Health benefits of walking in nature: a randomized controlled study under conditions of real-life stress.

We investigated the effects of recreational exposure to the natural environment on mood and psychophysiological responses to stress. We hypothesized that walking in nature has restorative effects over and above the effects of exposure to nature scenes (viewing-nature-on-TV) or physical exercise alone (walking-on-a-treadmill-in-a-gym) and that these effects are greater when participants were expected to be more stressed. Healthy university students (N=90) were randomly allocated to 1 of 3 conditions and tested during an exam-free period and again during their exam time. Mood and psychophysiological responses were assessed before and after the interventions, and again after a laboratory stressor. All interventions had restorative effects on cortisol levels (p < .001), yet walking in nature resulted in lower cortisol levels than did nature viewing (p < .05) during the exam period. Walking in nature improved mood more than watching nature scenes (p < .001) or physical exercise alone (p < .05).