Querzoli, Adele2024-07-122024-07-122022https://hdl.handle.net/2440/141591This item is only available electronically.Few adolescents currently meet the recommendations for physical activity (PA) despite evidence supporting its wide-ranging benefits including the mitigation of chronic mental health conditions. This study aimed to examine the relationship between PA and mental health in a large sample of Australian adolescents, and to assess the impact of age, gender and socioeconomic status on this relationship. 28,424 high school students (Mage = 14.8, SD = 1.5; 39.3% male, 58.6% female, 2.0% other) responded to an online survey assessing demographics, lifestyle activities (including PA), symptoms of depression and anxiety, general life satisfaction, hope and avoidance coping. The following hypotheses were tested: (1) higher frequency of PA is predictive of better mental health outcomes for adolescents, (2) a lower frequency of PA in females and those who identify as non-binary is predictive of poorer mental health outcomes, (3) PA declines as a function of age across adolescence and this reduction is predictive of poorer mental health outcomes amongst older adolescents, (4) PA is reduced with lower SES and this reduction is predictive of poorer mental health outcomes. Results revealed that more frequent PA predicts better mental health outcomes for adolescents. Adolescents of female and non-binary gender engaged in less frequent PA and experienced poorer mental health and wellbeing compared to males. Frequency of PA declined with age and older adolescents reported poorer mental health, and frequency of PA was reduced in adolescents of lower SES. There was a negative moderating impact of SES and female gender on the relationship between PA and mental health. Findings from this study will determine the demographic profiles of adolescents whose wellbeing can be most improved by higher PA engagement and inform targeted implementation of school-based interventions. Keywords: physical activity, adolescents, mental health, wellbeing, gender, non-binary, age, socioeconomic statusHonours; PsychologyThesis