There is little knowledge about exercise for patients with inclusion body myositis (IBM). Patients with IBM have limited access to rehabilitation and physiotherapy resources, despite a significant need for these services due to the progressive nature of the condition, which leads to a gradual decline in physical function. The purpose of the project is to develop and implement a 16-week exercise intervention at Oslo University Hospital (OUS) for patients with IBM living in Oslo and the surrounding area. The exercise sessions will take place once a week at OUS, under the guidance of physiotherapists with extensive clinical experience with this patient group. Patients are encouraged to exercise at home at least once a week between sessions at OUS to achieve sufficient amount of exercise that normally will improve physical fitness. The feasibility and benefits of the exercise intervention will be evaluated using various methods, such as focus group interviews, physical tests, and questionnaires. The study will also provide valuable insight into whether exercise can lead to improvements in muscle strength, fitness, and balance in patients with IBM.