Abstract
Objective: To evidence the existence of a positive relationship among physical activity, sleep quality and academic performance in high school students of a private school at Belo Horizonte. Methods: It’s a descriptive observational study, carried out with 33 adolescents aged 15-17 years. Questionnaires related to sleep quality (Epworth Sleepiness Scale), frequency / intensity of physical activities (International Physical Activity Questionnaire) and an identification questionnaire produced by the authors were applied. This results was compared to students grades through Pearson's Correlation Analysis. Results: It was not possible to establish relationships with statistical significance in the study. Even if the research did not succeed to show direct relacions about the variables, there is so many studies that proves and supports the hypothesis that exist a strong association about them. Conclusion: The results of the present study don't confirm the literature conclusions of the relationship among motor activity, sleep and academic performance. We believe that this fact is due a limited sample size of our study.