Spending 20 minutes in a park or other green space may be enough to reduce stress, suggests a study in Frontiers in Psychology. For eight weeks, 36 urban volunteers were asked to have a “nature experience” (NE)—sometimes called “nature pills”—for at least 10 minutes three or more times a week. NE was defined as spending time anywhere outdoors that made the participants feel that they were interacting with nature.
They were free to choose the time of day, duration, and place according to their preferences and schedules. They could sit or stroll but not exercise, read, have conversations, or use electronic devices. Stress levels were estimated via changes in levels of cortisol and another biomarker (alpha amylase) measured in saliva samples taken shortly before and after an NE several times over the eight weeks.
The greatest changes in these stress markers occurred after 20 to 30 minutes of NE, after which benefits continued to accrue, but gradually. A growing body of research has found that contact with nature can have a number of psychological and physical benefits.
This article first appeared in the UC Berkeley Wellness Letter.
Also see Local Green Spaces Improve Health.