Deconditioning

Deconditioning can be defined as the multiple, potentially reversible changes in body systems brought about by physical inactivity and disuse. Such changes often have significant functional and clinical consequences in older people. Deconditioning commonly occurs in two situations: (1) a sedentary lifestyle, which is common in older people even in the absence of significant disease or disability and may result in a slow, chronic decline in physical fitness; and (2) bed or chair rest during an acute illness, which can lead to disastrously rapid physical decline.

Decline in muscle strength and muscle bulk is the most important and consistent feature of deconditioning. Reduced maximal oxygen uptake during exercise, impairment of balance responses, and decreased cardiac output during exercise have also been linked to deconditioning but may primarily result from the reduction in muscle bulk.