Effects of Cognitive and Physical Load of Acute Exercise on Inhibitory Control and Prefrontal Cortex Hemodynamics in Children

ABSTRACT Introduction Evidence suggests that acute exercise benefits inhibitory control, but it remains unclear how physical and cognitive load influence this ability in preadolescent children, when faced with different types of distractors. We examined their moderating effects along with changes in prefrontal cortex hemodynamics. Methods Using a cross-over design, 29 participants completed 10 min of exercise (with an interactive training wall) at 1) low physical and low cognitive load, 2) low physical and high cognitive load, 3) high physical and low cognitive load, and 4) high physical and high cognitive load in a randomized order. Before and after each condition, they performed a Standard and Affective Stroop task. During both tasks, the lateral oxygenation difference (LOD) in the prefrontal cortex was measured by employing functional near-infrared spectroscopy. Results For the Standard Stroop task, there was no effect of physical and cognitive load on performance. In contrast, exercise with low compared to high cognitive load was associated with a greater reduction of reaction time and increase in accuracy on the Affective Stroop task. This was accompanied by a decrease in LOD on trials with low inhibitory control demands. Conclusions Acute exercise with low compared to high cognitive demand benefits the ability to resolve emotional conflict, but the control over inhibition of non-emotional information remains unaffected. This effect of cognitive load is complemented by an increased efficiency of the left prefrontal cortex, when no emotional conflict resolution is required.