Inspired by my recent backpacking trip in Northeast Pennsylvania through the rolling, tree-covered hills of the Loyalsock State Forest, I'm reminded of the immense benefits associated with exposure to the outdoors. Such benefits have been proven through a number of scientific studies, though you need only speak to an avid cyclist, surfer, hiker, or climber to understand the positive effects being outside has on your mental and physical health. Let's dive into the data and conventional wisdom around this topic.
Not only is gazing out over a mountain range good for the soul, it also prevents myopia (near-sightedness). Myopia has become more and more common, and its rise is likely due to increased time spent indoors staring at things close to your face (like whatever device you are currently reading this on). Interestingly, being highly educated may put you at increased risk of developing myopia due to increased time reading textbooks and writing papers. In a study of young adults, higher exposure to display screen equipment and increased use of a computer over time were associated with a higher risk of myopia. So, if you're currently a college student, video gamer, or work at a desk, you're likely at increased risk.
In a meta-analysis and systematic review (mostly in children), increased time outdoors was effective in preventing the onset of myopia as well as in slowing the myopic shift in refractive error. However, spending time outdoors was not effective in slowing progression in eyes that were already myopic. So, like most things regarding your health, you should be taking a prophylactic approach. Spending time outdoors may prevent you from developing near-sightedness, but it won't fix anything once you've passed a point of no return.
Sunlight is like the breath of life to the pomp of autumn. -Nathaniel Hawthorne
You've likely heard of the benefits of vitamin D. Perhaps you've even attempted to eat a diet high in vitamin D or take a supplement. Vitamin D is essential for developing and maintaining healthy bones. When vitamin D is present, you are better able to absorb calcium, a principal component of bone health. There are also a number of cellular functions happening constantly in your body that rely on vitamin D. It has anti-inflammatory and antioxidant properties, and it supports muscle function and brain cell activity.
There's a totally natural way to increase your vitamin D levels, and that's exposure to sunlight. Sunlight contains UV radiation which is able to penetrate your skin and convert 7-DHC (7-dehydrocholesterol) into a precursor of vitamin D. From there, an increase in skin temperature allows for the conversion of the precursor into the active form of vitamin D. The newly synthesized molecule is then transferred into your bloodstream where the rest of your tissues can reap the benefits from your time in the sun.
According to a large study of participants in the UK, time spent outdoors is associated with a decreased risk of depression and better outcomes across a range of mood and sleep measures. Specifically, each additional hour spent outdoors was associated with decreased risk of lifetime major depressive disorders, antidepressant use, anhedonia (inability to experience pleasure), low mood, and neuroticism. It was also associated with greater happiness, decreased tiredness, and decreased insomnia.
This study doesn't prove causation with any of these variables, but associative studies like this can still give us some clues about how we can better our lives. From this study and many others, all clues point to the massive benefit of spending time outdoors. Hope to see you out there!