ABSTRACT
BACKGROUND: This study examines whether the adolescents' current levels of physical activity are increased by their physicians' advice provided in the office, in accordance with the American Medical Association recommendation. METHODS: The first adolescent (12-21 years old) of whichever age and gender, passing through six family physicians' offices during a 6-month period was assigned to the intervention group, and the second adolescent of the same age and gender was assigned to the control group. Each patient was classified as active, partially active, and inactive, according to how they answered the questions about their physical activity levels, and patients in the intervention group were then provided with reinforcement, increase, or initiation counseling, respectively. Identical procedures were repeated at the 6- and 12-month office visits. Changes in prevalence of activity, as well as, duration, frequency, and intensity of exercise and/or sports were verified at each visit. RESULTS: Of the 87.5% of the original sample that completed the survey, 6- and 12-month data were available for 70.1%. Among the 392 adolescents that finished the study, those provided with counseling had 41.5% more active adolescents, as well as 26.8%, 38.0% and 26.2% higher duration, frequency and intensity, respectively, than the control group. CONCLUSIONS: The proportion of active adolescents, as well as, the duration, frequency and intensity of leisure time exercise and/or sports are increased by physician advice.