Neurologist explains why you feel lazier in winters: 'Quietly alters brain chemistry...'

If you are feeling lazier than usual, know the real reason lurking behind your winter lethargy.

Ever wondered why your energy level is lower than usual during winter? It is not just the cosy warmth of your blanket making it harder to get up; your brain itself undergoes certain changes during this season, which explains why you feel very sluggish and overall very drained. So to get a better understanding of this shift, why it happens and how you can get ahead of this seasonal slump, HT Lifestyle spoke to Dr Kunal Bahrani, chairman and group director - neurology at Yatharth Hospitals.

Ensure you get adequate sunlight exposure during winters. (Picture credit: Shutterstock)

He confirmed that there are several different ways this sluggishness shows up in your behaviour and general, everyday functioning. “It quietly alters the brain’s chemistry, pushing many people into a cycle of sluggishness, low mood, foggy thinking, disrupted sleep, and a sense of emotional heaviness that feels difficult to name. ” So you are not lazy, your brain itself during winters is mentally slower. The neurologist shared that this is seen often among the urban population who spend most time indoors.

Why are you ‘lazy’ in winter?

During winter, you are lazier than usual! (Picture credit: Freepik)

One of the core reasons this low energy occurs in winter is the lack of sunlight, as Dr Bahrani pointed out.Sharing the benefits of sunlight, he elaborated, “Sunlight is not just a source of warmth; it is a biological signal that regulates circadian rhythms, serotonin production, and the brain’s overall alertness. When exposure drops, even healthy individuals experience a measurable decline in cognitive speed, motivation, and emotional balance.”

Beyond reduced sunlight, rising winter pollution levels also contribute to this pervasive brain fog. Dr Bahrani noted that poor air quality can impact memory, leaving people struggling to focus and stay alert.

The third contributor is temperature. “As temperatures drop, physical activity reduces, and screen exposure increases. Both changes suppress the brain’s natural dopamine and serotonin cycles, further contributing to fatigue and low motivation," the doctor explained. "Reduced outdoor time also means reduced vitamin D synthesis, another factor linked with impaired cognitive function.”

All these causes taken together prove that winter laziness is actually a biological response, not just a lack of motivation. Persistent low mood and fatigue may escalate and lead to issues like Seasonal Affective Disorder.

What can you do to prevent?

To counter it, you need to make a few lifestyle changes.

The neurologist recommended spending some time in the sun each morning. He shared the clinical reason behind it: “Morning sunlight exposure, even for 15–20 minutes, helps reset circadian rhythms." Now, what if the day is very cloudy and the sunlight is very faint? Then the doctor suggested an alternative: "Light-therapy lamps mimic natural daylight and are increasingly used in colder countries with proven benefits.”

Along with adequate sunlight exposure, Dr Bahrani also explained that one should exercise regularly, follow a strict, structured screen routine, avoid being on the phone before bed, hydrate and eat a nutritionally rich diet. If one is still feeling tired, he suggested getting a medical evaluation, as persistent low mood or chronic exhaustion may also be a result of thyroid dysfunction, B12 deficiency, or clinical depression.

Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.