Inclusion Criteria:  Adults aged 18 to 55 years Shoulder symptoms lasting for a minimum of 3 months Clinical diagnosis of rotator cuff (supraspinatus and/or infraspinatus) tendinopathy Clinical diagnosis verified by/ combined with ultrasound  Exclusion Criteria:  Patients are excluded if they have  resting pain above 4/10 (NPRS) <90 degrees active elevation of the arm had a corticosteroid injection within the previous 12 weeks isolated subscapularis tendinopathy total rotator cuff tear diagnosed AC-joint pathology diagnosed labrum pathology diagnosed glenohumeral joint instability had prior shoulder surgery (all shoulder joints) diagnosed glenohumeral osteo arthrosis (OA) evaluated on x-ray, rheumatoid arthritis or periarthrosis General exclusion criteria are inability to speak or read Danish, inability to perform and maintain the physical training, or other conditions negatively influencing compliance.