This is why the psychology and physiology of endurance are inextricably linked: any task lasting longer than a dozen or so seconds requires decisions, whether conscious or unconscious, on how hard to push and when. Even in repeated all-out weightlifting efforts—brief five-second pulls that you’d think would be a pure measure of muscular force—studies have found that we can’t avoid pacing ourselves: your “maximum” force depends on how many reps you think you have left.
