Distinct life course leisure-time physical activity trajectories and related health behaviors: The Cardiovascular Risk in Young Finns Study

Physical activity (PA) has been suggested to play a role in the adoption of other health-enhancing behaviors. However, the evidence remains scarce. This dissertation research investigated the diverse pathways (i.e., trajectories) of leisure-time physical activity (LTPA) from childhood to middle age in the general population and the associations of these trajectories with other health-related behaviors (dietary behavior, screen and television time during leisure, binge drinking, smoking, and sleeping). The doctoral dissertation yielded four original publications (I–IV). Study I systematically reviewed the articles identifying PA trajectories and related factors. Self-reported data from the Cardiovascular Risk in Young Finns Study were used in studies II-IV. Participants (N=3553, 51% women) were aged between 9 and 18 years at baseline (1980) and between 33 and 49 years at the last follow-up (2011). Trajectories were identified with latent profile analyses (II-IV). Models were adjusted for selected covariates. The findings supported previous observations of the high prevalence and persistence of inactivity and low activity when compared to high or moderate activity in the general population (I-IV), especially in old age (I). Trajectories describing a decline in PA during childhood and adolescence were often reported whereas trajectories of increasing PA were observed in adults (I, III, IV). Men and women identified in the persistently active or increasingly active trajectories had a healthier diet (III, IV), lower smoking frequency, and fewer sleep difficulties (women only) when compared to their low-active or inactive peers (IV). Associations of screen and television viewing time with the LTPA trajectories were ambiguous (II, IV). Being persistently active or succeeding in increasing one´s LTPA level during the life course may be important, not only owing to the benefits of PA for health, but also because it may relate to the adoption of other health behaviors, in particular switching to a healthier diet. Causality should be addressed in future intervention studies with objective measurements.