Is intense physical exercise detrimental for cognition? A novel approach based on subjective, behavioral and physiological responses to a cognitive effort to failure to failure

Background Most previous research has investigated whether performing a demanding cognitive task reduces the time a person can hold a subsequent physical effort. However, no previous research has investigated if performing an intense physical exercise reduces the time a person can complete a cognitive task with an adequate level of performance. The aim of this study was to assess the subjective, behavioral and physiological responses of performing an intense physical exercise on a posterior cognitive tak until failure.Methods In a pre-registered, within-participant experiment, 29 active participants performed a cognitive task until failure after either running to exhaustion at 90% maximal aerobic speed or walking for 10 minutes (control). Brain activity was recorded via EEG, brain complexity measured, and subjective experience assessed using the Temporal Experience Tracing (TET) method. ResultsPhysical exercise reduced maximal force capacity and increased perceived exertion compared to the control, highlighting significant workload differences. Cognitive task durations were 4755.8 s (95% CI: 3326.8–5107.8) and 4308.2 s (95% CI: 3902.9–5481.2) for control and experimental conditions, with no significant difference (BF10 = 0.329). Subjective experience analysis revealed two task-demand clusters, but time spent in these states was similar across conditions. Cognitive performance was better during phases of low perceived demands. Brain complexity decreased after maximal aerobic effort, suggesting a physiological shift, though cognitive performance and subjective feelings remained unaffected.ConclusionThere was no evidence that short intense physical exercise negatively affected participants' ability to sustain a cognitive effort to failure.