Purpose: The purpose of this paper is to acquire improved comprehension of the motivational factors and the various constraints associated with individuals' participation in mass running events. Design/methodology/approach: A quantitative method was used for the purpose of this research, and 1.357 questionnaires were completed. This study proposed two broad hypotheses: intrapersonal constraints influence motivation factors (amotivation, intrinsic and extrinsic motivation); and motivation factors influence the intention to continuous participation. Findings: Both broad hypotheses were supported by the evidence while the lack of knowledge, interest, confidence and feelings of tiresomeness were found to contribute more to explaining motivation. All three motivational factors had a significant influence on intention. Research limitations/implications: The empirical evidence for this study came from runners only. The special attributes of running may have influenced the explored relationships in a way that may not be directly applicable to other activities. Further research in various activities is necessary before such findings are generalized. Originality/value: The aim of this paper is to provide empirical evidence of the relationships between the motivational factors and the various constraints associated with individuals' participation in mass sporting and physical activity events. This research focused on developing a model to explain relationships among constraints, motivators and participation, and empirically test the proposed model within the marathon running participants context.