ABSTRACT
Traditionally it has been assumed that highly motivated people terminate endurance exercise because of muscle fatigue or, more recently, because of the subconscious action of a central governor that forces humans to stop before exercise can cause serious bodily damage. This chapter described an alternative psychobiological model that integrates exercise physiology with motivation psychology and cognitive neuroscience to provide a single and testable theoretical explanation for the effects of both physiological and psychological manipulations on endurance performance. This psychobiological model also provides a novel explanation as to why perception of effort increases over time and how this fatigue interacts with motivational factors to determine for how long an individual can sustain endurance exercise.
