Dose-response relationship between green walking distance and pedestrians’ restorative outcomes: A pilot study with microclimate measurements

• The empirically observed 2 km green walks showed optimal restorative outcomes. • Continuous 2 km green walking was associated with stronger restorative effects. • Green walking distance and restorative outcomes showed a dose–response pattern. • Adverse walking environments were associated with reduced restorative outcomes. Walking is a widely accessible form of physical activity for urban residents, offering substantial benefits for both physical and mental health. While walking in green spaces has been shown to reduce stress and improve physiological markers, the dose–response relationship between walking distance and restorative outcomes remains unclear, as does the influence of complex environmental exposures on these benefits. A controlled walking experiment was conducted in a green space in autumn with 36 participants. Each completed two randomized walks (2 or 2.5 km) with a one-week washout. Subjective measures were collected before and after stress induction, at midpoint, and post-walk. Electrodermal activity was continuously recorded. Environmental factors—temperature, humidity, radiation, noise, and pollutants (NO₂, CO, PM 2.5 )—were monitored using a mobile station, and the universal thermal climate index was calculated. Wilcoxon test results showed that, among the distances tested, continuous walking for 2 km was associated with the greatest improvements in tonic arousal, acute electrodermal reactivity, and subjective psychological restoration. Shorter walks (1–1.5 km) and longer walks (2.5 km) yielded relatively smaller outcomes, suggesting a preliminary threshold. Linear mixed models and geographically weighted regression analyses indicated that uncomfortable environmental conditions acted as potential confounders and modulated restorative outcomes during walking, with air pollution, thermal conditions, and sensory satisfaction exerting measurable effects on electrodermal activity. The observed 2 km distance may serve as a tentative spatial reference for urban walking environment design, highlighting the importance of integrating microclimatic comfort, air quality, and aesthetic appeal to support restorative benefits for pedestrians.