2 | 57 A new life stage, a new sport activity? Measurements Our first dependent variable was starting a sport. Respondents were shown an illustrated guide sheet and asked which sports they had participated in regularly (at least once every 14 days) and intensively once in a while (at least four days per year for a large part of the day), during the past twelve months and earlier in their lives.1 Then the respondents were asked to indicate the age at which they started that sport. Respondents could provide a maximum of five starting ages. Based on these life-course data, we created a variable in which the value of “1” was assigned if a respondent had started a sport in a given year. This also applied to the 560 person-year combinations (0.8%) in which respondents started more than one sport. Respondents could therefore start multiple sports in the same year. In all other years the respondents were assigned the value of “0”. Our second dependent variable was starting a competitive club sport. The Sporters Monitor 2010 distinguished between competitive club sport (club sports that include participation in competitions), recreational club sport (club sports without participation in competitions), other formal organisational forms (like commercial fitness centres and community centres) and informal (non-)organisational forms (such as practising sport alone and with friends or family). Based on this information, we assigned a value of “4” to the years in which a respondent started a sport in a competitive club setting. We assigned a value of “3”, “2” and “1”to the years in which a respondent started a sport in a recreational club setting, some other formal setting and on an informal basis, respectively. In the years in which no sport was started, we gave the respondents a value of “0”. In the 302 person-year combinations (0.4%) in which respondents started two or more sports in different organisational forms, we elected to assign the value for the most intensive organisational form; that is, the activity that presumably took up the most (leisure) time and produced the most new social contacts. The Sporters Monitor 2010 used retrospective questions to chart the six major life events, specifically: starting a paid job, moving out to live on one’s own, starting to cohabit or getting married, birth of one’s first child, children leaving the parental home and retirement. For each life event, we gave respondents a value of “1” in the year in which they experienced the event. However, people may exhibit particular behaviour ahead of time, in the knowledge that they are on the verge of making a life transition. For this reason, we also assigned respondents