I'm currently reading the book "Pragmatic Thinking and Learning" by Andy Hunt. It mentions about this martial art that can help in concentration and control. The martial arts is called "Ki-Chun." However, I can't find it. I tried googling it but i can't really find anything about it. Does anybody know about ki-chun and how i can practice it? Or if there is any other martial arts along the line that I can learn online or through a book, I'd like to ask for recommendations.
Ki chun is qi gong or chi kung. I suspect ki chun is simply an anglicized version of a Korean pronunciation. Qi gong is a controversial subject on this site. Qi gong roughly translates to energy work, and is a very broad topic that encompasses many different theories and exercises about how the body and mind should be trained. To a Western audience, the more unusual elements are moving slowly without weights and mental training to clear the mind.
If you are interested in mental focus in particular, meditation is a relatively well documented and researched topic that is a subset of qi gong. When meditation is mixed with martial practices such as taiji or bagua, you quickly move to the point where instruction is required. You would be well served to start with meditation and breathing practices alone; it is quite true that learning to breathe better has significant benefits. Basic practices are also simple enough that you can start on your own.
The general breathing advice is to make your breathing relaxed, continuous, deep, and even. Start by closing your eyes and paying attention to your breathing for several minutes a day. You can do this lying down (simplest), sitting up straight, or standing. With continuous practice over some weeks/months, you should begin to notice changes. In my opinion, this should be sufficient to give you a taste of qi gong training; it requires dedicated personal practice and lots of patience, which is not suited for everyone at whatever their current stage of life is.