Spending just 20 minutes connecting with nature can help lower stress hormone levels, according to a study in the April 4, 2019, Frontiers in Psychology. Previous research has shown that interacting with nature reduces stress, but it is not clear how long and how often the engagement needs to be, or even what kind of nature experience is best.

Here, researchers asked 36 people to spend 10 minutes or longer, three days a week for eight weeks, in an outdoor place where they could interact with nature. The settings varied from yards to public parks to green areas near their place of work. They also either walked or sat during their nature time.

Levels of cortisol, a stress hormone, were measured from saliva samples taken before and after nature outings. The people also were instructed to not exercise beforehand and to avoid unrelated stimuli like social media, phone calls, conversations, and reading.

Spending at least 20 to 30 minutes immersed in a nature setting was associated with the biggest drop in cortisol levels. After that time, additional stress-reduction benefit accrued more slowly. Time of day and specific settings didn't affect stress levels. So the next time you need to de-stress or just work on your mental well-being, find a nature setting you enjoy and spend some time there.