Here is how I increase my lung strength. Really heavy darts that weight three times more than your used to. My first "weight" set was bamboo shafts wrapped in lots of steel wire, but big bolts and nuts on cones will last longer. I try to shoot them as fast an far as I can but only a few times in a row. You can strain yourself, Go easy. Trust me this will make standard darts feel like nothing and should increase your range and power .