Cognitive endurance after intense physical effort.

Previous research has primarily examined the effects of cognitive exertion on subsequent physical performance, yet the reciprocal relationship-how intense physical exercise influences cognitive endurance performance-remains largely unexplored. This study investigated the behavioral, subjective, and neurophysiological effects of maximal aerobic effort on sustained cognitive endurance performance. In a pre-registered, within-participant design, 29 physically active participants completed a cognitive task to failure following either exhaustive running at 90 % of their maximal aerobic speed or a 10-minute walking control condition. Electroencephalography (EEG) recorded brain activity, brain complexity was assessed, and subjective experiences were analyzed using the Temporal Experience Tracing (TET) method. Results indicated that maximal aerobic effort significantly reduced maximal force capacity and increased perceived exertion compared to the control condition, confirming a higher physiological workload. However, no significant differences were observed in cognitive task duration between conditions (control: 4755.8 s, 95 % CI [3326.8-5107.8]; experimental: 4308.2 s, 95 % CI [3902.9-5481.2]; BF₁₀ = 0.329). Subjective experience analysis revealed two distinct task-demand states, with comparable time allocation across conditions. EEG analyses indicated a decrease in brain complexity following exhaustive exercise, suggesting a physiological shift, yet cognitive performance and subjective experience remained unaffected. These findings provide no evidence that intense physical exercise negatively impacts cognitive endurance. Despite alterations in physiological and neural markers, participants sustained cognitive effort to failure with no significant decline in performance.