30 | Chapter 1 and characterised by changes in activity level and sort of activity (Butcher et al., 2002; Lunn, 2010; Scheerder et al., 2006; Seippel, 2005). These sport careers might be affected by the occurrence of major life events, as they often mark important life transitions and represent physical, psychological, social and/or economical changes in a person’s living situation (Bartley et al., 1997; Heikkinen, 2010; Hirvensalo & Lintunen, 2011; Tiessen-Raaphorst et al., 2010). So, investigating the impact of major life events on sport careers is of great importance for making sense of differences and changes in sport participation over the life course (Haycock & Smith, 2018; Hirvensalo & Lintunen, 2011). Furthermore, this is practically relevant, as the social significance of sport has surged in recent decades (Brookes & Wiggan, 2009), and creating possibilities for safe and nearby sport participation for everyone (i.e., “sports for all”), over the life course (i.e., “lifelong sport participation”) have become a priority in governmental policies and campaigns related to sports, physical activity and health (Council of Europe, 2001; Pilgaard, 2013; Van Tuyckom, 2011; Waardenburg & Van Bottenburg, 2013). Yet, sport participation research employing a life-course perspective has generally investigated age as a determinant, which is limited by the fact that it is just a proxy variable, indicating all potential age-related influences on sport participation (Breuer & Pawlowski, 2011; Breuer & Wicker, 2009; Hovemann & Wicker, 2009). Furthermore, most research regarded cross-sectional studies focussing on differences between age groups and sometimes on people with different household compositions and employment statuses. Few studies deal with the dynamics in individual sport careers (i.e., when exactly people start, stop or change sport participation), and even less do so in relation to the occurrence of major life events. It is against this background that the overarching aim of this dissertation is to determine to what extent major life events affect the sport participation of individuals in the Netherlands. To fulfil this objective, I study the impact of multiple major life events on a range of changes in sport participation over the life course across four empirical chapters. I pay specific attention to the transition to adulthood, as sustaining sport participation during this transition seems particularly challenging (Hirvensalo & Lintunen, 2011; Malina, 2001; Telama, 2009; Vanreusel et al., 1997). Overall, the findings of the four empirical studies clearly show that, in the Netherlands, sport participation is significantly affected by experiencing major life events. In my three quantitative studies, I find that different major