[Development and validation of a physical activity assessment questionnaire for adolescents].

OBJECTIVE To develop a physical activity questionnaire aimed at Brazilian adolescents and to assess its validity and reproducibility. METHODS A total of 94 adolescents (30 males and 64 females) aged 11-16 years were included in the study, which was conducted in 2004. The questionnaire comprised 17 questions on habitual physical activity in the last 12 months (15 questions on sports and physical exercise and two on transportation physical activity), and was standardized to yield final scores for weekly and yearly activity. As a reference, we used the multistage 20-meter shuttle run test, measuring variables maximum time in minutes, maximum speed, maximum oxygen uptake and maximum heart rate. For validity analysis, we used the Spearman coefficient and age-adjusted correlation. For reproducibility analysis, we repeated evaluations after 15 days and measured the intraclass correlation coefficient. RESULTS For the weekly score, the highest correlations were obtained for maximum time for the entire sample (r=0.19), maximum speed for males (r=0.20), and both maximum oxygen uptake and maximum time for females (r=0.17). For the yearly score, the highest correlations were obtained for maximum time for the entire sample (r=0.30), maximum heart rate for males (r=0.22), and maximum time for females (r=0.23). In reproducibility analyses, correlations were 0.61 for weekly score and 0.68 for yearly score. CONCLUSIONS The questionnaire was valid and reproducible. Its use is recommended for the evaluation of physical activity in epidemiological studies with adolescents.