title: Autonomic responses to exercise: deconditioning/inactivity.
abstract: Experimental models of physical inactivity associated with a sedentary lifestyle or extreme forms of inactivity with bed rest or spaceflight affect the balance between parasympathetic and sympathetic nervous system regulation of the cardiovascular system. Deconditioning effects are rapidly seen in the regulation of heart rate to compensate for physical modifications in blood volume and cardiac function. Reflex regulation of cardiovascular control during exercise by metaboreflex and baroreflex is altered by bed rest and spaceflight. These models of extreme inactivity provide a reference to guide physical activity requirements for optimal cardiovascular health.
authors.affiliation: Schlegel-University of Waterloo Research Institute for Aging, Waterloo, ON, Canada. Electronic address: Hughson@uwaterloo.ca.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Hughson
authors.affiliation: School of Kinesiology and Department of Physiology, Western University, London, ON, Canada.
authors.forename: J Kevin
authors.initials: JK
authors.lastname: Shoemaker
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000818:Animals; D001341:Autonomic Nervous System / Q000502:physiology*; D002319:Cardiovascular System; D015444:Exercise / Q000502:physiology*; D006801:Humans
keywords: Bed rest; Parasympathetic nervous system; Physical inactivity; Spaceflight; Sympathetic nervous system