Send to

Choose Destination
J Int Med Res. 2006 Mar-Apr;34(2):152-9.

The effects of exercise in forest and urban environments on sympathetic nervous activity of normal young adults.

Author information

Department of Material Systems Engineering and Life Science, Faculty of Engineering, University of Toyama, Toyama, Japan.


In Japan, forest-air bathing and walking (shinrin-yoku) has been proposed as a health-facilitating activity in which people spend a short period of time in a forest environment. Initially, we examined the usefulness of salivary amylase activity as an indicator of an individual's stress levels in a forest environment. The circadian rhythm of salivary amylase activity was measured in healthy young male subjects under stress-free conditions. The salivary amylase activity remained relatively constant throughout the day. Salivary amylase activity was then measured before and after walking in both urban and forest environments using a hand-held monitor. Our results indicated that (i) the circadian rhythm fluctuations in salivary amylase activity were much smaller than the stressor-induced variations; (ii) salivary amylase activity was an excellent indicator of the changes in sympathetic nervous activity; and (iii) the forest was a good environment in which people could experience much less environment-derived stress.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Atypon
Loading ...
Support Center