What does the doctor prescribe for stress? A ‘nature pill’ consisting of 20 minutes of contact with nature, enough time for significant decreases in cortisol, the stress hormone.
You likely know from experience that spending time outdoors and especially connected with nature lowers your stress. Scientifically, there have been dozens of studies that link spending time in nature with lowered stress levels.
The breakthrough with this specific study is they were able to determine the optimal length of time to spend outside, just 20 minutes, to see significantly lowered cortisol levels.
To see the maximum benefit, lead research Dr. MaryCarol Hunter from the University of Michigan says that “the greatest payoff, in terms of efficiently lowering levels of the stress hormone cortisol, you should spend 20 to 30 minutes sitting or walking in a place that provides you with a sense of nature."
Quantifying “Nature Time” And Its Impact On Lowering Cortisol
In the 21st century, as we near 2020, our lives have become increasingly sedentary, indoors and spent staring at a screen.
The motivation for this study was to quantify how long people should spend in nature to feel a meaningful decrease in stress. To do so, they asked the study’s participants to go outside and experience nature at least 3 times a week. They then tested cortisol levels through saliva samples before and after the nature time.
Participants were encouraged to spend at least 10 minutes outside, with no maximum duration. Participants were also free to customize their nature experiences to fit their lifestyle and environment.
The only constraints on their nature time were that it be during daylight, there be no strenuous aerobic exercise (i.e. running), no social media, internet, phone calls, conversations, and reading and that it lasts longer than 10 minutes.
What the researchers found is that the sweet spot was 20 to 30 minutes of sitting or walking in nature to get the greatest drop in cortisol levels. Beyond that, cortisol levels did decrease but at a lower rate.
Kids Who Spend Time in Nature Become Happier Adults
Another study dovetails into this one in highlighting the importance of nature time for kids and the impact it has on their adulthood.
The more kids interact with the outdoors and nature the happier and healthier they are as adults. The study was conducted on one million Danish residents who span a variety of educational, health and socioeconomic scenarios.
Taking into account potential complicating factors such as wealthier kids could have more access to green space, the study found that children who are surrounded by nature have a 55 percent lower risk of having mental health issues as adults.
Comb through literature and you’ll find dozens of other similar studies pointing to the measurable positive effects of being in nature to one’s overall mental and physical health.
Green spaces in urban environments and the protection of natural environments are necessary for the long-term health of an increasingly urbanized population.
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I am a geologist passionate about sharing Earth's intricacies with you. I received my PhD from Duke University where I studied the geology and climate of the Amazon. I am the founder of Science Trends, a leading source of science news and analysis on everything from climate change to cancer research. Let's connect @trevornace