try like breathing in as much air as u can and reserve some in ur rib cage or whatever and use ur diaphram first for air then when thats out use ur ribs reserves or watevs i heard it somewere it works man like breath in for 8 seconds and then breath out using ur diaphram for 4 seconds then another 4 seconds with ur reserve airrr in ur ribs and do it a couple of times see if that helps man