Pacing is however more frequently used in the context of chronic pain where it has a background in operant conditioning. First described by Wilbert Fordyce in 1976,
[18]pacing referred to a time-contingent and gradual increase of activity levels. Fordyce’s main idea was that chronic pain patients shouldn’t be directed by their symptoms but by plans, goals and targets. In this context, pacin referred to the careful planned route, based on positive reinforcements instead of the fear of pain, to reach those goals.
[19] Often a task was broken up into manageable parts or quotas so the patient can go forward step by step with breaks in between. Although the principles of operant conditioning are no longer central, in the chronic pain literature pacing still frequently refers to a planned and gradual increase of activity levels. ...This form of pacing is quite dissimilar and sometimes even contrary to the form of pacing used in ME/CFS.