Background The Activity in GEriatric acute CARe (AGECAR) is a randomized control trial to assess the effectiveness of an intrahospital strength and walk program during short hospital stays for improving functional capacity of patients aged 75 years or older.

Objective: The main objective of this study is to assess whether an inpatient exercise program, beyond other components of interdisciplinary care, could reduce hospital associated disability (HAD) in medical patients aged 75 years and older admitted to an acute care for elders (ACE) unit.

Population: The reference population will be patients aged 75 years and older admitted to the ACE unit from the emergency department. This study will include only patients discharged alive. Exclusion criteria include patients fully dependent at baseline, unable to sign informed consent, unstable medical condition, short stay (<3 days), end stage illness.

Interventions: Patients will be randomly assigned to a control or an intervention group. Participants allocated to the control group will receive usual care in the ACE unit with actions directed to prevent delirium and functional decline. The intervention group, in addition to the usual care, will receive an exercise program. Briefly, this program consisted of strengthening of lower limbs muscles, and walking, daily from Monday to Friday.

Inclusion Criteria:

• Participants will include approximately 150 elderly people aged 75 years or older recruited from patients admitted into the Geriatrics Department of the Hospital General Universitario Gregorio Marañón (Madrid, Spain).
• Able to ambulate, with or without personal/technical assistance.
• Able to communicate.
• Informed consent: Must be capable and willing to provide consent.

Exclusion Criteria:

• Duration of hospitalization < 72 hours
• Any factor precluding performance of the physical training program or testing procedures as determined by the attending physician. These factors include, but are not limited to the following:
• Terminal illness.
• Myocardial infarction in the past 3 months.
• Not capable of ambulation.
• Unstable cardiovascular disease or other medical condition.
• Upper or lower extremity fracture in the past 3 months.
• Severe dementia.
• Unwillingness to either complete the study requirements or to be randomised into control or intervention group.
• Presence of neuromuscular disease or drugs affecting neuromuscular function.