1 | 31 Synthesis life events relate to numerous differences and changes in sport participation over the life course. The impact of major life events that mark the transition to adulthood is mostly detrimental to sustaining sport participation. The impact of the two major life events that happen later in life seem to be in favour of sustaining sport participation, but this is only investigated in the first study regarding starting a sport. See Table 1.3 for a complete overview of the findings of my quantitative studies. My fourth study, employing a qualitative, narrative approach, underlines the quantitative findings regarding the impact of major life events on sport participation during the transition to adulthood and illuminates the mechanisms underlying the effects. I find that becoming and being a student, professional, partner and parent confronts people with new, more adult roles, responsibilities and activities. As a result, they perceived changes in temporal, social, physical, mental and/or economic resources, and experienced new opportunities and constraints for sport participation. Therefore, people re-evaluated their priorities and reconsidered whether or not and how to integrate practising sport in their new life situation as a student, professional, partner and/or parent. In general, participating in sport was deprioritised and more challenging after experiencing the life events. However, there is diversity in the choices that peoplemake regarding (changing) their sport participation during the transition to adulthood, whereby the narratives teach us that the choices largely depended on people’s willingness to structurally incorporate sport activities in their new life situations, and on if they saw a way to do so. This in line with Gropper et al. (2020), who state that similar life events do not necessarily have similar impacts on physical activity (including sport participation) across individuals. It also supports the conceptualisation of major life events from a lifespan developmental perspective. From this viewpoint, major life events are seen as disruptions in the life course, focussing on the adaptive dynamics following the events. It considers that the realistic impact of life events is not just determined by the event itself, but to a great extent by the individuals’ interpretation and appraisal of the events (John et al., 2019). See Table 5.1 (section 5.4.1) for a complete overview of the findings of my qualitative narrative study. Taken together, the findings of my studies underscore that major life events are “game changers” and enhance our understanding of when, why, and how people continue or change, sport participation, especially during the transition to adulthood.