Health professions need to prepare for the large increase in the number of older people with OA requiring health services including TJA surgery. Older age and poor physical function influences the postoperative prognosis of TJA. At discharge from hospital after TJA, studies have shown that gait speed can be severely impaired among older patients.

The investigators hypothesize that an exercise program of 6-12 weeks will be beneficial for patients that are undergoing TJA.

More than 300.000 Norwegians above 20 years of age have osteoarthritis (OA) . There has been a significant increase in the prevalence of OA over the decades. In the United States knee OA affects 19% of adults aged 45 years or older. OA is associated with an extensive high economic and personal burden, largely attributable to the effects of disability, comorbid disease, and the expense of treatment.

Given the aging population, the number of total joint arthroplasty procedures (TJA) for hip and knee is likely to increase substantially. In light of poor physical function prior to surgery among older patients and the likelihood of an added decrease during hospitalization and risk of poorer outcome after surgery, it is hypothesised that prehabilitation (preoperative exercise) would improve outcomes after surgery, however evidence for its efficacy is still lacking

Inclusion Criteria:

• Participants 70 years or older living at home with residential address in the county of Oslo or Akershus scheduled for elective primary total hip replacement due to end-stage osteoarthritis.
• Harris Hip Score >60.
• Participants must also be capable in Norwegian and be able to follow exercise sessions.

Exclusion Criteria:

• Patients with known rheumatoid arthritis or medical contraindications or those who are scheduled for revision of hip arthroplasty
• Unable to speak and understand the Norwegian language.
• Patients with neurological disorders affecting gait
• Medical contraindications for exercise