The effect of mental fatigue on the psychobiological response to a 10km cycling time trial: a neuroergonomic approach

Thumbnail Image



Journal Title

Journal ISSN

Volume Title


University of New Brunswick


Mental fatigue is best described as a change in psychophysiological state due to sustained cognitive or perceptual performance. The negative effects of mental fatigue on occupational and cognitive tasks have been well documented (Boksem, Meijman, & Lorist, 2005; Lorist et al., 2000; Lundberg et al., 2002). Few studies exist that examine the effect of mental fatigue on physical performance (Marcora, Staiano, & Manning, 2009; Mehta & Parasuraman, 2014); those that do suggest that mental fatigue negatively affects performance. The purpose of the study was to investigate the effect of mental fatigue on the psychobiological response to exercise, whilst controlling for aerobic capacity, perfectionism, and intrinsic motivation. A neuroergonomic approach was used by implementing Near Infrared Spectroscopy (NIRS) to examine cerebral hemodynamics. Participants (N=50) underwent two phases of testing: an initial screening phase and an experimental phase. A matched grouped design was implemented, randomly assigning participants to either the control or experimental group. The testing phase consisted of either a mentally fatiguing cognitive task, or a neutral control condition, followed by a 10km cycling time trial. Dependent variables were time to completion, heart rate, VO[2 (subscript)] peak power, oxygenated hemoglobin, deoxygenated hemoglobin, total oxygenation index, self-efficacy, and rate of perceived exertion. Data reduction was executed via principle component analysis, resulting in three new factors: performance and central physiological markers, negative peripheral physiological markers, and negative psychological markers. MANCOVA was performed with VO[2max (subscript)], self-orientated perfectionism, and motivation towards physical activity entered as covariates, and group as the only independent variable. Group failed to account for a significant amount of variability in the three factors after the variability shared between the covariates and the factors were controlled for (Pillai’s Trace = 0.19, F[(3, 43) subscript] = 0.275, p > 0.05, partial η[squared] = .019). Contrary to previous research, findings indicate that mental fatigue does not affect the psychobiological response to exercise. However, the sample consisted of predominantly well-trained individuals with similar psychological traits, which could have masked any mediating effects of the covariates. Mental fatigue appears to be a multidimensional construct, where an individual’s perception of mental fatigue is the most influential factor.