EasyBreezyMind
1 peer-reviewed source, DOI-verifiedUpdated Oct 1, 2026How we verify
Most nature research happens in labs. This study followed city residents in their normal lives, letting them choose when and where to spend time in nature, and measured their stress hormones before and after.
| Study type | Repeated-measures field study (8 weeks) |
|---|---|
| Who took part | 36 urban residents |
| What was tested | A “nature experience” of 10+ minutes, at least three times a week |
| Published | Frontiers in Psychology, 2019 |
| Free to read | Full text on PubMed Central |
| Licence | Open access, Creative Commons Attribution (CC BY) |
What the researchers did
Participants were asked to spend time in an outdoor place that gave them a sense of contact with nature, at least three times a week for 10 minutes or more. They gave saliva samples before and after these experiences at four points over the study.
What they found
- A nature experience produced a 21.3% per hour drop in cortisol beyond its normal daily decline.
- The benefit per minute was greatest between 20 and 30 minutes; benefits continued after that, but more slowly.
- Alpha-amylase, another stress marker, also fell — but only for people who mostly sat or walked gently.
What this doesn’t prove
- There was no separate control group; each person’s own daily cortisol rhythm served as the comparison.
- The sample was small.
- “Nature” was whatever felt natural to each participant, which makes exact doses hard to compare.
How to use this
Schedule a 20–30 minute “nature dose” a few times a week — a park, a tree-lined street, a garden. See where it ranks in our Evidence Matrix.
City dwellers who spent time in a place that felt like nature saw cortisol fall faster than its normal daily decline. The benefit per minute was greatest between 20 and 30 minutes.
Summary written by EasyBreezyMind in our own words. Original article: Hunter MR, Gillespie BW, Chen SY (2019). Urban Nature Experiences Reduce Stress in the Context of Daily Life Based on Salivary Biomarkers. Frontiers in Psychology. doi:10.3389/fpsyg.2019.00722. © The authors. Published open access under a Creative Commons Attribution (CC BY) licence. This summary is educational and is not endorsed by the authors.