Associations between type and timing of sedentary behaviour and affect in adolescents: An ecological momentary assessment study

There is limited evidence on the associations between type and timing of different sedentary behaviour with affect in adolescents. This study aimed to investigate within-person associations between different types of sedentary behaviour with core affect among a sample of Australian adolescents and explore if the association differs across different times of the day. Using ecological momentary assessment, 119 participants (Mage = 14.7 years, 54% male) self-reported engagement in different types of sedentary behaviour, as well as providing information on their affective states multiple times each day, over a four-day period. Data were analysed using multi-level and time-varying effects models. Playing video games and having a meal on the weekend was favourably associated with valence and tense arousal. Watching TV or a movie on the weekend was associated with lower tense arousal but also lower energetic arousal. Using social media and reading or doing homework on the weekend were also negatively associated with energetic arousal. Reading or doing homework and using social media on a weekday afternoon were inversely associated with valence. Playing video games using social media and reading or doing homework were inversely associated with energetic arousal on weekdays. Results from the time-varying effects models demonstrated that the magnitude of these effects may differ depending upon the time of the day that the sedentary behaviour occurs. The type, and to a lesser extent, the timing of sedentary behaviours are differently associated with affect in adolescents. These results may provide unique insights into why some types of sedentary behaviours are related to worse mental health and wellbeing and others are not.