To do this you must be able to control your ki enough to move it throughout your body. Focus all your energy in your Tan-Tien (just below the stomach.) Once this is acomplished preform some kind of trigger if you are a beginner and imagine ki flames erupting from your body. You should feel quite hyper and strong and needing to run if this is acomplished correctly. Also your eyes will go a bit blurry. If exousted do NOT preform this you may take to much energy from the rest of your body and collapse. Only risk this if you are trained in this technique and able to control how much energy you put in the build up.