Ahmad Fahruddin. 2211010025. THE INTEREST OF LONG-DISTANCE RUNNERS IN TRAIL RUNNING ACTIVITIES IN THE RTC RUNNERS COMMUNITY. Undergraduate Thesis. Tangerang: Faculty of Teacher Training and Education, Universitas Tangerang Raya, 2026. This study aimed to (1) identify the interest of long-distance runners in Trail Running activities within the RTC Runners community based on cognitive, affective, and psychomotor aspects, (2) identify the factors supporting the interest of long-distance runners in Trail Running activities within the RTC Runners community, and (3) identify the factors inhibiting the interest of long-distance runners in participating in Trail Running activities. This study employed a qualitative approach with a phenomenological design. The research data were obtained from seven members of the RTC Runners community, namely Dayat Hidayat, Alan Saputra, Marlisa Kurniaty, Zaki Asyrafi, Nur Syahban Dwi Purnomo, Oni R. Wardhani, and Fajri Ibnu Rahman. Data were collected through in-depth interviews, observation, and documentation. Data validity was ensured through source triangulation and technique triangulation. Data analysis was conducted through data reduction, data display, and conclusion drawing. The results showed that (1) the interest of long-distance runners in Trail Running activities within the RTC Runners community was categorized as good. In the cognitive aspect, participants demonstrated a good understanding of the definition, benefits, and differences between Trail Running and road running. In the affective aspect, participants expressed positive feelings such as enjoyment, challenge, satisfaction, and pride after participating in Trail Running activities. In the psychomotor aspect, participants showed active involvement through regular training, participation in Trail Running activities and Events, and a desire to continue participating in such activities in the future. (2) Supporting factors influencing participants’ interest included community support, peer support, perceived physical and psychological benefits, and positive experiences gained from participating in Trail Running activities. (3) Inhibiting factors included limited time, financial constraints, physical condition, challenging terrain, and unfavorable weather conditions. Nevertheless, these obstacles did not reduce the participants’ interest in continuing to participate in Trail Running activities. Keywords: interest, long-distance runners, Trail Running, running community, RTC Runners.