Objective As one of the basic well-beings and primary needs for the survival and development of mankind, health is closely influenced by a variety of multidimensional and complex influencing factors. Leisure-time physical activity (LTPA) is a physical activity of large flexibility in such factors as activity strength, duration, location selection and others, and together with the outstanding regulation effect on the physiological and psychological aspects, has seen a continuous and gradually expanded role in daily life. It is therefore regarded as the most promising type of changeable physical activities. Urban parks as a spatial store of comprehensive health resources have been rooted in green space system. They are combined with various service resources, providing a physical environment for LTPA. However, the majority of current research on LTPA predominantly concentrates on the direct relationship between the environment and behavior. Visual and auditory cues are typically presented in a parallel manner, lacking joint modeling at the same spatiotemporal location. Emotional perception, as a crucial psychological pivot through which environmental cues influence behavior, has not undergone systematic scrutiny. This has led to difficulties in the precise implementation of relevant design strategies. In the context of park settings, visual and auditory cues frequently co-occur at the same spatiotemporal point. They may influence an individual's subjective evaluations of safety, pleasure, and vitality through emotional regulation, thereby affecting their activity intensity and inclination to remain in the area. Consequently, there is an urgent need to conduct empirical research using the framework of "audio-visual environmental elements−emotional perception−leisure physical activities".

Methods In this paper, 144 landscape nodes in Taizi River Park, Liaoyang City, Liaoning Province were classified meticulously. In terms of visual object, the image acquisition method is conducted on a sunny day, and the circumferential three pictures are shot for each landscape node. ArcGIS 10.8 software was applied to match the image with GPS spatial data. The mask2Former semantic segmentation model was applied to the image data. According to Mapillary Vistas dataset, leisure-time physical activity related image vectors were embedded to build customized model according to the research purpose. The acquired image data were analyzed by this method. Color features (color saturation, color richness, and color harmony) of obtained image were analyzed using K-means algorithm. A “human-machine duel” score sheet was used for the emotional evaluation of the environment. For the acoustics, the environmental sound cues and the source category for the audio part were noted according to the ISO/TS 12913-2 standard and the soundscape screening of the Swedish soundscape quality scale protocol. Combining above-mentioned audiovisual data with other methods including questionnaire surveys and behavioral observation data, multiple stepwise regression model and mediation effect analysis were carried out to investigating the direct and mediating relationships among environmental elements of urban park, visitors’ emotional states and leisure physical activities.

Results Through the analysis of the audio-visual environment, emotional evaluation, and behavioral observation data collected in the field, this study has yielded a series of crucial findings. Visual and auditory elements within urban parks, including the blue view ratio, sky openness, natural sounds, and light guidance, can significantly enhance visitors' positive emotional experiences (such as a sense of security, vitality, and fulfillment). This, in turn, further increases the likelihood of light-intensity and moderate-intensity LTPA. Emotional perception exerted a partial mediating effect along multiple pathways, providing quantitative evidence for the "environment−emotion−behavior" framework. Specifically, sky openness and natural sound sources influenced light LTPA through emotional perception, while spatial enclosure affected moderate LTPA. These results suggest that an open skyline and a favorable water-related environment are conducive to eliciting positive emotions and promoting gentle physical activities. Moreover, moderately enclosed green spaces significantly facilitate moderate activities by enhancing the sense of security. In contrast, no significant emotional mediation pathway was identified for high-intensity physical activities. This might be attributed to the fact that high-intensity activities are more goal-driven and performance-oriented. Environmental factors primarily act on such activities by directly influencing aspects such as safety and convenience, rather than indirectly through emotions.

Conclusion This research delved into the interrelationship of "environment−emotion−behavior" within the context of urban parks, quantitatively validating the pivotal mediating role of emotional perception in the process where the audiovisual environment influences LTPA. This has advanced the comprehension of the mechanisms through which environmental elements facilitate behaviors. On a practical level, the research findings offer significant implications for enhancing the health-promoting benefits of urban parks. Looking ahead, the analytical framework and optimization strategies established in this study can serve as a theoretical foundation and practical reference for related disciplines. They can also drive the research agenda of integrating emotional perception into environmental interventions to promote behavioral change, thereby providing a scientific underpinning for the creation of healthy cities and active spaces.