The Science of Sunshine | How the Outside Keeps You Healthy

As the founder and lead Personal Trainer at TRIBE.MCR, trust me when I say that exercise and the outdoors are essential parts of my life. Working outdoors makes me feel fantastic and I love nothing more than seeing my clients getting out of the gym and raising a sweat outdoors. In my ‘other job’, as a junior doctor and future GP, I also take pride in seeing my patients improve their health by spending time outdoors, whether that is in a local park, or a wilder environment.

Yes, these are odd times, when getting some natural light is trickier, but more important than ever. The weather this weekend looks promising, but please be sure to follow government guidelines and help support the NHS. Get your fresh air in a responsible way that doesn’t put yourself or others at risk.

And now, here’s the science behind the benefits of your time outdoors.

Sunny view through the window

Sunlight exposure and Vitamin D

The most well-known benefit of sunlight exposure is that it drives up Vitamin D in our bodies. Vitamin D is important for calcium regulation and ensures healthy bones, teeth and muscles. Public Health England recommends a daily dose of 10 micrograms, which can be sourced from foods, e.g. oily fish and red meat, fortified products e.g. dairy replacements, supplementation and of course, through sunlight.

Between April and September we are able to achieve the recommended daily dose of Vitamin D by spending time in sunlight. The British Skin Foundation suggests that for people with lighter skin, this is 10-15 minutes per day and for those with darker skin, this is 25-40 minutes per day.

With adequate sun protection, this is a fantastic benefit of spending time outdoors. It is worth noting that during the winter months in the UK, we need to think about sourcing vitamin D from our diets and through supplementation. That is, unless you are lucky enough to spend the winter months in sunnier locations...

Man walking along concrete road

Sunlight and our internal body clock

Did you know that daily exposure to sunlight also helps us to set our internal body clock? Our internal body clock is a collection of over 20,000 nerve cells in an area of the brain called the hypothalamus. Natural light, which stimulates light receptors at the back of the eye, sets this internal body clock. What is generated is a circadian rhythm, which is important for sleep, metabolism and our mood.

Our circadian rhythm can be disrupted by spending long periods of time indoors and by exposing ourselves to artificial, ‘blue’ light during the evenings from their phones or tablet screens. Guilty? So are most people living in western world, who spend a reported 90% of their time indoors. The circadian rhythm can also be disrupted by jet lag, by working shifts, and having altered sleep patterns each day.

Groups of people walking in park in China


We can rectify this and reset our circadian rhythm by increasing our daily exposure to natural light. This can be achieved by simple changes to our daily schedule e.g. organising an outdoor walking meeting, or reclaiming your lunch break and taking a walk outside. Every little helps, as the research suggests that it is the accumulation of light exposure that is important, rather than the intensity.

Now, what if sunlight is pretty hard to come by? Is there any benefit to being outdoors in less appealing weather?

There sure is…

Spending time in nature, whatever the weather, has a huge range of benefits on our physical and mental health. I could reel off countless examples of moments spent in nature, when I feel more calm, more connected to the people I am with and refreshed.

The reason we feel this sense of calm is due to the activation of the parasympathetic, or ‘rest and digest’ nervous system. This prompts a lowering of our heart rate and blood pressure and gives physical signs to the brain that we can relax. Studies from Japan, where ‘Shinrin-yoku’ or forest bathing is used, have also shown lower levels of the stress hormone cortisol in the saliva of those spending time in nature.

We have also seen from studies using electroencephalography (EEG) - small electrodes on the scalp to detect brain activity - that spending time in a natural environment causes similar brain activity to that observed during meditation. Some psychologists also theorise that natural environments promote ‘effortless involuntary attention’, otherwise known as daydreaming. This might explain the clearer sense of mind, and fresh perspective that you achieve from being outdoors. 

view of a german town in the sunshine

The natural environment helps us to be more active...

In my role as the Public Health England Physical Activity Clinical Champion for North West of England, I take great interest in the ways that our environment influences our activity levels. We know from the Active People Survey that living, or spending time in natural environments is associated with higher levels of physical activity. The reasons for this are yet to be made clear, however current research suggests this may be linked to stress relief, distraction and self-esteem.

What is also interesting is that in natural environments, we are more likely to engage in physical activity that is planned and recreational e.g. hiking and climbing, compared to physical activity for the purposes of travel, or commuting to work in urban environments. These activities have a greater impact on our health and wellbeing due to the higher intensity of physical exertion. It also matters that when you are active outdoors and having fun, you are taking the conscious decision to spend #selfcare time away from work and other stressful life commitments.

children sitting on deckchair in the garden

So there you have it!

Being outdoors has so many benefits on our health, whatever the weather. This is why I founded the outdoor fitness community TRIBE.MCR and why I hope to continue to inspire people to get outdoors and get active for many years to come.

At the moment that may mean a short walk or an afternoon in the garden if you’re lucky enough to have one. But fresh air and sunlight are great wherever you get them. Enjoy the good weather but remember to be responsible. Keep it local, stay home, stay safe.


To help you get the best out of your time in the garden this bank holiday weekend, we've put together a guide to turning your garden into a wildlife sanctuary, and some sweet treats that can be cooked over your camping stove. Enjoy!

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Jessicarr is a Manchester based junior doctor, who has gone off-piste and is now a multi-hyphenate with a huge passion for preventative healthcare and getting people active. She spends half of her time working as a doctor and half of her time heading up the outdoor fitness community TRIBE.MCR.

She also works for Public Health England as the Physical Activity Clinical Champion for North West of England, a role which sees her working with and inspiring healthcare professionals to engage in conversations about physical activity with patients. In the future, she would like to work within General Practice and have a local, regional or maybe even national influence on the promotion of active lifestyles for all. Watch this space!


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