Anterior cruciate ligament reconstruction (ACLR) is high volume surgery, carried out in about 2800 patients annually in Denmark per year. ACLR patients (using hamstring auto-graft) have persistent hamstring strength deficiency when evaluated more than 1-2 years after ACL-reconstruction. The investigators have designed this randomized controlled trial (RCT) with the main purpose to investigate the effect of a targeted muscle strength exercise intervention on the neuromuscular rehabilitation of ACLR-patients compared with 'care-as- usual'.