Why You Should Spend More Time Outside

It´s Wednesday evening and you have come back from work. You are exhausted from work and all you want to do is relax. You check the TV guide, but there is nothing on TV, but you still turn on the box and watch something mildly entertaining. A cold beer and some chips. You are dreading the thought of going back to work, only to come back home to crack another bottle and watch some stupid movie you have seen 20 times. Only 40 more years you think to yourself and then feel the cold shiver running down your back everytime you realize how boring and sad your life is. But wait! There is a cure!! It is pretty cheap and has little to no side effects. Nature! Yes, nature, a brand new product by Random Events (TM)!

Thursday evening, still drained from work, you decide to battle your tiredness and go for a walk through a local park. The sun is still shining, but the heat of the afternoon is gone and you feel a cold breeze, not too cold but nice. No urge for a cold beer or another of these stupid shows. On your walk you run into active people who greet you, even though you are a stranger to them. You pass by a little river and listen to the sound of water. Birds are singing all around you. You take a deep breath. The times passes and you do not even notice. But tomorrow you have to work so you decide to head back home. For the first time in a long time you feel excited about tomorrow. You have the best night sleep in a while and wake up relaxed and eager to get things done.

There are likely a few people who can relate to this little story. Our work life is consuming most of the useful wake hours of our life. Many are working jobs that they have lost passion for, which impacts our mood and even behavior. People are too tired to engage in a healthy lifestyle, to work out and cook a healthy meal. Rather they drink beer and seek for cheap entertainment. This has impacts on our health and disconnects us from nature. Today I will write about how exposure to nature influences our health and mood, and how you can apply this to your daily life!

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While our life expectancy is on the rise in most countries, the proportion of chronic diseases is on the rise. In 2001, 60% of world-wide deaths were attributable to chronic disease (CD), while the total disease burden of CD was 46%. The WHO expects the disease burden of CD to rise to 57% by 2020. The main CDs are cardiovascular diseases, obesity and diabetes, which are also affecting more people at younger ages. These are trends that should make us worry.

Modern life has changed tremendously. People know computers better than hand-held tools, work jobs that cause them to sit for extended periods of time and lead less active lifestyles. This has brought us great comfort and a great deal of wealth, but is also likely the cause for the rise of CD. Modern medicine and vaccinates have helped to prevent death from infectious agents and physical wounds, but the negative effects of our seditary lifestyle on our health cannot be dealt with medically. Prevention is better than treatment - there seldom is a cure.

One such possible prevention strategy is very simple - being outside. There seems to be a correlation between health and exposure to nature. Researcher have looked into the effects of being in nature and found evidence that nature has indeed health benefits. Studies found relations between percentage of green space in people’s living environment and perceived health. People feel healthier if they have access to green spaces.

Health benefits of nature seem to be able to overcome income-disparity. A study has found that such health benefits are not relying on income status of people. Among the various benefits is a reduced risk for death from cardiovascular disease, which has been studied most extensively in comparison to other physiological effects. A study has found that walking in a forest can actually lead to surpression of the sympathetic nervous system (SNS) while activating the parasympathetic nervous system (PNS), thus "deactivating" or easing stress response and restoring a resting state. This effect was found to more pronounced in forest dwellers when compared to people walking in the city. It seems that nature gives beneficial activity a little "boost".

The physiological implications of spending time in nature and not well understood. It is probably not the case that merely looking at a tree will make you healthier. Being outside motivates us to participate in certain activities, which usually include moderate or low intensity physical activity (hiking and walking respectively). If this was true, it could explain many of the positive physiological reactions. On the other hand, where does that "boost" come from? It seems reasonable to assume that the decrese in stress is a contributing factor.

As previously mentioned, walking in a forest decreases the stress in subject. This has been found out by measuring the cerebral activity, as well as measuring salivary cortisol levels (a stress hormone). Both were decreased in people who participated in walking through the forest. Another study found that walking in a forest decreases fluctuations in the circadian rhythm of salivary amylase, when compared to stress induced changes. Stress is a danger to public health. As I have described in one of my previous posts, stress can lead to an increased risk of getting a disease (ranging from cardiovascular disease, to cancer, to simple infectious diseases).

Another possibly important benefit of being in nature is on our immune system. When people spent time in nature, compared to in a city, their natural killer cells were more active and numerous, and certain anti-cancer proteins were expressed more in lymphocytes. Thus being in nature can potentially play a role in disease prevention, as well as decreasing the cancer risk. This study has stated that reduced stress, as well as certain phytoncides from trees may play a role in the observed effects.

How do you implement this in your life? Well, easy answer, get out of the city into nature as much as you can. Being in nature may play a role in depression preventions. Engaging in short activities outside improved both, mood and self-esteem in several studies. There are differences in age and gender, as well as mental status, but the effects were still observed to be positive. Long periods of time in nature did have positive effects as well, but the greatest improvements were observed in short term activities. Thus you do not need to be outside for very long to benefit from it. And seriously, this is not far away from where I am currently staying, but is it not beautiful? You do not have to go far away from home. Go into a park. If you can, try to be close to water as presence of water seemed to enhance the observed effects.

There are a few problems, though. Many meta-studies failed to adopt an adequate search strategy, and several scientific disciplines ignore findings of other scientific disciplines. Another problem is that heterogenous data was pooled to draw a conclusion. This is problematic as it combines data that is not supposed to be combined, which could falsify conclusions. There is a need for more extensive, inter-disciplinary research that aims at investigating the effect of exposure to nature on health. However, the current evidence shows that being in nature is beneficial to our health, as it does reduce stress (which has been confirmed by several primary studies).

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Sources

• WHO statistics - Link
• Nature and Health Annual Review of Public Health - Link
• Cortisol on Wikipedia - Link
• Correlates of physical activity: why are some people physically active and others not? - Link

Health Benefits Of Exposure To Nature

• Nature-assisted therapy: Systematic review of controlled and observational studies - Link
• A systematic review of evidence for the added benefits to health of exposure to natural environments - Link
• Green space, urbanity, and health: how strong is the relation? - Link
• Effect of exposure to natural environment on health inequalities: an observational population study - Link
• Physiological Effects of Shinrin-yoku (Taking in the Atmosphere of the Forest) in an Old-Growth Broadleaf Forest in Yamagata Prefecture, Japan - Link
• Physiological Effects of Shinrin-yoku (Taking in the Atmosphere of the Forest)—Using Salivary Cortisol and Cerebral Activity as Indicators - Link
• The Effects of Exercise in Forest and Urban Environments on Sympathetic Nervous Activity of Normal Young Adults - Link
• The significance of parks to physical activity and public health - Link
  -A systematic review of evidence for the added benefits to health of exposure to natural environments - Link
• Visiting a forest, but not a city, increases human natural killer activity and expression of anti-cancer proteins - Link
• What is the Best Dose of Nature and Green Exercise for Improving Mental Health? A Multi-Study Analysis - Link

I hope you enjoyed today´s post and feel motivated to go out into nature. While the research still needs more data and better studies, evidence suggests that being outside is still beneficial. So instead of running on a treadmill or in the city, catch a ride to the nearest forest run there. Or, instead of sitting on your balcony reading, go to a nearby park and enjoy your book there. Being in nature can be combined with many activities, and I would suggest you doing that. Thank your for reading this post.

As always,
Cheers @lesshorrible!