Chi-Gung means moving energy, and the various practices of Chi Gung help build up internal energy. What is this energy, how do we use it? Through Chi Gung I have experienced the energy, and no matter what aspersions are cast at me I can stand and say the truth that it exists. Where does vitality come from? Why do some people have greater vitality than others? It is their vital energy that makes the difference and another word for that vital energy is chi. (for more discussion on energy go here)
Are you happy if you are vital? More likely so. So to find happiness helpful vitality should be sought. What do you know of that claims to give you vitality? Good eating perhaps and drugs? Drugs are out and good eating is discussed here so that leaves Chi Gung if you are going to try a positive step.
The ChiGung I practice is Chilel and you can ideally buy it from the source here (Go to books/media and choose 101 Miracles of Natural Healing DVD). Practice Chilel for a week, 20 minutes a day for 7 days of doing ….., and then tell me if your vitality has not improved.
There are many aspects to Chi Gung and Daniel Reid's book "A Complete Guide to Chi Gung" discusses these, well worth a read and worth keeping as a reference.
Tai Chi is a Chi Gung practice I did for years, and if you get an opportunity to learn that do so.
Yogic practices such as pranayama deal with vital energy through the breath. This is not my practice so I cannot be definitive yet reputable people attesting to it is convincing. If in meditation your heart tells you to investigate yoga please do so; the heart is your best guide.