1 | 19 Synthesis 2006). These events change a person’s educational, employment, marital and parental status, from a status that is generally more associated with adolescence (e.g., being unemployed, single, childless) to a more adult status (e.g., being employed, married, a parent) (Bell & Lee, 2005). How major life events affect sport participation may be understood by looking at changes in the availability of resources associated with each event (Hirvensalo & Lintunen, 2011; Holmes & Rahe, 1967). In the neo-Weberian tradition of looking at social action from a resource perspective (Bourdieu, 1978; Breen, 2005; Coleman, 1990; Sugden & Tomlinson, 2000; Weber, 1978), life chances – i.e., opportunities and hindrances to access scarce and valued outcomes, like sport participation – are distributed according to the resources available to an individual (Kraaykamp et al., 2013). Major life events and the associated status changes bring new roles and responsibilities, alongside a new organisation of everyday life, altering the temporal, social, physical, mental and/ or economic resources a person can draw on (Bartley et al., 1997; Heikkinen, 2010; Hirvensalo & Lintunen, 2011; Tiessen-Raaphorst et al., 2010). These changes in, for example, leisure time, social capital and support, finances, and someone’s physical or mental state, may trigger periods of socioeconomical adaptation and readjustment and lead to behavioural changes (Gropper et al., 2020; Holmes & Rahe, 1967). Therefore, major life events are expected to affect a person’s opportunities and constraints for participating in sport (Engel & Nagel, 2011; Kraaykamp et al., 2013; Lunn, 2010; Lunn et al., 2013; TiessenRaaphorst et al., 2010), and changes in a person’s sport behaviour during the life course may be interpreted as an alternation of their disposition in the field of sport for adapting to a new configuration of resources (Borgers et al., 2016b; Engel & Nagel, 2011; Pilgaard, 2013). In the empirical chapters, I develop a theoretical rationale for the impact of the life events, by applying this resource reasoning to the specific major life events and sport participation aspects under investigation, using relevant theories like time budget theory and temporal organisation theory (Southerton, 2006) and social motivation theory (Hills et al., 2000). This results in a concrete theoretical framework and expectations per chapter, helping me to guide research processes, and enabling me to embed the empirical findings within the framework for interpretation, increasing scientific thoroughness, reducing the risk of jumping to hasty conclusions, and improving the comparability of the studies. This way I advance upon earlier research, which often lacks theoretical rigour (Breuer & Wicker, 2008; Gropper et al., 2020).