Fig. 2. The central governor theory proposes that afferent sensory information from the heart, but also perhaps from the brain and respiratory muscles, informs the brain of any threat that hypoxia or ischaemia may develop in those organs. In response, the central governor acts via the motor cortex to reduce the efferent neural activation of the exercising muscles, thereby reducing the mass of muscle that can be recruited and, hence, reducing the exercise intensity that can be sustained. The existence of peripheral governors in skeletal muscle and heart is proved by the rapidly deleterious effects of ischaemia on contractile function of both the heart and skeletal muscles and the existence of the condition of myocardial hibernation (Noakes, 2001).