We investigated changes in cardiorespiratory performance, BMI and leisure-time physical activity among Finnish adolescents from 2003 to 2010. In addition, we compared cardiorespiratory performance levels between normal weight and overweight adolescents, grouped according to their physical activity. Participants were a national representative samples of 15-16-year-old adolescents in their final (ninth) year of comprehensive school in 2003 (n = 2258) and in 2010 (n = 1301). They performed an endurance shuttle run test and reported their height and weight and leisure time physical activity on a questionnaire. Results showed no significant secular changes in cardiorespiratory performance from 2003 to 2010. The mean BMI increased in boys. Leisure-time physical activity increased among normal weight girls. Adolescents of normal weight had better cardiorespiratory performance than those classified as overweight at both assessment points. BMI-adjusted physical activity was a significant determinant for cardiorespiratory performance among overweight adolescents, and very active overweight adolescents had similar cardiorespiratory performance levels as moderately active adolescents of normal weight. The results of the present study support the idea that the physical activity has the great importance for the cardiorespiratory performance in adolescents. Overweight adolescents, in particular, benefit from higher levels of physical activity.
Keywords: adolescent; cardiorespiratory fitness; overweight; physical activity.