In this cross-sectional study, we tested the associations between teacher autonomy support, self-determined motivation for physical education (PE), physical activity habits and non-participation in physical education in a sample of adolescents. A total of 715 adolescents (of whom 371 (51.89%) were girls) participated. The ages ranged from 14 to 18 years, with mean ages of 16.00 (SD = 0.79) for girls and 15.99 (SD = 0.75) for boys. The study questionnaire consisted of demographic questions and the Learning Climate Questionnaire, Revised Perceived Locus of Causality in Physical Education Questionnaire, Behavioural Regulation in Exercise Questionnaire 2, Self-Report Habit Index for Physical Activity, Godin Leisure-Time Exercise Questionnaire, Rosenberg Self-Esteem Scale, perceived physical fitness and frequency of non-participation in PE classes. The results showed that perceived teacher autonomy support was directly positively associated with physical activity habits and negatively with non-participation in physical education classes. Autonomous motivation for PE was a mediator between perceived teacher autonomy support and physical activity habits, meaning that higher autonomous motivation was related to higher physical activity habits. Motivation for PE was also a mediator between teacher autonomy support and non-participation in PE. Higher autonomous motivation for PE was associated with less frequent non-participation in PE classes. The findings can inform PE teachers' practice by showing that supporting students' autonomy and strengthening their self-determined motivation can facilitate increased participation in PE classes and the formation of students' physical activity habits.
Keywords: adolescents; learning climate; perceived locus of causality; physical activity habits; physical education; self-determination.