An interesting overview for those interested in the terms mentioned. Qi Gong, regardless of what someone believes about "Qi", is a nice warm up, reduces stress, helps us breathe deeper and more naturally. It is a regular part of practice in our classes with no need for extraneous validation; it is what it is and does what it does! Our lineage includes white crane tai chi and da dao chan qi gong. Even the hard style of Tang Soo Do has Nei Gun, or inner strength forms. Many other arts have similar warmup involving breathing and gentle movement. These practices seem to grow more important in time, with age, and injury.