Nanquan has always been famous for its great strength and ferocity, and some methods of practicing kungfu are very similar to hard qigong. You can improve your fighting ability by holding your breath. So it will be unnatural, and getting old will do some harm to your body. But this is not meaningless. Come on, relax. But it does take a period of hard training to achieve it, and not everyone can do it. But if you hold your breath, everyone will. It's faster, and there are many people who choose by nature.