LAUSR

Effective ways to reduce sedentary behaviour in adolescents are needed to mitigate the risk of chronic disease and poor mental health. Organised sport participation is the most practiced physical activity during adolescence. However, the influence sport participation has on sedentary behaviours remains unclear. This study investigated the associations between sport participation, total and domain-specific sedentary behaviour and physical activity during the transition from secondary school to university. A 3-year longitudinal survey followed Spanish secondary school students ( n  = 113) to their first year of university. Generalized linear models, adjusted by gender and year, assessed the relationships between sport participation, total and domain-specific sedentary behaviour and physical activity. Compared with non-sport participants, teenagers who played individual sports from baseline during secondary school spent significantly less total time sitting (− 110.5 min/day at weekends), watching television (− 18.7 min/day at weekends) or using the computer for leisure (− 37.4 min/day weekdays). Those who played team sports from baseline at secondary school spent less time sitting (− 126.4 min/day at weekends) or socialising (− 37 min/day at weekends) Conclusion : From secondary school to university , sport participation–based interventions might be an effective strategy to reduce sitting time spent on some domain-specific behaviours. Promoting sports could reduce the rise of sedentary behaviour during adolescence, a stage where sedentary behaviour evolves. What is Known: • Sitting too much and for too long is an important risk factor during adolescence. • Replacing adolescent’s sedentary time with moderate-to-vigorous physical activity has been associated with a better quality of life. What is New: • Playing sport is associated with spending less time in total SB on the transition from high school to college. • Not all SB domains are linked to sport participation with associations differing from whether participants played individual or team sports .