Int J Sports Med 2013; 34(12): 1029-1036
DOI: 10.1055/s-0033-1343402
Physiology & Biochemistry
© Georg Thieme Verlag KG Stuttgart · New York

Impact of Mental Fatigue on Self-paced Exercise

J. Brownsberger
1   Institute of Sport & Exercise Science, James Cook University, Cairns, Australia
,
A. Edwards
1   Institute of Sport & Exercise Science, James Cook University, Cairns, Australia
,
R. Crowther
1   Institute of Sport & Exercise Science, James Cook University, Cairns, Australia
,
D. Cottrell
2   Psychology, James Cook University, Cairns, Australia
› Author Affiliations
Further Information

Publication History



accepted after revision 04 March 2013

Publication Date:
14 June 2013 (online)

Abstract

The purpose of this study was to examine whether mental fatigue influences the perceived effort required to complete fairly light and hard effort self-paced exercise challenges. 12 participants completed 2 trials in a randomised cross-over design. Each participant was required to complete a time-matched pre-exercise task: 1) a continuous cognitive activity test (EXP condition; n=12), or 2) a time-matched passive neutral observation task (CON condition; n=12). Following the pre-exercise task, participants performed 2 consecutive bouts of self-paced cycling exercise again in randomized order at fairly light (RPE 11) and hard (RPE 15) effort. Physiological, psychological and EEG indices were measured throughout both conditions. EXP participants reported significantly greater sensations of fatigue (p<0.01) and demonstrated greater EEG beta-band activation compared with CON (p<0.01) prior to exercise. Power outputs from the exercise bouts were significantly reduced for EXP in both self-paced: RPE 11 (83±7 vs. 99±7 W;  p=0.005) and RPE 15 (132±9 vs. 143±8 W; p=0.028) trials. This study demonstrates that individuals with higher self-reported sensations of fatigue and elevations of EEG beta activity in the prefrontal cortex of the brain prior to exercise produce less work during self-paced exercise trials than in a control condition, probably due to an altered perception of effort.