Deconditioning is an integrated physiological response of the body to a reduction in metabolic rate, that is, to a reduction in energy use or in exercise level. Deconditioning and Reconditioning presents selected background information on the many aspects of ground-based and in-flight physiological research and applications. This multi-author volume emphasizes human research programs on prolonged bed rest, immersion and confinement studies simulating conditions of space flight, as well as data from humans in space. Consolidating this research, chapters cover the psycho-sociological aspects of confinement deconditioning, the effects of deconditioning and reconditioning on aerobic power, thermoregulation during deconditioning, and practical applications.