After a cartilage or meniscus repair in the knee joint, the patients experience a pronounced and persistent decrease of knee-extension strength in the operated leg, which negatively affect patients' functional performance and quality of life. A possible novel exercise modality to increase muscle strength early is a moderate blood flow restriction with low-load strength training (BFR-LLST) exercise. BFR-LLST involves application of a wrapping device to restrict the blood flow to the muscle(s) during exercise. BFR- LLST requires much less load than traditional strength training and has shown to produce positive training adaptations such as muscle hypertrophy and strength in the lower extremity in healthy subjects and patients with a knee surgery. To our knowledge, early rehabilitation with BFR-LLST has never been investigated in a population with weight bearing restrictions, such as patients recovering from cartilage or meniscus repair in the knee joint. Fear of symptom exacerbation and adverse events have precluded BFR-LLST early after knee surgery. The purpose of this study is to examine the feasibility of 9 weeks of supervised rehabilitation with BFR-LLST early after cartilage or meniscus repair in the knee joint.