Mental fatigue induced by prolonged self-regulation does not exacerbate central fatigue during subsequent whole-body endurance exercise

Abstract

It has been shown that the mental fatigue induced by prolonged self-regulation increases perception of effort and reduces performance during subsequent endurance exercise. However, the physiological mechanisms underlying these negative effects of mental fatigue are unclear. The primary aim of this study was to test the hypothesis that mental fatigue exacerbates central fatigue induced by whole-body endurance exercise. Twelve subjects performed 30 min of either an incongruent Stroop task to induce a condition of mental fatigue or a congruent Stroop task (control condition) in a random and counterbalanced order. Both cognitive tasks (CTs) were followed by a whole-body endurance task (ET) consisting of 6 min of cycling exercise at 80% of peak power output measured during a preliminary incremental test. Neuromuscular function of the knee extensors was assessed before and after CT, and after ET. Rating of perceived exertion (RPE) was measured during ET. Both CTs did not induce any decrease in maximal voluntary contraction (MVC) torque (p = 0.194). During ET, mentally fatigued subjects reported higher RPE (mental fatigue 13.9 ± 3.0, control 13.3 ± 3.2, p = 0.044). ET induced a similar decrease in MVC torque (mental fatigue –17 ± 15%, control –15 ± 11%, p = 0.001), maximal voluntary activation level (mental fatigue –6 ± 9%, control –6 ± 7%, p = 0.013) and resting twitch (mental fatigue –30 ± 14%, control –32 ± 10%, p < 0.001) in both conditions. These findings reject our hypothesis and confirm previous findings that mental fatigue does not reduce the capacity of the central nervous system to recruit the working muscles. The negative effect of mental fatigue on perception of effort does not reflect a greater development of either central or peripheral fatigue. Consequently, mentally fatigued subjects are still able to perform maximal exercise, but they are experiencing an altered performance during submaximal exercise due to higher-than-normal perception of effort.

The effect of cognitive strategies of association and dissociation on central nervous activation: A controlled trial with long distance runners

“…Our results are in consonance with those obtained by Pageaux et al [35], showing that selfregulation cognitive tasks did not affect endurance performance. Even, if the cognitive tasks were longer than 30 min.…”

“…This effect has been mainly observed when the cognitive tasks engagement that requires self-regulation for a period of 30 to 90 min impairs endurance performance during subsequent exercise [31][32][33]. However, no negative effects were found on the physiological system (cardio respiratory and metabolic) supporting endurance exercise, the impairment performance was considered as the effect of mental fatigue [34,35].…”

Effects of Mental Fatigue on Endurance Performance in the Heat

“…However, we can exclude physiological strain (17) and neuromuscular fatigue (24) as there have been no differences observed in these parameters due to mental fatigue. This underlines that the mechanisms causing the higher perception of effort during exercise in conditions of mental fatigue and heat are currently largely unknown.…”

“…Participants completed the NASA-TLX after the 45-min task and after the endurance task in accordance with a study of Pageaux et al (24).…”

Brain mechanisms that underlie the effects of motivational audiovisual stimuli on psychophysiological responses during exercise

“…The effects of the motivational stimuli on the central regions of the cortex are possibly 22 associated with the protective mechanisms of motivation on exercise engagement (for details, 23 see Pageaux, Marcora, Rozand, & Lepers, 2015). Corollary discharges emitted by the central 24 motor command theoretically decrease the amplitude of high-frequency waves in thepremotor gyrus and increase low-frequency waves in the frontal regions of the cortex (de 1 Morree et al, 2012).…”