Typologies of adolescent activity related health behaviours.

OBJECTIVES: To identify typologies of activity-related behaviours and demographic characteristics of these typologies among Australian adolescents. DESIGN: Cross-sectional study of 473 Secondary School students (41.4% boys, mean age 14.95±1.61 years) conducted in 2014-15. METHODS: Active travel to school, sport participation, leisure-time sedentary and demographic variables were self-reported in a survey. Duration of sedentary time and moderate-to-vigorous physical activity (mins/day) were accelerometer-derived. Latent class analysis (LCA) was conducted to identify typologies of activity-related health behaviours. One-way ANOVAs and chi-square tests were used to explore differences by demographic characteristics. RESULTS: Three typologies were identified: (1) "Physically inactive, highly sedentary" (44%); (2) "Moderately active, high screen-time" (42%); and (3) "Highly active, low sedentary" (14%). Differences between typologies were evident for age, sex, body mass index (BMI), cultural identity, employment status and socioeconomic position (SEP). Those in typology 3 (optimal behaviour pattern) tended to be younger, of higher SEP and lower BMI. CONCLUSIONS: This study found that older adolescents have less active, more sedentary profiles than younger adolescents. The findings support the need for targeted interventions to improve adolescent activity-related behaviour engagement.