Ultramarathon racing elicits changes in behavioral and electroencephalographic indices of executive function

The purpose of this study was to determine whether racing a 50-km ultramarathon alters behavioral and electrophysiological (EEG) indices of executive function. Seventy-six recreational runners (37 ± 10 yr; 39 F, 37 M) completed EEG assessments before and immediately after the race at one of six ultramarathons. Executive function was evaluated with a visual oddball task, with accuracy and reaction time as behavioral markers, N2 as an index of inhibitory control, and P3 as an index of attentional allocation. Motivation [Sport Motivation Scale (SMS)] and negative affect [Depression, Anxiety, and Stress Scale (DASS)-21] were assessed 7-14 days before the race. Average race time was 7 h 54 min (±2 h 8 min), with 2.5% (±1.7%) body mass loss. Reaction times were 2.2% shorter post race (<i>P</i> < 0.0001), alongside a 14% increase in variability (<i>P</i> < 0.0001). N2 and P3 amplitudes decreased by 28.1% (<i>P</i> = 0.008) and 17.9% (<i>P</i> < 0.0001), respectively, with P3 latency reduced 3.4% (<i>P</i> < 0.001). Larger N2 reductions were associated with higher identified (<i>r</i> = 0.29, <i>P</i> = 0.013) and introjected (<i>r</i> = 0.29, <i>P</i> = 0.012) motivation, whereas greater P3 reductions correlated with higher DASS-21 scores (<i>r</i> = -0.69, <i>P</i> < 0.001). Racing an ultramarathon reduced neural activity related to inhibitory control and attentional allocation, resulting in shorter, more variable behavioral responses. Associations with affective state and motivation subtypes measured in the weeks prior suggest that prerace psychological factors may influence cognitive resilience during ultramarathon competition.<b>NEW & NOTEWORTHY</b> Here we report the first large-sample electrophysiological evidence that ultramarathon racing reduces neural activity associated with executive function, leading to shorter but less precise behavioral responses.