There are many forms of breathing techniques employed in kung- fu practices but these are too elaborate and extensive to go into. However we will go into this topic lightly. Let us start with what is called reverse breathing. Reverse breathing is used for increasing and accumulating energy. This can be done standing sitting or lying. As you breathe in, pay attention to, and become aware of the expansion which takes place in your lower abdomen. Your lungs expand as a result of your diaphragm moving downwards thereby drawing in air and oxygen. Normally as you inhale your lower abdomen expands outwards as the diaphragm moves down. Reverse breathing involves reversing this pattern. Now you can try this. As you breathe in put your attention into your lower you abdomen, 2-3 inches (5-7 cm) below your naval, this is your lower energy fieled, the lower tan tien. As you breathe in, hold your attention and mind at this point and consciously contract the muscles in your lower abdomen. This function like a weight-lifter lifting weights. The more pressure and tension you put into a given area, the stronger it becomes. Repeat this as much as you feel the need. As you breathe out, let your lower abdomen relax and expand.
It is best to do this practice with your eyes closed, but if that is not possible, because you are driving, working or engaged in a conversation, it can just as well be done with your eyes open - and nobody will know that you're doing it. Do if for as long as you feel confortable. This practice builds strength in the Lower Tan Tien. Do it any time you want to replenish and increase your energy resources. See how it makes your feel.