Effects of Exercise on Functional Ability in People With Dementia in Nursing Homes:a Cluster Randomised Controlled Trial

Inclusion Criteria: * Confirmed diagnosis of Alzheimer's disease, vascular or mixed dementia according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV); * MMSE ≤ 20 (out of 30); * living in one of the participating NHs for at least 3 months at the moment of baseline measurements (this time period will allow NH staff to have a good knowledge about the patient and about recent changes in his/her health status); * to be able of walking at least 4 meters (with walking devices if needed but without human assistance); * to be able to rise from a chair without help or with minimal human assistance. Exclusion Criteria: * Mild dementia, illustrated by a MMSE \> 20 (out of 30) * Terminal illness with life expectancy less than 6 months; * Diagnosis of Parkinson's disease; * Diagnosis of dementia with Lewy bodies; * Unstable cardiovascular condition or any other health condition that might be deteriorated by physical exercise; * Planned transfer from the NH to another NH/home or to surgery during the 6-month period of intervention; * Already participating in physical exercise ≥ 2 times/week in the last 2 months prior to the date of baseline assessments.