Leisure-Time Physical Activity in Relation to the Stages of Changes and Achievement Goals in Adolescents: Comparative Study of Students in Spain, Costa Rica, and Mexico Fernández Baños, Raúl Ruiz-Juan, Francisco Baena Extremera, Antonio García Montes, María Elena Ortiz Camacho, María del Mar Physical education Goals orientations Stage of change The aim of this study was to analyze the relationship between levels of leisure-time sports and physical activity and the stages of change in high school students with goal orientations. Methods: The sample was conformed of 2168 students randomly selected to participate in a longitudinal study in Costa Rica (423), Mexico (408), and Spain (1337), with 1052 being boys, 1037 girls, and 79 who did not specify sex, aged between 11 and 16 years old (M = 12.49, SD = 0.81). We used a questionnaire to ask students about their leisure-time sports and physical activity, about stages of change and to measure achievement goals. Results: The results show that students are more active in Costa Rica, most of them being in a stage of active change. Conclusions: We found significant differences in achievement goals in all three countries, which shows that students in active stages have higher values than those in the inactive stage. 2019-03-26T17:41:11Z 2019-03-26T17:41:11Z 2018-07-23 journal article Fernández Baños, R. [et al.]. Leisure-Time Physical Activity in Relation to the Stages of Changes and Achievement Goals in Adolescents: Comparative Study of Students in Spain, Costa Rica, and Mexico. Sustainability 2018, 10, 2581. 2071-1050 http://hdl.handle.net/10481/55176 eng http://creativecommons.org/licenses/by/3.0/es/ open access Atribución 3.0 España MDPI