A Postexercise Executive Function Benefit From Passive and Active Exercise Does not Extend to Mental Fatigue Mitigation

A single bout of aerobic exercise improves executive function (EF) and is a benefit, in part, attributed to an increase in cerebral blood flow (CBF). It is, however, unknown whether a postexercise EF benefit mitigates mental fatigue (MF). My thesis assessed EF prior to and following separate 20-min conditions of active and passive cycle ergometry and a non- exercise control. Subsequently, a 20-min psychomotor vigilance task (PVT) was employed to determine whether the exercise intervention(s) decreased susceptibility to MF. Transcranial Doppler ultrasound was used throughout the protocol to estimate exercise- and PVT-based changes in CBF. Both exercise conditions increased CBF and produced a postexercise EF benefit. In turn, the PVT decreased CBF and increased subjective and objective measures of MF; however, frequentist and Bayesian statistics indicated the preceding exercise condition did not ameliorate these changes. Accordingly, exercise did not provide a neuroprotective mechanism mitigating MF in a sustained vigilance task.