Introduction: The relationship between the level of physical condition and academic performance has been studied for decades and this association has been corroborated in the general population of children. Aim: The aim of this work is to know the relationship between academic performance and athletic performance of triathletes aged 14-18 years old with a high level of aerobic fitness and training. Methods: To this end, the academic and sports performance of a sample of 14 triathletes with a high level of training and aerobic condition was studied. Results & discussion: The results show that there is a relationship between academic performance and athletic performance of triathlete children between 14 and 18 years of age with a high level of aerobic fitness and training. In addition, there is a strong association between linguistic academic performance and athletic performance. Conclusions: There is a relationship between academic performance and athletic performance of triathlete children between 14 and 18 years old with a high level of aerobic fitness and training. There is a strong association between linguistic academic performance and athletic performance of triathlete children between 14 and 18 years old with a high level of aerobic fitness and training.