Abstract: This study aims to explore the mechanism through which media exposure influences college students' fitness-shaping behavioral intentions, using the health action process approach (HAPA) and the technology acceptance model (TAM) as theoretical frameworks. An experimental method was used to conduct an empirical analysis of the psychological reactions and behavioral intentions of college students exposed to fitness-related short video content. The results show that there exists a positive relationship between media exposure and fitness-shaping behavioral intentions, and this relationship is clearly explained through the mediating roles of self-efficacy and perceived usefulness. Furthermore, video categories act as a moderator between media exposure, perceived usefulness, and fitness-shaping behavioral intentions, with experience-sharing videos being particularly effective in enhancing these outcomes. Based on these findings, it is recommended that fitness-related media content creation should give more consideration to enhancing users' self-efficacy and perceived usefulness. In the selection and design of video content, attention should be paid to the category of videos for experience sharing to promote the formation of fitness-shaping behavioral intentions more effectively.