P-30: Fysisk aktivitet og psykisk helse blant ungdom i Noreg; ei longitudinell studie

Physical activity and sedentary behaviour may relate differently to diverse indicators of mental health and differ between adolescent boys and girls.

Background: Recent data suggest that the mental health (MH) of many adolescents is less than optimal in Norway as elsewhere. Physical activity (PA) has been proposed as a possible modifiable factor that could influence MH in a positive way. Previous studies have mainly used a cross-sectional design to explore these associations and used a single measure of MH.

Purpose: To explore whether changes in objectively assessed volume (total PA) and intensity (moderate to vigorous physical activity (MVPA)) of PA and sedentary behaviour (SED) were associated with MH problems and mental wellbeing among adolescents.
Methods: Longitudinal data were collected in three waves between 2016 and 2018. Baseline participation comprised 599 adolescents (54.4% girls; mean age 13.3 years). Total PA, MVPA and SED were measured by ActiGraph GT3X+/BT. MH problems were measured by the strengths and diffi¬culties questionnaire and mental wellbeing by the Warwick–Edinburgh mental wellbeing scale. Linear regression analyses were used to model the associations between changes in PA or SED and MH.

Results: The results showed no evidence for changes in PA or SED being associated with changes in MH problems (P>0.05). For mental wellbeing, a positive relation- ship with change in PA volume was evident for girls (P<0.05). Among boys, a positive relationship between change in SED and mental wellbeing was found (P<0.05) implying that an increase in SED was associated with a higher score on mental wellbeing.

Conclusions: Our data show no clear evidence for any associations between PA or SED and MH problems among apparently healthy adolescent boys and girls. The relationships between PA or SED and mental wellbeing were less clear and differed between boys and girls.