| The purpose of this dissertation was to gain a better understanding of the motivational processes underlying lifelong involvement in sport. Accordingly, five sequential studies, which were grounded in the three empirically based social-cognitive models of motivation including the self-determination theory (Deci & Ryan, 1985; 2002), the achievement goal theory (Duda 2001; Nicholls, 1984), and the sport commitment model (Scanlan, Carpenter, Schmidt, Simmons, & Keeler, 1993; Scanlan et al., 2003), were conducted with Masters athletes from North America who participated in various track and field and swimming events. The results of Manuscript 1 and Manuscript 2 indicated that Masters athletes have multiple motives for sport but that intrinsic motivation to experience stimulation and integrated regulation, along with task goal orientation are most important. It was also found that motivational orientation of Masters athletes differs as a function of age, gender, and sport type. Task goal orientation was found to be positively related to all self-determined types of motivation, whereas ego goal orientation was positively related to introjected regulation, external regulation, and intrinsic motivation to experience stimulation. Masters athletes have motivational lapses, but they manage to overcome them by using various strategies including goal setting, imagery, and group training. The results of Manuscript 3 indicated that, when assessed over a one-year period, MAs' introjected regulation and amotivation for sport were most stable of the motivational types and that task goal orientation was more stable than ego goal orientation. Manuscript 4 found that Masters athletes' functional commitment was best predicted by sport enjoyment, personal investment, involvement opportunities, and lack of involvement alternatives. On the other hand, Masters athletes' obligatory commitment was predicted by sport enjoyment, social constraints, and lack of social support. Manuscript 4 also found that the determinants of sport commitment differed as a function of Masters athletes' stage within a 5-year age-category. It was found that functional commitment was predicted by involvement opportunities for relatively younger Masters athletes (those who were in their first or second year of any 5-year age category) and by sport enjoyment and personal investment for relatively older Masters athletes (who were in their fourth or fifth year of any 5-year age category). Also, obligatory commitment was predicted by social constraints and lack of social support for relatively younger Masters athletes; and by social constraints and sport enjoyment for relatively older Masters athletes. Finally, the results of Manuscript 5 provided preliminary evidence that relative age advantages exist in the older competitive sporting context. Specifically, it was found that the probability of setting a World/National record increased if Masters athletes were in the first year, and decreased if they were in the third, fourth, or fifth year of any 5-year age category. Furthermore, the likelihood of participating in the National championships increased if Masters athletes were in the first or second year, and decreased if they were in the fourth or fifth year of an age category. Overall, the results of this dissertation provide a number of insights about effective and appropriate motivational strategies for athletes and individuals of different ages and indicate that self-determination theory (Deci & Ryan, 1985; 2002), achievement goal theory (Duda 2001; Nicholls, 1984), and the sport commitment model (Scanlan et al., 1993; Scanlan et al., 2003) will offer unique insights and help explain motivated behaviour of athletes across the lifespan. |
