Effects of cognitive demand during acute exercise on inhibitory control and its electrophysiological indices: A randomized crossover study

The aim of this study was to examine the effects of cognitive demand during acute exercise on the behavioral and electrophysiological correlates of inhibitory control. In a within- participants design, 30 male participants (age range = 18-27 years) performed 20-min sessions of high cognitive-demand exercise (HE), low cognitive-demand exercise (LE), and an active control (AC) on separate days in a randomized order. A moderate-to-vigorous intensity interval step exercise was used as the exercise intervention. During the exercise periods, the participants were instructed to respond to the target among competing stimuli to impose different cognitive demands with their feet. A modified flanker task was administered to assess inhibitory control before and after the interventions, and electroencephalography was used to derive stimulus-elicited N2 and P3 components. Behavioral data showed that the participants performed significantly shorter reaction time (RT), regardless of congruency and a reduced RT flanker effect following HE and LE compared with the AC condition with large (ds = -0.934 to -1.07) and medium effect sizes (ds = -0.502 to -0.507), respectively. Electrophysiological data revealed that compared with the AC condition, acute HE and LE had facilitative effects on stimuli evaluation, as indicated by significantly shorter N2 latency for congruent trials and P3 latency regardless of congruency with medium effect sizes (ds = -0.507 to -0.777). Compared with the AC condition, only acute HE elicited more efficient neural processes in conditions requiring high inhibitory control demand, as indicated by significantly shorter N2 difference latency, with a medium effect size (d = -0.528). Overall, the findings suggest that acute HE and LE facilitate inhibitory control and the electrophysiological substrates of target evaluation. Acute exercise with higher cognitive demand may be associated with more refined neural processing for tasks demanding greater amounts of inhibitory control.