Individuals are increasingly using novel fitness technologies, such as running applications (apps), to support their workouts. The literature has particularly focused on the use of fitness apps at the individual level (i.e., to improve individuals’ exercise levels), while few studies have investigated the role of fitness apps in facilitating group exercise. Consequently, there is a paucity of information on how to enhance the exercise participation of individuals in fitness apps through the use of groups (i.e., how to entice more individuals to engage in exercise). By selecting running apps as the context, we focus on the feature of running spots that facilitates members’ offline group engagement, which has received scant attention. Drawing on the perspective of psychological distance and relational cohesion theory, we propose that the feature of running spots facilitating offline group engagement can improve group participation in running. To advance this line of research, we utilized a panel dataset of 151 running groups from a prevalent running app platform over a period of 38 weeks. The aim was to empirically evaluate the effects of offline group engagement facilitation (i.e., running spots) using a combination of the difference-in-differences approach and the propensity score matching technique. Our findings suggest that running spots promote groups’ participation in running. Furthermore, the impact of running spots is magnified when the groups are smaller or located moderately close to the spots. Our study contributes to the growing body of knowledge on fitness technologies by revealing ways to support group participation and uncovering the complex impact of offline group engagement facilitation (i.e., running spots). Our study has important implications for fitness app developers by demonstrating that features facilitating offline group engagement should be prioritized to improve group participation in running.