Beating the Winter Dip: How Business Founders Should Adapt to the Change of Season.

Most business owners think about their energy in terms of hours of sleep and amount of work, with light rarely making the list. Yet as a brain expert, sunlight is one of the most powerful and underused tools we have for supporting clear thinking, steady mood, and good decision-making.

A dedicated pathway in the eye, separate from vision, exists purely to detect light. It runs from specialised cells in the retina to the suprachiasmatic nucleus in the hypothalamus, the brain’s master clock. Morning light hitting those cells sets the timing of almost every biological rhythm: cortisol, melatonin, body temperature, digestion, immune function, mood and memory.

For someone running a business, this has very practical consequences. Bright light enhances activity in the prefrontal cortex, the part of the brain responsible for planning, judgement and emotional regulation. These are exactly the skills you rely on when negotiating, managing a team or making a call under pressure. Light also drives serotonin, which supports emotional stability, resilience to stress, and cognitive flexibility. Serotonin is the precursor to melatonin too, so the light you get during the day directly shapes how well you sleep that night, and how sharp you are the next morning.

Then there’s vitamin D, made in the skin through UVB exposure. It acts more like a hormone than a vitamin, with receptors throughout the brain in areas linked to mood and cognition. Deficiency is common in the UK, especially as we go towards winter, and is associated with low mood, fatigue and that foggy, sluggish feeling many people put down to simply being busy.

What happens when the clocks go back and the nights draw in?

By December, it can be dark before 4 pm in parts of the UK. For business owners, this tends to show up in a familiar pattern. You arrive at your desk in grey light, work under artificial lighting all day, and leave in darkness. Many people go days without meaningful outdoor light at all. It’s also worth remembering that your team is going through the same thing. Seasonal dips in energy and mood affect productivity, morale and sickness absence, and a business owner who understands this is in a much better position to plan around it.

How can we work with light through the working day?

One of the best things we can do for our brain in the colder months is to get outside. My biggest advice as a brain expert is to always get outside within 30 to 60 minutes of waking, even on a cloudy winter day. This sets your circadian rhythm, supports a healthy cortisol rise for alertness, kick-starts serotonin production, and starts a timer for melatonin release roughly 14 to 16 hours later. In winter, this is the single most important habit, because the temptation is to reach for our phone and stay under the duvet. Instead, I advise no phones for the first 20 minutes of the day. 

If you wake up and reach straight for your phone, it triggers an immediate flood of digital stimuli and notifications. It actually makes us skip the brain’s natural wake-up process. The urge to scroll forces us directly into a high alert state (beta waves).  Essentially, your brain goes from 0-100 with no warm-up whatsoever. This overstimulation impairs executive brain functioning for hours, meaning this one habit can negatively impact how your brain works for the rest of your day. So have a quick walk outside and jump in the shower: you just need to pass 20 minutes before you look at your phone. If life doesn’t make this possible, then light therapy lamps  have undergone much research and are a powerful tool for supporting brain health and cognition. I use a lamp myself from November to February, and there’s been a noticeable difference in my mood and energy levels

Midday light is the brightest of the day. In the darker months, this is your best window for a dose of daylight, and it’s the most effective way to blunt the post-lunch dip that makes afternoons feel particularly difficult when it comes to productivity. Again, when you’re on a deadline, heading outside can be hard but necessary. We know just 20 minutes of movement makes a huge difference to our brain, so a brisk outdoor walk before an afternoon meeting can help sharpen your focus and concentration.

As natural light fades, the brain expects to start winding down. Bright overhead lighting and screens, which emit plenty of blue light, signal daytime instead. Working late under strong light and answering emails in bed delays melatonin, pushes sleep later, and reduces the deep sleep that restores the brain, which then makes the next dark morning even harder.

Practical tips for business owners

• Get outside within the first hour of waking, every day, whatever the weather. Overcast outdoor light is still far brighter than indoor light. Ten to twenty minutes is ideal, but even really short bursts help. Walk to get a coffee, take a phone call outside, or walk part of your commute. 

• Ease into the clock change. In the days before and after, keep your wake time steady and get outside early. 

• Schedule your thinking around the light. Put strategic work, important meetings, and big decisions in the brighter part of the day or after a trip outside. Save admin and routine tasks for late afternoon.

• Take a midday light break and treat it as work. Even ten minutes outside improves afternoon alertness. Walking meetings and outdoor one-to-ones are an easy way to fit this in, and they set an example for your team.

• Light your workspace properly. Sit near a window where possible. If you or your team work long hours under artificial light, a bright light therapy lamp in winter can help.

• Think about your team. Encourage people to take proper breaks in daylight, consider flexible start times through the darkest months, and get outdoor light.

• Keep the bedroom dark with blackout curtains or a sleep mask, so you get the deep, restorative sleep that good decisions depend on.

• Take vitamin D seriously. In the UK, UVB light isn’t strong enough for the skin to make vitamin D between October and March, however much time you spend outside. A supplement through these months is simple, well-evidenced, and worth discussing with your GP, and it’s worth sharing with your team too.