Feeling sluggish in winter? New study confirms humans need extra sleep in colder months

Many animals enter a dormant state or hibernate during low temperatures. Bears, for example, can sleep for three months straight, alike hedgehogs or groundhogs. Although humans have adaptability to low temperatures due to clothing and abundant food reserves, allowing them to remain as active in winter as in summer. This widely recognized theory is now contradicted by the research conducted by Dr. Dieter Kunz's team. Their study published in the journal "Frontiers in Neuroscience" suggests that humans actually need more sleep in winter, somewhat resembling winter sleep in animals.

From a pool of 292 recruited individuals, the scientific team finally selected 188 people to participate in sleep studies (polysomnography). These participants were primarily chosen based on their lack of consumption of sleep-influencing medications. The researchers monitored crucial parameters to address the question of whether the time of year influences our sleep needs. Therefore, they considered the general quality of sleep, including the length of REM phases, sleep's type, and overall duration.

The analysis of the collected data provided an unexpected answer: the length of the REM phase in humans extends by an additional 30 minutes in winter compared to summer. As this is directly linked to our internal clock, it justifies our increased feeling of daytime sleepiness during the cold months because the body needs a longer time for regeneration.

Noteworthily, the study found a significant impact of the cold season on sleepiness even among city dwellers, who are typically exposed to high levels of artificial light pollution daily. The researchers had anticipated that urban residents would experience less seasonal effects on sleep patterns, but the reality contradicted this expectation. "Human winter sleep" proved to trouble city inhabitants as well.

Dr. Dieter Kunz explains that "even though we still function normally in winter, unlike other animals, our physiology becomes disrupted and we often feel like we're running on empty come February or March." In this light, it's not surprising that people have experienced sleep-related problems because of the ongoing winter before and now.

The scientists recommend that we particularly focus on the quality and cleanliness of our sleep during this challenging time. It's crucial to ensure that we get at least eight hours of uninterrupted sleep. Maintaining a regular sleep schedule by going to bed and waking up at similar times is also beneficial. Most importantly, we should embrace and understand that we need more rest during winter.