We don’t hibernate, but… do we need to sleep more in autumn and winter? Probably yes. It is a ‘mix’ of melatonin and seratonin levels, circadian rhythm, REM sleep hours, temperature and dietary changes.
No, it’s not laziness. With the arrival of autumn and winter, many of us notice a persistent feeling of tiredness, a desire to sleep more and a general drop in energy. Reduced sunlight, lower temperatures and changes in diet appear to play an important role in this phenomenon, according to sleep medicine experts.
North-American Karin Johnson, specialist in sleep medicine and spokesperson for the American Academy of Sleep Medicine (AASM), explains that, although the human body does not necessarily need more hours of sleep during these seasons, It’s natural to feel more sleepy.
This is because the levels of melatonin — the hormone that regulates the sleep-wake cycle — tends to increase when the days are shorter. In excess, melatonin can cause drowsiness and lack of energy.
Another factor is the disruption of , the 24-hour clock that controls sleep and alertness. With less natural light during the day, this rhythm tends to change.
When we don’t get enough light in the morning, the body has more difficulty waking up and adjusting to the new cycle. Spending more time indoors, typical of the cold months, worsens this disconnection with the natural rhythm of the environment.
A study published in 2023 in the journal Frontiers in Neuroscience also revealed that people have more REM sleep — the phase of sleep associated with dreams and essential for regulating mood and cognitive function — in winter than in summer. Although humans do not hibernate like animals, they tend to adopt similar behavior: they slow down, look for more consistent foods and sleep more.
A temperature It also influences sleep. Sleeping in slightly cooler environments promotes deeper rest, but excess heat caused by indoor air conditioning can intensify drowsiness. Furthermore, the body spends more energy conserving heat, which contributes to so-called “winter fatigue”.
As dietary changes are another relevant factor. In cold weather, it is common to consume heavier meals rich in carbohydrates — comfort meals —, which require more digestion time and reduce the willingness to engage in physical activity. This cycle of less energy and less movement reinforces tiredness.
Around 5% of adults also suffer from Seasonal Affective Disorder (SAD), a form of depression associated with less sun exposure. Lack of light decreases serotonin levels and increases melatonin production, resulting in apathy and increased drowsiness.
The key? AND sleep when you feel the need and wake up when you wake up – if possible.
