LAUSR

OBJECTIVES Previous studies have indicated that only a small proportion of Portuguese adolescents attain sufficient levels of physical activity for health. However, it is unknown whether the levels of moderate to vigorous physical activity (MVPA) have changed over a considerable time period in this country. Therefore, the aims of the present study were to examine the 10-year trend changes in self-reported MVPA among adolescents and also investigate differences by sex and age. DESIGN AND METHOD This study compared two cross-sectional cohorts of youngsters aged 12-18 years, recruited in 2006 (N=1010; 461 boys and 549 girls) and in 2016 (N=1096; 461 boys and 635 girls), using identical procedures and instruments. The outcome variable, MVPA, was assessed by using the PACE+ screening measure. RESULTS Main results showed a considerable decline in the overall levels of physical activity between 2006 and 2016 (-10.8%), as well as a small and declining proportion of adolescents achieving the international physical activity recommendations (2006: 10.7%; 2016: 8.1%). Age and sex-specific comparisons by time periods indicated that the 13- and 14-year-old male adolescents reported lower levels of MVPA in 2016 than their counterparts in 2006, and that the MVPA decline between the subgroups of 12- and 18-year-olds was higher in girls, in both 2006 and 2016. CONCLUSIONS This study provides evidence of a secular decrease in self-reported MVPA levels among Portuguese adolescents. These results reinforce the need for interventions and policies aimed at promoting a more active lifestyle throughout adolescence.