Why you need a "light shower"

What do the first couple of hours of your day look like? Are you lying in bed, hitting snooze, in denial that a new day has started and that it needs you in it? This is called sleep inertia.

Or perhaps you were woken up by a little person at 5 am and are tending to their needs for the first 3 hours of your day before sending them off to school or child care.

Maybe your mornings are spent wandering around your home half asleep until you’ve hooked yourself up to your caffeine IV drip, enabling you to start to get with the program.

Among all the chaos or sleepiness (or a mix of both), how much daylight are you getting?

Professor Russell Foster says in the same way you give your body a water shower in the morning, you need to give your brain a light shower. He recommends we aim to spend 30 minutes outside each and every morning.

‘There’s a wonderful study showing that dog walkers had much better sleep patterns than non-dog walkers,’ Foster told me. ‘My interpretation is that it’s not because dogs are a companion animal – it’s because the owners are having to get up in the morning and empty out the dogs – and as a result, getting the light exposure.’

Dr Samer Hattar, Neuroscientist and Chief of the Section on Light and Circadian Rhythms at the National Institute of Mental Health, says we might not even need as long as 30 minutes. ‘For the circadian clock, you don’t need more than 15 to 20 minutes and even that’s an overkill,’ Hattar told me. ‘Possibly as low as 5 minutes of very bright light is enough.’

Let’s get specific about how much light we need to shift our clock into daytime mode. To do that, we need to talk about lux. Lux is a measure of illuminance – a fancy-sounding technical term that simply means the total amount of light that falls on a surface.

Higher lux levels = bright. Lower = dim.

The typical apartment or house has lux levels of around 100–400 (depending on how well lit the rooms are), compared to outside, which ranges from 1000 to 10,000 on a cloudy or overcast day through to 100,000 on a sunny day.

Research led by Professor Leon Lack from Flinders University exposed participants to either dim light (100 lux) or bright light (2500 lux) first thing in the morning for one week. Participants who were exposed to the bright light in the morning reported feeling sleepy at night more than 1 hour earlier, compared to a control group and the dim light group, whose body clocks remained unchanged. In addition, in the three weeks following the experiment, the bright light group experienced more restful sleep and less fatigue during the day compared to the control group.

If you’re unable to get outside, whether that be for mobility reasons or because you live in a part of the world where morning light happens fairly late, such as the Scandinavian countries), Foster says that supplementary light has been shown to improve our sleep/wake cycle.

Foster says the latest research shows that ramping up light intensities from when you get out of bed, to ideally reach outputs in excess of 2000 lux via a light box seems to be beneficial. ‘Would I use one if I needed to? Yes, I would,’ he claims.

Finally, and in case you need another reason to get excited about morning light, when I spoke to Hattar he had just finished analysing data about the benefits that morning light exposure has on our mood.

Put it into action

Go for a morning walk (after sunrise, not before) for between 10 and 30 minutes every morning to reset your circadian clock. If walking is not viable, then just sit outside, whether that be on your balcony, in your backyard or on a park bench, during the first couple of hours of your morning.

If you are thinking to yourself: how on earth am I meant to find time for a morning walk amid the chaos of getting my kids up and ready for school – not to mention getting myself ready – feeding the dog, making the bed, packing my lunch and so on, your plan B is to at the very least sit next to a window that will bathe you in natural light for the majority of the morning. One study found that compared to people whose desks were in a windowless environment, those who sat next to a window reported having much better sleep at night.

Alternatively, if you don’t have the ability to be near a window, get yourself a light box that emits at least 2000–4000 lux and pop it next to you for the first hour or so of your workday.