Motivational self-talk mitigates the harmful impact of mental fatigue on endurance performance

Abstract

In sports, athletes might train or compete with some degree of mental fatigue that has an impact on performance. The present study investigated the effect of strategic motivational self-talk on endurance performance in mentally fatigued individuals. Twelve healthy men performed three cycling endurance tests at 80% peak power output until exhaustion. Two experimental conditions (mental fatigue [MF] and mental fatigue plus motivational self-talk [MF + M−ST]) and a control condition (CO) were set out. Mental fatigue was induced via 30 min Stroop task; an electroencephalogram of the frontal cerebral cortex was continually monitored. Affective state and perceived exertion were recorded during each session and subjective workload after the endurance exercise trials. Theta band power spectral density was significantly higher in both experimental condition (MF and MF + M−ST) compared to CO, without significant differences between MF and MF + M−ST. Endurance performance was significantly worse in MF (227 ± 63s) than in CO (329 ± 84s). However, motivational self-talk reversed the deleterious effect of MF on endurance performance as in MF + M−ST (368 ± 139s) it was significantly better than MF and not significantly different from CO. Displeasure and perceived exertion scores were similar at the end of exercise and presented similar rate of increase among conditions. Mental demand after exercise was significantly greater in MF than in CO condition. These results suggest that motivational self-talk mitigates the negative effect of MF on endurance performance due to an elevated engagement with the task. Lay summary: This study examined to what extent the deliberate and planned use of cue words to enhance motivation (i.e., motivational self-talk), influenced endurance performance in mentally fatigued individuals. The harmful impact of mental fatigue on endurance performance was mitigated by using motivational self-talk during cycling exercise.