Humans goes into pseudo-hibernation too, we sleep more in winter

Humans do not hibernate, but something similar still happens in winter: we sleep more, particularly in the REM phase, the one in which we dream. The confirmation comes from a study published in the journal Frontiers in Neuroscience by the Charité University of Medicine in Berlin, involving 188 people with problems related to sleep quality.

According to the researchers, it would be advisable to adapt our work and school schedules according to the season, thus allowing us to wake up later in the winter months, or we should have to learn to go to sleep a little earlier during the colder season. The participants in the study were living in an urban environment, therefore with little exposure to natural light and with high levels of light pollution, factors that should alter behaviors related to seasonality and the amount of light.

Nevertheless, the researchers led by Aileen Seidler have found surprising changes in the transition from summer to winter: the total sleep time lengthens by about 1 hour in the cold months, but the most significant fact is a similar extension by half an hour of the REM phase, which is known to be directly linked to our circadian clock, itself influenced by light.

The authors of the study warned that these results will need to be confirmed by further research involving a larger sample and with people not affected by sleep problems, as these seasonal changes could be even more marked in the healthy population. "Seasonality is ubiquitous in every living being on this planet," says Dieter Kunz, who coordinated the study. “Even though we continue to perform unchanged, during the winter human physiology is down-regulated – adds Kuntz – with a sensation of ‘running- on-empty’ in February or March. In general, societies need to adjust sleep habits, including length and timing, to season, or adjust school and working schedules to seasonal sleep needs.”