Konstabel, Kenn, juhendajaSultson, Hedvig, juhendajaOjala, HelisTartu Ülikool. Sotsiaalteaduste valdkondTartu Ülikool. Psühholoogia instituut2024-06-112024-06-112024https://hdl.handle.net/10062/99293Physical (in)activity has been cross-sectionally and longitudinally associated with mental health problems, depression and anxiety. So far, physical activity’s (PA) objective measures remain underutilized compared to subjective measures. In the current thesis, cross-sectional and longitudinal associations between objectively measured sedentary behaviour (SB), light PA (LPA), moderate to vigorous PA (MVPA), and both depressive and anxiety symptoms were investigated using the data from the younger cohort of the Estonian Children Personality Behaviour and Health Study (ECPBHS). Physical activity and mental health data were measured when participants were 18, 25, and 33 years old. Objective PA was measured by ActiGraph (first and second wave) and GENEActive (third wave) accelerometers. Associations were investigated by cross-lagged panel analysis. Associations between SB and MVPA, but not between LPA and depressive and anxiety symptoms, were found. Both SB and MVPA predicted cross-sectional and longitudinal depressive symptoms, and MVPA predicted cross-sectional anxiety symptoms. According to our findings, to keep anxiety and depressive symptoms low and prevent depression in the future, it is recommended to use interventions that decrease SB levels and increase MVPA levels. Due to inconsistent results, future studies are warranted to investigate the objectively measured PA and mental health associations both cross-sectionally and longitudinally.enAttribution-NonCommercial-NoDerivs 3.0 EstoniaCLPMobjective PAanxietydepressionCLPMobjektiivne KAärevusdepressioonmagistritöödThesis