Understanding Winter Lethargy: Causes and Remedies

In winter, it's not uncommon for some to wake up each morning with a sluggish brain, as if after a night of heavy drinking. However, often the night hasn't been shorter than usual, nor soaked in the scent of bourgueil. Here's why.

One thing is clear: although it's rare to wake up every morning with the energy of a step aerobics coach in fluorescent cycling shorts, since the beginning of January, the difficulty in opening one's eyes and starting the day has increased. The symptoms are classic: sometimes longer nights, a feeling of sluggishness in the morning, fatigue despite apparently good quality sleep, or a brain that only wakes up several hours after getting out of bed. This is quite normal. Here's why.

The Impact of the Season

The first culprit of this wave of lethargy that hits the country at the start of January is easy to identify: the season. We each have varying sensitivity to it, but winter affects mood and body due to the decrease in natural light. For some, when they leave home in the morning, it's dark, and when they return, it's also dark. However, outdoor light helps to regulate our internal biological clock. When it decreases or we're not exposed to it enough, our rhythms are disrupted. "Without necessarily talking about seasonal depression, we know that for a majority of the population, a lack of light is accompanied by a feeling of lower well-being than usual and a greater propensity for sleep," comments Dr. Philippe Beaulieu, a sleep doctor and cognitive-behavioral therapist.

The decrease in brightness also makes us "produce a little melatonin (the sleep hormone) during the day," adds Vanessa Slimani, a psychiatrist attached to the sleep pathology service at Pitié-Salpêtrière (Paris). "That's why we feel tired and have trouble waking up in the morning, and it impacts mood and seasonal depression."

The sun's rays are also less bright in winter than in summer. "The difference is significant: during a summer day, natural light is estimated between 100 and 130,000 lux, against 2,000 to 20,000 in winter," illustrates chronobiologist Claire Leconte.

A Consequence of the Health Context

This overall drop in form is also due to what we have been experiencing for nearly two years. "Profiles of hyper sleepers have been identified in the consequences of the health situation," reports Dr. Philippe Beaulieu.

Specifically, these periods of epidemic waves act on our rhythms by desynchronizing the markers that regulate the biological clock. The result? Sleep and its quality are altered. "Some have degraded nights and others have what we call phase shifts. In short, we see a lack of benchmarks and sleep moments that shift."

Unsurprisingly, the current atmosphere also generates a dose of chronic stress, "with the fear of illness or the resurgence of teleworking which for some is liberating but for others very confining. Not to mention that we are immersed in a context of uncertainty and the human brain doesn't like that," explains the sleep doctor. Finally, without realizing it, some may also experience more restless nights with a more oppressive dream activity.

Simple Tips for Remediation

To improve one's state upon waking up, chronobiologist Claire Leconte reminds us: it is crucial to be exposed to daylight. "We force ourselves to have a minimum of one hour of natural light daily. To benefit from it, the lunch break is the best time because the light is the best. You can eat quickly, for example, then go out, or prepare food and eat outside," recommends the professional.

Light therapy lamps, recommended as a medical treatment for seasonal depression since 2005, can also be used. "The lamp sends a strong signal to the 'biological clock,' it regulates it. By exposing ourselves to it, we eliminate the presence of melatonin (the sleep hormone) in the brain, we have a dynamizing and anti-depressant effect," says Philippe Beaulieu. The effects are felt three to four days after use, indicates Vanessa Slimani. "Provided that you expose yourself to it every morning until March or April, when we recover natural light, for 30 minutes, the lamp 20 cm from the face, at 10,000 lux."

Sport is the second major synchronizer of the biological clock. And even if one does not feel up to it, an effort is essential to avoid the vicious circle of fatigue calling fatigue. As natural light is the best during this time, Claire Leconte advises taking advantage of the moment to practice physical activity. "In addition, sport amplifies its effects," explains the chronobiologist.

Moreover, some believe they sleep correctly, but this is not necessarily the case. "It is then necessary to respect one's need for sleep as much as possible, adds Claire Leconte, being attentive to the moment when one is sure to fall asleep quickly. When we suddenly feel cold, for example, we go to bed, it means the brain is ready to sleep." As a reminder, screens delay the onset of melatonin, the sleep hormone, so stay away from them several hours before bedtime.