Welcome to Phase 5 Muscle Pump and Flex - This is a very interesting Phase. We are going to lighten our weights and pump out multiple reps. Here we are pushing more blood into muscle, forcing bigger muscular pumps. Then we flex the working muscle. The more blood you can flood into a muscle (other than just always pushing more weight) the more it will respond to growing. The flexing portion of the set helps move that blood in and out of the muscle, giving you a greater pump. This contributes to having better muscle control, in turn creating a stronger muscle contraction. The Mind Muscle connection is critically important here.