A member of my extended family who is a famous lawyer once said to me that she couldn't understand people who do things for their health when they aren't having any health problems.
I'm sick of hearing people ask, "What is this good for?" The operative this being some exercise or even some entire internal martial art.
But I'm even more sick of the answers other teachers give. "This is good for lowering blood pressure," "This one is helpful for diabetes symptoms," "Do this everyday and you'll never get migraines," "This is proven to help with balance problems as you age."
This is all just as lazy as the infantile martial arts extremists who say you should practice so that if by a stroke of bad luck you happen to get attacked, you will be thoroughly trained to defend yourself against all odds.
Listen world! If you want to have a long life, your best shot is having friends of different ages in different walks of life. Be part of a complex active social network.
If you want to be healthy, take a walk everyday.
The reasons for studying internal martial arts are: truth and beauty. Study because you want to explore the truth about how your body works, how it feels, how it changes, and how it operates in diverse situations. Study because you want to experience the truth about the stuff you are made of, about the situation of your birth.
The discovery of beauty requires perception, sentience, introspection, and re-creation. The discovery of beauty comes from making mistakes, from getting it wrong, from mis-seeing things and then changing your way of knowing.
Please, trust me. If you know your body inside out from deep daily experience and exploration you will have tools for healing and transformation that are beyond what most other people can comprehend. It's like an extra bonus that comes with the territory.
Qigong was invented as a distinct category during the Communist era to answer the inane question, "What is this good for?"