Background: The beneficial effects of physical activity (PA) for both physical and mental well-being are well established. Given that adolescence presents a critical developmental period during which lifelong patterns of PA become established, the exploration of the longitudinal impact of adolescent psychopathology on adult PA status is of interest.

Objectives: To explore the longitudinal association between adolescent psychopathology at age 14 years and subsequent PA engagement at age 21 years.

Methods: We analysed prospective data from 3663 young adults who participated in the Mater-University of Queensland Study of Pregnancy. Psychopathology was measured using the Youth Self-Report (YSR) at age 14 years. Participants’ engagement in three types of PA (vigorous exercise, moderate exercise and walking) at age 21 years was dichotomized into either none or any. For our main analysis, we examined the association between the YSR score and subsequent PA engagement using logistic regression. We also conducted sensitivity analyses of longitudinal associations between the YSR internalizing and externalizing symptoms score at age 14 years and PA engagement at age 21 years.

Findings: We found no longitudinal association between the total YSR score at age 14 years and PA engagement at age 21 years. In addition, there was no longitudinal association between the YSR internalizing or externalizing symptoms and PA engagement.

Conclusions: Our findings suggest that there is no longitudinal association between adolescent psychopathology and PA in young adulthood.