Cognitive Control of Pacing During Endurance Exercise: Everyone is a Quitter

Contemporary accounts of control of pacing during endurance exercise focus on physical limitations, generally assuming humans work to that physical limit. Conceptually, control is ceded to the body at the beginning of an exercise bout and is returned to central cognition upon achieving a state of exhaustion. We advance an alternative decision-making model of control of pacing, where the decision whether to persist in the effort is revisited continuously, and cessation of the exercise bout is an explicit, cognitively controlled decision. Our model depends on the following assumptions and features: 1) decisions are made in discrete cycles, 2) repetitive bodily motions depend on a central pattern generator, 3) afferent physiological feedback produces a sense of perceived exertion, 4) central cognition mediates between perceived exertion and the value of persisting (motivation) to perform an ongoing cost-benefit analysis, and 5) cessation of exercise occurs when an explicit decision is made to discontinue the effort.