Attention fluctuates over time and is prone to fatigue. Thus, maintaining sustained attention is difficult. The goal of this article is to evaluate the metacognitive penetrability of attention by examining whether dynamic control over the pacing of an ongoing attention-demanding task helps individuals maintain attention. In Experiments 1 and 2, breaks were found to provide a small localized benefit in performance, but self-administered breaks were no more beneficial than ones imposed by the experimenter. Experiment 3 and 4 provided subjects full control over the onset of each trial. Subjects who self-paced stimuli now outperformed yoked controls who experienced the stimuli at a fixed rate and also those who experienced the exact same schedule as the self-pacing subjects. Experiment 5 replicated this set of findings and demonstrated that the benefit of self-pacing was diminished under dual-task conditions. Taken together, it appears that providing workers control over the pace of work allows them to coordinate the occurrence of cognitively demanding events with moments of heightened attention. However, the improvement in performance is subject to important boundary conditions on the parameters of control, does not diminish the vigilance decrement associated with fatigue, and is reduced under conditions in which attention is divided. (PsycInfo Database Record (c) 2024 APA, all rights reserved).