Subjective Assessment of Physical and Mental Fatigue Does Not Predict Objective Decline of Cognitive Functions After...

Although acute exercise can have positive effects on individual's cognitive functioning, performing ultra-endurance race can diminish these benefits. No previous studies have examined if cognitive decline can be estimated by subjective perception; thus, changes in cognitive functions and their relation to subjectively reported parameters (SRPs) were evaluated. Before, immediately after, and ~20h post ultra-endurance race, 43 amateur cyclists filled out questionnaire rating SRPs and performed digit symbol test (DST), stroop test (ST), finger tapping test (FTT). Changes between three timepoints were determined by one-way repeated measures ANOVA or Friedman test. Mixed model regression was used to test relationship between cognitive functions and SRPs. DST results exhibit no changes in post-race measurement, but an improvement of performance in recovery period was observed for correct number count (increase by 8,6 taps per 2 min, p < 0.001) and mean reaction time (decrease by 190 ms, p < 0.001). In ST, average time for correct reactions post-race increased in all three stages by 22, 35, and 68 ms, respectively (p < 0.001), with no changes in accuracy. For FTT, non-dominant hand showed decline in performance post-race. Changes in several SRPs (effort to answer the questions, physical strength, sleep quality, and stress levels during the previous day) were associated with changes in participants' cognitive performance. Short-term decline in cognitive functions was observed after ultra-endurance race, indicating possible increase in accident risk for participants. SRPs assessing sleep, current effort, stress, and physical strength, but not fatigue, may be reliable predictors of these changes.