Integration of central and peripheral regulation of the circulation during exercise: Acute and chronic adaptations

Physical movement lasting any more than a few seconds (e.g., exercise), requires coordination of motor control with concomitant changes in the cardiovascular and respiratory support necessary to respond to the rapid increases in metabolic demand. Without such coordination, delivery of oxygen and removal of waste products become rate limiting and will restrict the duration, speed, and quality of movement. Fortunately, under healthy conditions, the central and peripheral nervous systems contribute importantly to this remarkable level of coordination via complex mechanisms that remain to be fully elucidated. The purposes of this review are to present the current state of knowledge regarding: (i) mechanisms by which the body maintains appropriate perfusion pressure to all organs during acute bouts of exercise, and (ii) alterations occurring in these mechanisms via central nervous system adaptations when exercise is performed or not performed on a regular basis (e.g., physically active versus sedentary lifestyle, respectively). Results from studies performed in humans and laboratory animals provide the reader a well-rounded knowledge base. They are intended to instill an appreciation of what is known, and not known, about how the brain regulates the cardiovascular system during acute bouts of exercise, and the adaptations that occur when individuals exercise regularly versus when chronically sedentary. Discussion of the latter is intended to provide novel mechanisms for the increased incidence of cardiovascular disease in sedentary individuals versus a reduced incidence in individuals who are regularly active.