Exercise Density Influences the Expression of a Postexercise Inhibitory Control Benefit: Evidence from a Low-Volume...

Executive function (EF) is improved following a single bout of exercise. Recently, it has been proposed the timing between exercise and rest intervals (i.e., exercise density) within a single bout of exercise (or across days or months of exercise) may serve as an important moderator in the expression and/or magnitude of an EF benefit. Here, participants (N = 25) completed separate interval exercise conditions - as well as a non-exercise control - wherein ten 1-min intervals of exercise (40% of 1 repetition max leg extensions at 0.25 Hz) were interspersed with 1-min (high-density: HD) or 2-min (low-density: LD) of rest. Prior to and following exercise (∼5-min), the antisaccade task (i.e., saccade mirror-symmetrical to a target) was used to assess the inhibitory control component of EF. Antisaccades were selected given the task's hands- and language-free nature and because they are mediated via EF networks showing task-dependent single-bout exercise changes. Peak systolic middle cerebral artery velocity (MCAv_peak), perceived exertion, arousal and neuromuscular fatigue were measured to identify a potential psychophysiological metric associated with a putative density-linked postexercise EF change. Frequentist and Bayesian statistics demonstrated that the LD - but not HD - condition produced a pre- to postexercise reduction in antisaccade reaction times (RTs), and across LD and HD conditions psychophysiological metrics did not demonstrate an association with postexercise antisaccade RT changes. Hence, results provide nascent evidence that density may moderate a single bout postexercise inhibitory control benefit and demonstrate that density may provide a framework to understand the interdependent psychophysiological mechanisms contributing to the benefit.