Author(s): JASON, K., BERTRAND, C., RAINE, L.B., WATROUS, J.N.H., HILLMAN, C.H., Institution: NORTHEASTERN UNIVERSITY, Country: UNITED STATES, Abstract-ID: 1136

Inhibitory control, an important domain of executive function, reflects the ability to suppress prepotent responses. Aerobic fitness and body composition are two modifiable factors that independently relate to inhibitory control, with prior research showing that greater aerobic fitness is related to enhanced inhibitory control in children and greater body fat is related to poorer inhibitory control. This study examined continuous measures of aerobic fitness and body composition as independent predictors of task performance and event-related brain potential (ERP) outcomes during a Go/NoGo task. 102 children (mean age: 10.07 ± .67) completed VO2peak assessments and DXA scans prior to performing a Go/NoGo task while ERPs were recorded. Inhibitory control measures of response accuracy, reaction time (RT), and standard deviation of RT (SDRT) were analyzed using linear regressions. Linear mixed-effects models were performed separately for fat-free aerobic fitness (FFVO2peak) and body composition (whole body fat percent) to examine their main and interaction effects on N2 and P3 amplitude and latency across the seven midline sites (Fz, FCz, Cz, CPz, Pz, POz, Oz). Greater aerobic fitness predicted superior NoGo accuracy (β = 0.27; 95% CI [0.07, 0.46], p = .008) and reduced SDRT (β = -0.22; 95% CI [-1.72, 0.08], p = .032) but was unrelated to Go task performance. Higher whole-body fat percentage predicted shorter NoGo RT (β = -0.20; 95% CI [-0.04, 0.002], p = .031) but was unrelated to accuracy or SDRT. During the Go task, a significant Fitness x Site interaction was revealed for N2 amplitude (F (6, 600) = 2.34, p = .030) and P3 amplitude (F (6, 600) = 2.91, p = .008), while body composition was associated with P3 latency (F (6, 600) = 2.17, p = .045). During NoGo trials, a Fitness x Site interaction was revealed for N2 amplitude (F (6, 600) = 2.30, p = .033), whereas body composition showed no associations with N2 or P3 components. These findings demonstrate dissociable, topographic effects between fat-free aerobic fitness and body composition on inhibitory control and its neural underpinnings. Higher fitness was associated with enhanced behavioral performance and larger N2 and P3 amplitudes, indicating greater neural resource allocation and cognitive control, whereas greater whole-body fat was selectively related to shorter RT and P3 latency, suggesting a distinct association with processing speed rather than neural recruitment related to inhibitory control. Findings suggest aerobic fitness is a modifiable factor associated with inhibitory control in children.