RESUMEN
Objective: To determine the practice of physical activity on the part of adolescents from public schools in the city of Picos, Piauí. Methods: A descriptive study involving a sample of 145 adolescents of both genders aged 12 to 18 years. Data collection occurred from August to December 2010, using a specifically designed form. Results: Among the participants, 62.8% were female with average age of 14.8 years (± 3.19). It was observed that 49.7% of the participants were classified as physically inactive. Of these, 86.1% were female (p = 0.000), 58.3% were aged between 12 and 14 years, 8.3% had a high body mass index, 9.7% had altered glucose and 45.8% had high blood pressure. Discussion: Female and younger adolescents are more sedentary. This result is similar to the results of other studies on the same subject. Conclusion: The regular practice of physical activity offers many health benefits and can contribute to the prevention of chronic non-communicable diseases.