I notice that in some martial arts style they encourage you to do reverse breathing, that is to expand your abdominal when breathing out and to contract it when breathing in.
Another thing I notice is that in Aikido, it is harder style of aikido which practice this method. My suspicion is that it is similar in Kung Fu. My question is whether any soft martial arts style practice this breathing method and if there are, can you tell me what is the point of this method?