This exploratory study contributes with in-depth insights into the user acceptance of real-life personalized coaching in social fitness smartphone apps. We have defined a set of novel coaching concepts, where a dyad with strong social ties perform real-life exercises, set and track the progress of shared fitness goals. To gain a user-centred context, we have adopted a mixed-methods design and conducted a twofold experiment. First, we have participated in survey where 1530 participants shared their views on the proposed coaching concepts. Second, we have developed a prototype social fitness app and have conducted a small pilot study to learn from the participants’ first-hand experience. Our findings highlight a number of approaches for enhancing coaching-based social fitness apps. We identify target groups that clearly show interest towards the presented coaching concepts. We report on user preferences towards taking a particular user role. We discuss the user experiences with the pilot app, and we pinpoint set of user barriers for using apps based on personalized coaching.