Urban green space exposure reduces subjective stress and physiological arousal

Stress is a major risk factor for mental disorders, and urban living is a key environmental contributor. Nature exposure may promote stress recovery and mental health, but how physiological arousal and subjective stress change across green versus gray space during naturalistic urban mobility is poorly understood. This preregistered study (https://doi.org/10.17605/OSF.IO/HF4RW) employed geolocation-based ambulatory assessment to examine psychophysiological arousal and subjective stress during transitions between urban green and gray environments. Thirty-six healthy urban residents completed a counterbalanced circular walking route in Cologne, Germany, with continuous GPS, cardiovascular, and electrodermal recording alongside ecological momentary assessment of subjective stress, affect, and exertion. Green compared to gray spaces were associated with lower subjective stress and higher affective well-being, with cardiac indices reflecting reduced autonomic arousal during green space exposure. Autonomic changes surrounding environmental transitions persisted beyond the immediate transition window, suggesting that physiological benefits of green space exposure extend into subsequent gray environments. These findings underscore the public health potential of urban green infrastructure for preventing stress-related mental health conditions.