Physical activity might not be the protective factor for health risk behaviours and psychopathological symptoms in adolescents.

Aim: This study aims to examine the effect of physical activity (PA) intensity on tobacco or alcohol abuse, suicide behaviours and psychopathological symptoms in junior and senior high school students in China. Methods: A total of 5453 students from nine middle schools participated in a self-administered anonymous survey to report their frequency of moderate and vigorous PA at a normal learning week. Tobacco or alcohol use in the past 30 days, suicide behaviours during the past 12 months were asked. The Symptoms Checklist 90 was used to assess general mental problem and nine special psychopathological symptoms. The Rosenberg's Self-esteem Scale and School Life Satisfaction Rating Questionnaire for Adolescent were selected to rate the respondents' self-esteem and school life satisfaction. Results: Percentage of high-, low–moderate- and very-low-intensity PA was 22.0%, 37.0% and 41.0%, respectively. By using multivariable multinomial logistic regression, it was indicated that low–moderate-intensity PA was a protective factor of depression (odds ratio (OR) was 0.61, 95% confidence interval (CI) was 0.40–0.91) and psychotic symptoms (OR 0.54, 95% CI 0.31–0.93), while high-intensity PA was a risk factor of binge drinking (OR: 1.81, 95% CI: 1.29–2.54), suicide ideation (OR: 1.26, 95% CI: 1.04–1.54), general psychological disorders (OR: 1.43, 95% CI: 1.11–1.84), and hostile symptoms (OR: 1.46, 95% CI: 1.03–2.07). Conclusion: Different intensity PA in adolescents had different association with risk health behaviours and psychopathological symptoms. The reasons are worth further researching. [ABSTRACT FROM AUTHOR]