The Central Governor Model of Exercise Regulation proposes that the brain regulates exercise performance by continuously modifying the number of motor units that are recruited in the exercising limbs. This occurs in response to conscious and subconscious factors that are present before and during the exercise, and those which act purely during exercise. The goal of this control is to insure that humans always exercise with reserve and terminate the exercise bout before there is a catastrophic failure of homeostasis. The brain uses the unpleasant (but illusory) sensations of fatigue to insure that the exercise intensity and duration are always within the exerciser’s physiological capacity. This model therefore predicts that the ultimate performances are achieved by athletes who best control the progression of these illusory symptoms during exercise. (For more details see St Clair Gibson et al., ; Noakes et al., , ; St Clair Gibson and Noakes, ; Tucker, ; Tucker and Noakes, ; Noakes, ,).