Twenty-eight patients recovering from anterior cruciate ligament (ACL) surgery were randomized to receive 12 weeks of low-intensity, blood flow restriction quadriceps-hamstring exercise training (n=14) or high-intensity, unrestricted exercise training (n=14). The primary outcome of interest was knee muscle strength in flexion and extension. Secondary outcomes of interest included the Lysholm score, International Knee Documentation Committee (IKDC) score, and the Knee Injury and Osteoarthritis Outcomes Score (KOOS), measured on the 4th, 8th and 12th week. Results revealed significantly greater muscle strength in extension in the intervention group vs. control at week 12, and in flexion at weeks 8 and 12. IKDC scores, Lysholm scores, and KOOS sub-scores for symptoms, pain, and daily activity were significantly in favour of the intervention group at 8 and 12 weeks of follow-up.