Blood flow restriction (BFR) uses an inflatable cuff placed around the arm or leg that allows arterial flow of blood into the limbs, but restricts venous flow of blood out of this limb. Exercise is then performed at a very low resistance and high number of repetitions. This creates an increase in hormones and growth factors to this area, resulting in muscle growth and increased strength. BFR achieves a similar result to heavier resistance training with a much lighter resistance. This can be especially effective in a rehab program where recovering tissue cannot tolerate a high amount of resistance while exercising.