Preoperative Exercise in Patients Undergoing Total Hip or Knee Replacement

Inclusion Criteria: * Patients scheduled for elective primary, unilateral total hip or knee replacement in Svendborg Community Hospital, Odense University Hospital, Denmark. * Patients with osteoarthritis * Age over 18 Exclusion Criteria: * Not being able to read and understand Danish. * Patients with co-morbidity diseases where a moderate level of physical exercise is contraindicated, e.g. severe heart disease and neurological deficits. * Patients unable to attend intervention. * Rheumatoid arthritis (RA). A history of or ongoing use of medication for RA or other inflammatory arthritis such as gold, methotrexate, plaquenil etc. * Lack of wish to participate or unwillingness to sign an informed consent. * Specific for hip patients: a history of severe sequelae due to congenital hip-dysplasia requiring specialized postoperative training. A history of femoral neck and trochanteric fracture. * Patients planned to have bilateral joint replacement within same procedure.