Predictive validity of objective measures of physical fitness for the new onset of mental disorders in adolescents and young adults.

All eligible studies were undertaken since 2010, suggesting this is an emerging but unfinished field of research. The study design and methodological limitations indicate that the reported results should be treated with caution. However, if the meta-analytic findings are reliably replicated for new cohorts of males and females, they have implications for research into the prevention of non-communicable diseases, as our review suggests that interventions should target physical and mental health in equal measure.