Fitness and Screen Time at Age 13 Relates to Academic Performance at Age 16.

Aim: Investigate the longitudinal relationship between physical activity, organised physical activity, fitness, screen time and academic performance among Swedish adolescents.

Methods: Data from 1139 adolescents at age 13, included vigorous physical activity (accelerometry), fitness (submaximal ergometer test), screen time and organised physical activity participation (self-reported) and academic performance (math and Swedish grades at ages 13 and 16 from registry). Academic performance at age 16 was categorised as A-D (higher grades or pass) or E, F (fail or at-risk of failing). Multilevel logistic regression models were used to examine the relationships while adjusting for gender, parental education, parental country of birth and academic performance at age 13.

Results: Higher fitness at age 13 was associated with increased odds of receiving A-D at age 16 (OR: 1.04 per mL, 99% CI 1.00, 1.07, p = 0.003). High screen time during weekdays was associated with reduced odds (OR: 0.40, 99% CI 0.20, 0.81, p = 0.001) compared to low screen time.

Conclusion: Academic performance at the end of compulsory school (age 16) was related to fitness and screen time 3 years earlier. These findings create a paradigm for future randomised controlled trials to explore how influencing these factors might affect academic performance.