Objective: To examine the association between leisure time physical activity over a three year period and health related behaviour, social relationships, and health status in late adolescence as part of a nationwide longitudinal study. Methods: Five birth cohorts of adolescent twins aged 16 at baseline (n = 5028; 2311 boys and 2717 girls) participated in the study. Questionnaires on leisure time physical activity, other health related behaviour, social relationships, and health status were sent to the twins on their 16th and 17th birthdays and six months after their 18th birthday. The combined response rate to the three questionnaires was 75.8% for boys and 81.7% for girls. Those who answered in all three questionnaires that their frequency of physical activity was 4-5 times a week or more were defined as persistent exercisers, and those who exercised at most twice a month in all three were defined as persistently inactive. Logistic regression analyses were used to identify baseline variables associated with outcome measures. Results: Overall, 20.4% of boys and 13.0% of girls were persistent exercisers and 6.5% of boys and 5.3% of girls were persistently inactive. In both sexes, smoking, irregular breakfast eating, attending vocational school, and poor self perceived current health were significantly associated with persistent inactivity. Conclusions: Persistent physical inactivity in adolescents is associated with a less healthy lifestyle, worse educational progression, and poor self perceived health. Tailoring methods to promote physical activity may prove useful for influencing other health habits. Such programmes are indicated for vocational schools in particular.

Participation in physical activity during childhood and adolescence is frequently mentioned as one factor likely to promote a more active lifestyle in adulthood with its health benefits. We studied the changes in leisure-time physical activity pattern and self-reported fitness during a three-year period in adolescence and investigated whether the type of sports has an effect on stability of physical activity at leisure. A questionnaire with identical physical activity items was sent to Finnish twins on their 16th and 17th birthdays and 6 months after the 18th birthday. A total of 1338 boys and 1596 girls responded to all three questionnaires, with response rates of 73.6% and 86.5%. The proportions of very active adolescents and adolescents with very good self-reported fitness seem to be alike at each age. Among girls, 23.7% to 27.7% reported being very active (4-5 times a week) and 13.7% to 15.1% considered their physical fitness to be very good at the ages of 16, 17 and 18. Among boys, the comparable percentages were 31.5% to 35.5% and 30.6% to 34.4%. However, the longitudinal three-year follow up showed substantial changes over time among individuals from one physical activity group to another. Only 19.1% of boys and 11.2% of girls were persistent exercisers (i.e., very active on all three years) and 15.6% of boys and 5.1% of girls were persistently fit (i.e., very good self-reported fitness on all three years). Stability of leisure-time physical activity was highest among those who participated in several different types of sports. Among boys the proportion of persistent exercisers was highest for those who participated in cross-country skiing, jogging and body-building (22.0-41.5%) and among girls for those who participated in ball games (11.9-28.6%). Those who participated in organised sports were more often persistent exercisers than those who did not (odds ratio = 13.2 for boys (CI 9.4-18.7) and 8.9 for girls (CI 6.4-12.5)). Also, those who participated in organised sports were more often persistently fit (odds ratio = 7.3 for boys (CI 5.2-10.2) and 10.4 for girls (CI 6.4-16.9). Adolescents are recommended to participate in and try different types of sports, and especially for girls ball games would appear to favour long-term maintenance of leisure-time physical activity.

Studies of parental influence on children's physical activity have had different results. Parental effect on physical activity during adolescence is less studied, and three generation studies have not been carried out. The purpose of our study was to examine intra- and intergenerational associations of leisure time physical activity among family members in three generations. Due to the major changes in society during this time, we also took into consideration the socioeconomic status of the adult subjects. The material consisted of 3254 twins at the age of 16, their parents and grandparents. Twins and their parents received a questionnaire in 1991-1993, which included questions about the health and lifestyle, socioeconomic status and leisure time physical activity. The parents' questionnaire also included questions about their own parents' leisure time physical activity and socioeconomic status. Based on these questions adolescents, parents and grandparents were classified into physical activity classes. The socioeconomic classification of parents and grandparents was based on their occupation. Intragenerational physical activity patterns were significantly associated with each other. Among adolescents the strongest correlation were between monozygotic boys (0.720) and monozygotic girls (0.638). Physical activity patterns were not associated between generations, but there was a significant difference between very active and inactive mothers concerning their daughters' physical activity. Farmers had the lowest proportion of very active subjects only among the parental generation. Because physical activity patterns do not appear to be transmitted from one generation to the next, it is probable that by constant training and education we can obtain the benefits of physical activity.

Background: To evaluate medical and dental students' utilization of electronic information resources.

Sedentary behavior often begins in childhood and is associated with the development of risk factors for many chronic diseases in adulthood. Physical activity is considered important in the prevention of unfavorable changes in the risk factors. We investigated whether health-related behaviors, school type and health status are associated to physical activity among adolescents. A questionnaire was sent to all Finnish 16-year-old twins in 1991-93. A total of 3,254 twins responded. The response rate was 88%. Physical activity was classified into five categories (very active, active, moderately active, hardly active, inactive) based on self-reported frequency and intensity of physical activity. The analysis considered all subjects as individuals. Smoking was strongly associated with physical activity among girls and boys. Those who smoked regularly were less active. The type of school was also associated with physical activity. In general, those who attended comprehensive school or high school were physically more active, while those in vocational schools, particularly boys, were less active. Girls in lower physical activity groups reported more psychosomatic symptoms. Associations of self-reported health-related behaviors, school type and health status to physical activity seem to be the same among boys and girls. However, as the more active students are in comprehensive school or high school and the less active in vocational school, and physical inactivity is related to smoking and use of alcohol, health education should be tailored by school type.