Investigating the Effects of Exercise, Physical Fitness and Activity, on Cognitive Function and Academic Performance in Adolescent Schoolboys: A Three-Pronged Approach

Abstract

Exercise has been postulated to illicit cognitive improvements across the lifespan, with adolescence being an opportune phase to examine these effects due to the brain’s plasticity during this period. Although there have been general consensus amongst researchers supporting a positive association between physical activity and cognition, literature in the adolescent population have been found to be lacking in both quality and quantity. This thesis aims to fully investigate the exercise-induced cognitive enhancement relationship in adolescents as well as its possible impacts on academic performance through a systematic review of current literature, a cross-sectional study, randomised-controlled trial and an acute-dose response study. Results from the systematic review indicated that the use of non-validated cognitive and academic assessments as well as the poor reporting of exercise intensity and dose, contributed to the limited and low-quality literature. As such a strong focus on validated cognitive and academic measures as well as clear quantification of exercise prescription were used in the subsequent study designs. A key finding of this thesis was that contrary to literature, fitter boys with healthy body composition were found to have poorer cognitive function (CF) and academic performance (AP) compared to their less fit and overweight/obese counterparts. Although the eight-week body intervention protocol significantly improved cardiorespiratory fitness and body mass in adolescent schoolboys, no significant improvement in cognition or academic performance were observed. Similarly, no significant improvements were observed in CF or AP after single bouts of acute exercise types (aerobic, resistance and stretching). In conclusion, this thesis highlights novel trends in a specific population (Singaporean adolescent schoolboys) with valuable insights on adolescent-specific exercise, cognition and academic testing protocols that can be useful in future studies.