Self-control is essential for managing our actions, yet its exertion is perceived as effortful. Performing a task may require effort not only because of its inherent difficulty but also due to its potential for inducing boredom, as boredom has been shown to be self-control demanding by itself. So far, the extent of self-control demands during boredom and its temporal dynamics remain elusive. We will employ a multimethod approach to address this knowledge gap. Ninety-five participants will take part in an easy and difficult version of the Stroop task. During both tasks, they will indicate several times their current sensation of task difficulty, boredom, boredom-related effort, and difficulty-related effort. We will test if pupil size, as a physiological indicator for cognitive effort, is predicted more accurately by overall cognitive effort (difficulty- and boredom-related) than by task-difficulty-related effort alone. This research will uncover the level of effort in experiencing boredom which is pertinent not only for self-control research but also to any research area dealing with boredom or the performance of repetitive tasks.