Objectives: To identify typologies of activity-related behaviours in childhood and adolescence and to explore transitions between the identified typologies. Additionally, we aimed to identify demographic indicators associated with the transitions and typology membership. Design: Prospective cohort study Setting: Czech Republic Participants: Individuals involved in the Czech part of the European Longitudinal Study of Pregnancy and Childhood (ELSPAC-CZ) study, aged 11 to 18 years. The study involved more than 563 individuals of which 380 provided complete data the analysis. Primary outcome measures: Time spent outdoors, participation in organised physical activity (PA) and sport activities, time watching television and using personal computer, and total sleep duration. Latent variables defined by the Latent Transition Analysis. Results: Four typologies of activity-related behaviours were identified and labelled to reflect their behavioural profiles: 1) Actives (high outdoor time and organised PA and sport participation, low screen time, optimal sleep duration), 2) Active screeners (median outdoor time, high organised PA and sport participation, high screen time, optimal sleep duration), 3) Poor sleepers (average outdoor time and organised PA and sport participation, low screen time, not meeting sleep guidelines), and 4) Averages (average duration of all behaviours and optimal sleep duration). A major shift in typology membership from 11 to 18 years was observed with a decreasing proportion of individuals in typologies characterised by a high proportion of outdoor time and participation in organised PA and sport activities (i.e. Actives; Active screeners). A high proportion of individuals also transitioned to the typology with poor sleeping habits (i.e. Poor sleepers). Sex and maternal education were associated with the typology membership and transition probabilities (p < 0.05). Conclusions: Our findings highlight the importance of implementing lifestyle interventions in childhood to prevent possible sleep disorders and low physical activity later in life.