Functional Brain Responses to Short-Duration Light Physical Activity in Children: Insights from Near-Infrared Spectroscopy

Background/Objectives: The prefrontal cortex (PFC) plays a crucial role in cognitive functions such as attention, working memory and executive functions. Physical activity (PA), even at light-intensity, has been shown to increase PFC activity. However, most studies have focused on moderate- to vigorous-intensity exercises or on adults, while little data is available for children engaging in light-intensity PA (LPA). The aim of this study was to investigate the changes in the hemodynamics of the PFC during short-term, light-intensity exercises in children using functional near-infrared spectroscopy (fNIRS). The secondary aim was to compare the responses between two exercise patterns differing in duration (10 vs. 20 seconds).Methods: Thirty-eight healthy children aged 10 to 14 years from private schools in Barcelona participated in this study. Seven light-intensity exercises were performed in randomized order according to two patterns: Pattern 1 (10 seconds per exercise) and Pattern 2 (20 seconds per exercise). Changes in oxygenated hemoglobin (oxy-Hb) were measured by fNIRS in three PFC regions: right (R-PFC), middle (M-PFC) and left (L-PFC). Analysis of covariance (ANCOVA) was used to determine significant differences, with gender, age and resting oxy-Hb Z-scores as covariates.Results: Significant increases in oxy-Hb Z-scores were observed in the M-PFC during event A (Upward Stretch) and in all PFC regions during event D (Trunk Twist) in pattern 1. Events related to coordination and balance, such as balancing on one leg, also elicited significant activation of the PFC. However, simpler movements, such as hand washing and elbow circles, showed no significant changes. Comparisons between patterns 1 and 2 showed no significant differences, suggesting that duration alone has no effect on PFC activation.Conclusions: Light-intensity coordination and balance exercises stimulate PFC activity, even for short durations. These results emphasize the potential for integrating such exercises in school or rehabilitation settings to promote cognitive and motor development in children.