Sleep better, feel better: the benefits of going outside

With the arrival of colder, rainier and darker days, social networks are filled with images of cozy and warm-looking interiors: sofa, blanket, steaming tea, a movie or a book.

Why go outside if it is not strictly necessary?

This stay at home helps to understand the figure that is always repeated when talking about the spaces in which we spend our days: we spend between 85% and 90% of the time indoors.

The European Commission said so in 2003 on the population of the EU and also a study published

in 2001, according to which Americans spent 87% of their time in closed buildings and 6% in vehicles that were also closed.

The number of hours we spend between four walls changes according to the season: in summer we are more outdoors if we can and it is not sweltering hot and in winter we tend to take refuge indoors more, although, according to a survey carried out in 2021 by the company OnePoll, everything also depends on which is our favorite station.

Still, unless we work outdoors, it is very likely that we will stay that 85-90% of the time indoors on average.

What are we missing by not being able to spend more time outside?

"Light is a synchronizer of the circadian system," explains María José Martínez Madrid, Doctor of Medicine from the University of Murcia and coordinator of the Chronobiology working group of the Spanish Sleep Society (SES).

Recommendations for good sleep hygiene usually focus on not getting too much light at night, but exposure to it during the day is just as important.

“You have to receive natural light during the day, at least two hours, although it is more difficult than it seems.

But if light is not received during the day, then at night no melatonin is synthesized.

It is a mechanism that needs that contrast, daylight and darkness at night.

If we don't receive light during the day we are going to be more sleepy and less active, and also at night we are going to sleep worse, ”she points out.

Although at night it is artificial light that keeps us awake at night, the light we receive during the day must be natural, if possible received directly and not through a window.

“When we receive light from the computer, even all day, it is scarce.

Although it is blue light, it is a light that does not have the intensity that we need nor does it have the full spectrum of light, ”he clarifies.

The time spent outdoors is also related to better visual health, something about which there is also quite a lot of scientific unanimity.

One of the most recent studies, from this year, concluded that, although the intensity of the interior light did not influence the development of myopia in children (the classic "if you read in the dark you will damage your eyesight" has enough of myth), the time spent outdoors did: increasing this time protects non-myopic children against myopia.

This study did not find the same result for children who were already nearsighted (that it slowed down an increase in their myopia), but others have found it.

The ophthalmologist Rosario Gómez de Liaño, head of the Strabismus Unit at the San Carlos Clinical Hospital, president of the International Society of Strabology and full professor at the Complutense University of Madrid, explains that these benefits of being abroad come in various ways.

"It is known, for example, that they are ultraviolet, which can have an influence through various mechanisms," she points out.

Eye care recommendations for computer work always recommend breaks where you look into the distance, so it's tempting to attribute the eye benefits of being outdoors also to the fact that we're more likely to be with eyes looking beyond a few centimeters.

However, Gómez de Liaño insists that light is the most important thing.

“It was seen, for example, that if the child read inside the house or outside the house, it was totally different.

It wasn't the fact of playing and looking from afar, it was the fact of the light”, he emphasizes.

The importance of mental health

A few months ago, a video went viral on TikTok (and, by the way, Instagram) with a girl walking in an exaggerated sulk down a snowy road, to the rhythm of an

and with the text “taking a stupid walk for my stupid health mental".

Going out for a walk, getting some fresh air, is one of the tips that is often repeated like a saint's hand for when we have a bad day.

“When we go out into the street we realize that there is another world.

And that makes us see that being inside the house we feel not as good as we could feel if we went out more”, explains Juan Ignacio Aragonés, professor of Social Psychology at the Complutense University of Madrid and member of the Association of Environmental Psychology Psicamb.

In addition, there are more possibilities for social interaction, which can also increase that well-being.

However, he clarifies that he does not say it with data in hand, but rather out of “common sense”.

The data proves him right.

According to a study published last year in the

, the average time that the more than 400,000 British participants spent abroad each day was 2.5 hours.

Each additional hour was associated with less odds of depression and antidepressant use, less frequency of anhedonia and low mood, less neuroticism, and greater self-perceived happiness.

Although all this can also mean that you go out more because you feel better and not the other way around, reasons have been sought to prove that this stupid walk can help our stupid mental health.

The different investigations have been focusing on three.

First of all, exposure to natural light, which regulates the cycles of melatonin, serotonin and cortisol, among others.

Alterations in these circadian cycles are related to depression, so helping regulate one could help keep the other at bay.

There is also the relationship between the time we spend outside and physical activity: outside the home we tend to be more active (even if it is a walk), which also helps us feel better.

Finally, the positive impact of spending time in natural spaces has been well studied: according to a 2019 study, two hours a week in natural spaces is related to better health and greater general well-being.

If our going outside goes through a park or an excursion to the forest, the benefits are greater.

But what if that time outdoors is spent in an urban, polluted and, ultimately, stressful environment?

This is the critique of a study published in 2016 in the

: “The results of the study support the notion that increasing time spent outdoors can result in mental health benefits.

However, this study questions whether that benefit is experienced equally among different groups, particularly given differences in occupational experiences and environmental characteristics of neighborhoods.

Along these same lines, Dr. Rosario Gómez de Liaño refers to recent research that relates pollution to the increase in myopia.

They are, she insists, aspects that are being studied even now, and "not all studies or all magazines are the same", so some of these things "will remain and others will not", but it is something that must be taken into account also.

In other words, going out into the street in a semi-pedestrianized neighborhood, with parks and green areas, is not the same as doing it in one taken over by traffic and asphalt.

If the environment is friendly, the health benefits are multiplied.

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