Atherosclerosis precursors in Finnish children and adolescents. X. Leisure-time physical activity.

As part of the more extensive project concerned with atherosclerosis precursors in Finnish children, this article aims at describing the method developed for epidemiological estimation of habitual physical activity, discussing the reliability and validity of the method and reporting the results of the application of this strategy in the measurement of habitual physical activity among 3 to 18-year-old Finnish boys and girls. The questionnaire for the measurement of physical activity was addressed to the parents of 3- and 6-year-old subjects (younger group) and to the subjects themselves in 9- to 18-year-olds (older group). Using four variables in the younger group and nine variables in the older group, sum indices of physical activity were made. Internal consistency coefficients (Kuder--Richardson) varied in the younger group from .57 to .63 and in the older group from .56 to .79. Most Finnish children and adolescents were physically active during their leisure-time. For comparison of passive and active children, screening for passive ones was difficult. Differences between East and West Finland associated with many risk factors, were not detected in the physical activity patterns of children and adolescents. On the other hand, the physical activity pattern was significantly determined by the local environment. In sparsely populated areas, young people were more inactive than in densely populated areas.