Problem: physical activity stimulates cognitive development, helps prevent disease and improves health, so it should contribute to improving the academic performance of high school students. Objective: to describe the relationship between the level of physical activity and the academic performance of a sample of high school students. Method: descriptive-correlational study, in a sample of 100 students from an educational institution in Tunja-Colombia, to whom the short version IPAQ questionnaire was applied. Descriptive statistics were used to analyze the data, applying the chi-square test and their p-value. Results: these present controversies, because students, in general, have high levels of physical activity, but there is no significant relationship with academic performance; in both sexes there is low performance in mathematics, being lower in men. Conclusion: it is necessary to implement strategies so that the practice of physical activity contributes to the cognitive development of the students.