Deconditioning is a change in physical fitness due to inactivity – including the loss of physical, psychological and functional capacity due to inactivity. It can occur rapidly in older adults and is not straightforward or quick to remedy. It has a range of negative health impacts, including falls, depression, type II diabetes, cardiovascular disease and musculoskeletal problems.

Deconditioning is the decline in physical function of the body as a result of physical inactivity and/or bedrest or an extremely sedentary lifestyle. It is a complex process of physiological change resulting in functional losses in such areas as movement, mental status, degree of continence and ability to accomplish activities of daily living. The most important feature of deconditioning is a decline in muscle strength and bulk. It is often seen in the elderly and the infirm due to bed rest and inactivity. Risk factors include illness, disability, chronic disease, medical and psychosocial circumstances.