STABILITY OF HABITUAL PHYSICAL-ACTIVITY AND SPORT PARTICIPATION - A LONGITUDINAL TRACKING STUDY

Although one of the most important aims of physical education and publ ic sport policy is to encourage life-long habitual physical activity, very little is known of the stability or tracking of physical activity . As a part of a larger research project called Cardiovascular Risks i n Young Finns, the purpose of the study reported here was to investiga te the stability (tracking) of leisure-time physical activity and spor t participation at intervals of 3, 6, 9 and 12 years from age 9 to 30. The subjects, chosen by stratified random sample, represent five geog raphical areas of the country and eight gender-age cohorts (9, 12, 15 and 18 years old in 1980). Physical activity and sport participation w ere measured using a short questionnaire. Tracking was analysed by Spe arman's rank order correlations and by simplex model. The tracking cor relations within a 3-year interval of all individual variables were si gnificant but rather low. The tracking correlations of the sum index o f physical activity comprising five variables varied from 0.50 to 0.80 among boys and from 0.40 to 0.61 among girls. Simplex models that fit ted the data very well showed higher stability coefficients than rank order correlations. With one exception the correlations of physical ac tivity index within the 12-year interval were significant but low.