Effect of exercise on inhibitory control is dose-dependent for adolescents

Adolescence is an important stage for brain maturation. To investigate the effect of different exercise doses on inhibitory control in adolescents aged 12 to 14-year old, an after-school exercise program was offered 5 days per week for 12 weeks during a school semester. Thirsty-four adolescents (17 boys) from the first six classes were randomly divided into low-dose exercise group (LE group, one 30-min aerobic exercise bout per day, n = 16) and high-dose exercise group (HE group, two 30-min aerobic exercise bouts per day, n = 18), while 23 adolescents (10 boys) in the control group (CON, zero 30-min exercise bout, n = 23) were from the last two classes. All the participants in different classes received the same physical education with the same contents, duration, and intensity at class. All the participants completed flanker tests and cardiorespiratory tests before and after exercise intervention. The HE group showed more significant improvements on inhibitory control and (VO2peak)-V-center dot than CON (p < 0.05). Changes in physical activity (PA) were significantly correlated with changes in interference scores (Spearman rho =-0.30, p < 0.05), (VO2peak)-V-center dot (Spearman rho = 0.31, p < 0.05), and BF percentage (Spearman rho =-0.32, p < 0.05). This study demonstrated that effect of exercise on inhibitory control in adolescents is dose-dependent, which highlights the need to focus on the exercise dose in daily life for improving cognition among adolescents.