JOURNAL OF SPORTS SCIENCE & MEDICINE
Department of Public Health, University of Helsinki, Helsinki
(Online): 01 September 2003
This review is based on the following orginal publications, which will be referred to in the text as Studies I-IV:
I. Aarnio, M., Kujala, U.M. and Kaprio, J. (1997) Associations of health-related behaviors, school type and health status to physical activity patterns in 16 year old boys and girls. Scandinavian Journal of Social Medicine 25, 156-167.
II. Aarnio, M., Winter, T., Kujala, U.M. and Kaprio, J. (1997) Familial aggregation of leisure-time physical activity - a three generation study. International Journal of Sports Medicine 18, 549-556.
III. Aarnio, M., Winter, T., Peltonen, J., Kujala, U.M. and Kaprio, J. (2002) Stability of leisure-time physical activity during adolescence - a longitudinal study among 16-, 17- and 18-year-old Finnish youth. Scandinavian Journal of Medicine and Science in Sports 12, 179-185.
IV. Aarnio, M., Winter, T., Kujala, U.M. and Kaprio J. (2002) Associations of health-related behaviour, social relationships, and health status with persistent physical activity and inactivity: a study of Finnish adolescent twins. British Journal of Sports Medicine 36, 360-364.
Regular exercise has been shown to exert many positive effects on health. Sedentary behaviour often originates in childhood and many common adult chronic diseases are related to inactivity. Adolescent physical activity patterns and health habits are important subjects to study because of the known associations of physical activity with other health habits and the evidence that these associations track into adulthood.
The data for this study were gathered as a part of FinnTwin16, a longitudinal study of five consecutive birth cohorts of Finnish twins, their siblings and parents. The study material was collected by identifying twins born in 1975-1979. Questionnaires concerning leisure-time physical activity, health-related behaviours, social relationship and health status were sent to twins on their 16th and 17th birthdays, and six months after their 18th. The maximal cohort size was 4906 boys and girls, and the response rate 75.8% to 81.7%.
The results of this study reveal that persistently active adolescents smoked less than inactive ones, and usually had better health and nutritional habits, such as use of spreads and regular breakfast eating, and better self-estimated health. They attended high schools rather than vocational schools and tended to have better academic achievement. Participating in organised sport, in many different types of sport, or in power sports and ball games were also associated with persistent physical activity. Parents' and grandparents' physical activity were not associated with adolescent physical activity except in the case of very active mothers and daughters, but a co-twin's physical activity was associated.
There was a gender difference in physical activity patterns: boys were more active than girls. No gender difference was found in health related-behaviours, except that girls reported more psychosomatic symptoms such as tension, in the low physical activity categories than boys.
The known health benefits of physical activity and risk of declining activity during adolescence makes young people at this stage of life an important target group for physical activity promotion programmes. Based on this study, physically active adolescents seem to progress to a healthier and more educated life. Adolescents approaching the completion of their compulsory education and thus the end of their systematic physical education can be considered a particular risk group for inactivity.
KEY WORDS: Leisure activities, exercise, health status, food habits, smoking, life style, family health, family relations, adolescence, adolescent behavior, twins, cohort studies.