Resumo. Background: In this opinion we consider the roles of physical and cognitive effort in choosing between actions that make different physical and cognitive demands. View of the past: In choosing between a less or more demanding physical task, the cognitive effort of each was not expected to have a large effect. Current state: However, people are willing to expend extra physical effort to clear their minds (to avoid cognitive effort), a phenomenon called pre-crastination. Future perspective: Because pre-crastination can lead to premature decisions, a new priority is to understand the tradeoffs between physical and mental effort.