Acute Respiratory Failure (ARF) requiring mechanical ventilation affects 1.1 million of the 4.4 million people admitted to United States Intensive Care Units (ICU) every year. Patients with ARF have an average ICU and hospital length of stay (LOS) of 8 and 15 days, respectively, with median hospital costs greater than $30,000 United States. Patients with ARF experience deconditioning, muscle weakness, joint contractures, dyspnea, depression, and reduced health-related quality of life, all of which may contribute to prolonged hospitalization and increased costs. Mechanistically, it is understood that patients with ARF demonstrate acute inflammation which may contribute to the above cited problems. While the investigators' research and that of others has shown that rehabilitation therapy can increase functional outcomes while lowering biomarkers of inflammation in the frail aged and other clinical populations, it is not known whether such rehabilitation therapy can result in improved functional capacity and functional performance and reduce inflammation in ARF patients. There is previous evidence for the feasibility and safety of rehabilitation therapy in ARF patients. Therefore, the investigators propose a two-arm, randomized trial in 326 patients with ARF to compare Standardized Rehabilitation Therapy initiated in the ICU and administered throughout the hospitalization versus usual care (control). Standardized Rehabilitation Therapy will consist of: passive range of motion, physical therapy and progressive resistance exercise (strength training). The regimen will be administered 7 days/week by a Mobility Team consisting of a critical care nurse, physical therapist and nursing assistant.

The investigators will determine whether standardized rehabilitation therapy will reduce hospital LOS, improve functional capacity and performance, improve quality of life, reduce inflammation and reduce hospital costs as compared to usual care.

This study's primary objective is to determine whether standardized rehabilitation therapy will decrease hospital length of stay.

Hypothesis: Compared to usual care, standardized rehabilitation therapy will reduce hospital length of stay for patients with Acute Respiratory Failure.

Inclusion Criteria:

• Age ≥ 18 years
• Mechanically ventilated via an Endotracheal tube or Bipap
• Lung Injury

Exclusion Criteria:

• Previously enrolled in TARGET STUDY
• Inability to walk without assistance prior to acute ICU illness (use of a cane or walker not exclusion)
• Cognitive impairment prior to acute ICU illness (non-verbal)
• Acute stroke
• Body mass index (BMI) > 50
• Neuromuscular disease that could impair weaning
• Hip fracture, unstable cervical spine or pathological fracture
• Mechanically ventilated > 80 hours
• Current hospitalization or transferring hospital stay > 7 days
• Ineligible cancer treatment within the last 6 month
• Moribund
• Do Not Resuscitate(DNR)/Do Not Intubate(DNI) on admission
• Other Research Study