Inclusion Criteria:  Hospitalized adults, aged 18 years or over Admitted to the ICU requiring invasive mechanical ventilation for > 48 hours and remain in the ICU for a minimum of four days Living at home before the current admission (not in a facility and/or no fixed abode)  Exclusion Criteria:  Non-English speaking (insufficient English language skills to read and understand questionnaires and patient information consent form) Pre-existing documented cognitive impairment Spinal cord injury or other primary neuromuscular disease New lower limb fracture with altered weight bearing status Expected survival < 3 months according to the treating medical team Active substance abuse or psychosis Lack of access to telephone / computer or inability to use these resources independently (which would impact on ability to complete the intervention) Pregnancy Suicidality Incarcerated Cardiac surgery within this ICU admission (as these patients routinely receive a standard outpatient rehabilitation through cardiac rehabilitation) Poor premorbid mobility defined as < 10 metres ambulation +/- gait aid independently