Introducing nature at the work floor: A nature-based intervention to reduce stress and improve cognitive performance.

BACKGROUND Although a growing body of research has shown that exposure to nature has restorative effects on human health, the potential beneficial effects of nature-based interventions in the working environment are still underexplored. METHODS We performed a randomized controlled study with a nature-based program during working hours. We enrolled employees, randomized the participants into two groups being an intervention and a control group. Twice a week for three consecutive weeks, the intervention group participated in nature-based activities for 2 h. The primary outcomes were cognitive performance, burnout assessment, salivary cortisol levels, and continuous stress levels. We performed intervention-response analyses using mixed-effects models that included random effects for each participant across the different examinations. RESULTS Compared to the control group (n = 20), the intervention group (n = 25) participating in the nature-based program had a lower Burnout Assessment Tool score (-14.9% CI-16.2 to -14.3, difference; p < 0.001), lower salivary cortisol levels (-29.3% CI-34.7 to -25.3; p < 0.001) and higher visual information processing speed (7.4% CI6.9-8.0; p < 0.001). Selective attention of the participants that participated in the nature-based program improved during the interventions (-10.6 CI-19.6 to -6.9, p = 0.045), compared to the controls. CONCLUSIONS This study provides novel evidence that exposure to nature during work hours reduces stress and improves cognitive performance. The trial is registered with ClinicalTrials.gov, number: NCT04111796.