Taking at least twenty minutes out of your day to take a short getaway in the middle of nature considerably reduces the level of stress hormones (cortisol). This is the conclusion of a study that established for the first time the most effective duration of contact with nature needed to relieve stress in an urban context.
Nature walks could be a low-cost solution to reducing the negative health effects of stress, stemming from increasing urbanization and screen-dominated lifestyles. To help healthcare professionals looking for evidence-based guidelines on exactly what to prescribe, Prof. Hunter and his colleagues designed an experiment that would give a realistic estimate of an effective dose.
Over an 8-week period, participants were instructed to take a “nature capsule” lasting 10 minutes or more, at least 3 times a week. Levels of cortisol, a stress hormone, were measured from saliva samples taken before and after the experiment once every two weeks.
Participants were free to choose the time of day, duration and location of their nature experience, which was defined as any outdoor location, which the participant believed gave them the impression of having interacted with nature. There were a few constraints to minimize factors known to influence stress: going on the getaway in daylight, not doing aerobic exercise, and avoiding using social media, the internet, phone calls, conversations and reading .
Incorporating personal flexibility into the experiment helped identify the optimal duration of a “nature capsule”, no matter when and where it is taken, and under the normal circumstances of modern life, with its unpredictability and his busy schedule. To accommodate busy lifestyles, while providing meaningful results, the experimental design was innovative in other ways as well.
The data revealed that a 20-minute nature experience was enough to significantly reduce cortisol levels. But if you spend a little more time immersed in an experience in the middle of nature, 20 to 30 minutes sitting or walking, cortisol levels will drop to the maximum. Thereafter, other stress-reducing benefits continue to accrue, but at a slower rate.
MaryCarol R. Hunter, Brenda W. Gillespie: Urban Nature Experiences Reduce Stress in the Context of Daily Life Based on Salivary Biomarkers Front. Psychol., doi.org/10.3389/fpsyg.2019.00722