Scandinavian Journal of Public Health, 2011; 39: 704–713 ORIGINAL ARTICLE Will they stay fit and healthy? A three-year follow-up evaluation of a physical activity and health intervention in Polish youth MICHAL BRONIKOWSKI 1 & MALGORZATA BRONIKOWSKA 2 1 Department of Methodology of Teaching Physical Education, University School of Physical Education, 61-871 Poznan ´, Poland, and 2 Olympism and Ethnology of Sport, University School of Physical Education, Poznan, Poland Abstract Aims: In this paper we evaluate the sustainability of changes of involvement in physical activity. The paper examines the effectiveness of a model aiming at influencing the frequency of leisuretime physical activity, physical fitness and body constituency in youth. Methods: The baseline of this study was a randomly selected sample of 13 year olds who participated in an intervention programme carried out in three schools in Poznan in 2005–08. From a total of 199 adolescent boys a subsample of 38 individuals from the experimental group and 34 from the control group were followed for 15 months after the interventional programme finished. From 170 girls, a subsample of 33 from the experimental group and 32 girls from the control group were also randomly selected for the follow-up study. Among the variables monitored were: physical fitness, body constituency, and frequency of leisuretime physical activity. All the variables were monitored in pre-test, post-test and follow-up examinations. Results: It was established that 15 months after the end of the interventional programme boys and girls from the intervention groups maintained a higher level of leisuretime physical activity than their control group peers, and similarly in the case of selected health-related components of physical fitness. No distinctive differences were found in the case of body constituency, though, apart from muscle mass and the sum of skinfolds in girls. Conclusions: The study exposed an increase in leisuretime physical activity in time and a positive influence on selected components of health-related variables. The findings confirm the effectiveness of a multi-level intervention programme involving self-determined out-of-school physical activity planning for school-age youths, indicating the importance of personal and social context. Key Words: Fitness, lifestyle, physical activity intervention, school youth Background Physical fitness and activity both have a direct impact on health, especially in childhood and adolescents as well as in elderly people [1] and this influences the setting of some patterns of behaviours. However, since the state of health in elderly people is an outcome of the patterns of health-related behaviour and general lifestyle in earlier phases of life, it is important to initiate children in the appropriate patterns of activity at a relatively early age. In Polish youth, Cabak and Woynarowska [2] found that only 35% have met the criteria of recommended physical activity (PA), which places Poland in the mid-range of other European countries. The study of Chen et al. [3] in Japanese children shows that unfavourable lifestyles in childhood are associated with poor qual- ity of life in early adolescence, and the authors call for an organized educational approach to increasing levels of PA in youth. Regular physical activity (PA) is a protective factor against the development of diseases associated with a sedentary lifestyle and any well-designed intervention programme should help to reduce cardiovascular risk [4]. Therefore some action needs to be taken so that a greater number of individuals from that age group undertake the rec- ommended amount of regular PA of five times per week. The positive effects of improved PA in society can be achieved in various ways, for example by Correspondence: Michal Bronikowski, Department of Methodology of Teaching Physical Education, University School of Physical Education, Poznan, Zaklad Metodyki Wychowania Fizycznego, Ul. Krolowej Jadwigi 27/39, 61-695 Poznan ´, Poland. E-mail: bronikowski.michal@wp.pl (Accepted 1 August 2011) ß 2011 the Nordic Societies of Public Health DOI: 10.1177/1403494811421059