The purpose of this study was to examine the experiences of individuals who perform long-distance running as a serious leisure activity within the framework of the Self-Determination Theory. According to the theoretical framework, the aim was to understand how participation in a serious leisure activity affects the basic psychological needs of autonomy, competence, and relatedness. In this phenomenological study, runners were observed in their own serious leisure area. The semi-structured interview technique was used in the study. Interviews were conducted with 15 women and 21 men, a total of 36 recreational long-distance runners, who participated in running groups in Ankara, Turkey. As a result of the participants’ opinions and the observations, themes were formed according to the basic concepts of autonomy, competence, and relatedness within the framework of the Self-Determination Theory. According to the opinions of participants, the effects of participation in long-distance running on the relatedness need were more prominent than other psychological needs. This study reveals that as a serious leisure activity long-distance running provides participants within a sense of success, psychological relief, and happiness by satisfying different levels of the basic psychological needs of the participants.