wake compared to other people. They prefer to go to bed after 23-24 hours, but it is harder for them to get up in the early morning hours. Many owls are impressed by their nightlife. They are happy to work at night and choose such professions in order not to get up too early, and even better to plan their work schedule themselves.
Everything would be fine, but some “owls” cannot synchronize their biorhythms with the requirements of the usual labor regime in which they have to live, and then the syndrome of the delayed sleep phase becomes a serious violation, leading to insomnia.
“Larks” – people who have a circadian rhythm moves forward, that is, those with advanced sleep phase syndrome . They have a period of oscillation of circadian rhythms less than 24 hours. People “larks” sleep as much time as the rest, but their rhythm of going to bed is shifted to an earlier evening. They want to sleep early, fall asleep quickly and get up very early in the same morning hours. They work best in the morning with a fresh head, and by the end of the day their working capacity decreases. Evening and third shifts are not for the “larks”, they hardly endure night duty, clubs and discos. It turned out that people-larks, better than owls, adapt to the temporary organization of the regime, and therefore it is easier for them to overcome insomnia associated with a change of time zone.
However, some members of this group who have advanced sleep phase syndrome may also have problems leading to sleep disturbance.
“Pigeons” – people of the day type. Their circadian rhythm is most adapted to the usual change of day and night. The period of their best mental and physical activity is observed from 10 to 18 hours. They are better adapted to the change of light and darkness. But even with them when traveling over long distances with changing time zones and night work, there is a failure of their own biological clocks. For example, with a 3-hour time difference, they develop insomnia at night, drowsiness and fatigue during the day, and a decrease in performance. Moving to the west can lengthen the biorhythms of “pigeons”, and shorten when flying to the east. If the time difference is more than 4 hours, the development of a new stereotype of sleep and wakefulness will occur in “pigeons” only after 7-14 days, and the level of steroid hormones normalizes in 2-3 months. Moving east “pigeons” are transferred easierthan to the west. This information will be useful to those people who love to travel long distances and, especially, who prefer to spend their short (7-10 days) vacation away from their homes.
It should be noted that many people belong to intermediate chronotypes and are not bright representatives of “owls”, “larks” or “pigeons”.
To check which type belongs to the people, you can use the questionnaire Ostberg , below.