BFR, or Blood Flow Restriction, is a training technique that involves applying a band or cuff to the upper or lower limbs to partially restrict blood flow during exercise. This method allows individuals to achieve muscle growth and strength gains with lighter weights, making it beneficial for rehabilitation and those unable to lift heavy loads. The technique works by creating a hypoxic environment in the muscle, which stimulates growth factors and increases muscle protein synthesis. BFR is often used in physical therapy settings and by athletes looking to enhance their performance while minimizing the risk of injury.