26 | Chapter 1 When do young adults stop practising a sport? An event history analysis on the impact of four major life events (chapter 3) The third chapter builds on the previous one by examining the relationship between major life events and dropping out of (instead of picking up) a sport in general and in a club setting in particular. So, after investigating if major life events help or hinder “desirable” sport behaviour (i.e., starting a sport; chapter 2), I now study the role of major life events on the risk of exhibiting “undesirable” sport behaviour (i.e., stopping a sport). Additionally, I focus on the transition to adulthood, since this is, for many, a period of key individual life events in which, typically, the stability (also called “tracking”) of physical and sport activity is found to be quite low and we see a sharp decline in sport participation. The main research question is: to what extent are stopping a sport and ending a sport club membership affected by major life events among young adults? I focus on beginning to work, starting to live on one’s own, starting to cohabit or gettingmarried, and the birth of one’s first child. These life events are specifically chosen because they are commonly experienced by young adults, and they represent major transitions in the process of becoming an adult in the life domains of employment, residency, personal relationships and parenting. Building on the theoretical rationale discussed in chapter two, I employ a theoretical framework in the neo-Weberian tradition of understanding social action from a resource perspective. Based on changes in temporal and social resources associated with the occurrence of the major life events, I argue that they increase a young adult’s risk to stop practising a sport in general and to end a sport club membership in particular. To test the theoretical expectations, I again employ detailed retrospective lifecourse data from the Dutch SportersMonitor 2010, now to reconstruct the sport careers histories and occurrence of the aforementioned life events between the ages of 18 and 35. This resulted in two risk sets. The first consists of the years in which 2272 respondents were at risk of stopping sport participation, because they participated in at least one sport (regardless of the context). The second consists of the years in which 1530 respondents were at risk of ending sport club membership, because they were practising at least one sport in a club context. Event history analyses indicate that the risk to stop practising a sport increases when young adults begin to work, move out to live on their own, and start cohabiting or get married, as expected. The risk of ending a sport club membership rises when young adults start to live on their own and when they cohabit or get married. The birth of the first child increases the risks of both