Sleeping owls

Sleep: When owls turn into larks

Night owls live with what is known as social jetlag: The times for school and work are mainly designed for people who go to bed early and are awake in the morning. Research shows that people who always go to bed very late have an increased risk of metabolic disorders and heart disease, but also of anxiety and depression.

As British researchers from Birmingham and Surrey discovered in their study, however, it is possible to change one's own sleep rhythm. For the experiment, 22 extreme night owls took part in a training. Around half of the subjects were asked to set the alarm two to three hours earlier in the morning for three weeks and to lie down earlier in the evening. After waking up, they should have breakfast soon and try to get a lot of daylight; Sports activities should also take place in the morning hours. Coffee and naps after 3 p.m. were taboo. The control group was only told to always have their lunch at the same time. Before and after the intervention, the subjects were questioned and examined in the sleep laboratory.

This article is contained in Spectrum Psychology, 1/20 (January / February)

The participants who completed the complete training succeeded in shifting their sleep rhythm forward by almost two hours - without sleeping less overall than before and without lying awake longer in bed in the evening. Instead of falling asleep at 2:46 a.m. on average, they now fell asleep at 1:03 a.m. and woke up around two hours earlier in the morning. The timing of their meals also moved forward. In the test subjects in the control group, on the other hand, the sleep phase moved a little further back.

The reduced social jet lag had a number of positive effects: The values ​​for depression and stress had almost halved in the treatment group after training. In addition, participants felt less sleepy during the day.

"The internal clock - which has a decisive influence on the type of sleep - is basically genetically predetermined," says Thomas Kantermann, who is researching the subject at the FOM University in Essen and was not involved in the study. "But we already knew that behavior and the environment also play a role." What is new is that a combination of many measures can achieve such a significant shift in sleep in everyday life. Anyone who would like to present their own internal clock can therefore actively participate. "Implementing all the requirements together would be difficult for many," says Kantermann. It is therefore important to investigate in further studies and with more test subjects what has the greatest effect on the sleep rhythm.